WO2022152852A1 - Antagonists of mrgx2 - Google Patents

Antagonists of mrgx2 Download PDF

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WO2022152852A1
WO2022152852A1 PCT/EP2022/050754 EP2022050754W WO2022152852A1 WO 2022152852 A1 WO2022152852 A1 WO 2022152852A1 EP 2022050754 W EP2022050754 W EP 2022050754W WO 2022152852 A1 WO2022152852 A1 WO 2022152852A1
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propanamide
piperidin
mmol
alkyl
chloropyridin
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PCT/EP2022/050754
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French (fr)
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Edward Brnardic
Jon Collins
Yu Guo
Anthony HANDLON
Louis Lafrance
Daniel Paone
Barry Shearer
Matthew Tallant
Guosen Ye
Maben YING
Huichang Zhang
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Glaxosmithkline Intellectual Property Development Limited
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Publication of WO2022152852A1 publication Critical patent/WO2022152852A1/en

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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D237/00—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings
    • C07D237/02—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings not condensed with other rings
    • C07D237/06—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D237/10—Heterocyclic compounds containing 1,2-diazine or hydrogenated 1,2-diazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D237/22—Nitrogen and oxygen atoms
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P17/00—Drugs for dermatological disorders
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P3/00—Drugs for disorders of the metabolism
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P35/00—Antineoplastic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P37/00—Drugs for immunological or allergic disorders
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P9/00—Drugs for disorders of the cardiovascular system
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
    • C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
    • C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
    • C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
    • C07D213/72—Nitrogen atoms
    • C07D213/76—Nitrogen atoms to which a second hetero atom is attached
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
    • C07D401/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/14—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing three or more hetero rings
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D403/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00
    • C07D403/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings
    • C07D403/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, not provided for by group C07D401/00 containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D405/00—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom
    • C07D405/02—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings
    • C07D405/12—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D413/00—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and oxygen atoms as the only ring hetero atoms
    • C07D413/02—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and oxygen atoms as the only ring hetero atoms containing two hetero rings
    • C07D413/12—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and oxygen atoms as the only ring hetero atoms containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D413/00—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and oxygen atoms as the only ring hetero atoms
    • C07D413/14—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and oxygen atoms as the only ring hetero atoms containing three or more hetero rings
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D417/00—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00
    • C07D417/02—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00 containing two hetero rings
    • C07D417/12—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00 containing two hetero rings linked by a chain containing hetero atoms as chain links
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D417/00—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00
    • C07D417/14—Heterocyclic compounds containing two or more hetero rings, at least one ring having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by group C07D415/00 containing three or more hetero rings

Definitions

  • This invention relates to compounds which are antagonists of MrgX2 (Mas-related Gene X2) and thus are useful as therapeutic agents.
  • mast cells ordinarily reside near blood vessels or nerves, beneath or within epithelia, within airways, gastrointestinal, and genitourinary tracts and near smooth muscle and mucus-producing glands.
  • IgE antibodies activated by IgE antibodies, secreting a wide range of substances with local and systemic effects, including histamine, serotonin, proteases, chemokines, and cytokines. Indeed, mast cells are implicated in the progression and/or maintenance of many diseases.
  • Mrgprb2 is the mouse receptor for several cationic molecules, collectively called basic secretagogues, and the ortholog of the human receptor MRGPRX2 (also known and referred to herein as MrgX2).
  • MrgX2 and MrgX2 have been reported to be expressed only on certain populations of mast cells. This knowledge provides an opportunity to target mast cell degranulation in a very precise manner.
  • Natural endogenous ligands of Mrgprb2/MRGPRX2 have been reported and are mostly neuropeptides, including substance P (SP), vasoactive intestinal polypeptide (VIP), Cortistatin-14, and pituitary adenylate cyclase activating polypeptide (PACAP). Others include P-defensin, cathelici din (LL-37), and proadrenomedullin N-terminal 20 peptide (PAMP9-20). Given the close proximity between mast cells and sensory nerves in various pathological conditions, it follows that neuropeptide-activated MRGPRX2 could contribute to symptoms of neurogenic inflammation including pain, swelling and pruritus.
  • SP substance P
  • VIP vasoactive intestinal polypeptide
  • Cortistatin-14 Cortistatin-14
  • PAMP9-20 proadrenomedullin N-terminal 20 peptide
  • Mrgprb2/MRGPRX2 agonists induce various symptoms such as flushing, swelling and itch in wild type mice, but not in Mrgprb2-deficient mice.
  • Mrgprb2-deficent mice have also demonstrated significant reductions in inflammation (leukocyte infiltration, including mast cells), swelling, pain and overall clinical score in various disease models.
  • An important and relevant observation was the demonstration that Substance P injection could stimulate the infiltration of leukocytes in wild type and NKR1 (canonical Substance P receptor) KO mice whereas the response was substantially blunted in Mrgprb2 null mice.
  • Mrgprb2/MRGPRX2 as a key receptor in mediating Substance P-induced inflammatory responses, including pain.
  • a Substance P / Mrgprb2 sensory cluster was demonstrated to be critical in driving the clinical score of a severe preclinical model of atopic dermatitis.
  • PACAP and the antimicrobial peptide, LL-37 which is implicated in cutaneous inflammation, were both demonstrated to be upregulated in rosacea. Indeed, mast cell-deficient mice do not develop inflammation/flushing following LL-37 injection thus inferring a role for Mrgprb2.
  • mast cell involvement has been highlighted for inflammatory bowel disease (IBD) and arthritis as well as asthma and migraine.
  • IBD inflammatory bowel disease
  • RA rheumatoid arthritis
  • the number of degranulated mast cells is increased in synovial tissue and is correlated with disease activity, as it is for patients with IBD.
  • a positive correlation between serum Substance P levels and chronic pain intensity has been noted in both osteoarthritic and RA patients and a recent article suggested that the SP- MRGPRX2 axis may play a role in the pathogenesis of RA, especially in the regulation of inflammation and pain.
  • PACAP a role of PACAP in migraine pathogenesis and that it is mediated via activation of mast cells.
  • a potent, selective antagonist of MRGPRX2 that blocks IgE-independent mast cell de-granulation is expected to provide therapeutic benefit in mast-cell driven pathologies including skin disorders such as urticaria, atopic dermatitis and rosacea as well as additional indications like inflammatory bowel disease, arthritis and migraine.
  • the compounds of the present invention may be formulated into pharmaceutical compositions prior to administration to a subject.
  • a pharmaceutical composition comprising a compound of Formula (I) or pharmaceutically acceptable salt thereof as defined herein, and a pharmaceutically acceptable excipient.
  • compositions of the invention may be adapted for administration by any appropriate route, for example oral, inhaled, injectable etc.
  • the pharmaceutically acceptable excipient may be any suitable pharmaceutically acceptable excipient such as an edible carbohydrate, for example, starch or mannitol.
  • a method of treating an MrgX2-mediated disease or disorder in a human in need thereof comprising administering to the human a therapeutically effective amount of a compound of Formula (I) or pharmaceutically acceptable salt thereof or a pharmaceutical composition as defined herein.
  • compound of Formula (I) or pharmaceutically acceptable salt thereof for use in the treatment of an MrgX2 -mediated disease or disorder.
  • the compounds of the present invention i.e. compounds of Formula (I) or pharmaceutically acceptable salts thereof as defined herein may be advantageous in a number of respects.
  • compounds defined herein are antagonists of MrgX2 and thus may be advantageous in treating MrgX2 mediated diseases.
  • alkyl refers to a saturated, straight or branched hydrocarbon moiety having the specified number of carbon atoms.
  • (Ci-Cejalkyl) refers to an alkyl moiety containing from 1 to 6 carbon atoms. Exemplary alkyls include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, pentyl, and hexyl.
  • alkoxy refers to a group containing an alkyl radical attached through an oxygen linking atom.
  • (C 1 -C 4 )alkoxy refers to a straight- or branched-chain hydrocarbon radical having at least 1 and up to 4 carbon atoms attached through an oxygen linking atom.
  • Exemplary “(C 1 -C 4 )alkoxy” groups useful in the present invention include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, isobutoxy, and t-butoxy.
  • alkyl When the term “alkyl” is used in combination with other substituent groups, such as "halo(C 1 -C 4 )alkyl", “aryl(C 1 -C 4 )alkyl-”, “(C 1 -C 6 )alkyl-OH” or " (C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl-", the term “alkyl” is intended to encompass a divalent straight or branched-chain hydrocarbon radical, wherein the point of attachment is through the alkyl moiety.
  • halo(C 1 -C 4 )alkyl is intended to mean a radical having one or more halogen atoms, which may be the same or different, at one or more carbon atoms of an alkyl moiety containing from 1 to 4 carbon atoms, which is a straight or branched-chain carbon radical.
  • halo(C 1 -C 4 )alkyl groups useful in the present invention include, but are not limited to, -CF 3 (trifluoromethyl), -CCl 3 (trichloromethyl), 1,1- difluoroethyl, 2-fluoro-2-methylpropyl, 2,2-difluoropropyl, 2,2,2-trifluoroethyl, and hexafluoroisopropyl.
  • aryl(C 1 -C 4 )alkyl” or “phenyl(C 1 -C 4 )alkyl” groups useful in the present invention include, but are not limited to, benzyl and phenethyl.
  • Examples of "(C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl-" groups useful in the present invention include, but are not limited to, methoxymethyl, methoxyethyl, methoxyisopropyl, ethoxymethyl, ethoxyethyl, ethoxyisopropyl, isopropoxymethyl, isopropoxyethyl, isopropoxyisopropyl, t- butoxymethyl, t-butoxyethyl, and t-butoxyisopropyl.
  • the term “cycloalkyl” refers to a non-aromatic, saturated, cyclic hydrocarbon ring containing the specified number of carbon atoms.
  • (C 3 -C 8 )cycloalkyl refers to a non-aromatic cyclic hydrocarbon ring having from three to eight ring carbon atoms.
  • Exemplary "(C 3 -C 8 )cycloalkyl” groups useful in the present invention include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.
  • 4- to 6-membered heterocycloalkyl refers to a group or moiety comprising a non-aromatic, monovalent monocyclic radical, which is saturated or partially unsaturated, containing 4, 5, or 6 ring atoms, which includes one or two heteroatoms selected independently from oxygen, sulfur, and nitrogen.
  • 4- to 6-membered heterocycloalkyl groups useful in the present invention include, but are not limited to azetidinyl, oxetanyl, pyrrolidinyl, pyrazolidinyl, pyrazolinyl, imidazolidinyl, imidazolinyl, oxazolinyl, thiazolinyl, tetrahydrofuranyl, dihydrofuranyl,
  • aryl refers to monocyclic, fused bicyclic, or fused tricyclic groups having 6 to 14 carbon atoms and having at least one aromatic ring.
  • aryl groups are phenyl, naphthyl, indenyl, dihydroindenyl, anthracenyl, phenanthrenyl, and the like.
  • heteroaryl refers to a group or moiety comprising an aromatic monovalent monocyclic or bicyclic radical, containing 5 to 10 ring atoms, including 1 to 4 heteroatoms independently selected from nitrogen, oxygen and sulfur. This term also encompasses bicyclic heterocyclic-aryl compounds containing an aryl ring moiety fused to a heterocycloalkyl ring moiety, containing 5 to 10 ring atoms, including 1 to 4 heteroatoms independently selected from nitrogen, oxygen and sulfur.
  • heteroaryls useful in the present invention include, but are not limited to, furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, isothiazolyl, pyridinyl, pyridazinyl, pyrazinyl, pyrimidinyl, triazinyl, benzofuranyl, isobenzofuryl, 2,3-dihydrobenzofuryl, 1,3- benzodioxolyl, dihydrobenzodioxinyl, benzothienyl, indolizinyl, indolyl, isoindolyl, dihydroindolyl, benzimidazolyl, dihydrobenzimidazolyl, benzoxazolyl, di
  • Examples of 5-membered “heteroaryl” groups include furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, and isothiazolyl.
  • Examples of 6- membered “heteroaryl” groups include oxo-pyridyl, pyridinyl, pyridazinyl, pyrazinyl, and pyrimidinyl.
  • 6,6-fused “heteroaryl” groups include quinolinyl, isoquinolinyl, quinoxalinyl, cinnolinyl, phthalazinyl, quinazolinyl, 1,5-naphthyridinyl, 1,6- naphthyridinyl, 1,7-naphthyridinyl, 1,8-naphthyridinyl, and pteridinyl.
  • 6,5- fused “heteroaryl” groups include benzofuranyl, benzothienyl, benzimidazolyl, benzthiazolyl, indolizinyl, indolyl, isoindolyl, and indazolyl.
  • 5- or 6-membered heteroaryl refers to a group or moiety comprising an aromatic monovalent monocyclic radical, containing 5 or 6 ring atoms, including at least one carbon atom and 1 to 4 heteroatoms independently selected from nitrogen, oxygen, and sulfur.
  • Selected 5-membered heteroaryl groups contain one nitrogen, oxygen, or sulfur ring heteroatom, and optionally contain 1, 2, or 3 additional nitrogen ring atoms.
  • Selected 6-membered heteroaryl groups contain 1, 2, or 3 nitrogen ring heteroatoms.
  • 5- or 6-membered heteroaryl groups useful in the present invention include, but are not limited to furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrazinyl, pyrimidinyl, and triazinyl.
  • halogen and halo refer to fluoro, chloro, bromo, or iodo substituents.
  • hydroxy or “hydroxyl” refer to the radical -OH.
  • the term "optionally” means that the subsequently described event(s) may or may not occur, and includes both event(s) that occur and event(s) that do not occur.
  • “Pharmaceutically acceptable” refers to those compounds (including salts), materials, compositions, and dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
  • treatment refers to alleviating the specified condition, eliminating or reducing one or more symptoms of the condition, slowing or eliminating the progression of the condition, and delaying the reoccurrence of the condition in a previously afflicted or diagnosed patient or subject.
  • the term "effective amount” means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal, or human that is being sought, for instance, by a researcher or clinician.
  • therapeutically effective amount means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder.
  • therapeutically effective amounts of a compound of Formula (I) as well as salts thereof may be administered as the raw chemical. Additionally, the active ingredient may be presented as a pharmaceutical composition.
  • pharmaceutically acceptable salts refers to salts that retain the desired biological activity of the subject compound and exhibit minimal undesired toxicological effects.
  • X 1 is CR 5a . In another embodiment X 1 is CR 5a and R 5a is hydrogen. In an embodiment of the invention X 2 is N. In an embodiment of the invention X 3 is CR 5b . In some instances, X 3 is CR 5b and R 5b is hydrogen. In another embodiment of the invention X 4 is CR 6b . In some instances, R 6b is hydrogen In certain embodiments of the invention X 1 is CR 5a , R 5a is hydrogen, X 2 is N, X 3 is CR 5b , R 5b is hydrogen and X 4 is CR 6b wherein R 6b is hydrogen.
  • X 1 is CR 5a
  • R 5a is hydrogen
  • X 2 is N
  • X 3 is N
  • X 4 is CR 6b wherein R 6b is hydrogen
  • Y may be N or CH.
  • Y is N
  • Y is CH
  • Z is O.
  • Z is C(R 2 ).
  • Z is C(R 2 ) 2 .
  • Each R 2 may be hydrogen, F or CH 3 .
  • each R2 is H or each R 2 is F.
  • n may be 0 or 1 as stated above. In an embodiment of the invention n is 1.
  • R 1 is halogen, (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, - O-(C 2 -C 6 )alkenyl, -O-(C 1 -C 6 )alkyl-(C 3 -C 8 )cycloalkyl, -O-(C 3 -C 8 )cycloalkyl, -O-aryl, -O- heteroaryl, -CO 2 (C 1 -C 6 )alkyl or -NH(C 1 -C 6 )alkyl wherein any said (C 1 -C 6 )alkyl, -O- heteroaryl, -O-aryl or aryl is optionally substituted one, two, or three times by R 8 .
  • R 1 is O-aryl optionally substituted one, two, or three times by R 8 .
  • R 1 is O-phenyl substituted one, two, or three times by R 8 .
  • R 8 may be F.
  • R 1 is halogen (e.g., fluorine or chlorine) or -O-(C 1 -C 6 )alkyl-(C 3 -C 8 )cycloalkyl.
  • R 3 is a 5-membered heteroaryl ring, hydrogen, halogen or OH.
  • R 3 is H, F or OH.
  • R 4 is hydrogen, halogen, 5-membered heteroaryl or 5-6 membered lactam.
  • lactam refers to a cyclic amide.
  • a 5- membered lactam may also be referred to as ⁇ -lactam.
  • a 6-membered lactam may also be referred to as ⁇ -lactam.
  • R 7a and R 7b may be the same or different.
  • R 7a is hydrogen, OH, halogen or methyl.
  • R 7b is hydrogen, OH, halogen or methyl.
  • R 7a and R 7b are each hydrogen.
  • R 7a is hydrogen and R 7b is methyl.
  • R 8 is halogen.
  • R 8 is F.
  • R 10 is -(C 1 -C 6 )alkyl and R 11 is H.
  • R 10 is CH 3 and R11 is H.
  • R 1 is -O-aryl substituted twice with R 8 ;
  • X 1 is CR 5a ;
  • X 2 is N;
  • X 3 is CR 5b ;
  • X 4 is CR 6b ;
  • Y is N;
  • Z is C(R 2 ) 2 ;
  • n is 1;
  • R 2 is hydrogen or F;
  • R 3 , R 4 , R 5a , R 5b and R 6b are each hydrogen;
  • R 7a and R 7b are each hydrogen;
  • R 8 is F;
  • R 10 is CH 3 ; and
  • R 11 is H.
  • R 1 is Cl or O-(C 1 -C 6 )alkyl-(C 3 -C 8 )cycloalkyl;
  • X 1 is N or CR 5a;
  • X 2 is N;
  • X 3 is CR 5b ;
  • X 4 is CR 6b ;
  • Y is N;
  • Z is C(R 2 ) 2 ;
  • R 2 is F or hydrogen;
  • R 3 is hydrogen;
  • R 4 is 5-membered heteroaryl;
  • R 5a , R 5b , R 6b is hydrogen;
  • R 7a is hydrogen;
  • R 7b is hydrogen or CH 3
  • R 10 is CH3; and
  • R 11 is hydrogen.
  • references herein to a compound of Formula (I) or a salt thereof includes a compound of Formula (I) as a free base or acid, or as a salt thereof, for example as a pharmaceutically acceptable salt thereof.
  • the invention is directed to a compound of Formula (I).
  • the invention is directed to a salt of a compound of Formula (I).
  • the invention is directed to a pharmaceutically acceptable salt of a compound of Formula (I).
  • the invention is directed to a compound of Formula (I) or a salt thereof.
  • the invention is directed to a compound of Formula (I) or a pharmaceutically acceptable salt thereof.
  • a salt of a compound of Formula (I) is preferably pharmaceutically acceptable.
  • “Pharmaceutically acceptable’ refers to those compounds (including salts), materials, compositions, and dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
  • Pharmaceutically acceptable salts include, amongst others, those described in Berge, J. Pharm.
  • Non-pharmaceutically acceptable salts are within the scope of the present invention, for example for use as intermediates in the preparation of a compound of Formula (I) or a pharmaceutically acceptable salt thereof.
  • Non-pharmaceutically acceptable salts may be used, for example as intermediates in the preparation of a compound of Formula (I) or a pharmaceutically acceptable salt thereof.
  • Suitable pharmaceutically acceptable salts can include acid or base addition salts.
  • Base addition salts can be formed by reaction of a compound of Formula (I) with the appropriate base, optionally in a suitable solvent such as an organic solvent, to give the salt which can be isolated by a variety of methods, including crystallisation and filtration.
  • Acid addition salts can be formed by reaction of a compound of Formula (I) with the appropriate acid, optionally in a suitable solvent such as an organic solvent, to give the salt which can be isolated by a variety of methods, including crystallisation and filtration.
  • Salts may be prepared in situ during the final isolation and purification of a compound of Formula (I). If a basic compound of Formula (I) is isolated as a salt, the corresponding free base form of that compound may be prepared by any suitable method known to the art, including treatment of the salt with an inorganic or organic base. Similarly, if a compound of Formula (I) containing a carboxylic acid or other acidic functional group is isolated as a salt, the corresponding free acid form of that compound may be prepared by any suitable method known to the art, including treatment of the salt with an inorganic or organic acid.
  • salt formation may include 1, 2 or more equivalents of acid.
  • Such salts would contain 1, 2 or more acid counterions, for example, a dihydrochloride salt.
  • Stoichiometric and non-stoichiometric forms of a pharmaceutically acceptable salt of a compound of formula (I) are included within the scope of the invention, including sub- stoichiometric salts, for example where a counterion contains more than one acidic proton.
  • Representative pharmaceutically acceptable acid addition salts include, but are not limited to, 4-acetamidobenzoate, acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate (besylate), benzoate, bisulfate, bitartrate, butyrate, calcium edetate, camphorate, camphorsulfonate (camsylate), caprate (decanoate), caproate (hexanoate), caprylate (octanoate), cinnamate, citrate, cyclamate, digluconate, 2,5-dihydroxybenzoate, di succinate, dodecyl sulfate (estolate), edetate (ethylenediaminetetraacetate), estolate (lauryl sulfate), ethane- 1,2-disulfonate (edisylate), ethanesulfonate (esylate), formate, fumarate, galactarate
  • Representative pharmaceutically acceptable base addition salts include, but are not limited to, aluminium, 2-amino-2-(hydroxymethyl)-l,3-propanediol (TRIS, tromethamine), arginine, benethamine (N-benzylphenethylamine), benzathine (N,N’- dibenzylethylenediamine), bi s-(2 -hydroxy ethyl)amine, bismuth, calcium, chloroprocaine, choline, clemizole (1-p chlorobenzyl-2-pyrrolildine-l’-ylmethylbenzimidazole), cyclohexylamine, dibenzylethylenediamine, diethylamine, diethyltriamine, dimethylamine, dimethylethanolamine, dopamine, ethanolamine, ethylenediamine, L-histidine, iron, isoquinoline, lepidine, lithium, lysine, magnesium, meglumine (N-methylglucamine), piperazine,
  • the compounds according to Formula (I) may contain one or more asymmetric center (also referred to as a chiral center) and may, therefore, exist as individual enantiomers, diastereomers, or other stereoisomeric forms, or as mixtures thereof.
  • Chiral centers such as chiral carbon atoms, may also be present in a substituent such as an alkyl group.
  • the stereochemistry of a chiral center present in Formula (I), or in any chemical structure illustrated herein, is not specified the structure is intended to encompass all individual stereoisomers and all mixtures thereof.
  • compounds according to Formula (I) containing one or more chiral center may be used as racemic mixtures, enantiomerically enriched mixtures, or as enantiomerically pure individual stereoisomers.
  • Individual stereoisomers of a compound according to Formula (I) which contain one or more asymmetric center may be resolved by methods known to those skilled in the art. For example, such resolution may be carried out (1) by formation of diastereoisomeric salts, complexes or other derivatives; (2) by selective reaction with a stereoisomer-specific reagent, for example by enzymatic oxidation or reduction; or (3) by gas-liquid or liquid chromatography in a chiral environment, for example, on a chiral support such as silica with a bound chiral ligand or in the presence of a chiral solvent.
  • stereoisomers may be synthesized by asymmetric synthesis using optically active reagents, substrates, catalysts or solvents, or by converting one enantiomer to the other by asymmetric transformation.
  • the compounds according to Formula (I) may also contain double bonds or other centres of geometric asymmetry. Where the stereochemistry of a centre of geometric asymmetry present in Formula (I), or in any chemical structure illustrated herein, is not specified, the structure is intended to encompass the trans (E) geometric isomer, the cis (Z) geometric isomer, and all mixtures thereof. Likewise, all tautomeric forms are also included in Formula (I) whether such tautomers exist in equilibrium or predominately in one form.
  • the compound of Formula (I) is selected from the compounds in Table 1 or pharmaceutically acceptable salts thereof.
  • the invention provides a pharmaceutical composition
  • a pharmaceutical composition comprising a compound or pharmaceutically acceptable salt thereof as defined herein, and a pharmaceutically acceptable excipient.
  • the excipient may be any suitable pharmaceutically acceptable excipient.
  • pharmaceutically-acceptable excipient means a pharmaceutically acceptable material, composition or vehicle involved in giving form or consistency to the pharmaceutical composition.
  • Each excipient must be compatible with the other ingredients of the pharmaceutical composition such that interactions which would substantially reduce the efficacy of the compound of the invention when administered to an individual and interactions which would result in pharmaceutical compositions that are not pharmaceutically acceptable are avoided.
  • each excipient must of course be of sufficiently high purity to render it pharmaceutically-acceptable.
  • the compounds of formula (I) are antagonists of MrgX2 and, as such can be useful in the treatment of MrgX2 -mediated diseases or disorders.
  • a method of treating an MrgX2 -mediated disease or disorder in a human in need thereof comprising administering to the human a therapeutically effective amount of the compound of Formula (I) as described herein or pharmaceutically acceptable salt thereof or the pharmaceutical composition as described herein.
  • the MrgX2 -mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, prurigo nodularis, irritable bowel syndrome, chronic inducible urticaria, atopic dermatitis, osteoarthritis, rosacea, migraine, pseudo- analphylaxis, mast cell activation syndrome, mastocytosis, pruritus, neurodermatitis, contact urticaria, allergic rhinitis, asthma, acute contact dermatitis, ulcerative colitis, crohns disease, idiopathic chronic cough, rheumatoid arthritis, multiple sclerosis, geographic atrophy, endometriosis, seborrheic dermatitis, psoriasis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, neuropathic itch, periodontitis, autism, abdominal aortic aneurysms, deep vein thrombosis, amyotrophic lateral sclerosis, inter
  • the MrgX2-mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine.
  • the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug- induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine.
  • the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain.
  • the MrgX2- mediated disease or disorder is chronic spontaneous urticaria.
  • the method of the present invention comprises administering a therapeutically acceptable amount of the compound or composition in any suitable way.
  • the present invention provides a compound or pharmaceutically acceptable salt thereof as described herein for use in therapy.
  • the present invention provides a compound or pharmaceutically acceptable salt thereof as defined herein for use in the treatment of an MrgX2 -mediated disease or disorder.
  • the MrgX2 -mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine.
  • the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug- induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine.
  • the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain.
  • the MrgX2- mediated disease or disorder is chronic spontaneous urticaria.
  • the present invention also provides use of a compound or pharmaceutically acceptable salt as defined herein in the manufacture of a medicament for use in the treatment of an MrgX2 -mediated disease or disorder.
  • the MrgX2-mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine.
  • the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine.
  • the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain.
  • the MrgX2-mediated disease or disorder is chronic spontaneous urticaria.
  • LC/MS Method 1 was conducted on a Shimadzu LCMS-2020 Xselect CSH C 1 8 column (50mm x 3.0 mm i.d. 2.5pm packing diameter) eluting with 0.1% formic acid in water (solvent A) and 0.1% formic acid in acetonitrile (solvent B), using the following elution gradient 0.01-3.60 min.: 30% to 70% B, 3.60-4.40 min to 95% B, 5.10-5.20 min. to 5% B, at a flow rate of 1.2 mL/ min. at 45°C.
  • LC/MS Method 2 UPLC was conducted on an Acquity UPLC CSH C 1 8 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 0.1% formic acid in water (solvent A) and 0.1% formic acid in acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: l% to lOO% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C.
  • Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative-scan positive and negative mode electrospray ionisation, scan range of 100 to 1000 AMU, with targeted sample frequency of 8 Hz.
  • LC/MS Method 3 UPLC was conducted on an Acquity UPLC CSH Cl 8 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 10 mM ammonium bicarbonate in water adjusted to pH 10 with 25% ammonium hyrdroxide solution (solvent A) and acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: 0% to 100% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C. Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative-scan positive and negative mode
  • LC/MS Method 4 was conducted on a Shimadzu LCMS-2020 Ascentis CSH C 1 8 column (50mm x 3.0 mm i.d. 2.7pm packing diameter) eluting with 0.05% TFA in water (solvent A) and 0.05% TFA in acetonitrile (solvent B), using the following elution gradient 0.01-1.10 min.: 5% to 95% B, 1.80-1.90 to 5% B, at a flow rate of 1.5 mL/ min. at 40°C.
  • LC/MS Method 5 UPLC was conducted on an Acquity UPLC CSH Cl 8 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 0.1% TFA in water (solvent A) and 0.1% TFA in acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: 1% to 100% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C.
  • Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative- scan positive and negative mode electrospray ionisation, scan range of 100 to 1000 AMU, with targeted sample frequency of 8 Hz.
  • LC/MS Method 7 was conducted on a Poroshell HPH-18 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with 6.5 mM NH4HCO3 + NH3 H2O (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-2.00 min.: 10% to 95% B, 2.60-2.75 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
  • LC/MS Method 8 was conducted on a Ascentis Express C 1 8 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with water/0.05%TFA (solvent A) and acetonitrile/0.05%TFA (solvent B), using the following elution gradient: 0.01-2.00 min.: 5% to 95% B, 2.60-2.75 min. to 5% B, at a flow rate of 1.5 mL/ min. at 40°C.
  • LC/MS Method 9 was conducted on a Kinetex 2.6 um EVO C 1 8 100A column (50mm x 3.0 mm i.d. 2.6 pm packing diameter) eluting with water/5 mM NH4HCO3 (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-2.10 min.: 10% to 95% B, 2.70-2.75 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
  • LC/MS Method 11 The column used was a Kinetex 2.6 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 12 The column used was a Kinetex 2.6um EVO C 1 8 100A, 2.6 pm, 3.0 x 50 mm. A linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 2.90 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 13 The column used was a Kinetex 2.6um EVO Cl 8 100A, 2.6 pm, 3.0 x 50 mm.
  • a linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 5.00 min with a total run time of 5.60 min.
  • the column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 14 The column used was a Xselect CSH C 1 8, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: Water/0.1%FA) and ending at 95% B (B: Acetonitrile/0.1%FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 15 The column used was a Poroshell HPH-C 1 8, 2.7 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 90% A (A: water-6.5 mM NH4HCO3+NH3H2O) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.50 mL/min.)
  • LC/MS Method 16 The column used was a Xselect CSH C 1 8, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 100% B (B: Acetonitrile/0.1% FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.)
  • LC/MS Method 17 The column used was a Kinetex XB-C 1 8, 2.6 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: Water/0.1%FA) and ending at 100% B (B: Acetonitrile/0.1%FA) over 2.60 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 18 The column used was a Ascentis Express C 1 8, 2.7 pm, 2.1 x 50 mm. A linear gradient was applied, starting at 90% A (A: water-0.1% FA) and ending at 95% B (B: Acetonitrile-0.1% FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.00 mL/min.
  • LC/MS Method 19 The column used was a CORTECS C 1 8, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water-0.09%F A) and ending at 95% B (B: Acetonitrile-0.1% FA) over 2.60 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 20 The column used was a Xselect CSH C 1 8, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 95% B (B: Acetonitrile/0.1% FA) over 4.70 min with a total run time of 5.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.) LC/MS Method 21 : The column used was a Kinetex XB- C 1 8, 2.6 pm, 3.0 * 50 mm.
  • a linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 90% B (B: Acetonitrile/0.1% FA) over 2.60 min with a total run time of 3.00 min.
  • the column temperature was at 40 °C with the flow rate of 1.20 mL/min.
  • LC/MS Method 22 The column used was a Xselect CSH C 1 8, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.1% FA) over 1.10 min, then to 0% B from 1.70 to 1.75 min, with a total run time of 2.00 min.
  • the column temperature was at 40 °C with the flow rate of 1.20 mL/min.)
  • LC/MS Method 23 The column used was a Cortecs C 1 8, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.1% FA) over 2.00 min, then to 5% B from 2.80 to 2.90 min, with a total run time of 3.00 min.
  • the column temperature was at 40 °C with the flow rate of 1.00 mL/min.)
  • LC/MS Method 24 The column used was a Cortecs C 1 8, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.05% TFA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.05% TFA) over 2.00 min, then to 5% B from 2.80 to 2.90 min, with a total run time of 3.00 min.
  • the column temperature was at 40 °C with the flow rate of 1.00 mL/min.).
  • LC/MS Method 25 The column used was a Xselect CSH C 1 8, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 97% A (A: water/0.1% FA) and ending at 97% B (B: Acetonitrile/0.1% FA) over 2.70 min with a total run time of 2.5 min. The column temperature was at 40 °C with the flow rate of 1.0 mL/min.)
  • LC/MS Method 26 was conducted on a Kinetex 2.6 um EVO C 1 8 100A column (50mm x 3.0 mm i.d. 2.6 pm packing diameter) eluting with water/5 mM NH4HCO3 (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-1.10 min.: 10% to 95% B, 1.80-1.85 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
  • LC/MS Method 27 was conducted on a Kinetex XB-C 1 8 column (30mm x 2.1 mm i.d. 1.7 pm packing diameter) eluting with Water/0.05%TFA (solvent A) and Acetonitrile/0.05%TF A (solvent B), using the following elution gradient: 0.01-0.60 min.: 5% to 95% B, 1.00-1.05 min. to 5% B at a flow rate of 1.0 mL/ min. at 40°C.
  • LC/MS Method 28 was conducted on a Poroshell HPH-C 1 8 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with 6.5 mM NH4HCO3+NH3H2O (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-1.10 min.: 10% to 95% B, 1.80-1.90 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
  • Step 2 To 6-(cyclopropylmethoxy)pyridazin-3-amine (5.00 g, 30.30 mmol, 1.0 eq) and 2- bromopropanoic acid (6.91 g, 45.46 mmol, 1.5 eq) in DCM (150 mL) were added DMAP (1.11 g, 9.09 mmol, 0.3 eq) and DCC (12.48 g, 60.60 mmol, 2.0 eq).
  • Step 2 A mixture of 5-(cyclopropylmethoxy)-2-nitropyridine (6.6 g, 34.0 mmol, 1.0 eq), MeOH (60.0 mL) and Pd/C (0.6 g, 10%) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen. The reaction was stirred 2 h at 25 °C under an atmosphere of hydrogen (balloon), filtered, and concentrated to give crude 5- (cyclopropylmethoxy)pyridin-2-amine (5.8 g) as a yellow solid, which was used without further purification.
  • Step 3 To 5-(cyclopropylmethoxy)pyridin-2-amine (0.50 g, 3.05 mmol, 1.0 eq) and 2- bromopropanoic acid (0.7 g, 4.57 mmol, 1.5 eq) in DCM (10 mL) at 25 °C was added DCC (0.94 g, 4.57 mmol, 1.5 eq), in portions. After 2 h, the reaction was filtered, concentrated and purified by prep-TLC with ethyl acetate: petroleum ether (1: 10) to give 2-bromo-N-(5- (cyclopropylmethoxy)pyridin-2-yl)propanamide (0.9 g, yield: 53%, purity: 95%) as a white solid.
  • Step 2 To 6-nitro-N-propylpyridin-3-amine (780 mg, 4.30 mmol) and DMAP (52.6 mg, 0.430 mmol) in DCM (20 mL) at 0 °C was added Boc2O (1.099 mL, 4.74 mmol). The mixture was stirred at RT for 3 h, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert- butyl (6-nitropyridin-3-yl)(propyl)carbamate (1.20 g, 4.27 mmol, 99 % yield) as a light yellow oil.
  • Step 3 To tert-butyl (6-nitropyridin-3-yl)(propyl)carbamate (1.20 g, 4.27 mmol) in ethanol (30 mL) under N 2 was added Pd/C, 10% (0.045 g, 0.427 mmol), and the mixture was hydrogenated under an H 2 balloon overnight. The mixture was filtered through Celite and concentrated to afford tert-butyl (6-aminopyridin-3-yl)(propyl)carbamate (1.02 g, 4.06 mmol, 95 % yield) as an off white solid, which was used without purification.
  • Step 2 A mixture of (E)-5-(prop-1-en-1-yl)pyridin-2-amine (659 mg, 4.91 mmol) and 10% Pd on carbon (150mg, 0.141 mmol) in ethanol (24 mL) was evacuated and purged with hydrogen several times, stirred under a balloon of hydrogen overnight, filtered and concentrated. The residue was stirred with EtOAc (10 mL), and insoluble material was filtered and discarded. The filtrate was purified over silica column, eluting with 0-15% EtOH in EtOAc to afford 5-propylpyridin-2-amine (170 mg, 1.248 mmol, 25.4 % yield).
  • Step 3 A mixture of 2-bromopropanoic acid (271.4 mg, 1.77 mmol, 1.1 eq), DCC (498 mg, 2.41 mmol, 1.5 eq), DMAP (19.6 mg, 0.16 mmol, 0.1 eq) and 5-phenoxypyridin-2-amine (300 mg, 1.61 mmol, 1.0 eq) in DCM (5 mL) was stirred 2 h, quenched with water (100 mL) and extracted with EA (100 mL x3).
  • Step 2 To a mixture of 5-((5-fluoropyridin-2-yl)oxy)pyridin-2-amine (80 mg, 0.390 mmol) and 2- bromopropanoic acid (0.042 mL, 0.468 mmol) in dichloromethane (2 mL) were added DCC (121 mg, 0.585 mmol) and DMAP (4.76 mg, 0.039 mmol). After 2.5 h, the mixture was filtered. The filter cake was washed with DCM and the filtrate was concentrated.
  • Step 2 A mixture of 5-(2,4-difluorophenoxy)pyrazin-2-amine (40 g, 179 mmol), (R)-2- bromopropanoic acid (32.9 g, 215 mmol) and silver nitrate (4.57 g, 26.9 mmol) in DCM (700 mL) was treated portionwise with DCC (44.4 g, 215 mmol), maintaining a temperature between 15 and 20 °C using a cold water bath.
  • DCM 700 mL
  • Step 1 To 5-chloropyridin-2-amine (2.56 g, 19.93 mmol) and pyridine (2.417 mL, 29.9 mmol) in THF (80 mL) at 0 °C was added (S)-1-chloro-1-oxopropan-2-yl acetate (3.0 g, 19.93 mmol), dropwise. The mixture was stirred for 1 h, warmed to RT overnight, diluted with H 2 O and extracted with EtOAc (3 X).
  • the material was repurified by reverse phase HPLC (Column: XSELECT CSH C 1 8; 150 mm x 30 mm i.d.; 5 ⁇ m packing diameter; mobile phase 30%-99% acetonitrile:water with 0.1% TFA, flow rate 40 mL/min, retention time 11.6 min) to provide 2-cyclohexyl-N-(6- (cyclopropylmethoxy)pyridazin-3-yl)propanamide (7.5 mg, 0.025 mmol, 9.07 % yield).
  • LCMS (m/z) 304 (M+H) + , RT 1.05 min.
  • LCMS Method 5 1 H NMR (CDCl3) ⁇ ppm: 9.35 (br.
  • Example 2 was synthesized in an analogous manner using the indicated Intermediate.
  • Step 2 To 2-(tetrahydro-2H-pyran-4-yl)propanoic acid (58.7 mg, 0.371 mmol) and HATU (141 mg, 0.371 mmol) in DMF (1 mL) was added a solution of 5-(2,4-difluorophenoxy)pyridin- 2-amine (Intermediate 17, Step 2) (55 mg, 0.248 mmol) and DIEA (0.065 mL, 0.371 mmol) in DMF (1 mL). The reaction was stirred at 50 °C overnight, then at 90 °C for 90 min. Additional DIEA (0.065 mL, 0.371 mmol) was added, and heating was continued for 45 min.
  • Step 2 To ethyl 2-(1,4-dioxaspiro[4.5]decan-8-yl)propanoate (0.48 g, 1.98 mmol) in EtOH (6 mL) was added NaOH(aq) (5N, 1.98 mL, 9.90 mmol). The reaction was heated to 90 °C for 90 min, and then at 40 °C overnight. The mixture was concentrated to remove volatile organics, diluted with water and washed with Et 2 O (2X). The aqueous layer was acidified with 6N HCl and extracted with EtOAc (3X).
  • Step 4 To 2-(4-oxocyclohexyl)propanoic acid (92 mg, 0.540 mmol) and HATU (205 mg, 0.540 mmol) in DMF (0.9 mL) was added a solution of 5-(2,4-difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (80 mg, 0.360 mmol) and DIEA (0.094 mL, 0.540 mmol) in DMF (0.9 mL).
  • This material was chirally separated (column: ChiralPak IG, 20x250mm, 5 micron; flow rate: 20mL/min, solvents: 85:15 AcCN: MeOH [0.1% isopropylamine] for the first 9 minutes, then 50:50 AcCN: MeOH [0.1% isopropylamine], and returning to starting conditions at 19 minutes) to provide four stereoisomers of N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(4-hydroxycyclohexyl)propenamide with retention times of 7.16, 8.04, 10.62 and 11.36 min.
  • Step 2 Ethyl 2-(4,4-difluorocyclohexylidene)acetate (1.87 g, 9.16 mmol), methanol (60 mL) and palladium on carbon (370 mg, 0.348 mmol) (10% w/w, 50% wet) were stirred under an atmosphere of H2 for 16 h, filtered through Celite (rinsing with EtOAc) and concentrated to give crude 5-(pyridin-3-yloxy)pyridin-2-amine (1.81 g, 8.78 mmol, recovery: 96%) as a colorless oil, which was used without purification.
  • Step 3 To ethyl 2-(4,4-difluorocyclohexyl)acetate (250 mg, 1.212 mmol) in THF (3 mL) at -78 °C was added LDA (2M, 1.212 mL, 2.424 mmol), dropwise. After 30 min, iodomethane (0.303 mL, 4.85 mmol)) in THF (0.5 mL) was added dropwise, and the reaction was stirred for 20 min, allowed to warm to rt and stirred overnight. The reaction was quenched with NH4Cl(aq) solution and diluted with EtOAc.
  • Step 4 To ethyl 2-(4,4-difluorocyclohexyl)propanoate (0.267 g, 1.212 mmol) in dioxane (5 mL) was added a solution of LiOH (0.145 g, 6.06 mmol) in water (1.2 mL). The reaction was stirred overnight, acidified with 2N HCl and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give partially hydrolyzed product. This material was taken up in EtOH (4 mL), treated with NaOH(aq) (5M, 1.212 mL, 6.06 mmol) and heated to 70 °C for 2.5 h.
  • Step 5 To 2-(4,4-difluorocyclohexyl)propanoic acid (63.5 mg, 0.331 mmol) and HATU (126 mg, 0.331 mmol) in DMF (0.7 mL) was added 6-(cyclopropylmethoxy)pyridazin-3-amine (39 mg, 0.236 mmol) (Intermediate 1, Step 1) (80 mg, 0.360 mmol) and DIEA (0.058 mL, 0.331 mmol), washing down walls of the vessel with DMF (0.5 mL).
  • reaction was stirred at 60 °C for 18 h, diluted with EtOAc, washed with pH 4 phosphate buffer (2X) and brine, dried over Na 2 SO 4 , concentrated and purified by silica gel chromatography (12 g cartridge), eluting with 40% EtOAc in heptanes to provide 41 mg of a white solid.
  • This material was chirally separated (column: AD-H, 20x250mm, 5 micron; flow rate: 20 mL/min, solvents: 50:50 AcCN: MeOH) to provide two stereoisomers of N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(4-oxocyclohexyl)propanamide with retention times of 10.107 and 16.565 min.
  • the second peak (16.565 min) was collected to give (R)-N-(6- (cyclopropylmethoxy)pyridazin-3-yl)-2-(4,4-difluorocyclohexyl)propanamide, 13.89 mg.
  • Step 2 To methyl (2S,4R)-4-hydroxypyrrolidine-2-carboxylate (22.72 g, 157 mmol) in DCM (626 ml) was added triethylamine (43.6 ml, 313 mmol) followed by benzyl bromide (37.2 ml, 313 mmol), and the reaction was refluxed at 65 °C overnight. After cooling to 4 °C, NaOH(aq) (5M, 200 mL) was added until the pH reached 12-14. The layers were separated, and the aqueous phase was extracted with DCM (2 X 100 mL). The organic layers were combined, and about 200 mL of DCM was removed in vacuo to reduce the volume.
  • the organic phase was neutralized with HCl(aq) (1.0 M, 200 mL), the layers were separated, and the organic phase was extracted with HCl (1.0 M, 50 mL).
  • the combined aqueous layers were neutralized with sat’d aq NaHCO3 (100 mL), with ice cooling, and the pH was adjusted to 12-14 by adding solid K2CO3.
  • Step 3 To methyl (2S,4R)-1-benzyl-4-hydroxypyrrolidine-2-carboxylate (23 g, 98 mmol) in DCM (489 ml) was added tert-butyldiphenylchlorosilane (25.1 ml, 98 mmol). The reaction was cooled to 0 °C, and triethylamine (13.63 ml, 98 mmol) was added, dropwise, followed by DMAP (2.389 g, 19.55 mmol). The mixture was allowed to warm to rt, then stirred overnight and treated with water (200 mL). The aqueous layer was isolated and extracted with EtOAc (200 mL).
  • Step 4 To a suspension of LiAlH 4 (52.8 ml, 106 mmol) in THF (100 ml) at 0 °C was added a solution of methyl (2S,4R)-1-benzyl-4-((tert-butyldiphenylsilyl)oxy)pyrrolidine-2- carboxylate (25 g, 52.8 mmol) in THF (100 ml), dropwise. After 10 min, the reaction was heated to reflux (80 °C) for 2 h, then cooled to 0 °C. Water (4 mL), 3.75M NaOH solution (4 mL), and additional water (12 mL) were successively added. The mixture was filtered through Celite, rinsing with THF.
  • Step 6 To oxalyl chloride (0.50 mL, 5.71 mmol) in DCM (15 mL) at -78°C was added dimethyl sulfoxide (0.80 mL, 11.27 mmol), dropwise. After 10 minutes a solution of (3R,5R)-1- benzyl-5-((tert-butyldiphenylsilyl)oxy)piperidin-3-ol (1.21 g, 2.71 mmol) in DCM (5 mL) was added dropwise. After 20 minutes, triethylamine (3.0 mL, 21.52 mmol) was added, and after 5 min, the cooling bath was removed. After 30 minutes. the mixture was poured into water and extracted with DCM (2 X).
  • Step 8 To (5R)-1-benzyl-5-((tert-butyldiphenylsilyl)oxy)-3-(trifluoromethyl)-3- ((trimethylsilyl)oxy)piperidine (100 mg, 0.171 mmol) in EtOH (3 mL), under a nitrogen atmosphere, was added 10% palladium on carbon (20 mg, 0.019 mmol). The reaction vessel was fitted with a hydrogen-filled balloon, evacuated and purged with hydrogen (3X), then stirred under a hydrogen atmosphere overnight. The reaction vessel was evacuated and purged with nitrogen, additional 10% palladium on carbon (20 mg, 0.019 mmol) was added, and the reaction vessel was evacuated and purged with hydrogen (3X), then stirred under a hydrogen atmosphere overnight.
  • Example 12 2-(3-(1,1-dioxidothiomorpholino)piperidin-1-yl)-N-(5-(4-fluorophenoxy)pyrazin-2- yl)propanamide
  • Step 1 tert-Butyl 3-oxopiperidine-1-carboxylate (1 g, 5.02 mmol) and thiomorpholine 1,1-dioxide (1.018 g, 7.53 mmol) were stirred in DCE (20 mL) for 5 minutes, followed by addition of acetic acid (0.287 mL, 5.02 mmol) and sodium triacetoxyborohydride (3.19 g, 15.06 mmol).
  • Step 2 tert-Butyl 3-(1,1-dioxidothiomorpholino)piperidine-1-carboxylate (100 mg, 0.314 mmol) was stirred in TFA (1 mL) for 30 min, diluted with DCM and toluene, concentrated and azeotroped with toluene (2X) to yield crude 4-(piperidin-3-yl)thiomorpholine 1,1-dioxide, trifluoroacetic acid salt (137 mg, 0.330 mmol, recovery: 96%) as a bright yellow oil, which was used without purification.
  • Step 3 A mixture of 2-bromo-N-(5-(4-fluorophenoxy)pyrazin-2-yl)propanamide (Intermediate 21) (100 mg, 0.294 mmol), 4-(piperidin-3-yl)thiomorpholine 1,1-dioxide, TFA salt (102 mg, 0.307 mmol), and TEA (0.246 mL, 1.764 mmol) in DMA (2 mL) was stirred at 40 °C overnight.
  • Example 15 Isopropyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2-yl)amino)-1-oxopropan-2-yl)piperidine- 1 carboxylate Step 1 To ethyl 2-(piperidin-4-yl)acetate hydrochloride (1.246 g, 6 mmol) suspended in EtOAc (15 mL) was added sodium carbonate solution (25 mL). After stirring until clear, the organic layer was isolated, dried over Na 2 SO 4 and filtered. To the filtrate was added triethylamine (1.004 mL, 7.20 mmol), and the reaction was cooled in an ice bath.
  • Step 2 To isopropyl 4-(2-ethoxy-2-oxoethyl)piperidine-1-carboxylate (1.00 g, 3.89 mmol) in THF (10 mL) at -78 °C was added LDA (2M, 2.332 mL, 4.66 mmol), dropwise. After 20 min, iodomethane (0.292 mL, 4.66 mmol) in THF (1 mL) was added dropwise, and the reaction was stirred for 20 min, allowed to warm to rt and stirred overnight. The reaction was quenched with NH4Cl(aq) solution and diluted with EtOAc.
  • Step 3 To isopropyl 4-(1-ethoxy-1-oxopropan-2-yl)piperidine-1-carboxylate (0.20 g, 0.737 mmol) in EtOH (4 mL) was added NaOH(aq) (5N, 0.737 mL, 3.69 mmol). The reaction was heated to 60 °C 1 h, aged in a refrigerator overnight, concentrated, acidified to pH 1 and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give crude 2-(1-(isopropoxycarbonyl)piperidin-4-yl)propanoic acid (216 mg, 0.888 mmol, recovery: quantitative) as a colorless oil, which was used without further purification.
  • Step 4 To 2-(1-(isopropoxycarbonyl)piperidin-4-yl)propanoic acid (104 mg, 0.428 mmol) and HATU (163 mg, 0.428 mmol) in DMF (1.2 mL) was added 5-(2,4- difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (68 mg, 0.306 mmol) and DIEA (0.075 mL, 0.428 mmol).
  • Step 2 A mixture of LiOH (1M, 25.9 ml, 25.9 mmol) and tert-butyl 4-(1-ethoxy-1-oxopropan-2- yl)piperidine-1-carboxylate (740 mg, 2.59 mmol) in dioxane (10 ml) was stirred overnight, quenched with NH4Cl and a small amount of 10% citric acid, and extracted with EtOAc. The organic layer was dried over NaHCO 3 and concentrated to give crude 2-(1-(tert- butoxycarbonyl)piperidin-4-yl)propanoic acid (717.6 mg, 2.79 mmol, 108 % yield), which was used without purification.
  • Step 3 A solution of DIEA (0.295 ml, 1.688 mmol) and 5-(2,4-difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (250 mg, 1.125 mmol) in DMF (0.5 ml) was added to 2-(1-(tert- butoxycarbonyl)piperidin-4-yl)propanoic acid (434 mg, 1.688 mmol) and HATU (701 mg, 1.844 mmol) in DMF (0.5 ml), and the reaction was heated to 60°C.
  • Step 4 TFA (2 ml, 26.0 mmol) was added to tert-butyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2- yl)amino)-1-oxopropan-2-yl)piperidine-1-carboxylate (345 mg, 0.748 mmol) in CHCl3 (1.5 mL). After 20 minutes, the reaction was concentrated and partitioned between DCM and NaHCO3(aq). The DCM layer was concentrated to give crude N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(piperidin-4-yl)propanamide which was used without purification.
  • Step 5 Trifluoroacetic anhydride (14.36 ⁇ l, 0.102 mmol) was added to DIEA (48.4 ⁇ l, 0.277 mmol) and N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(piperidin-4-yl)propanamide (33.4mg, 0.092 mmol) in CHCl3 (308 ⁇ l) at 0 °C. The reaction was allowed to come to 24 °C for 1 h, then cooled back to 0°C. More trifluoroacetic anhydride (20 ⁇ l, 0.142 mmol) was added, and the mixture was brought back 24 °C and stirred overnight.
  • reaction was purified via MDAP (XSELECT CSH C 1 8 column), eluting with 50-99% AcCN in 10 mM ammonium bicarbonate in H 2 O (adjusted to pH 10 with ammonia) to give N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(1-(2,2,2-trifluoroacetyl)piperidin-4-yl)propanamide (10 mg, 0.022 mmol, 23.66 % yield).
  • Example 22 and 23 were synthesized in an analogous manner using the designated Intermediate.
  • Example 24 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3- (trifluoromethyl)piperidin-1-yl)propanamide A mixture of 3-(trifluoromethyl)piperidin-3-ol hydrochloride (200 mg, 1.18 mmol, 1.0 eq), TEA (590 mg, 5.90 mmol, 5.0 eq) and (R)-2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide (Intermediate 3) (351 mg, 1.18 mmol, 1.0 eq) in THF (10 mL) was stirred for 12 h at 40 °C, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 2).
  • Vibration circular dichroism Inspection of VCD data in the analysis range indicated that the VCD difference spectrum obtained by subtracting the VCD spectrum of the two stereoisomers differing at the trifluoromethyl position when compared with the VCD difference spectrum of the calculated VCD of fs1ss minus that of fs2sr is a good match with experimentally determined values. Therefore the absolute configuration of the chiral center alpha to the trifluoromethyl group was confirmed to be (R). The confidence limit for this assignment was estimated to be 100% based on the current database that includes 88 previous correct assignments for different chiral structures. The IR spectrum of the sample was compared with the IR spectrum calculated for the various Models. Again, the model spectrum is in good qualitative agreement with experimental results, confirming the overall structure of this sample (i.e., its molecular connectivity) and providing additional support for satisfactory coverage of its solution phase conformational space by the computational analysis.
  • Example 30 was synthesized in an analogous manner using the designated Intermediate Example 31 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide
  • S 4,4-difluoropiperidine hydrochloride (173 mg, 1.1 mmol, 1.1 eq) in THF (10 mL) were added 2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (298 mg, 1.0 mmol, 1.0 eq) and TEA (606 mg, 6.0 mmol, 6.0 eq).
  • the reaction was stirred for 15 h at 60 o C, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over Na 2 SO 4 and concentrated.
  • the product was purified by reverse phase column (XBridge Prep C 1 8 OBD), eluting with 42-60% AcCN in water (10 mm/L NH 4 HCO 3 ) to give 220 mg of product.
  • Examples 32-33 was synthesized in an analogous manner using the designated Intermediate.
  • Example 34 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1- yl)propanamide Step 1 To tert-butyl 4,4-difluoro-3-hydroxypiperidine-1-carboxylate (source: Shanghai AQBioPharma Co. Ltd ) (200 mg, 0.84 mmol, 1.0 eq) in DCM (6 mL) was added TFA (2 mL).
  • the first peak (16.220 min) was collected and further chirally separated (column: CHIRALPAK IA, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH 3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 6.060 and 7.216 min.
  • Example 44 was synthesized in an analogous manner using the designated Intermediate Example 45a and 45b Ex.45a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(trifluoromethyl)piperidin-1- yl)propanamide or Ex.45b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-4,4-difluoro-3- (trifluoromethyl)piperidin-1-yl)propanamide Step 1 A mixture of 1-benzylpiperidin-4-one (10.0 g, 52.8 mmol, 1.0 eq), TEA (8.84 mL, 63.4 mmol, 1.2 eq), chlorotriethylsilane (9.56 g, 63.4 mmol, 1.2 eq) and sodium iodide (9.50 g, 63.4 mmol, 1.2 eq) in acet
  • Step 2 To a sealed tube containing trifluoromethyl iodide (6.45 g, 32.9 mmol, 10.0 eq) at -90 o C was added 1-benzyl-4-((triethylsilyl)oxy)-1,2,3,6-tetrahydropyridine (1.0 g, 3.29 mmol, 1.0 eq), acetonitrile (15.0 mL), Ru(bpy)3Cl2.6H2O (0.12 g, 0.16 mmol, 0.05 eq), sodium bicarbonate (0.55 g, 6.58 mmol, 2.0 eq) and H 2 O (0.09 mL, 4.94 mmol, 1.5 eq).
  • Step 4 A mixture of 1-benzyl-4,4-difluoro-3-(trifluoromethyl)piperidine (400 mg, 1.43 mmol, 1.0 eq), and Pd/C (152 mg, 10%) in MeOH (15.0 mL) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen. The reaction was stirred 1 h at room temperature under an atmosphere of hydrogen (balloon) and filtered.
  • Step 5 A mixture of (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (374 mg, 1.42 mmol, 1.2 eq), 4,4-difluoro-3-(trifluoromethyl)piperidine HCl salt (268 mg, 1.20 mmol, 1.0 eq), TEA (1.98 mL, 14.19 mmol, 10.0 eq) and silver(I) nitrate (241 mg, 1.42 mmol, 1.0 eq) in DMA (4.0 mL) was stirred for 12 h at 40 o C, poured into H 2 O (20 mL) and extracted with ethyl acetate (20 mL x 3).
  • the first peak (4.301 min) was collected and further separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: [8 mM NH 3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 11.125 and 13.034 min.
  • Example 50a and 50b Ex.50a: (S)-2-((S)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.50b: (S)-2-((R)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide Step 1 To methyl 3,3,3-trifluoro-2-oxopropanoate (10 g, 64 mmol, 1eq) in DCM (100 mL) was added NH 2 Boc (7.5 g, 64 mmol, 1eq).
  • Step 2 To methyl 2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-hydroxypropanoate (11.4 g, 42 mmol, 1 eq) in diethyl ether (50 mL) was added trifluoroacetic anhydride (8.7 g, 42 mmol, 1 eq). After cooling to 0 o C for 1.5 h, pyridine (6.6 g, 84 mmol, 2 eq) was added slowly.
  • Step 3 To prop-2-yn-1-amine (10 g, 0.18 mol, 1 eq) and triethylamine (54 g, 0.54 mol, 3 eq) in DCM (200 mL) at 0 o C was added chlorotrimethylsilane (39 g, 0.36 mol, 2 eq), dropwise. The mixture was stirred 16 h at room temperature, quenched with water (300 mL) and extracted with ethyl acetate (200 mL x 3).
  • Step 4 To 1,1,1-trimethyl-N-(prop-2-yn-1-yl)-N-(trimethylsilyl)silanamine (8.3 g, 42 mmol, 1.2 eq) in THF (100 mL) at -78 o C was added n-BuLi (17 mL, 42 mmol, 2.5 M in hexane, 1.2 eq), dropwise. After 10 min, a solution of methyl (Z)-2-((tert-butoxycarbonyl)imino)- 3,3,3-trifluoropropanoate (9 g, 35 mmol, 1 eq) in THF (10 mL) was added dropwise.
  • Step 7 A mixture of 3-(trifluoromethyl)piperidin-3-amine (1.7 g, 10.1 mmol, 13 eq), (R)-2-bromo- N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (200 mg, 0.76 mmol, 1 eq) and triethylamine (230 mg, 2.3 mmol, 3 eq) in THF (5 mL) was stirred at 40 o C for 48 h, diluted with water (50 mL) and extracted with ethyl acetate (50 mL x 3).
  • This material was chirally separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH 3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 6.745 and 8.605 min.
  • Example 52a and 52b Ex.52a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3,3-difluoro-4-hydroxypyrrolidin-1- yl)propanamide or Ex.52b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3,3-difluoro-4- hydroxypyrrolidin-1-yl)propanamide
  • Step 3 To benzyl 3-((2-oxoethyl)carbamoyl)piperidine-1-carboxylate (700 mg, 2.30 mmol, 1.0 eq) in dichloromethane (50 mL) was added Cl 3 CCCl 3 (1032 mg, 4.59 mmol, 2.0 eq), PPh 3 (1207 mg, 4.59 mmol, 2.0 eq) and TEA (4651 mg, 4.59 mmol, 2.0 eq).
  • Step 4 A mixture of benzyl 3-(oxazol-2-yl)piperidine-1-carboxylate (140 mg, 0.49 mmol, 1.00 eq) and Pd/C (10%, 70 mg) in methanol (10 mL) was stirred under hydrogen for 2 h, filtered and concentrated to give 2-(piperidin-3-yl)oxazole (70 mg, yield: 75%, purity: 80%) as a yellow oil, which was used without purification.
  • Step 5 To 2-(piperidin-3-yl)oxazole (70 mg, 0.5 mmol, 1.0 eq) and (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (121 mg, 0.5 mmol, 1.0 eq) in THF (10 mL) was added TEA (233 mg, 2.5 mmol, 5.0 eq). The reaction was stirred at 40 °C for 48 h, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3).
  • Example 54a and 54b Ex.54a: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-(oxazol-4-yl)piperidin-1-yl)propanamide or Ex.54b: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-(oxazol-4-yl)piperidin-1-yl)propanamide
  • Step 1 To 1-(piperidin-3-yl)ethan-1-one hydrochloride salt (1.00 g, 6.25 mmol, 1.0 eq) and TEA (3.10 g, 30.69 mmol, 5.0 eq) in DCM (50 mL) at 0 o C was added benzyl carbonochloridate (1.25 g, 7.50 mmol, 1.2 eq), dropwise. The resulting solution was stirred at room temperature for 16 h, poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3).
  • Step 3 A mixture of benzyl 3-(2-bromoacetyl)piperidine-1-carboxylate (500 mg, 1.47 mmol, 1.00 eq) and formamide (5 mL) was stirred at 90 o C for 1 h.
  • Step 4 A mixture of benzyl 3-(oxazol-4-yl)piperidine-1-carboxylate (180 mg, 0.67 mmol, 1.00 eq) and Pd/C (10%, 100 mg) in MeOH (15 mL) was stirred for 3 h under an atmosphere of hydrogen, filtered and concentrated to give 4-(piperidin-3-yl)oxazole (90 mg, yield: 90 %, purity: 95%) as yellow oil, which was used without purification.
  • Step 5 A mixture of 4-(piperidin-3-yl)oxazole (90 mg, 0.59 mmol, 1.0 eq), (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (155 mg, 0.59 mmol, 1.0 eq) and TEA (598 mg, 5.88 mmol, 10.0 eq) in THF (8 mL) was stirred for 18 h at 40 o C, quenched with water (80 mL) and extracted with ethyl acetate (80 mL x 3).
  • Example 56 (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5- yl)piperidin-1-yl)propanamide
  • Step 1 A mixture of 1-benzyl 3-methyl 4-oxopiperidine-1,3-dicarboxylate (20.0 g, 68.73 mmol, 1.0 eq) and TsOH (2 g, 11.6 mmol, 0.2 eq) and ethane-1,2-diol (22.0 g, 354.83 mmol, 5.0 eq) in toluene (500 mL) was heated to reflux under a Dean-Stark apparatus.
  • Step 2 To 8-benzyl 6-methyl 1,4-dioxa-8-azaspiro[4.5]decane-6,8-dicarboxylate (16.0 g, 47.80 mmol, 1.0 eq) in MeOH (300 mL) and H 2 O (150 mL) at 25 °C was added NaOH (5.73 g, 143.3 mmol, 3.0 eq). After 16 h, the organic solvent was removed under vacuum, and the reaction was diluted with water (100 mL). The pH was adjusted to 3 with 1 M HCl, and the mixture was extracted with ethyl acetate (300 mL x 2).
  • Step 3 To 8-((benzyloxy)carbonyl)-1,4-dioxa-8-azaspiro[4.5]decane-6-carboxylic acid (13.50 g, 42.10 mmol, 1.0 eq) in DMF (100 mL) at 25 o C was added HATU (19.19 g, 50.50 mmol, 1.2 eq) and DIEA (16.40 g, 127.2 mmol, 3.0 eq). After 30 min, NH 4 Cl (4.46 g, 84.20 mmol, 2.0 eq) was added.
  • Step 4 A mixture of benzyl 6-carbamoyl-1,4-dioxa-8-azaspiro[4.5]decane-8-carboxylate (13.20 g, 41.30 mmol, 1.0 eq) in DMF-DMA (250 mL) was stirred at 110 o C for 3 h, concentrated under vacuum, then dissolved in AcOH (200 mL). N2H4 ⁇ H2O (80 %, 15 mL) was added, and the reaction was stirred at 90 o C.
  • Step 5 To benzyl 6-(1H-1,2,4-triazol-3-yl)-1,4-dioxa-8-azaspiro[4.5]decane-8-carboxylate (10.0 g, 29.10 mmol, 1.0 eq) in DMF (100 mL) at 0 o C was added NaH (1.75 g, 43.70 mmol, 1.5 eq, 60%), in portions. After 30 min, benzyl chloride (5.44 g, 34.9 mmol, 1.2 eq) was added dropwise, and the resulting mixture was stirred at 25 o C.
  • Step 7 To benzyl 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)-4-oxopiperidine-1-carboxylate (5.80 g, 13.81 mmol, 1.0 eq) in DCM (100 mL) at 0 o C was added DAST (8.89 g, 55.24 mmol, 4.0 eq) in DCM (150 mL), dropwise. The reaction was stirred at room temperature overnight, quenched with ice water (150 mL) and exacted with DCM (150 mL x 2).
  • Step 8 A mixture of benzyl 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)piperidine- 1-carboxylate (3.3 g, 7.46 mmol) and palladium hydroxide on carbon (5.24 g, 7.46 mmol) in methanol (60 mL) was stirred under hydrogen at 25°C for 2 h, filtered, concentrated and purified over C 1 8 silica (120 g column), eluting with 5-95% AcCN in water (10 mM NH4HCO3) to afford 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)piperidine (1.7 g, 2.51 mmol, 33.7 % yield) as a colorless oil.
  • Step 2 To potassium tert-butoxide (2.70 g, 28.09 mmol, 2.5 eq) in THF (20 mL) was added tri- tert-butylphosphane (2.26 g, 1.12 mmol, 0.1 eq, 10 wt% in hexanes) and palladium (II) acetate (252 mg, 1.12 mmol, 0.1 eq). After 10 min, tert-butyl 4-oxopiperidine-1- carboxylate (3.35 g, 16.85 mmol, 1.5 eq) and 3-bromo-1-(4-methoxybenzyl)-1H-pyrazole (3.00 g, 11.23 mmol, 1.0 eq) were added.
  • Step 3 To tert-butyl 3-(1-(4-methoxybenzyl)-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate (50.00 g, 129.87 mmol, 1.0 eq) in dichloromethane (400 mL) at 0 °C was added DAST (41.82 g, 259.74 mmol, 2.0 eq), dropwise, and the mixture was stirred at room temperature for 10 h. The reaction was quenched with water (500 mL) and extracted with dichloromethane (500 mL x 3).
  • Step 4 A solution of tert-butyl 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-pyrazol-3-yl)piperidine- 1-carboxylate (450 mg, 1.11 mmol, 1.0 eq) in trifluoroacetic acid (10 mL) was stirred at 100 °C for 10 h. The solvent was removed to give 450 mg crude 4,4-difluoro-3-(1H- pyrazol-5-yl)piperidine TFA salt, as a yellow oil which was used without purification.
  • Examples 62-64 were synthesized in an analogous manner using the designated Intermediate in Step 5
  • Example 65 (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide Step 1
  • DIPEA 1-(piperidin-3-yl)ethenone hydrochloride (2.0 g, 12.22 mmol) in THF (50 mL) at 0 °C)
  • DIPEA 5.34 mL, 30.6 mmol
  • benzyl carbonochloridate 1.919 mL, 13.44 mmol
  • Example 76 (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(propylamino)pyridin-2-yl)propanamide Step 1 To 3-(1H-pyrazol-5-yl)piperidine (Example 65, Step 3 racemate) (95 mg, 0.626 mmol) and tert-butyl (R)-(6-(2-bromopropanamido)pyridin-3-yl)(propyl)carbamate (Intermediate 14) (220 mg, 0.570 mmol) in DMSO (4.0 mL) was added triethylamine (0.318 mL, 2.278 mmol).
  • Step 2 A mixture of tert-butyl (6-((2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamido)pyridin-3-yl)(propyl)carbamate (220 mg, 0.482 mmol) and TFA (4.0 mL, 51.9 mmol) was stirred for 1 hour, concentrated and made basic with sat. NaHCO 3 .
  • Step 1 To 1H-pyrazole-3-boronic acid (1.27 g, 11.11 mmol) and 3-bromo-5-methylpyridine (1.50 g, 8.55 mmol) in dioxane (68 mL) were added 1M aqueous cesium fluoride (3.93 g, 25.64 mmol), Pd 2 dba 3 (577 mg, 0.60 mmol), and S-Phos (537 mg, 1.28 mmol) under argon.
  • 1M aqueous cesium fluoride (3.93 g, 25.64 mmol
  • Pd 2 dba 3 577 mg, 0.60 mmol
  • S-Phos 537 mg, 1.28 mmol
  • Step 2 3-Methyl-5-(1H-pyrazol-5-yl)pyridine (240 mg, 1.51 mmol) was dissolved in MeOH (76 mL) and TFA (0.23 mL), and the mixture was hydrogenated using an H-Cube (70 mm CatCart of 5 % Rh/Al 2 O 3 , 100 °C, 50 bar, 0.5 mL/min). The collected material was concentrated, and the crude product was purified by prep HPLC (conditions not reported) to afford trans-3-methyl-5-(1H-pyrazol-5-yl)piperidine (145 mg, 58 %) as a yellow oil.
  • Example 78a and 78b Ex.78a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-(2- hydroxyethyl)-1H-pyrazol-3-yl)piperidin-1-yl)propanamide or Ex.78b: (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-(2-hydroxyethyl)-1H-pyrazol- 3-yl)piperidin-1-yl)propanamide Step 1 To (2S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoro-3-(1H-pyrazol-3- yl)piperidin-1-yl)propanamide (Example 61) (490 mg, 1.21
  • This material was chirally separated (column: CHIRAL ART Cellulose - SB, 2 x 25 cm, 5 ⁇ m, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide four peaks with retention times of 14.926, 17.919, 20.788 and 33.897 min.
  • Step 1 To 1H-pyrazole-3-boronic acid (1.27 g, 11.11 mmol) and 3-bromo-4-methylpyridine (1.50 g, 8.55 mmol) in dioxane (69 mL) were added 1M aqueous cesium fluoride (3.93 g, 25.64 mmol), Pd2dba3 (577 mg, 0.60 mmol), and S-Phos (537 mg, 1.28 mmol) under argon. The mixture was stirred in a pressure proof vessel for 16-20 hours at 100 °C, concentrated and purified by column chromatography, eluting with 0-5 % MeOH in CHCl3.
  • Example 80 (S)-2-((S)-3-(1H-pyrrol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide Step 1 To tert-butyl 3-oxopiperidine-1-carboxylate (10 g, 50 mmol, 1.0 eq) in THF (200 mL) at - 78 o C was added LiHMDS (60 ml, 60 mmol, 1.2 eq, 1 M in tetrahydrofuran), dropwise.
  • LiHMDS 60 ml, 60 mmol, 1.2 eq, 1 M in tetrahydrofuran
  • HMPA HMPA (17.4 ml, 100 mmol, 2.0 eq) was added dropwise, followed after 15 min by dropwise addition of PhNTf2 (21.4 g, 60 mmol, 1.2 eq) in THF (80 mL). The temperature was increased to room temperature naturally, and the reaction mixture was stirred for 13 h, quenched with water (200 mL) and extracted with ethyl acetate (500 mL ⁇ 3).
  • Step 2 A mixture of tert-butyl 5-(((trifluoromethyl)sulfonyl)oxy)-3,6-dihydropyridine-1(2H)- carboxylate (5.5 g, 16.6 mmol, 1.0 eq), (1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl)boronic acid (5.25 g, 24.9 mmol, 1.5 eq), Pd(dppf)Cl2 (1.22 g, 1.66 mmol, 0.1 eq) and Na2CO3 (3.52 g, 33.2 mmol, 2.0 eq) in dioxane (160 mL) and water (40 mL) was evacuated and flushed with nitrogen three times, stirred at 90 °C for 12 h, filtered, concentrated and diluted with water (100 mL).
  • Step 3 A mixture of tert-butyl 5-(1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl)-3,6-dihydropyridine- 1(2H)-carboxylate (4 g, 11.5 mmol, 1.0 eq), tetrahydrofuran (20 mL) and CH 3 ONa (20 mL, 30% in methanol) was stirred for 1 h, concentrated, diluted with water (100 mL) and extracted with ethyl acetate (100 mL ⁇ 3).
  • Step 4 A mixture of tert-butyl 5-(1H-pyrrol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.1 g, 4.4 mmol, 1.0 eq), methanol (20 mL) and Pd(OH) 2 /C (110 mg, 0.2 eq) was evacuated and flushed three times with hydrogen, stirred 2 h under hydrogen, filtered, concentrated and purified over a silica gel column, eluting with methanol : dichloromethane (1:10) to give 673 mg (purity: 95%, yield: 61%) tert-butyl 3-(1H-pyrrol-2-yl)piperidine-1-carboxylate as a yellow solid.
  • Step 5 To tert-butyl 3-(1H-pyrrol-2-yl)piperidine-1-carboxylate (673 mg, 2.69 mmol, 1.0 eq) in DMF (15 mL) at 0 o C was added NaH (215 mg, 5.38 mmol, 2.0 eq, 60%). After 30 min, 4- methylbenzenesulfonyl chloride (615 mg, 3.23 mmol, 1.2 eq) was added, and the mixture was stirred at room temperature for 2 h, quenched with water (20 mL) and extracted with ethyl acetate (100 mL ⁇ 3).
  • Step 6 A mixture of tert-butyl 3-(1-tosyl-1H-pyrrol-2-yl)piperidine-1-carboxylate (849 mg, 2.1 mmol, 1.0 eq), dichloromethane (8 mL) and TFA (2 mL) was stirred for 0.5 h and concentrated to give 606 mg (purity: 90%, yield: 95%) 5-(1-tosyl-1H-pyrrol-2-yl)-1,2,3,6- tetrahydropyridine as a yellow solid, which was used without purification.
  • Step 7 A mixture of 5-(1-tosyl-1H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine (as a free base) (606 mg, 2 mmol, 1.0 eq), 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (1.05 g, 4 mmol, 2.0 eq) and TEA (2.02 g, 20 mml, 10.0 eq) in tetrahydrofuran (10 mL) was stirred at 40 o C for 12 h, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1: 2) to give 628 mg (purity: 95%, yield: 65%) N-(5- chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-2-yl)piperidin-1-yl)propanamide as
  • Step 8 A mixture of N-(5-chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-2-yl)piperidin-1- yl)propanamide (520 mg, 1.07 mmol, 1.0 eq) and TBAF (25 mL, 1M in tetrahydrofuran) was stirred at 50 o C for 72 h, concentrated, diluted with water (50 mL) and extracted with ethyl acetate (50 mL ⁇ 3).
  • the second peak (13.259 min) was collected and further chirally separated (column: CHIRAL PAK IF, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH 3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 10.904 and 12.886 min.
  • the second peak (12.886 min) was collected to give 20 mg (purity: 99%, yield: 5.6%) of (S)-2-((S)-3-(1H-pyrrol-2-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide as a white solid.
  • Example 81a and 81b Ex.81a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-methyl-1H- pyrazol-3-yl)piperidin-1-yl)propanamide or Ex.81b: (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-methyl-1H-pyrazol-3- yl)piperidin-1-yl)propanamide Step 1 To t-BuONa (3.16 g, 32.8 mmol, 2.5 eq) in THF (16 mL) at 25 o C were added (t-Bu)3P (10 % in hexane, 2.66 g, 1.32 mmol, 0.1 eq) and Pd(OAc) 2 (294 mg, 1.30 mmol,
  • Step 2 To tert-butyl 3-(1-methyl-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate (1 g, 4.36 mmol, 1.0 eq) in DCM (10 mL) at 0 o C was added DAST (1.40 g, 8.72 mmol, 2.0 eq), dropwise. The reaction was stirred for 18 h at room temperature, quenched with ice water (60 mL) and extracted with DCM (60 mL x 3).
  • Step 5 Benzyl 3-carbamoyl-5-methylenepiperidine-1-carboxylate (6.2 g, 22.6 mmol, 1.0 eq) in DMF-DMA (70 mL) was stirred for 3 hours at 110 o C and concentrated to give 6.3 g crude benzyl (E)-3-(((dimethylamino)methylene)carbamoyl)-5-methylenepiperidine-1- carboxylate as a yellow oil, which was used without purification.
  • Step 6 To benzyl (E)-3-(((dimethylamino)methylene)carbamoyl)-5-methylenepiperidine-1- carboxylate (6.3 g, 19.1 mmol, 1.0 eq) in AcOH (60 mL) was added N 2 H 4. H 2 O (80%, 6 mL), and the mixture was stirred at 90 o C. After 18 h, the reaction was concentrated, diluted with water (300 mL) and extracted with ethyl acetate (300 mL x 3).
  • Step 7 To benzyl 3-methylene-5-(1H-1,2,4-triazol-5-yl)piperidine-1-carboxylate (4.8 g, 16.1 mmol, 1.0 eq) in DMF (50 mL) at 0 o C was added NaH (60%, 966 mg, 24.2 mmol, 1.5 eq), in portions. After 30 min, benzyl chloride (3.8 g, 24.2 mmol, 1.5 eq) was added dropwise, and the reaction was stirred at room temperature. After 2 h, the mixture was quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3).
  • Step 8 A mixture of benzyl 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5- methylenepiperidine-1-carboxylate (3.0 g, 7.17 mmol, 1.0 eq) and Pd/C (300 mg) in MeOH (30 mL) was stirred for 15 h under an H2 atmosphere, filtered and concentrated to give 2.0 g crude 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylpiperidine as yellow oil, which was used without purification. LCMS (m/z) 287 (M+H)+.
  • Step 9 To 3-(1-(4-Methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylpiperidine (2.0 g, 7.0 mmol, 1.0 eq) in THF (50 mL) were added (R)-2-Bromo-N-(5-fluoropyridin-2-yl)propanamide (Intermediate 4) (1.72 g, 7.0 mmol, 1.0 eq) and TEA (7.0 g, 70.0 mmol, 10.0 eq), and the mixture was stirred at 40 o C. After 72 h, the reaction was quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3).
  • the first peak (10.037 min) was collected further chirally separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide two peaks with retention times of 15.100 and 18.300 min.
  • the first peak (15.100 min) was collected to give 20 mg (purity: 98.8%, yield: 2%) (S)-N-(5-fluoropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-1,2,4-triazol-5-yl)piperidin-1- yl)propanamide as white solid.
  • Step 3 A mixture of tert-butyl 5-(1H-pyrrol-3-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.66 g, 6.69 mmol, 1.0 eq) and Pd(OH) 2 /C (200 mg, 20%) in MeOH (20 mL) was stirred for 15 h under an atmosphere of hydrogen, filtered and concentrated go give 1.24 g (purity: 40%, yield: 74%) of tert-butyl 3-(1H-pyrrol-3-yl)piperidine-1-carboxylate as a yellow solid, which was used without purification.
  • Step 6 A mixture of 3-(1-tosyl-1H-pyrrol-3-yl)piperidine (as free base) (527 mg, 1.73 mmol, 1.0 eq), 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (454 mg, 1.73 mmol, 1.0 eq), TEA (1.40 g, 13.86 mmol, 8.0 eq) and KI (287 mg, 1.73 mmol, 1.0 eq) in THF (20 mL) was stirred for 15 h at 60 o C, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3).
  • Step 7 N-(5-Chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-3-yl)piperidin-1-yl)propanamide (240 mg, 0.49 mmol, 1.0 eq) in TBAF (20 mL, 1.0 mol/L in THF) was stirred for 35 h at 50 o C, quenched with NH4Cl (50 mL, aq., sat.) and extracted with ethyl acetate (50 mL x 3).
  • the first peak (5.126 min) was further chirally separated (column: CHIRAL PAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH 3 in MeOH], Mobile Phase B: EtOH, A:B 85:15) to provide two peaks with retention times of 10.141 and 11.277 min.
  • the second peak (11.277 min) was collected to give 2.8 mg (purity: 99.7%, yield: 2%) of (S)-2-((R)-3-(1H- pyrrol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide as a white solid.
  • Example 84 (2S)-N-(5-chloropyridin-2-yl)-2-(3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidin-1- yl)propanamide Step 1 To 4-bromo-1H-pyrazole (2.00 g, 13.61 mmol) and 1-(chloromethyl)-4-methoxybenzene (2.77 g, 17.69 mmol) in DMSO (40 mL) was added K2CO3 (5.64 g, 40.8 mmol). After 4 hours, the mixture was diluted with water and extracted with DCM (3X).
  • Step 2 To tert-butyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.5 g, 4.85 mmol), Na2CO3 (1.028 g, 9.70 mmol) and 4-bromo-1-(4- methoxybenzyl)-1H-pyrazole (1.944 g, 7.28 mmol) in water (5.00 mL) and dioxane (15.0 mL) was added PdCl 2 (dppf)-CH 2 Cl 2 adduct (0.396 g, 0.485 mmol).
  • Step 3 To tert-butyl 5-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.80 g, 4.87 mmol) in ethanol (10 mL) under N 2 was added Pd/C, 10% (0.052 g, 0.487 mmol).
  • Step 4 A mixture of tert-butyl 3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidine-1-carboxylate (1.52 g, 4.09 mmol) and TFA (5.0 mL, 64.9 mmol) was stirred at RT for 30 min, heated at 50 °C overnight, cooled to RT, concentrated and treated carefully with sat. NaHCO 3 until basic. The mixture was extracted with DCM (3X).
  • Step 1 To 3-(1H-1,2,4-triazol-5-yl)pyridine (1.0 g, 6.84 mmol) and potassium carbonate (1.891 g, 13.68 mmol) in DMF (25 mL) was added (2-(chloromethoxy)ethyl)trimethylsilane (2.427 mL, 13.68 mmol).
  • Step 2 To 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5-yl)pyridine (1.83 g, 6.62 mmol) in methanol (50 mL) was added acetic acid (0.758 mL, 13.24 mmol) followed by palladium hydroxide (20% on carbon) (2.324 g, 3.31 mmol). The reaction was evacuated and purged with hydrogen several times, then stirred overnight under a balloon of hydrogen. The mixture was filtered through Celite, concentrated, treated with 10% aq K 2 CO 3 (30 mL) and extracted with 15% IPA/DCM (2 x 80 mL).
  • Example 86 was synthesized in an analogous manner using the designated Intermediate in Step 3.
  • Example 87 (2S)-2-(3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide
  • Step 1 A mixture of benzyl 3-carbamoylpiperidine-1-carboxylate (2.0 g, 7.62 mmol) and 1,1- dimethoxy-N,N-dimethylmethanamine (10.0 mL, 75 mmol) was heated at 100 °C for 3 h, concentrated and dissolved in acetic acid (10 mL).
  • Example 88a and 88b Ex.88a: (S)-2-((R)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.88b: (S)-2-((S)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide Step 1 To 4-bromo-1H-pyrazole (2.00 g, 13.61 mmol) in THF (50 mL) was added NaH (0.653 g, 16.33 mmol).
  • Step 2 To tert-butyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.50 g, 4.85 mmol), Na 2 CO 3 (1.028 g, 9.70 mmol) and 4-bromo-1-((2- (trimethylsilyl)ethoxy)methyl)-1H-pyrazole (2.017 g, 7.28 mmol) in water (5.00 mL) and dioxane (15.0 mL) was added PdCl2(dppf)-CH2Cl2adduct (0.396 g, 0.485 mmol).
  • Step 3 To tert-butyl 5-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-4-yl)-3,6- dihydropyridine-1(2H)-carboxylate (1.68 g, 4.43 mmol) in ethanol (10 mL) under N2 was added Pd/C, 10% (0.047 g, 0.443 mmol), and the mixture was hydrogenated under an H2 balloon overnight.
  • Step 4 A mixture of tert-butyl 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-4- yl)piperidine-1-carboxylate (350 mg, 0.917 mmol) and TFA (3.0 mL, 38.9 mmol) was stirred for 3 hours and concentrated to afford 3-(1H-pyrazol-4-yl)piperidine, trifluoroacetic acid salt (243 mg, 0.916 mmol, 100 % yield) as a colorless wax, which was used without purification.
  • Step 1 To 2-(benzyloxy)-5-bromopyridine (1.00 g, 3.80 mmol, 1.0 eq) and tert-butyl 5-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.41 g, 4.56 mmol, 1.2 eq) in dioxane/water (50 mL, 4/1) were added Pd(dppf)Cl2 (621 mg, 0.85 mmol, 0.2 eq) and sodium carbonate (1.21 g, 11.40 mmol, 3.0 eq). The reaction was flushed with nitrogen and stirred at 60 o C.
  • Step 2 A mixture of tert-butyl 6'-(benzyloxy)-5,6-dihydro-[3,3'-bipyridine]-1(2H)-carboxylate (1.20 g, 3.28 mmol, 1.0 eq) and Pd/C (10%, 1.20 g) in methanol (15 mL) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen.
  • Step 4 A mixture of [3,3'-bipiperidin]-6-one (as free base) (300 mg, 1.65 mmol, 1.0 eq), (R)-2- bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (522 mg, 1.98 mmol, 1.2 eq) and triethylamine (833 mg, 8.35 mmol, 5.0 eq) in tetrahydrofuran (20 mL) was stirred for 16 h at 40 o C, poured into water (80 mL) and extracted with ethyl acetate (80 mL x 3).
  • Step 2 To XtalFluor-E (199 g, 868 mmol) in DCM (585 mL) at -1.1 °C was slowly added a solution of triethylamine trihydrofluoride (140 g, 868 mmol) and pyridine (34.3 g, 434 mmol) in DCM (414 mL), followed by a solution of tert-butyl 3-(6-methoxypyridin-3-yl)- 4-oxopiperidine-1-carboxylate (133 g, 434 mmol) in DCM (794 mL).
  • Step 3 To a 48% aqueous solution of hydrobromic acid (40.9 mL, 361 mmol) was added a solution of tert-butyl 4,4-difluoro-3-(6-methoxypyridin-3-yl)piperidine-1-carboxylate (12.6 g, 38.4 mmol) in toluene (40 mL), dropwise. The reaction was stirred at 95 °C overnight, concentrated, taken up in 2-MeTHF (100 mL) and treated with a 3M solution of hydrochloric acid in cyclopentylmethyl ether (CPME) (130 mL).
  • CPME cyclopentylmethyl ether
  • the first-eluting isomer (3.981 min) was stirred in AcCN (250 mL) at 60 °C with activated charcoal (3 g) for 90 min. The mixture was filtered through Celite, concentrated, and the residue was triturated with AcCN to provide (S)-5-(4,4-difluoropiperidin-3-yl)pyridin-2(1H)-one (2.568 g, 11.87 mmol, recovery: 31 %) as a light tan solid.
  • Step 4 (S)-5-(4,4-difluoropiperidin-3-yl)pyridin-2(1H)-one (500 mg, 2.334 mmol) was dissolved in methanol (10 mL) and platinum(IV) oxide (106 mg, 0.467 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. The reaction was stirred at room temperature for 40 h. The reaction was filtered through Celite and solid was washed by methanol (3 X 10 mL).
  • Step 5 To a solution of (R)-2-bromo-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (Intermediate 17) (196 mg, 0.550 mmol) in DMA (2 ml) was added (S)-4',4'-difluoro-[3,3'- bipiperidin]-6-one (120 mg, 0.550 mmol) followed by TEA (0.230 mL, 1.650 mmol) and silver nitrate (187 mg, 1.100 mmol). The mixture was stirred at rt overnight. The reaction mixture was diluted with EtOAc (10 mL) and then filtered to remove silver salts.
  • Step 2 XtalFluor-E (6210 mg, 27.1 mmol) was dissolved in Dichloromethane (DCM) (30 mL) and chilled with an ice batch. In an separate vial, triethylamine trihydrofluoride (4.42 mL, 27.1 mmol) and pyridine (1.097 mL, 13.56 mmol) were dissolved in Dichloromethane (DCM) (15 mL) and the mixture was then slowly added into reaction. The mixture was stirred in icebath for 20 min.
  • DCM Dichloromethane
  • tert-butyl 3-(6-(benzyloxy)pyridin-3-yl)-4-oxopiperidine-1-carboxylate (5186 mg, 13.56 mmol) in Dichloromethane (DCM) (15 mL) was then slowly added to the reaction. The reaction was then stirred for 30 min with icebath and additional 3h at room temperature. The reaction was chilled in an icebath.100 mL sat. NaHCO3 solution was slowly added to reaction mixture, followed by 100 mL DCM. The ending point pH ⁇ 8. Layers were separated and aqueous layer was extracted by DCM (2 X 100 mL). The combined organic layer was washed by brine and dried over Na2SO4.
  • DCM Dichloromethane
  • Step 3 tert-butyl 3-(6-(benzyloxy)pyridin-3-yl)-4,4-difluoropiperidine-1-carboxylate (1.16 g, 2.87 mmol) was dissolved in Methanol (15 mL) and Pd-C (0.305 g, 0.287 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. After one hour of reaction, LCMS showed all starting material was consumed and desired product was formed. The reaction was filtered through Celite and solid was washed by methanol (3 X 10mL).
  • Step 4 tert-butyl 4,4-difluoro-3-(6-oxo-1,6-dihydropyridin-3-yl)piperidine-1-carboxylate (460 mg, 1.463 mmol) and cesium carbonate (715 mg, 2.195 mmol) was dissolved in N,N- Dimethylformamide (DMF) (6.5 mL).2,2,2-trifluoroethyl trifluoromethanesulfonate (0.316 mL, 2.195 mmol) was then added to the reaction. The reaction was stirred at room temperature for 1h. The reaction was then diluted with EtOAc (100 mL) and the organic layer was washed with water (20 mL) and brine (20 mL).
  • DMF N,N- Dimethylformamide
  • Step 5 tert-butyl 4,4-difluoro-3-(6-oxo-1-(2,2,2-trifluoroethyl)-1,6-dihydropyridin-3- yl)piperidine-1-carboxylate (330 mg, 0.833 mmol) was dissolved in Methanol (10 mL) and Pd-C (89 mg, 0.083 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. After one hour of reaction, LCMS showed all starting material was consumed and desired product was formed. The reaction was filtered through Celite and solid was washed by methanol (3 X 10mL).
  • Step 6 To tert-butyl 4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidine]-1-carboxylate (300 mg, 0.749 mmol) was added HCl in dioxane (3 mL, 12.00 mmol). After stirring at room temperature for 2h, The organic solvents were removed in vacuo to give 4',4'- difluoro-1-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-6-one, Hydrochloride (250 mg, 0.742 mmol, 99 % yield). The product was used in next step without purification.
  • the mixture was stirred at rt overnight.
  • the reaction mixture was filtered to remove some silver salts.
  • the filtrate was diluted with EtOAc and washed with satd. K2CO3 solution.
  • the organic phase was washed 1x with a mix of satd. K2CO3 solution and brine, then dried over Na2SO4, filtered and concentrated.
  • the sample was purified by reverse phase C 1 8 AQ 100g Gold (Gradient 50% to 80% B over 19min, flow rate 60 mL/min, A: Water with 10mM Ammonium Bicarb and 0.075% Ammonium Hydroxide/B: Acetonitrile) and obtained (2S)-2-(4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide (107 mg, 0.180 mmol, 45.9 % yield) (mixture of 4 diastereomers).
  • Example 99 was synthesized in an analogous manner, using the designated Intermediate in Step 7.
  • Example 100a and 100b Ex.100a: (S)-2-((R)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.100b: (S)-2-((S)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
  • Step 1 To tert-butyl 3-hydroxypiperidine-1-carboxylate (3.00 g, 15.93 mmol, 1.0 eq) and TEA (2.26 g, 22.39 mmol, 1.5 eq) in DCM (100 mL) at 0 °C was added MsCl (1.87 g, 16.42 mmol, 1.1 eq), dropwise. The reaction was stirred at room temperature for 2 h, poured into water (300 mL) and extracted with dichloromethane (200 mL x 3).
  • Step 2 To 1H-pyrazole (975 mg, 14.29 mmol, 2.0 eq) and DMF (50 mL) at 0 °C was added NaH (60%, 516 mg, 12.9 mmol, 1.8 eq), in portions. The reaction was stirred at room temperature for 1 hour, then tert-butyl 3-((methylsulfonyl)oxy)piperidine-1-carboxylate (200 mg, 7.14 mmol, 1.0 eq) in DMF (10 mL) was added. The mixture was stirred at 100 °C for 16 h, poured into water (400 mL) and extracted with ethyl acetate (300 mL x 3).
  • Step 3 A mixture of tert-butyl 3-(1H-pyrazol-1-yl)piperidine-1-carboxylate (300 mg, 1.36 mmol, 1.0 eq), dichloromethane (9 mL) and TFA (3 mL) was stirred at rt for 2 h and concentrated to give 3-(1H-pyrazol-1-yl)piperidine as a yellow solid, which was used without purification.
  • Step 4 A mixture of 3-(1H-pyrazol-1-yl)piperidine (as free base) (90 mg, 0.6 mmol, 1.0 eq), (R)- 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (156 mg, 0.6 mmol, 1.0 eq) and TEA (301 mg, 3.0 mmol, 5.0 eq) in THF (10 mL) was stirred at 40 °C for 24 h, poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3).
  • Example 101a and 101b Ex.101a: (S)-2-((R)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.101b: (S)-2-((S)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide Step 1 To DMF (10 mL) and NaH (60%, 240 mg, 6.00 mmol, 1.0 eq) was added 2H-1,2,3-triazole (412 mg, 5.97 mmol, 1.0 eq).
  • tert-butyl 3-((methylsulfonyl)oxy)piperidine- 1-carboxylate (Example 100, Step 1) (2.00 g, 7.17 mmol, 1.2 eq) in DMF (3 mL) was added dropwise, and the reaction was stirred at 60 o C. After 20 h, the mixture was poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3).
  • Step 1 To 1H-pyrazole-3-boronic acid (1.17 g, 10.25 mmol) and 3-bromo-2-methylpyridine (1.50 g, 8.55 mmol) in dioxane (68 mL) were added 1M aqueous cesium fluoride (3.28 g, 21.36 mmol), Pd2dba3 (412 mg, 0.43 mmol), and S-Phos (358 mg, 0.85 mmol), under argon. The mixture was stirred in a pressure-proof vessel for 16-20 hours at 100 °C, diluted with water and extracted with DCM.
  • Example 103 (S)-N-(5-chloropyridin-2-yl)-2-((2S,3R)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2R,3S)-2-methyl-3-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (1:1 mix.) Step 1 2-Methyl-3-(1H-pyrazol-5-yl)pyridine (Example 102, Step 1) (893 mg, 5.61 mmol) in MeOH (56 mL) and TFA (0.87 mL) was hydrogenated using an H-Cube (70 mm CatCart of 10 % Pd/C, 80 °C, 50 bar, 1 mL/min).
  • Step 1 To 1-((benzyloxy)carbonyl)piperidine-3-carboxylic acid (5.0 g, 18.99 mmol) in acetonitrile (60 mL) was added CDI (3.70 g, 22.79 mmol), in portions. After 1 h, potassium 3-ethoxy- 3-oxopropanoate (3.23 g, 18.99 mmol) and magnesium chloride (1.808 g, 18.99 mmol) were added, and the resulting mixture was stirred overnight, concentrated, diluted with water, neutralized with citric acid and extracted with EtOAc (3X).
  • Step 2 To benzyl 3-(3-ethoxy-3-oxopropanoyl)piperidine-1-carboxylate (4.86 g, 14.58 mmol) in ethanol (60 mL) was added hydrazine monohydrate (1.095 g, 21.87 mmol), slowly, and the mixture was stirred overnight and concentrated. The residue was purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 30-90% EtOAc in DCM to afford benzyl 3-(3-hydroxy-1H-pyrazol-5-yl)piperidine-1-carboxylate (3.69 g, 12.25 mmol, 84 % yield) as a colorless oil.
  • Step 3 To benzyl 3-(3-hydroxy-1H-pyrazol-5-yl)piperidine-1-carboxylate (800 mg, 2.65 mmol) in ethanol (30 mL) under N 2 was added Pd/C, 10% (28.3 mg, 0.265 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite and concentrated to afford 5-(piperidin-3-yl)-1H-pyrazol-3-ol (416 mg, 2.488 mmol, 94 % yield) as an off white solid, which was used without purification. LCMS (ES, m/s): 168 [M+H] + .
  • Step 4 To 5-(piperidin-3-yl)-1H-pyrazol-3-ol (170 mg, 1.015 mmol) and (R)-1-((5-chloropyridin- 2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (300 mg, 0.846 mmol) in DMSO (4.0 mL) was added DIEA (0.591 mL, 3.38 mmol). After 2 days, the mixture was diluted with water and extracted with EtOAc (3 X).
  • Example 105 (2S)-N-(5-chloropyridin-2-yl)-2-(3-(4-methyl-1H-pyrazol-5-yl)piperidin-1-yl)propanamide 670 7 Step 1 To 1-((benzyloxy)carbonyl)piperidine-3-carboxylic acid (5.5 g, 20.89 mmol), N,O- dimethylhydroxylamine hydrochloride (2.445 g, 25.07 mmol), HOBt (4.80 g, 31.3 mmol) and DIEA (10.95 mL, 62.7 mmol) in THF (100 mL) at 0 °C was added EDC (6.01 g, 31.3 mmol), in portions.
  • Step 2 To benzyl 3-(methoxy(methyl)carbamoyl)piperidine-1-carboxylate (6.05 g, 19.75 mmol) in THF (80 mL) at -78 °C was added ethylmagnesium bromide (3.0 M in ether, 7.90 mL, 23.70 mmol), dropwise, and the mixture was allowed to warm up to RT. After 1 hour, the reaction was quenched with sat. NH4Cl and extracted with EtOAc (3 X).
  • Step 3 To benzyl 3-propionylpiperidine-1-carboxylate (4.91 g, 17.83 mmol) in DMF (40 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (6.37 g, 53.5 mmol), and the mixture was heated at 140 °C for 6 h, then concentrated. The residue was dissolved in ethanol (40.0 mL), and con. HCl (1.0 mL, 11.85 mmol) was added dropwise. After 10 min, hydrazine monohydrate (1.749 mL, 35.7 mmol) was added. The reaction was refluxed overnight, cooled to RT, concentrated, diluted with water and extracted with EtOAc (3 X).
  • Step 5 To 3-(4-methyl-1H-pyrazol-5-yl)piperidine (138 mg, 0.835 mmol) and (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (200 mg, 0.759 mmol) in DMSO (4.0 mL) was added triethylamine (0.423 mL, 3.04 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X).
  • Example 106 (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide Step 1 To ethyl piperidine-3-carboxylate (6.0 g, 38.2 mmol) and sodium bicarbonate (12.82 g, 153 mmol) in THF (120 mL) and water (60 mL) at 0 °C was added Cbz-Cl (8.17 mL, 57.2 mmol), dropwise. After stirring at RT overnight, the mixture was diluted with water and extracted with EtOAc (3 X).
  • Step 3 To 1-benzyl 3-ethyl 3-methylpiperidine-1,3-dicarboxylate (9.2 g, 30.1 mmol) in methanol (90 mL) and water (30.0 mL) was added LiOH (1.443 g, 60.3 mmol). After 1 h, the mixture was diluted with water, the MeOH was removed, and the pH was adjusted to approximately 3-4 with 2N HCl.
  • Step 4 To 1-((benzyloxy)carbonyl)-3-methylpiperidine-3-carboxylic acid (5.5 g, 19.83 mmol), N,O-dimethylhydroxylamine hydrochloride (2.322 g, 23.80 mmol), HOBt (4.56 g, 29.7 mmol) and DIEA (10.39 mL, 59.5 mmol) in THF (80 mL) at 0 °C was added EDC (5.70 g, 29.7 mmol), in portions. The mixture was allowed to warm to RT overnight, diluted with water and extracted with EtOAc (3 X).
  • Step 5 To benzyl 3-(methoxy(methyl)carbamoyl)-3-methylpiperidine-1-carboxylate (5.16 g, 16.11 mmol) in THF (50 mL) at -78 °C was added methylmagnesium bromide in 2-Me-THF (approximately 3.4 M, 5.68 mL, 19.33 mmol), dropwise, and the reaction was allowed to warm to RT. After 1 hour, the mixture was quenched with sat. NH 4 Cl and extracted with EtOAc (3 X).
  • Step 6 To benzyl 3-acetyl-3-methylpiperidine-1-carboxylate (2.78 g, 10.10 mmol) in DMF (20 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (3.61 g, 30.3 mmol). The mixture was heated at 140 °C for 6 hours and concentrated. The residue was dissolved in ethanol (20 mL), and conc. HCl (0.6 mL, 7.11 mmol) was added dropwise. After 10 min, hydrazine monohydrate (4.95 mL, 101 mmol) was added, and the resulting mixture was refluxed overnight, then concentrated. The residue was diluted with water and extracted with EtOAc (3 X).
  • Step 7 To benzyl 3-methyl-3-(1H-pyrazol-5-yl)piperidine-1-carboxylate (1.56 g, 5.21 mmol) in ethanol (20 mL) under N 2 was added Pd/C, 10% (0.055 g, 0.521 mmol), and the mixture was hydrogenated under an H 2 balloon overnight. The reaction was filtered through Celite, washed with EtOH, and concentrated to afford 3-methyl-3-(1H-pyrazol-5-yl)piperidine (0.865 g, 5.23 mmol, 100 % yield) as colorless oil. LCMS (ES, m/s): 166 [M+H]+.
  • Step 8 To 3-methyl-3-(1H-pyrazol-5-yl)piperidine (142 mg, 0.860 mmol) and (R)-1-((5- chloropyridin-2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (305 mg, 0.860 mmol) in DMSO (6 mL) was added DIEA (0.300 mL, 1.719 mmol). After 2 days, the mixture was diluted with water and extracted with EtOAc (3 X).
  • Step 2 To benzyl 3-(methoxy(methyl)carbamoyl)pyrrolidine-1-carboxylate (2.0 g, 6.84 mmol) in THF (30 mL) at -78 °C was added methylmagnesium bromide in 2-Me-THF (approximately 3.4 M, 2.57 mL, 8.21 mmol), dropwise, and the reaction was allowed to warm to RT. After 1 hour, the mixture was quenched with sat. NH 4 Cl and extracted with EtOAc (3 X).
  • Step 4 To benzyl 3-(1H-pyrazol-5-yl)pyrrolidine-1-carboxylate (1.05 g, 3.87 mmol) in ethanol (20 mL) under N2 was added Pd/C, 10% (0.041 g, 0.387 mmol), and the mixture was hydrogenated under an H 2 balloon overnight. The reaction was filtered through Celite, washed with EtOH, and concentrated to afford 5-(pyrrolidin-3-yl)-1H-pyrazole (520 mg, 3.79 mmol, 98 % yield) as colorless oil. LCMS (ES, m/s): 138 [M+H]+.
  • Example 108a and 108b Ex.108a: (S)-N-(5-chloropyridin-2-yl)-2-((R)-2- (trifluoromethyl)morpholino)propanamide or Ex.108b: (S)-N-(5-chloropyridin-2-yl)-2- ((S)-2-(trifluoromethyl)morpholino)propanamide
  • the first peak (5.256 min) was collected and further chirally separated (column: CHIRALPAK IG, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide two peaks with retention times of 6.608 and 7.240 min.
  • Example 109 (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-morpholinopropanamide (R)-2-bromo-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (Intermediate 17) (110 mg, 0.308 mmol) and silver nitrate (52.3 mg, 0.308 mmol) were dissolved in N,N- Dimethylformamide (DMF) (3 mL) at RT. Then added morpholine (0.040 mL, 0.462 mmol) and TEA (0.064 mL, 0.462 mmol).
  • DMF N,N- Dimethylformamide
  • Examples 110-113 were synthesized in an analogous manner using the designated amine.
  • a Ca 2+ mobilization assay was used to assess the activity of the compounds of this invention.
  • a HEK293 cell line with stably expressing human MRGPRX2 and mouse Galphal5 genes was used in the assay. Briefly, cells were seeded into black clear-bottomed 384-well plates at 1.5 x io 4 cells/well and culture at 37°C for 24 hours prior to assay.
  • FLIPR TETRA Molecular Devices
  • An activation dose response curve was produced for Cortistatin-14 to determine the EC50 value of the agonist on the day of assay.
  • Compounds of this invention were prepared as 1 mM or 10 mM solution in DMSO.
  • the pIC50s for each compound of this invention were averaged to determine a mean value, for a minimum of 2 experiments.
  • the compounds of Examples 1 – 113 inhibited MRGPRX2 activation in the above method with a pIC50 value between approximately 5 and 9.4.
  • Biological Data The exemplified compounds were tested according to the FLIPR TETRA assay described above and were found to be MrgX2 antagonists with pIC50 > 5.
  • the compounds of examples 1-113 exhibited a pIC50 between 5 and 9.4.
  • Examples 8, 24, 30, 33, 49, 57, 61, 77, 92, 94, 95, 98 and 111 exhibited a pIC50 ⁇ 8.0.

Abstract

This application relates to compounds of Formula (I), which are antagonists of MrgX2 (Mas-related Gene X2) and thus are useful as therapeutic agents, specifically therapeutic agents for use in the treatment of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine.

Description

ANTAGONISTS OF MRGX2
FIELD OF THE INVENTION
This invention relates to compounds which are antagonists of MrgX2 (Mas-related Gene X2) and thus are useful as therapeutic agents.
BACKGROUND TO THE INVENTION
Mature mammalian mast cells ordinarily reside near blood vessels or nerves, beneath or within epithelia, within airways, gastrointestinal, and genitourinary tracts and near smooth muscle and mucus-producing glands. Classically, mast cells are activated by IgE antibodies, secreting a wide range of substances with local and systemic effects, including histamine, serotonin, proteases, chemokines, and cytokines. Indeed, mast cells are implicated in the progression and/or maintenance of many diseases.
Recent work has emphasized the role of the Mas-related G protein-coupled receptor (MRGPR) family, specifically, Mrgprb2, in mast cell activation. Mrgprb2 is the mouse receptor for several cationic molecules, collectively called basic secretagogues, and the ortholog of the human receptor MRGPRX2 (also known and referred to herein as MrgX2). To date, Mrgprb2 and MRGPRX2 have been reported to be expressed only on certain populations of mast cells. This knowledge provides an opportunity to target mast cell degranulation in a very precise manner.
Natural endogenous ligands of Mrgprb2/MRGPRX2 have been reported and are mostly neuropeptides, including substance P (SP), vasoactive intestinal polypeptide (VIP), Cortistatin-14, and pituitary adenylate cyclase activating polypeptide (PACAP). Others include P-defensin, cathelici din (LL-37), and proadrenomedullin N-terminal 20 peptide (PAMP9-20). Given the close proximity between mast cells and sensory nerves in various pathological conditions, it follows that neuropeptide-activated MRGPRX2 could contribute to symptoms of neurogenic inflammation including pain, swelling and pruritus. Various observations using knock-out (KO) mice are consistent with the Mrgprb2/MRGPRX2 receptors playing a role in mast cell-mediated neurogenic inflammation. For instance, Mrgprb2/MRGPRX2 agonists induce various symptoms such as flushing, swelling and itch in wild type mice, but not in Mrgprb2-deficient mice. Mrgprb2-deficent mice have also demonstrated significant reductions in inflammation (leukocyte infiltration, including mast cells), swelling, pain and overall clinical score in various disease models. An important and relevant observation was the demonstration that Substance P injection could stimulate the infiltration of leukocytes in wild type and NKR1 (canonical Substance P receptor) KO mice whereas the response was substantially blunted in Mrgprb2 null mice. This observation extends the role of Mrgprb2/MRGPRX2 as a key receptor in mediating Substance P-induced inflammatory responses, including pain. Indeed, a Substance P / Mrgprb2 sensory cluster was demonstrated to be critical in driving the clinical score of a severe preclinical model of atopic dermatitis.
In addition to the various reports using Mrgprb2-deficient mice, further evidence suggests a role for various ligands of MRGPRX2 in human disease. For example, in addition to the number of MRGPRX2-expressing mast cells being significantly increased in severe chronic urticaria, PACAP nerve fibres were demonstrated to be in close proximity to tryptase-positive mast cells, providing the morphological basis for increased mast cell - sensory interactions. In support of this, patients with urticaria exhibit enhanced wheal reactions vs healthy individuals to MRGPRX2 agonists (e.g., Substance P) when injected intradermally. In addition, PACAP and the antimicrobial peptide, LL-37, which is implicated in cutaneous inflammation, were both demonstrated to be upregulated in rosacea. Indeed, mast cell-deficient mice do not develop inflammation/flushing following LL-37 injection thus inferring a role for Mrgprb2.
In addition to skin disorders, mast cell involvement has been highlighted for inflammatory bowel disease (IBD) and arthritis as well as asthma and migraine. In patients with rheumatoid arthritis (RA), the number of degranulated mast cells is increased in synovial tissue and is correlated with disease activity, as it is for patients with IBD. A positive correlation between serum Substance P levels and chronic pain intensity has been noted in both osteoarthritic and RA patients and a recent article suggested that the SP- MRGPRX2 axis may play a role in the pathogenesis of RA, especially in the regulation of inflammation and pain. Finally, there is a growing body of evidence for a role of PACAP in migraine pathogenesis and that it is mediated via activation of mast cells.
A potent, selective antagonist of MRGPRX2 that blocks IgE-independent mast cell de-granulation is expected to provide therapeutic benefit in mast-cell driven pathologies including skin disorders such as urticaria, atopic dermatitis and rosacea as well as additional indications like inflammatory bowel disease, arthritis and migraine. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided compounds of formula (I) or pharmaceutically acceptable salts thereof:
Figure imgf000004_0001
Formula (I) wherein: X1 is N or CR5a; X2 is N or CR6a; X3 is N or CR5b X4 is N or CR6b Y is N or CH; Z is SO2, O, C=O, NR12 or C(R2)2; n is 0 or 1; R1 is hydrogen, halogen, (C1-C6)alkyl, -(C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1- C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1-C6)alkyl), -(C1-C6)alkyl-(C3-C8)cycloalkyl, -(C1-C6)alkyl-aryl, 5- or 6-membered heteroaryl(C1-C4)alkyl-, (C3-C8)cycloalkyl, (C2-C6)alkenyl, -(C2-C6)alkenyl-(C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -O-(C2- C6)alkenyl, -O-(C1-C6)alkyl-(C3-C8)cycloalkyl), -O-(C3-C8)cycloalkyl, -O-aryl, -O-heteroaryl, -CO2H, -CO2(C1-C6)alkyl, -CO2(C3-C8)cycloalkyl, -O2C(C1-C6)alkyl, -O2C(C3-C8)cycloalkyl, -NH2, -NH(C1- C6)alkyl, -N((C1-C6)alkyl)((C1-C6)alkyl), aryl, or 5-6 membered heteroaryl, wherein the (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, (C1-C6)alkoxy, -O-aryl, -O-heteroaryl, aryl, or 5-6 membered heteroaryl of R1 is optionally substituted one, two, or three times by R8; each R2 is independently hydrogen, hydroxyl, halogen, or (C1-C6)alkyl; each R3 and R4 is independently selected from hydrogen, -CN (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -NH2, -NH(C1-C6)alkyl, -N((C1-C6)alkyl)((C1- C6)alkyl), 5-membered heteroaryl, 5-6 membered heterocycloalkyl or 5-6 membered lactam, wherein the (C1-C6)alkyl, 5-membered heteroaryl, 5-6 membered heterocycloalkyl PB67047FF or 5-6 membered lactam of R3 or R4 is optionally substituted one, two, or three times by R9; each of R5a, R5b, R6a and R6b is independently hydrogen, halogen, (C1-C6)alkyl, - (C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1-C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1-C6)alkyl), (C2- C6)alkenyl, -NH2, -NH((C1-C6)alkyl), -N((C1-C6)alkyl)((C1-C6)alkyl), -NCH2, or -CHNH; or R1 and R5a or R5b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur, wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; or any of R5a , R5b, R6a and R6b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur; wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; each of R7a and R7b is independently selected from hydrogen, halogen, -OH or(C1-C6)alkyl optionally substituted one, two, or three times by halogen; each R8 is independently halogen, (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1- C6)alkoxy, -O-(C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl, wherein any said (C1- C6)alkyl, (C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl is further optionally substituted one, two, or three times by halogen; each R9 is independently halogen, (C1-C6)alkyl, -(C1-C6)alkyl-OH, -(C1-C6)alkyl- O-(C1-C6)alkyl, -(C1-C6)alkyl-aryl, or -OH, wherein any said -(C1-C6)alkyl-aryl is optionally substituted one, two, or three times by (C1-C6)alkoxy; R10 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; R11 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; and R12 is CO2-(C1-C6 alkyl), C(=O)-(C1-C6 alkyl) optionally substituted with 1, 2 or 3 halogen atoms or SO2-C1-C6 alkyl. The compounds of the present invention may be formulated into pharmaceutical compositions prior to administration to a subject. According to a second aspect of the invention, there is provided a pharmaceutical composition comprising a compound of Formula (I) or pharmaceutically acceptable salt thereof as defined herein, and a pharmaceutically acceptable excipient.
The pharmaceutical compositions of the invention may be adapted for administration by any appropriate route, for example oral, inhaled, injectable etc.
The pharmaceutically acceptable excipient may be any suitable pharmaceutically acceptable excipient such as an edible carbohydrate, for example, starch or mannitol.
According to a third aspect of the invention, there is provided a method of treating an MrgX2-mediated disease or disorder in a human in need thereof comprising administering to the human a therapeutically effective amount of a compound of Formula (I) or pharmaceutically acceptable salt thereof or a pharmaceutical composition as defined herein.
According to a further aspect of the invention, there is provided a compound of Formula (I) or pharmaceutically acceptable salt thereof for use in therapy.
According to a still further aspect of the invention, there is provided compound of Formula (I) or pharmaceutically acceptable salt thereof for use in the treatment of an MrgX2 -mediated disease or disorder.
According to a final aspect of the invention, there is provided use of the compound of Formula (I) or pharmaceutically acceptable salt thereof, in the manufacture of a medicament for use in the treatment of an MrgX2-mediated disease or disorder.
The compounds of the present invention i.e. compounds of Formula (I) or pharmaceutically acceptable salts thereof as defined herein may be advantageous in a number of respects. In particular, compounds defined herein are antagonists of MrgX2 and thus may be advantageous in treating MrgX2 mediated diseases.
DETAILED DESCRIPTION OF THE INVENTION
DEFINITIONS
Terms herein are used within their accepted meanings. The following definitions are meant to clarify, but not limit, the terms defined.
As used herein, the term "alkyl" refers to a saturated, straight or branched hydrocarbon moiety having the specified number of carbon atoms. The term "(Ci-Cejalkyl" refers to an alkyl moiety containing from 1 to 6 carbon atoms. Exemplary alkyls include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, pentyl, and hexyl. As used herein, the term "alkoxy" refers to a group containing an alkyl radical attached through an oxygen linking atom. The term “(C1-C4)alkoxy” refers to a straight- or branched-chain hydrocarbon radical having at least 1 and up to 4 carbon atoms attached through an oxygen linking atom. Exemplary “(C1-C4)alkoxy” groups useful in the present invention include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, isobutoxy, and t-butoxy. When the term "alkyl" is used in combination with other substituent groups, such as "halo(C1-C4)alkyl", "aryl(C1-C4)alkyl-", “(C1-C6)alkyl-OH” or " (C1-C4)alkoxy(C1-C4)alkyl-", the term "alkyl" is intended to encompass a divalent straight or branched-chain hydrocarbon radical, wherein the point of attachment is through the alkyl moiety. The term "halo(C1-C4)alkyl" is intended to mean a radical having one or more halogen atoms, which may be the same or different, at one or more carbon atoms of an alkyl moiety containing from 1 to 4 carbon atoms, which is a straight or branched-chain carbon radical. Examples of "halo(C1-C4)alkyl" groups useful in the present invention include, but are not limited to, -CF3 (trifluoromethyl), -CCl3 (trichloromethyl), 1,1- difluoroethyl, 2-fluoro-2-methylpropyl, 2,2-difluoropropyl, 2,2,2-trifluoroethyl, and hexafluoroisopropyl. Examples of "aryl(C1-C4)alkyl" or “phenyl(C1-C4)alkyl” groups useful in the present invention include, but are not limited to, benzyl and phenethyl. Examples of "(C1-C4)alkoxy(C1-C4)alkyl-" groups useful in the present invention include, but are not limited to, methoxymethyl, methoxyethyl, methoxyisopropyl, ethoxymethyl, ethoxyethyl, ethoxyisopropyl, isopropoxymethyl, isopropoxyethyl, isopropoxyisopropyl, t- butoxymethyl, t-butoxyethyl, and t-butoxyisopropyl. As used herein, the term “cycloalkyl” refers to a non-aromatic, saturated, cyclic hydrocarbon ring containing the specified number of carbon atoms. The term "(C3-C8)cycloalkyl" refers to a non-aromatic cyclic hydrocarbon ring having from three to eight ring carbon atoms. Exemplary "(C3-C8)cycloalkyl" groups useful in the present invention include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. As used herein, the term "4- to 6-membered heterocycloalkyl" refers to a group or moiety comprising a non-aromatic, monovalent monocyclic radical, which is saturated or partially unsaturated, containing 4, 5, or 6 ring atoms, which includes one or two heteroatoms selected independently from oxygen, sulfur, and nitrogen. Illustrative examples of 4- to 6-membered heterocycloalkyl groups useful in the present invention include, but are not limited to azetidinyl, oxetanyl, pyrrolidinyl, pyrazolidinyl, pyrazolinyl, imidazolidinyl, imidazolinyl, oxazolinyl, thiazolinyl, tetrahydrofuranyl, dihydrofuranyl,
1.3-dioxolanyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, tetrahydropyranyl, dihydropyranyl, 1,3-dioxanyl, 1,4-dioxanyl, 1,3 -oxathiol any 1, 1,3-oxathianyl, 1,3-dithianyl,
1.4-oxathiolanyl, 1,4-oxathianyl, and 1,4-dithianyl.
As used herein, the term "aryl" refers to monocyclic, fused bicyclic, or fused tricyclic groups having 6 to 14 carbon atoms and having at least one aromatic ring. Examples of “aryl” groups are phenyl, naphthyl, indenyl, dihydroindenyl, anthracenyl, phenanthrenyl, and the like.
As used herein, the term "heteroaryl" refers to a group or moiety comprising an aromatic monovalent monocyclic or bicyclic radical, containing 5 to 10 ring atoms, including 1 to 4 heteroatoms independently selected from nitrogen, oxygen and sulfur. This term also encompasses bicyclic heterocyclic-aryl compounds containing an aryl ring moiety fused to a heterocycloalkyl ring moiety, containing 5 to 10 ring atoms, including 1 to 4 heteroatoms independently selected from nitrogen, oxygen and sulfur. Illustrative examples of heteroaryls useful in the present invention include, but are not limited to, furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, isothiazolyl, pyridinyl, pyridazinyl, pyrazinyl, pyrimidinyl, triazinyl, benzofuranyl, isobenzofuryl, 2,3-dihydrobenzofuryl, 1,3- benzodioxolyl, dihydrobenzodioxinyl, benzothienyl, indolizinyl, indolyl, isoindolyl, dihydroindolyl, benzimidazolyl, dihydrobenzimidazolyl, benzoxazolyl, dihydrobenzoxazolyl, benzthiazolyl, benzoisothiazolyl, dihydrobenzoisothiazolyl, indazolyl, imidazopyridinyl, pyrazolopyridinyl, benzotriazolyl, triazolopyridinyl, purinyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, tetrahydroisoquinolinyl, quinoxalinyl, cinnolinyl, phthalazinyl, quinazolinyl, 1,5-naphthyridinyl, 1,6-naphthyridinyl, 1,7- naphthyridinyl, 1,8-naphthyridinyl, and pteridinyl. Examples of 5-membered "heteroaryl" groups include furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, thiazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, and isothiazolyl. Examples of 6- membered "heteroaryl" groups include oxo-pyridyl, pyridinyl, pyridazinyl, pyrazinyl, and pyrimidinyl. Examples of 6,6-fused “heteroaryl” groups include quinolinyl, isoquinolinyl, quinoxalinyl, cinnolinyl, phthalazinyl, quinazolinyl, 1,5-naphthyridinyl, 1,6- naphthyridinyl, 1,7-naphthyridinyl, 1,8-naphthyridinyl, and pteridinyl. Examples of 6,5- fused “heteroaryl” groups include benzofuranyl, benzothienyl, benzimidazolyl, benzthiazolyl, indolizinyl, indolyl, isoindolyl, and indazolyl.
As used herein, the term "5- or 6-membered heteroaryl" refers to a group or moiety comprising an aromatic monovalent monocyclic radical, containing 5 or 6 ring atoms, including at least one carbon atom and 1 to 4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. Selected 5-membered heteroaryl groups contain one nitrogen, oxygen, or sulfur ring heteroatom, and optionally contain 1, 2, or 3 additional nitrogen ring atoms. Selected 6-membered heteroaryl groups contain 1, 2, or 3 nitrogen ring heteroatoms. Illustrative examples of 5- or 6-membered heteroaryl groups useful in the present invention include, but are not limited to furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrazinyl, pyrimidinyl, and triazinyl.
As used herein, the terms "halogen" and "halo" refer to fluoro, chloro, bromo, or iodo substituents.
As used herein, the terms "hydroxy" or “hydroxyl” refer to the radical -OH.
As used herein, the term "optionally" means that the subsequently described event(s) may or may not occur, and includes both event(s) that occur and event(s) that do not occur.
"Pharmaceutically acceptable" refers to those compounds (including salts), materials, compositions, and dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
As used herein, the term "treatment" refers to alleviating the specified condition, eliminating or reducing one or more symptoms of the condition, slowing or eliminating the progression of the condition, and delaying the reoccurrence of the condition in a previously afflicted or diagnosed patient or subject.
As used herein, the term "effective amount" means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal, or human that is being sought, for instance, by a researcher or clinician.
The term "therapeutically effective amount" means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function. For use in therapy, therapeutically effective amounts of a compound of Formula (I) as well as salts thereof, may be administered as the raw chemical. Additionally, the active ingredient may be presented as a pharmaceutical composition. As used herein, the term "pharmaceutically acceptable salts" refers to salts that retain the desired biological activity of the subject compound and exhibit minimal undesired toxicological effects. These pharmaceutically acceptable salts may be prepared in situ during the final isolation and purification of the compound, or by separately reacting the purified compound in its free acid or free base form with a suitable base or acid, respectively. STATEMENT OF THE INVENTION The present invention provides compounds of formula (I) or pharmaceutically acceptable salts thereof:
Figure imgf000010_0001
wherein: X1 is N or CR5a; X2 is N or CR6a; X3 is N or CR5b X4 is N or CR6b Y is N or CH; Z is SO2, O, C=O, NR12 or C(R2)2; n is 0 or 1; R1 is hydrogen, halogen, (C1-C6)alkyl, -(C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1- C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1-C6)alkyl), -(C1-C6)alkyl-(C3-C8)cycloalkyl, -(C1-C6)alkyl-aryl, 5- or 6-membered heteroaryl(C1-C4)alkyl-, (C3-C8)cycloalkyl, (C2-C6)alkenyl, -(C2-C6)alkenyl-(C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -O-(C2- C6)alkenyl, -O-(C1-C6)alkyl-(C3-C8)cycloalkyl), -O-(C3-C8)cycloalkyl, -O-aryl, -O-heteroaryl, -CO2H, -CO2(C1-C6)alkyl, -CO2(C3-C8)cycloalkyl, -O2C(C1-C6)alkyl, -O2C(C3-C8)cycloalkyl, -NH2, -NH(C1- C6)alkyl, -N((C1-C6)alkyl)((C1-C6)alkyl), aryl, or 5-6 membered heteroaryl, wherein the (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, (C1-C6)alkoxy, -O-aryl, -O-heteroaryl, aryl, or 5-6 membered heteroaryl of R1 is optionally substituted one, two, or three times by R8; each R2 is independently hydrogen, hydroxyl, halogen, or (C1-C6)alkyl; each R3 and R4 is independently selected from hydrogen, -CN (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -NH2, -NH(C1-C6)alkyl, -N((C1-C6)alkyl)((C1- C6)alkyl), 5-membered heteroaryl, 5-6 membered heterocycloalkyl or 5-6 membered lactam, wherein the (C1-C6)alkyl, 5-membered heteroaryl, 5-6 membered heterocycloalkyl or 5-6 membered lactam of R3 or R4 is optionally substituted one, two, or three times by R9; each of R5a, R5b, R6a and R6b is independently hydrogen, halogen, (C1-C6)alkyl, - (C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1-C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1-C6)alkyl), (C2- C6)alkenyl, -NH2, -NH((C1-C6)alkyl), -N((C1-C6)alkyl)((C1-C6)alkyl), -NCH2, or -CHNH; or R1 and R5a or R5b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur, wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; or any of R5a , R5b, R6a and R6b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur; wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; each of R7a and R7b is independently selected from hydrogen, halogen, -OH or(C1-C6)alkyl optionally substituted one, two, or three times by halogen; each R8 is independently halogen, (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1- C6)alkoxy, -O-(C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl, wherein any said (C1- C6)alkyl, (C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl is further optionally substituted one, two, or three times by halogen; each R9 is independently halogen, (C1-C6)alkyl, -(C1-C6)alkyl-OH, -(C1-C6)alkyl- O-(C1-C6)alkyl, -(C1-C6)alkyl-aryl, or -OH, wherein any said -(C1-C6)alkyl-aryl is optionally substituted one, two, or three times by (C1-C6)alkoxy; R10 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; R11 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; and R12 is CO2-(C1-C6 alkyl), C(=O)-(C1-C6 alkyl) optionally substituted with 1, 2 or 3 halogen atoms or SO2-C1-C6 alkyl. In an embodiment of the invention, X1 is CR5a. In another embodiment X1 is CR5a and R5a is hydrogen. In an embodiment of the invention X2 is N. In an embodiment of the invention X3 is CR5b. In some instances, X3 is CR5b and R5b is hydrogen. In another embodiment of the invention X4 is CR6b. In some instances, R6b is hydrogen In certain embodiments of the invention X1 is CR5a, R5a is hydrogen, X2 is N, X3 is CR5b, R5b is hydrogen and X4 is CR6b wherein R6b is hydrogen. In an alternative embodiment X1 is CR5a, R5a is hydrogen, X2 is N, X3 is N and X4 is CR6b wherein R6b is hydrogen. Y may be N or CH. In some embodiments of the invention Y is N, in alternative embodiments of the invention Y is CH. Z is O, C=O, NR12 or C(R2)2. In one embodiment Z is O. In another embodiment Z is C=O. In an alternative embodiment Z is NR12 wherein R12 is R12 is CO2-(C1-C6 alkyl)-, C(=O)-(C1-C6 alkyl)-halogen, specifically, R12 is CO2CH(CH3)2 or -C(=O)CF3. In an embodiment Z is C(R2). In an embodiment Z is C(R2)2. Each R2 may be hydrogen, F or CH3. In an embodiment each R2 is H or each R2 is F. In compounds of Formula (I), n may be 0 or 1 as stated above. In an embodiment of the invention n is 1. In embodiments of the invention R1 is halogen, (C1-C6)alkyl, (C3-C8)cycloalkyl, - O-(C2-C6)alkenyl, -O-(C1-C6)alkyl-(C3-C8)cycloalkyl, -O-(C3-C8)cycloalkyl, -O-aryl, -O- heteroaryl, -CO2(C1-C6)alkyl or -NH(C1-C6)alkyl wherein any said (C1-C6)alkyl, -O- heteroaryl, -O-aryl or aryl is optionally substituted one, two, or three times by R8. In one embodiment, R1 is O-aryl optionally substituted one, two, or three times by R8. In another embodiment, R1 is O-phenyl substituted one, two, or three times by R8. In both of these embodiments R8 may be F. In another embodiment, R1 is halogen (e.g., fluorine or chlorine) or -O-(C1-C6)alkyl-(C3-C8)cycloalkyl. In an embodiment of the invention R3 is a 5-membered heteroaryl ring, hydrogen, halogen or OH. In another embodiment R3 is H, F or OH. In an embodiment R4 is hydrogen, halogen, 5-membered heteroaryl or 5-6 membered lactam. The term “lactam” as used herein refers to a cyclic amide. A 5- membered lactam may also be referred to as γ-lactam. A 6-membered lactam may also be referred to as δ-lactam. R7a and R7b may be the same or different. In embodiments of the invention R7a is hydrogen, OH, halogen or methyl. In embodiments of the invention R7b is hydrogen, OH, halogen or methyl. In some embodiments R7a and R7b are each hydrogen. In alternative embodiments R7a is hydrogen and R7b is methyl. In embodiments of the invention R8 is halogen. In particular embodiments, R8 is F. In an embodiment R10 is -(C1-C6)alkyl and R11 is H. In a specific embodiment R10 is CH3 and R11 is H. In particular embodiments: R1 is -O-aryl substituted twice with R8; X1 is CR5a; X2 is N; X3 is CR5b; X4 is CR6b; Y is N; Z is C(R2)2; n is 1; R2 is hydrogen or F; R3, R4, R5a, R5b and R6b are each hydrogen; R7a and R7b are each hydrogen; R8 is F; R10 is CH3; and R11 is H. In another embodiment: R1 is Cl or O-(C1-C6)alkyl-(C3-C8)cycloalkyl; X1 is N or CR5a; X2 is N; X3 is CR5b; X4 is CR6b; Y is N; Z is C(R2)2; n is 1; R2 is F or hydrogen; R3 is hydrogen; R4 is 5-membered heteroaryl; R5a, R5b, R6b is hydrogen; R7a is hydrogen; R7b is hydrogen or CH3 R10 is CH3; and R11 is hydrogen. It is to be understood that the references herein to a compound of Formula (I) or a salt thereof includes a compound of Formula (I) as a free base or acid, or as a salt thereof, for example as a pharmaceutically acceptable salt thereof. Thus, in one embodiment, the invention is directed to a compound of Formula (I). In another embodiment, the invention is directed to a salt of a compound of Formula (I). In a further embodiment, the invention is directed to a pharmaceutically acceptable salt of a compound of Formula (I). In another embodiment, the invention is directed to a compound of Formula (I) or a salt thereof. In a further embodiment, the invention is directed to a compound of Formula (I) or a pharmaceutically acceptable salt thereof. Because of its potential use in medicine, it will be appreciated that a salt of a compound of Formula (I) is preferably pharmaceutically acceptable. ‘Pharmaceutically acceptable’ refers to those compounds (including salts), materials, compositions, and dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts include, amongst others, those described in Berge, J. Pharm. Sci., 1977, 66, 1-19, or those listed in P H Stahl and C G Wermuth, editors, Handbook of Pharmaceutical Salts; Properties, Selection and Use, Second Edition Stahl/Wermuth: Wiley- VCH/VHCA, 2011 (see http://www.wiley.com/WileyCDA/WileyTitle/productCd-3906390519.html).
Non-pharmaceutically acceptable salts are within the scope of the present invention, for example for use as intermediates in the preparation of a compound of Formula (I) or a pharmaceutically acceptable salt thereof. Non-pharmaceutically acceptable salts may be used, for example as intermediates in the preparation of a compound of Formula (I) or a pharmaceutically acceptable salt thereof.
Suitable pharmaceutically acceptable salts can include acid or base addition salts.
Base addition salts can be formed by reaction of a compound of Formula (I) with the appropriate base, optionally in a suitable solvent such as an organic solvent, to give the salt which can be isolated by a variety of methods, including crystallisation and filtration.
Acid addition salts can be formed by reaction of a compound of Formula (I) with the appropriate acid, optionally in a suitable solvent such as an organic solvent, to give the salt which can be isolated by a variety of methods, including crystallisation and filtration.
Salts may be prepared in situ during the final isolation and purification of a compound of Formula (I). If a basic compound of Formula (I) is isolated as a salt, the corresponding free base form of that compound may be prepared by any suitable method known to the art, including treatment of the salt with an inorganic or organic base. Similarly, if a compound of Formula (I) containing a carboxylic acid or other acidic functional group is isolated as a salt, the corresponding free acid form of that compound may be prepared by any suitable method known to the art, including treatment of the salt with an inorganic or organic acid.
It will be understood that if a compound of Formula (I) contains two or more basic moi eties, the stoichiometry of salt formation may include 1, 2 or more equivalents of acid. Such salts would contain 1, 2 or more acid counterions, for example, a dihydrochloride salt.
Stoichiometric and non-stoichiometric forms of a pharmaceutically acceptable salt of a compound of formula (I) are included within the scope of the invention, including sub- stoichiometric salts, for example where a counterion contains more than one acidic proton. Representative pharmaceutically acceptable acid addition salts include, but are not limited to, 4-acetamidobenzoate, acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate (besylate), benzoate, bisulfate, bitartrate, butyrate, calcium edetate, camphorate, camphorsulfonate (camsylate), caprate (decanoate), caproate (hexanoate), caprylate (octanoate), cinnamate, citrate, cyclamate, digluconate, 2,5-dihydroxybenzoate, di succinate, dodecyl sulfate (estolate), edetate (ethylenediaminetetraacetate), estolate (lauryl sulfate), ethane- 1,2-disulfonate (edisylate), ethanesulfonate (esylate), formate, fumarate, galactarate (mucate), gentisate (2,5-dihydroxybenzoate), glucoheptonate (gluceptate), gluconate, glucuronate, glutamate, glutarate, glycerophosphorate, glycolate, hexylresorcinate, hippurate, hydrabamine (N,N'-di(dehydroabietyl)-ethylenediamine), hydrobromide, hydrochloride, hydroiodide, hydroxynaphthoate, isobutyrate, lactate, lactobionate, laurate, malate, maleate, malonate, mandelate, methanesulfonate (mesylate), methyl sulfate, mucate, naphthalene-l,5-disulfonate (napadisylate), naphthalene-2-sulfonate (napsylate), nicotinate, nitrate, oleate, palmitate, p-aminobenzenesulfonate, p- aminosalicyclate, pamoate (embonate), pantothenate, pectinate, persulfate, phenyl acetate, phenyl ethy lb arbiturate, phosphate, polygalacturonate, propionate, p-toluenesulfonate (tosylate), pyroglutamate, pyruvate, salicylate, sebacate, stearate, subacetate, succinate, sulfamate, sulfate, tannate, tartrate, teoclate (8-chlorotheophyllinate), thiocyanate, triethiodide, undecanoate, undecylenate, and valerate.
Representative pharmaceutically acceptable base addition salts include, but are not limited to, aluminium, 2-amino-2-(hydroxymethyl)-l,3-propanediol (TRIS, tromethamine), arginine, benethamine (N-benzylphenethylamine), benzathine (N,N’- dibenzylethylenediamine), bi s-(2 -hydroxy ethyl)amine, bismuth, calcium, chloroprocaine, choline, clemizole (1-p chlorobenzyl-2-pyrrolildine-l’-ylmethylbenzimidazole), cyclohexylamine, dibenzylethylenediamine, diethylamine, diethyltriamine, dimethylamine, dimethylethanolamine, dopamine, ethanolamine, ethylenediamine, L-histidine, iron, isoquinoline, lepidine, lithium, lysine, magnesium, meglumine (N-methylglucamine), piperazine, piperidine, potassium, procaine, quinine, quinoline, sodium, strontium, t- butylamine, and zinc.
The compounds according to Formula (I) may contain one or more asymmetric center (also referred to as a chiral center) and may, therefore, exist as individual enantiomers, diastereomers, or other stereoisomeric forms, or as mixtures thereof. Chiral centers, such as chiral carbon atoms, may also be present in a substituent such as an alkyl group. Where the stereochemistry of a chiral center present in Formula (I), or in any chemical structure illustrated herein, is not specified the structure is intended to encompass all individual stereoisomers and all mixtures thereof. Thus, compounds according to Formula (I) containing one or more chiral center may be used as racemic mixtures, enantiomerically enriched mixtures, or as enantiomerically pure individual stereoisomers.
Individual stereoisomers of a compound according to Formula (I) which contain one or more asymmetric center may be resolved by methods known to those skilled in the art. For example, such resolution may be carried out (1) by formation of diastereoisomeric salts, complexes or other derivatives; (2) by selective reaction with a stereoisomer-specific reagent, for example by enzymatic oxidation or reduction; or (3) by gas-liquid or liquid chromatography in a chiral environment, for example, on a chiral support such as silica with a bound chiral ligand or in the presence of a chiral solvent. The skilled artisan will appreciate that where the desired stereoisomer is converted into another chemical entity by one of the separation procedures described above, a further step is required to liberate the desired form. Alternatively, specific stereoisomers may be synthesized by asymmetric synthesis using optically active reagents, substrates, catalysts or solvents, or by converting one enantiomer to the other by asymmetric transformation.
The compounds according to Formula (I) may also contain double bonds or other centres of geometric asymmetry. Where the stereochemistry of a centre of geometric asymmetry present in Formula (I), or in any chemical structure illustrated herein, is not specified, the structure is intended to encompass the trans (E) geometric isomer, the cis (Z) geometric isomer, and all mixtures thereof. Likewise, all tautomeric forms are also included in Formula (I) whether such tautomers exist in equilibrium or predominately in one form.
In an embodiment of the invention, the compound of Formula (I) is selected from the compounds in Table 1 or pharmaceutically acceptable salts thereof.
Table 1
Figure imgf000017_0001
Figure imgf000018_0001
Figure imgf000019_0001
Figure imgf000020_0001
Figure imgf000021_0001
Figure imgf000022_0001
Figure imgf000023_0001
Figure imgf000024_0001
In a second aspect the invention provides a pharmaceutical composition comprising a compound or pharmaceutically acceptable salt thereof as defined herein, and a pharmaceutically acceptable excipient. The excipient may be any suitable pharmaceutically acceptable excipient.
As used herein, "pharmaceutically-acceptable excipient" means a pharmaceutically acceptable material, composition or vehicle involved in giving form or consistency to the pharmaceutical composition. Each excipient must be compatible with the other ingredients of the pharmaceutical composition such that interactions which would substantially reduce the efficacy of the compound of the invention when administered to an individual and interactions which would result in pharmaceutical compositions that are not pharmaceutically acceptable are avoided. In addition, each excipient must of course be of sufficiently high purity to render it pharmaceutically-acceptable.
The compounds of formula (I) are antagonists of MrgX2 and, as such can be useful in the treatment of MrgX2 -mediated diseases or disorders.
In an aspect of the present invention there is provided a method of treating an MrgX2 -mediated disease or disorder in a human in need thereof comprising administering to the human a therapeutically effective amount of the compound of Formula (I) as described herein or pharmaceutically acceptable salt thereof or the pharmaceutical composition as described herein.
The MrgX2 -mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, prurigo nodularis, irritable bowel syndrome, chronic inducible urticaria, atopic dermatitis, osteoarthritis, rosacea, migraine, pseudo- analphylaxis, mast cell activation syndrome, mastocytosis, pruritus, neurodermatitis, contact urticaria, allergic rhinitis, asthma, acute contact dermatitis, ulcerative colitis, crohns disease, idiopathic chronic cough, rheumatoid arthritis, multiple sclerosis, geographic atrophy, endometriosis, seborrheic dermatitis, psoriasis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, neuropathic itch, periodontitis, autism, abdominal aortic aneurysms, deep vein thrombosis, amyotrophic lateral sclerosis, interstitial cystitis, coronary artery disease, cancer, sickle cell disease, obesity, ulcers.
In one embodiment, the MrgX2-mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine. In an embodiment, the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug- induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine. In another embodiment the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain. In an embodiment the MrgX2- mediated disease or disorder is chronic spontaneous urticaria. The method of the present invention comprises administering a therapeutically acceptable amount of the compound or composition in any suitable way.
In a further aspect the present invention provides a compound or pharmaceutically acceptable salt thereof as described herein for use in therapy.
In a further aspect the present invention provides a compound or pharmaceutically acceptable salt thereof as defined herein for use in the treatment of an MrgX2 -mediated disease or disorder. The MrgX2 -mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine. In an embodiment, the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug- induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine. In another embodiment the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain. In an embodiment the MrgX2- mediated disease or disorder is chronic spontaneous urticaria.
In another aspect the present invention also provides use of a compound or pharmaceutically acceptable salt as defined herein in the manufacture of a medicament for use in the treatment of an MrgX2 -mediated disease or disorder. The MrgX2-mediated disease or disorder may be selected from the group consisting of chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, and migraine. In an embodiment, the MrgX2-mediated disease or disorder is chronic spontaneous urticaria, mastocytosis, cold urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, rheumatoid arthritis, fibromyalgia, nasal polyps, neuropathic pain, inflammatory pain, chronic itch, drug-induced anaphlactoid reactions, metabolic syndrome, oesophagus reflux, asthma, cough, or migraine. In another embodiment the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, atopic dermatitis, rosacea, Crohns disease, ulcerative colitis, irritable bowel syndrome, neuropathic pain, or inflammatory pain. In an embodiment the MrgX2-mediated disease or disorder is chronic spontaneous urticaria.
The following non-limiting examples illustrate the present invention.
EXAMPLES
LCMS methods
LC/MS Method 1 : was conducted on a Shimadzu LCMS-2020 Xselect CSH C18 column (50mm x 3.0 mm i.d. 2.5pm packing diameter) eluting with 0.1% formic acid in water (solvent A) and 0.1% formic acid in acetonitrile (solvent B), using the following elution gradient 0.01-3.60 min.: 30% to 70% B, 3.60-4.40 min to 95% B, 5.10-5.20 min. to 5% B, at a flow rate of 1.2 mL/ min. at 45°C.
LC/MS Method 2: UPLC was conducted on an Acquity UPLC CSH C18 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 0.1% formic acid in water (solvent A) and 0.1% formic acid in acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: l% to lOO% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C. Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative-scan positive and negative mode electrospray ionisation, scan range of 100 to 1000 AMU, with targeted sample frequency of 8 Hz.
LC/MS Method 3: UPLC was conducted on an Acquity UPLC CSH Cl 8 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 10 mM ammonium bicarbonate in water adjusted to pH 10 with 25% ammonium hyrdroxide solution (solvent A) and acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: 0% to 100% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C. Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative-scan positive and negative mode
LC/MS Method 4: was conducted on a Shimadzu LCMS-2020 Ascentis CSH C18 column (50mm x 3.0 mm i.d. 2.7pm packing diameter) eluting with 0.05% TFA in water (solvent A) and 0.05% TFA in acetonitrile (solvent B), using the following elution gradient 0.01-1.10 min.: 5% to 95% B, 1.80-1.90 to 5% B, at a flow rate of 1.5 mL/ min. at 40°C.
LC/MS Method 5: UPLC was conducted on an Acquity UPLC CSH Cl 8 column (30mm x 2.1mm i.d. 1.7pm packing diameter) eluting with 0.1% TFA in water (solvent A) and 0.1% TFA in acetonitrile (solvent B), using the following elution gradient 0-1.85 min.: 1% to 100% B, 1.9 to 2.0 min. 100% B, at a flow rate of 1.3 mL/ min. at 45°C. Mass spectrum was recorded on a Waters Acquity QDa mass detector using alternative- scan positive and negative mode electrospray ionisation, scan range of 100 to 1000 AMU, with targeted sample frequency of 8 Hz.
LC/MS Method 6: was conducted on a Ascentis Express C18 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with water/0.05%TFA (solvent A) and acetonitrile/0.05%TFA (solvent B), using the following elution gradient: 0.01-2.00 min.: 5% to 100% B, 2.80-2.90 min. to 5% B, at a flow rate of 1.5 mL/ min. at 40°C.
LC/MS Method 7: was conducted on a Poroshell HPH-18 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with 6.5 mM NH4HCO3 + NH3 H2O (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-2.00 min.: 10% to 95% B, 2.60-2.75 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
LC/MS Method 8: was conducted on a Ascentis Express C18 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with water/0.05%TFA (solvent A) and acetonitrile/0.05%TFA (solvent B), using the following elution gradient: 0.01-2.00 min.: 5% to 95% B, 2.60-2.75 min. to 5% B, at a flow rate of 1.5 mL/ min. at 40°C.
LC/MS Method 9: was conducted on a Kinetex 2.6 um EVO C18 100A column (50mm x 3.0 mm i.d. 2.6 pm packing diameter) eluting with water/5 mM NH4HCO3 (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-2.10 min.: 10% to 95% B, 2.70-2.75 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
LC/MS Method 10: column used was a Ascentis Express C18, 2.7 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water-0.05% TFA) and ending at 95% B (B: Acetonitrile-0.05% TFA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.50 mL/min
LC/MS Method 11 : The column used was a Kinetex 2.6 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
LC/MS Method 12: The column used was a Kinetex 2.6um EVO C18 100A, 2.6 pm, 3.0 x 50 mm. A linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 2.90 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min. LC/MS Method 13: The column used was a Kinetex 2.6um EVO Cl 8 100A, 2.6 pm, 3.0 x 50 mm. A linear gradient was applied, starting at 90% A (A: Water-5 mM NH4HCO3) and ending at 95% B (B: Acetonitrile) over 5.00 min with a total run time of 5.60 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
LC/MS Method 14: The column used was a Xselect CSH C18, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: Water/0.1%FA) and ending at 95% B (B: Acetonitrile/0.1%FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
LC/MS Method 15: The column used was a Poroshell HPH-C18, 2.7 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 90% A (A: water-6.5 mM NH4HCO3+NH3H2O) and ending at 95% B (B: Acetonitrile) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.50 mL/min.)
LC/MS Method 16: The column used was a Xselect CSH C18, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 100% B (B: Acetonitrile/0.1% FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.)
LC/MS Method 17: The column used was a Kinetex XB-C18, 2.6 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: Water/0.1%FA) and ending at 100% B (B: Acetonitrile/0.1%FA) over 2.60 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
LC/MS Method 18: The column used was a Ascentis Express C18, 2.7 pm, 2.1 x 50 mm. A linear gradient was applied, starting at 90% A (A: water-0.1% FA) and ending at 95% B (B: Acetonitrile-0.1% FA) over 2.70 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.00 mL/min.
LC/MS Method 19: The column used was a CORTECS C18, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water-0.09%F A) and ending at 95% B (B: Acetonitrile-0.1% FA) over 2.60 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.
LC/MS Method 20: The column used was a Xselect CSH C18, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 95% B (B: Acetonitrile/0.1% FA) over 4.70 min with a total run time of 5.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.) LC/MS Method 21 : The column used was a Kinetex XB- C18, 2.6 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) and ending at 90% B (B: Acetonitrile/0.1% FA) over 2.60 min with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.)
LC/MS Method 22: The column used was a Xselect CSH C18, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.1% FA) over 1.10 min, then to 0% B from 1.70 to 1.75 min, with a total run time of 2.00 min. The column temperature was at 40 °C with the flow rate of 1.20 mL/min.)
LC/MS Method 23: The column used was a Cortecs C18, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.1% FA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.1% FA) over 2.00 min, then to 5% B from 2.80 to 2.90 min, with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.00 mL/min.)
LC/MS Method 24: The column used was a Cortecs C18, 2.7 pm, 2.1 * 50 mm. A linear gradient was applied, starting at 95% A (A: water/0.05% TFA) at 0.01 min and moving to 100% B (B: Acetonitrile/0.05% TFA) over 2.00 min, then to 5% B from 2.80 to 2.90 min, with a total run time of 3.00 min. The column temperature was at 40 °C with the flow rate of 1.00 mL/min.).
LC/MS Method 25: The column used was a Xselect CSH C18, 2.5 pm, 3.0 * 50 mm. A linear gradient was applied, starting at 97% A (A: water/0.1% FA) and ending at 97% B (B: Acetonitrile/0.1% FA) over 2.70 min with a total run time of 2.5 min. The column temperature was at 40 °C with the flow rate of 1.0 mL/min.)
LC/MS Method 26: was conducted on a Kinetex 2.6 um EVO C18 100A column (50mm x 3.0 mm i.d. 2.6 pm packing diameter) eluting with water/5 mM NH4HCO3 (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-1.10 min.: 10% to 95% B, 1.80-1.85 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C.
LC/MS Method 27: was conducted on a Kinetex XB-C18 column (30mm x 2.1 mm i.d. 1.7 pm packing diameter) eluting with Water/0.05%TFA (solvent A) and Acetonitrile/0.05%TF A (solvent B), using the following elution gradient: 0.01-0.60 min.: 5% to 95% B, 1.00-1.05 min. to 5% B at a flow rate of 1.0 mL/ min. at 40°C.
LC/MS Method 28: was conducted on a Poroshell HPH-C18 column (50mm x 3.0 mm i.d. 2.7 pm packing diameter) eluting with 6.5 mM NH4HCO3+NH3H2O (solvent A) and acetonitrile (solvent B), using the following elution gradient: 0.01-1.10 min.: 10% to 95% B, 1.80-1.90 min. to 10% B at a flow rate of 1.2 mL/ min. at 40°C. Intermediates Intermediate 1 2-bromo-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)propanamide
Figure imgf000031_0001
Step 1 Sodium (1.96 g, 85.22 mmol, 1.1 eq) was added to cyclopropylmethanol (78.14 g, 1.09 mol, 14.0 eq), in batches, and the mixture was stirred at rt. After 30 min, 6- chloropyridazin-3-amine (10.00 g, 77.52 mmol, 1.0 eq) was added. The reaction mixture was flushed with nitrogen and stirred at 130 oC. After 12 h, the mixture was poured into ice water (800 mL) and extracted with ethyl acetate (800 mL x 3). The combined organic layers were washed with brine (1000 mL x 2), dried over sodium sulfate, concentrated and purified by prep HPLC (column: C18 cirregular 40 - 60 um 60 A 330 g), eluting with 5- 40% AcCN in water (10 mmol/L, NH4HCO3), to give 6-(cyclopropylmethoxy)pyridazin-3- amine (10.5 g, yield: 82%, purity: 93%) as yellow solid. LCMS: (ES, m/z): 166 [M+H]+. 1H NMR: (400 MHz, CDCl3) δ 6.89-6.78 (m, 2H), 4.63 (s, 2H), 4.19 (d, J = 7.2 Hz, 2H), 1.35-1.22 (m, 1H), 0.63-0.57 (m, 2H), 0.37-0.31 (m, 2H). Step 2 To 6-(cyclopropylmethoxy)pyridazin-3-amine (5.00 g, 30.30 mmol, 1.0 eq) and 2- bromopropanoic acid (6.91 g, 45.46 mmol, 1.5 eq) in DCM (150 mL) were added DMAP (1.11 g, 9.09 mmol, 0.3 eq) and DCC (12.48 g, 60.60 mmol, 2.0 eq). After 16 h, the reaction was filtered, concentrated, and purified over a silica gel column, eluting with ethyl acetate in petroleum ether (0-15%, 30 min) to give 2-bromo-N-(6- (cyclopropylmethoxy)pyridazin-3-yl)propanamide (4.8 g, yield: 53%, purity: 95%) as a yellow oil. LCMS: (ES, m/z): 300 [M+H]+. 1H NMR: (400 MHz, CDCl3) δ 11.55 (br, 1H), 8.60 (d, J=9.6 Hz, 1H), 7.13 (d, J=9.6 Hz, 1H), 5.48-5.41 (m, 1H), 4.31 (d, J=7.2 Hz, 2H), 1.92 (d, J=7.2 Hz, 3H), 1.75-1.67 (m, 1H), 0.71-0.68 (m, 2H), 0.42-0.37 (m, 2H).
Intermediate 2 (from the aryl bromide), was synthesized in an analogous manner.
Figure imgf000032_0002
Intermediate 3
2-bromo-7V-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide
Figure imgf000032_0001
Step 1 To 6-nitropyridin-3-ol (1.00 g, 7.14 mmol) in DMF (15 mL) at 25°C was added (bromomethyl)cyclopropane (1.156 g, 8.57 mmol) and K2CO3 (1.973 g, 14.28 mmol). After 8 h, water (100 mL) was added, and the mixture was extracted with EtOAc (3 X 100 mL). The combined organic extracts were washed with brine (100 mL), dried over sodium sulfate, concentrated and purified over silica (80 g), eluting with 0-50% EtOAc in pet ether. To give 5-(cyclopropylmethoxy)-2-nitropyridine (1.25 g, 5.79 mmol, purity: 90%, yield: 81%) as yellow solid. LCMS: (ES, m/z): 195 [M+H]+, RT= 0.938 min, LC/MS Method 4. 1H NMR: (400 MHz, CDCl3) δ 8.26-8.29 (m, 2H), 7.38-7.41 (m, 1H), 4.00 (d, J=8 Hz, 2H), 1.27-1.39 (m, 1H), 0.72-0.77 (m, 2H), 0.42-0.46 (m, 2H). Step 2 A mixture of 5-(cyclopropylmethoxy)-2-nitropyridine (6.6 g, 34.0 mmol, 1.0 eq), MeOH (60.0 mL) and Pd/C (0.6 g, 10%) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen. The reaction was stirred 2 h at 25 °C under an atmosphere of hydrogen (balloon), filtered, and concentrated to give crude 5- (cyclopropylmethoxy)pyridin-2-amine (5.8 g) as a yellow solid, which was used without further purification. LCMS: (ES, m/z): 165 [M+H]+. Step 3 To 5-(cyclopropylmethoxy)pyridin-2-amine (0.50 g, 3.05 mmol, 1.0 eq) and 2- bromopropanoic acid (0.7 g, 4.57 mmol, 1.5 eq) in DCM (10 mL) at 25 °C was added DCC (0.94 g, 4.57 mmol, 1.5 eq), in portions. After 2 h, the reaction was filtered, concentrated and purified by prep-TLC with ethyl acetate: petroleum ether (1: 10) to give 2-bromo-N-(5- (cyclopropylmethoxy)pyridin-2-yl)propanamide (0.9 g, yield: 53%, purity: 95%) as a white solid. LCMS: (ES, m/z): 299 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ 8.02-7.99 (m, 2H), 8.03-8.01 (m, 1H), 4.76-4.69 (m, 1H), 3.90 (d, J=6.9 Hz, 2H), 1.84 (d, J=6.9 Hz, 3H), 1.32-1.28 (m, 1H), 0.69-0.62 (m, 2H), 0.41-0.35 (m, 2H). Intermediate 4 2-bromo-N-(5-fluoropyridin-2-yl)propanamide
Figure imgf000034_0001
A mixture of 2-bromopropanoic acid (16.3 g, 107.2 mmol, 1.2 eq), DCM (200 mL), DCC (27.6 g, 134.0 mmol, 1.5 eq) and 5-fluoropyridin-2-amine (10.0 g, 89.3 mmol, 1.0 eq) was stirred for 2.0 h at 25 oC, filtered, concentrated and dissolved in DCM (50 ml). Silica (100 - 200 mesh, 60.0 g) was added, and the mixture was concentrated and loaded onto a silica gel column (330 g, 100 - 200 mesh). The column was eluted with ethyl acetate/petroleum ether (1/9) to give 2-bromo-N-(5-fluoropyridin-2-yl)propanamide (20.0 g, purity: 90%, yield: 90%) as yellow oil. LCMS: (ES, m/z): 247 [M+H]+. 1H NMR: (400 MHz, CD3OD) δ 8.22 (d, J = 3.2 Hz, 1H), 8.18 - 8.15 (m, 1H), 7.64 - 7.59 (m, 1H), 4.76 - 4.69 (m, 1H), 1.84 (d, J = 6.8 Hz, 3H). Intermediates 5-9 (6, 7 and 9 via the acid chloride intermediate) were synthesized in an analogous manner.
Figure imgf000034_0002
Figure imgf000035_0001
Figure imgf000036_0002
Intermediate 10
(7?)-2-bromo-7V-(5-propoxypyridin-2-yl)propanamide
Figure imgf000036_0001
Step 1
To 6-nitropyri din-3 -ol (1.5 g, 10.71 mmol), propan- l-ol (0.643 g, 10.71 mmol) and triphenylphosphine (4.21 g, 16.06 mmol) in THF (40 mL) at 0 °C was added DIAD (3.12 mL, 16.06 mmol), dropwise. The mixture was allowed to warm up to RT overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in hexanes 0-30%) to afford 2-nitro-5-propoxypyridine (1.95 g, 10.70 mmol, 100 % yield) as a pale yellow oil. LCMS: (ES, m/z): 183 [M+H]+. 'H NMR: (400 MHz, DMSO-t/6) 8 ppm: 8.27- 8.37 (m, 2H), 7.68-7.75 (m, 1H), 4.17 (t, J=6.6 Hz, 2H), 1.72-1.84 (m, 2H), 1.00 (t, J=7.5 Hz, 3H).
Step 2
To 2-nitro-5-propoxypyridine (1.95 g, 10.70 mmol) in ethanol (40 mL) under N2 was added Pd/C, 10% (0.114 g, 1.070 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite, concentrated, and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 20-70% EtOAc in hexanes to afford 5-propoxypyridin-2-amine (400 mg, 2.63 mmol, 24.55 % yield) as an off white solid. LCMS: (ES, m/z): 153 [M+H]+. 1H NMR (400 MHz, DMSO- d6) δ ppm: 7.57-7.67 (m, 1H), 7.09 (dd, J=8.9, 3.1 Hz, 1H), 6.33-6.45 (m, 1H), 5.42 (s, 2H), 3.81 (t, J=6.5 Hz, 2H), 1.57-1.74 (m, 2H), 0.94 (t, J=7.3 Hz, 3H). Step 3 To (R)-2-bromopropanoic acid (402 mg, 2.63 mmol) in DCM (15 mL) was added 2 drops of DMF followed by oxalyl chloride (0.230 mL, 2.63 mmol), dropwise. After 1 hour, the reaction was cooled to 0 °C, and 5-propoxypyridin-2-amine (400 mg, 2.63 mmol) was added, followed by TEA (0.733 mL, 5.26 mmol). After 1 hour at RT, the reaction was diluted with water, extracted with DCM (3X), washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford (R)-2-bromo-N-(5- propoxypyridin-2-yl)propanamide (396 mg, 1.379 mmol, 52.5 % yield) as a colorless wax. LCMS: (ES, m/z): 287 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 10.71 (s, 1H), 8.05 (d, J=2.7 Hz, 1H), 8.00 (d, J=9.0 Hz, 1H), 7.44 (dd, J=9.0, 3.2 Hz, 1H), 4.85 (q, J=6.7 Hz, 1H), 3.98 (t, J=6.6 Hz, 2H), 1.66-1.80 (m, 5H), 0.97 (t, J=7.5 Hz, 3H). Intermediates 11-13 were synthesized in an analogous manner
Figure imgf000038_0001
Figure imgf000039_0002
Intermediate 14 tert-butyl (A)-(6-(2-bromopropanamido)pyridin-3-yl)(propyl)carbamate
Figure imgf000039_0001
Step 1
To 5 -chi oro-2 -nitropyridine (1.0 g, 6.31 mmol) and propan- 1 -amine (0.559 g, 9.46 mmol) in DMSO (20 mL) was added DIPEA (2.203 mL, 12.62 mmol). The mixture was stirred at 60 °C for 2 days, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-50% EtOAc in hexanes to afford 6-nitro-A-propylpyri din-3 -amine (780 mg, 4.30 mmol, 68.2 % yield) as yellow solid. LCMS: (ES, m/z): 182 [M+H]+. 'H NMR: (400 MHz, DMSO-t/e) 6 ppm: 8.11 (d, J=9.0 Hz, 1H), 7.88 (d, J=2.7 Hz, 1H), 7.43 (br t, J=4.8 Hz, 1H), 7.05 (dd, J=9.0, 2.9 Hz, 1H), 3.10-3.19 (m, 2H), 1.59 (sxt, J=7.2 Hz, 2H), 0.95 (t, J=7.3 Hz, 3H). Step 2 To 6-nitro-N-propylpyridin-3-amine (780 mg, 4.30 mmol) and DMAP (52.6 mg, 0.430 mmol) in DCM (20 mL) at 0 °C was added Boc2O (1.099 mL, 4.74 mmol). The mixture was stirred at RT for 3 h, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert- butyl (6-nitropyridin-3-yl)(propyl)carbamate (1.20 g, 4.27 mmol, 99 % yield) as a light yellow oil. LCMS: (ES, m/z): 282 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 8.64 (d, J=2.7 Hz, 1H), 8.31 (d, J=8.8 Hz, 1H), 8.14 (dd, J=8.9, 2.6 Hz, 1H), 3.67-3.76 (m, 2H), 1.47-1.60 (m, 2H), 1.43 (s, 9H), 0.84 (t, J=7.5 Hz, 3H). Step 3 To tert-butyl (6-nitropyridin-3-yl)(propyl)carbamate (1.20 g, 4.27 mmol) in ethanol (30 mL) under N2 was added Pd/C, 10% (0.045 g, 0.427 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The mixture was filtered through Celite and concentrated to afford tert-butyl (6-aminopyridin-3-yl)(propyl)carbamate (1.02 g, 4.06 mmol, 95 % yield) as an off white solid, which was used without purification. LCMS: (ES, m/z): 252 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.70 (d, J=2.4 Hz, 1H), 7.19 (dd, J=8.7, 2.6 Hz, 1H), 6.40 (d, J=8.8 Hz, 1H), 5.91 (s, 2H), 3.37-3.47 (m, 2H), 1.20- 1.50 (m, 11H), 0.81 (t, J=7.3 Hz, 3H). Step 4 To (R)-2-bromopropanoic acid (426 mg, 2.79 mmol) in DCM (10 mL) was added 2 drops of DMF followed by oxalyl chloride (0.244 mL, 2.79 mmol), dropwise. After 1 h, the reaction was cooled to 0 °C, and a solution of tert-butyl (6-aminopyridin-3- yl)(propyl)carbamate (700 mg, 2.79 mmol) and TEA (0.776 mL, 5.57 mmol) in 5 mL of DCM was added. The resulting reaction was stirred at RT for 1 hour, diluted with water and extracted with DCM (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-25% EtOAc in hexanes to afford tert-butyl (R)-(6-(2-bromopropanamido)pyridin-3-yl)(propyl)carbamate (220 mg, 0.570 mmol, 20.45 % yield) as an off white solid. LCMS: (ES, m/z): 386 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 10.93 (s, 1H), 8.23 (d, J=2.3 Hz, 1H), 8.06 (d, J=8.8 Hz, 1H), 7.71 (dd, J=8.9, 2.6 Hz, 1H), 4.75-4.91 (m, 1H), 3.55 (t, J=7.3 Hz, 2H), 1.74 (d, J=6.8 Hz, 3H), 1.39-1.48 (m, 2H), 1.37 (s, 9H), 0.82 (t, J=7.4 Hz, 3H). Intermediate 15 (R)-2-bromo-N-(5-propylpyridin-2-yl)propanamide
Figure imgf000041_0001
Step 1 To 5-bromopyridin-2-amine (0.85 g, 4.91 mmol), bis(triphenylphosphine)palladium(II) chloride (0.345 g, 0.491 mmol) and potassium phosphate, tribasic (3.13 g, 14.74 mmol) in dioxane (24 mL) and water (8 mL) was added (E)-4,4,5,5-tetramethyl-2-(prop-1-en-1-yl)- 1,3,2-dioxaborolane (1.126 mL, 5.90 mmol). The flask was evacuated and purged with nitrogen several times, stirred at 95 °C 1 h, cooled to RT, poured into water (20 mL) and extracted with 15% IPA in DCM (2 x 40 mL). The combined organic layers were dried over MgSO4 and concentrated. The residue was triturated with diethyl ether (6 mL) to afford (E)-5-(prop-1-en-1-yl)pyridin-2-amine (762 mg, 5.68 mmol, quantitative yield), which was used without purification. LCMS: (ES, m/z): 135 [M+H]+. Step 2 A mixture of (E)-5-(prop-1-en-1-yl)pyridin-2-amine (659 mg, 4.91 mmol) and 10% Pd on carbon (150mg, 0.141 mmol) in ethanol (24 mL) was evacuated and purged with hydrogen several times, stirred under a balloon of hydrogen overnight, filtered and concentrated. The residue was stirred with EtOAc (10 mL), and insoluble material was filtered and discarded. The filtrate was purified over silica column, eluting with 0-15% EtOH in EtOAc to afford 5-propylpyridin-2-amine (170 mg, 1.248 mmol, 25.4 % yield). LCMS: (ES, m/z): 137 [M+H]+. 1H NMR (DMSO-d6) δ: 7.72 (d, J=2.3 Hz, 1H), 7.21 (dd, J=8.4, 2.4 Hz, 1H), 6.38 (d, J=8.5 Hz, 1H), 5.63 (s, 2H), 2.35 (t, J=7.5 Hz, 2H), 1.49 (sxt, J=7.4 Hz, 2H), 0.86 (t, J=7.3 Hz, 3H). Step 3 To (R)-2-bromopropanoic acid (0.108 mL, 1.197 mmol) in DCM (4 mL) was added oxalyl chloride (0.105 mL, 1.197 mmol), followed by DMF (0.009 mL, 0.120 mmol). After 1 h, this reaction was added dropwise to a solution of 5-propylpyridin-2-amine (163 mg, 1.197 mmol) and pyridine (0.223 mL, 2.75 mmol) in DCM (4 mL) at 0 °C. After 1 h, the reaction was poured into ethyl acetate (50 mL), washed with water (50 mL) and brine, dried over MgSO4, concentrated and purified by silica gel chromatography, eluting with 5- 40% ethyl acetate in hexanes to afford (R)-2-bromo-N-(5-propylpyridin-2-yl)propanamide (260 mg, 0.959 mmol, 80 % yield). LCMS: (ES, m/z): 271 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 10.79 (s, 1 H), 8.19 (d, J=1.8 Hz, 1 H), 8.00 (d, J=8.3 Hz, 1 H), 7.66 (dd, J=8.4, 2.1 Hz, 1 H), 4.79 - 4.98 (m, 1 H), 2.52 - 2.59 (m, 2 H), 1.74 (d, J=6.8 Hz, 3 H), 1.58 (sxt, J=7.4 Hz, 2 H), 0.83 - 1.00 (m, 3 H). Intermediate 16 2-bromo-N-(5-phenoxypyridin-2-yl)propanamide
Figure imgf000042_0001
Step 1 A mixture of 5-bromo-2-nitropyridine (2 g, 10 mmol, 1.0 eq), phenol (1.7 g, 18.0 mmol, 1.8 eq) and Cs2CO3 (4.2 g, 13 mmol, 1.3 eq) in DMF (20 mL) was stirred overnight, quenched with water (100 mL) and extracted with EA (100 mL x 3). The combined organic phases were dried over Na2SO4 , concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (1:5) to give 1.7 g (purity: 82%, yield: 77%) 2- nitro-5-phenoxypyridine as a yellow oil. LCMS: (ES, m/z): 217 [M+H]+. 1H NMR: (400 MHz, CDCl3) δ ppm 8.35 (d, J=2.8 Hz, 1H), 8.26 (d, J=8.9 Hz, 1H), 7.43 (dd, J=8.9, 2.8 Hz, 1H), 7.18-7.11 (m, 2H), 6.97-6.93 (m, 1H), 6.89-6.84 (m, 2H). Step 2 To 2-nitro-5-phenoxypyridine (800 mg, 3.7 mmol, 1.0 eq) and Fe (2.49 g, 44.4 mmol, 12.0 eq) in MeOH and H2O (15 mL, MeOH: H2O=4: 1) was added NH4Cl (400 mg, 7.4 mmol, 2.0 eq), in batches. The reaction was stirred 12 h at 80 oC, filtered, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 330 mg (purity: 96%, yield: 48%) of 5-phenoxypyridin-2-amine as a white solid. LCMS: (ES, m/z): 187 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 7.75 (d, J=2.9 Hz, 1H), 7.36- 7.28 (m, 2H), 7.20 (dd, J=8.9, 2.9 Hz, 1H), 7.04 (t, J=7.3 Hz, 1H), 6.92-6.86 (m, 2H), 6.50 (d, J=8.9 Hz, 1H), 5.88 (s, 2H). Step 3 A mixture of 2-bromopropanoic acid (271.4 mg, 1.77 mmol, 1.1 eq), DCC (498 mg, 2.41 mmol, 1.5 eq), DMAP (19.6 mg, 0.16 mmol, 0.1 eq) and 5-phenoxypyridin-2-amine (300 mg, 1.61 mmol, 1.0 eq) in DCM (5 mL) was stirred 2 h, quenched with water (100 mL) and extracted with EA (100 mL x3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with ethyl acetate : petroleum ether (1:3) to give 370 mg (purity: 91%, yield: 71%) 2-bromo-N-(5-phenoxypyridin-2- yl)propanamide as a colourless oil. LCMS: (ES, m/z): 321 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ 10.93 (s, 1H), 8.17 (d, J=2.9 Hz, 1H), 8.12 (d, J=9.0 Hz, 1H), 7.56 (dd, J=9.0, 3.0 Hz, 1H), 7.45-7.36 (m, 2H), 7.19-7.12 (m, 1H), 7.08-7.01 (m, 2H), 4.91-4.86 (m, 1H), 1.75 (d, J=6.7 Hz, 3H). Intermediate 17 (with nitro reduction by Pd/C-catalyzed hydrogenation) was synthesized in an analogous manner from 5-halo-2-nitropyridine.
Figure imgf000044_0002
Intermediate 18 2-bromo-N-(5-((5-fluoropyridin-2-yl)oxy)pyridin-2-yl)propanamide
Figure imgf000044_0001
Step 1 To 6-aminopyridin-3-ol hydrochloride (1.466 g, 10 mmol) in DMSO (10 mL) was added sodium hydride (60% dispersion, 0.800 g, 20.00 mmol). After 15 min, 2,5- difluoropyridine (0.813 mL, 9.00 mmol) was added, and the reaction was heated to 110 °C. After 90 min, the mixture was diluted with EtOAc and washed with sat’d aq potassium carbonate solution (6X). The combined aqueous layers were back extracted with EtOAc (2X), and this second batch of organic extracts was combined and washed with sat’d aq potassium carbonate solution (6X). The combined organics were washed with brine, dried over Na2SO4, filtered and concentrated to give 5-((5-fluoropyridin-2-yl)oxy)pyridin-2- amine (1.99 g, 9.70 mmol, purity: 100 %, recovery: 97 %), which was used without further purification. LCMS (m/z) 206 (M+H)+. 1H NMR (400 MHz, CD3OD) δ 7.97 (d, J=3.18 Hz, 1H), 7.76 (d, J=2.93 Hz, 1H), 7.63 (ddd, J=3.18, 7.64, 8.99 Hz, 1H), 7.31 (dd, J=2.81, 8.93 Hz, 1H), 7.00 (dd, J=3.67, 9.05 Hz, 1H), 6.65 (d, J=9.05 Hz, 1H). Step 2 To a mixture of 5-((5-fluoropyridin-2-yl)oxy)pyridin-2-amine (80 mg, 0.390 mmol) and 2- bromopropanoic acid (0.042 mL, 0.468 mmol) in dichloromethane (2 mL) were added DCC (121 mg, 0.585 mmol) and DMAP (4.76 mg, 0.039 mmol). After 2.5 h, the mixture was filtered. The filter cake was washed with DCM and the filtrate was concentrated. The crude material was then purified via normal phase chromatography (Combiflash, 12 g golden column, 30 ml/min, 0-25 % EtOAc in heptane) to afford the desired product 2- bromo-N-(5-((5-fluoropyridin-2-yl)oxy)pyridin-2-yl)propanamide (80 mg, 0.235 mmol, 60.3 % yield) as a colorless thick oil. LCMS (ES, m/s): 340.1 [M+H]+, rt = 0.92 min, Method 3, 1H NMR (400 MHz, DMSO-d6) δ ppm 8.78 (br. s., 1 H) 8.29 (d, J=9.05 Hz, 1H), 8.22 (d, J=2.45 Hz, 1H), 8.00 (d, J=2.93 Hz, 1H), 7.60 (dd, J=8.93, 2.57 Hz, 1H), 7.44-7.54 (m, 1H), 7.01 (dd, J=8.93, 3.55 Hz, 1H), 4.56 (q, J=7.09 Hz, 1H), 1.99 (d, J=7.09 Hz, 3H). Intermediate 19 was synthesized in an analogous manner.
Figure imgf000046_0002
Intermediate 20 2-bromo-N-(5-phenoxypyrazin-2-yl)propanamide
Figure imgf000046_0001
Step 1 A mixture of 5-bromopyrazin-2-amine (7 g, 40.2 mmol), copper(I) iodide (1.532 g, 8.05 mmol), dimethylglycine (0.830 g, 8.05 mmol), cesium carbonate (19.66 g, 60.3 mmol), and phenol (4.92 g, 52.3 mmol) in dioxane (40 mL) was stirred at 110 °C for 18 h, cooled to room temperature and partitioned between EtOAc and brine. The biphasic mixture was filtered over Celite, then separated. The organic layer was washed with brine (2X), dried over sodium sulfate, concentrated and purified over silica gel (220 g Gold column), eluting with 0-56% MeOH in DCM to give 5-phenoxypyrazin-2-amine (5.141 g, 26.1 mmol, 64.9 % yield) as a yellow solid. LCMS: (ES, m/z): 188 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 6.21 (s, 2 H) 6.91-7.03 (m, 2 H) 7.09 (t, J=7.34 Hz, 1 H) 7.30-7.41 (m, 2 H) 7.57 (d, J=0.98 Hz, 1 H) 7.83 (d, J=1.47 Hz, 1 H). Step 2 To 5-phenoxypyrazin-2-amine (500 mg, 2.67 mmol) and 2-bromopropanoic acid (0.264 mL, 2.94 mmol) in DCM (10 mL) at 0 °C was added DCC (661 mg, 3.21 mmol), in two batches. The reaction was stirred at rt for 20 h, filtered, concentrated and purified by flash chromatography (24g GOLD column), eluting with 0-100% EtOAc in heptanes to give 2- bromo-N-(5-phenoxypyrazin-2-yl)propanamide (908 mg, 2.54 mmol, 95 % yield) as a yellow solid. LCMS: (ES, m/z): 322 [M+H]+. 1H NMR: (400 MHz CDCl3) δ ppm 9.08 (d, J=0.98 Hz, 1H), 8.60 (br s, 1H), 8.14 (d, J=1.47 Hz, 1H), 7.41-7.51 (m, 2H), 7.23-7.32 (m, 1H), 7.14-7.20 (m, 2H), 4.54-4.67 (m, 1H), 2.00 (d, J=6.85 Hz, 4H). Intermediate 21 was synthesized in an analogous manner.
Figure imgf000048_0002
Intermediate 22
(A)-2-bromo-N-(5-(2,4-difluorophenoxy)pyrazin-2-yl)propanamide
Figure imgf000048_0001
Step 1
A mixture of 5-bromopyrazin-2-amine (33.0 g, 190 mmol), 2,4-difluorophenol (29.6 g, 228 mmol), dimethylglycine (3.91 g, 37.9 mmol), cesium carbonate (93.0 g, 284 mmol) and copper(I) iodide (7.22 g, 37.9 mmol) in dioxane (600 mL) was heated at 110 °C. After 2 h, the mixture was concentrated, diluted with EtOAc, washed with sat’d aq sodium carbonate solution (2 x 100 mL) and brine (1 x 100 mL), dried over magnesium sulfate, filtered and concentrated. The resulting residue was dissolved in MeCN (200 mL), water was added (500 mL), and the mixture was stirred at rt for 1 h. The resulting solid precipitate was collected by filtration, dissolved in EtOAc concentrated onto silica gel and purified by column chromatography, eluting with 0-100% ethyl acetate in heptane give 17.0 g (purity: 100%, yield: 40%) of 5-(2,4-difluorophenoxy)pyrazin-2-amine as a white solid. LCMS rt = 0.72 min, Method 5, (ES, m/z) 224 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 7.92 (d, J=1.5 Hz, 1H), 7.45-7.38 (m, 2H), 7.28 (td, J=9.2, 5.6 Hz, 1H), 7.13-7.05 (m, 1H), 6.16 (s, 2H). Step 2 A mixture of 5-(2,4-difluorophenoxy)pyrazin-2-amine (40 g, 179 mmol), (R)-2- bromopropanoic acid (32.9 g, 215 mmol) and silver nitrate (4.57 g, 26.9 mmol) in DCM (700 mL) was treated portionwise with DCC (44.4 g, 215 mmol), maintaining a temperature between 15 and 20 °C using a cold water bath. The resulting mixture was stirred at rt overnight, filtered and loaded onto a silica gel column, eluting with 5-40% ethyl acetate in heptane to give a yellow solid which was triturated with heptane to give 43 g (purity: 97%, yield: 67%) (R)-2-bromo-N-(5-((5-chloropyridin-2-yl)oxy)pyridin-2- yl)propanamide as a pale yellow solid. LCMS (ES, m/z) 358 [M+H]+, rt = 1.03 min, Method 5. Analytical Chiral HPLC (Chiral IG 150 x 4.6 mm, 70:30 EtOH:Heptane): 3.43 min (desired product, major isomer) and 4.35 min (minor isomer), % ee = 92%. 1H NMR: (400 MHz, DMSO-d6) δ 11.16 (s, 1H), 8.80 (d, J=1.0 Hz, 1H), 8.47 (d, J=1.5 Hz, 1H), 7.58-7.36 (m, 2H), 7.28-7.06 (m, 1H), 4.86 (q, J=6.8 Hz, 1H), 1.75 (d, J=6.8 Hz, 3H). Intermediate 23 (R)-1-((5-chloropyridin-2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate
Figure imgf000050_0001
Step 1 To 5-chloropyridin-2-amine (2.56 g, 19.93 mmol) and pyridine (2.417 mL, 29.9 mmol) in THF (80 mL) at 0 °C was added (S)-1-chloro-1-oxopropan-2-yl acetate (3.0 g, 19.93 mmol), dropwise. The mixture was stirred for 1 h, warmed to RT overnight, diluted with H2O and extracted with EtOAc (3 X). The organic extracts were washed with 0.5 N HCl (2 X) and brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-30% EtOAc in hexanes to afford (S)-1-((5-chloropyridin-2-yl)amino)-1-oxopropan-2-yl acetate (4.8 g, 19.78 mmol, 99 % yield) as a colorless oil. LCMS: (ES, m/z): 243 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 10.88 (s, 1H), 8.39 (dd, J=2.7, 0.7 Hz, 1H), 8.06 (d, J=8.6 Hz, 1H), 7.91 (dd, J=9.0, 2.7 Hz, 1H), 5.12 (q, J=6.8 Hz, 1H), 2.07 (s, 3H), 1.41 (d, J=6.8 Hz, 3H). Step 2 To (S)-1-((5-chloropyridin-2-yl)amino)-1-oxopropan-2-yl acetate (4.8 g, 19.78 mmol) in methanol (60 mL) and water (20.00 mL) was added LiOH (0.947 g, 39.6 mmol). After1 h, the mixture was diluted with H2O, and MeOH was removed. The resulting solid was collected by filtration, washed with H2O and air dried to afford (S)-N-(5-chloropyridin-2- yl)-2-hydroxypropanamide (3.66 g, 18.24 mmol, 92 % yield) as an off white solid, which was used without purification. LCMS: (ES, m/z): 201 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 8.37 (dd, J=2.7, 0.7 Hz, 1H), 8.11-8.16 (m, 1H), 7.93 (dd, J=8.8, 2.7 Hz, 1H), 4.23 (q, J=6.8 Hz, 1H), 1.30 (d, J=6.8 Hz, 3H). Step 3 To (S)-N-(5-chloropyridin-2-yl)-2-hydroxypropanamide (1.0 g, 4.98 mmol), 4-nitrobenzoic acid (1.000 g, 5.98 mmol) and triphenylphosphine (1.961 g, 7.48 mmol) in THF (25 mL) at 0 °C was added DIAD (1.454 mL, 7.48 mmol), dropwise. The mixture was allowed to warm to RT overnight, diluted with H2O and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-30% EtOAc in hexanes to afford (R)-1-((5-chloropyridin-2-yl)amino)-1- oxopropan-2-yl 4-nitrobenzoate (1.74 g, 4.98 mmol, 100 % yield) as an off white solid. LCMS: (ES, m/z): 350 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 11.10 (s, 1H), 8.41 (d, J=2.7 Hz, 1H), 8.35-8.40 (m, 2H), 8.21-8.27 (m, 2H), 8.07 (d, J=9.0 Hz, 1H), 7.92 (dd, J=9.0, 2.7 Hz, 1H), 5.44 (q, J=6.8 Hz, 1H), 1.60 (d, J=6.8 Hz, 3H). Step 4 To (R)-1-((5-chloropyridin-2-yl)amino)-1-oxopropan-2-yl 4-nitrobenzoate (1.72 g, 4.92 mmol) in methanol (15 mL) and water (5.00 mL) was added LiOH (0.236 g, 9.84 mmol). After 1 h, the mixture was diluted with H2O, and the MeOH was removed. The resulting solid was collected by filtration, washed with H2O and air dried to afford (R)-N-(5- chloropyridin-2-yl)-2-hydroxypropanamide (0.96 g, 4.79 mmol, 97 % yield) as an off white solid, which was used without purification. LCMS: (ES, m/z): 201 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 9.72-9.87 (m, 1H), 8.35-8.39 (m, 1H), 8.13 (dd, J=8.8, 0.7 Hz, 1H), 7.93 (dd, J=9.0, 2.7 Hz, 1H), 5.80-5.91 (m, 1H), 4.23 (q, J=6.8 Hz, 1H), 1.30 (d, J=6.8 Hz, 3H). Step 5 To (R)-N-(5-chloropyridin-2-yl)-2-hydroxypropanamide (960 mg, 4.79 mmol) in THF (20 mL) was added tosyl-Cl (958 mg, 5.02 mmol), followed by DMAP (877 mg, 7.18 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-40% EtOAc in hexanes to give (R)-1-((5-chloropyridin-2- yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (610 mg, 1.719 mmol, 35.9 % yield) as a colorless oil. LCMS: (ES, m/z): 355 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm: 10.85 (s, 1H), 8.39 (dd, J=2.2, 1.0 Hz, 1H), 7.88-7.98 (m, 2H), 7.74-7.83 (m, 2H), 7.43 (d, J=8.1 Hz, 2H), 5.15 (q, J=6.7 Hz, 1H), 2.36 (s, 3H), 1.38 (d, J=6.8 Hz, 3H). EXAMPLES Example 1 2-cyclohexyl-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)propanamide
Figure imgf000052_0001
To 2-cyclohexylpropanoic acid (44.7 mg, 0.286 mmol) in DCM (3 mL) was added DCC (67.4 mg, 0.327 mmol). After 15 min, 6-(cyclopropylmethoxy)pyridazin-3-amine (Intermediate 1, Step 1) (45 mg, 0.272 mmol) and DMAP (3.33 mg, 0.027 mmol) were added, and the reaction was stirred overnight. Additional 2-cyclohexylpropanoic acid (25.5 mg, 0.163 mmol), DCC (33.7 mg, 0.163 mmol), DMAP (3.33 mg, 0.272 mmol) and THF (2 mL) were added, and after 5 h the mixture was heated to 50 °C overnight. The reaction was concentrated, treated with pH 4 phosphate buffer and ectracted with EtOAc (4X). The combined extracts were washed with brine, concentrated and purified by silica gel chromatography (40 g cartridge), eluting with 20% EtOAc in heptanes. The material was repurified by reverse phase HPLC (Column: XSELECT CSH C18; 150 mm x 30 mm i.d.; 5 µm packing diameter; mobile phase 30%-99% acetonitrile:water with 0.1% TFA, flow rate 40 mL/min, retention time 11.6 min) to provide 2-cyclohexyl-N-(6- (cyclopropylmethoxy)pyridazin-3-yl)propanamide (7.5 mg, 0.025 mmol, 9.07 % yield). LCMS (m/z) 304 (M+H)+, RT= 1.05 min. LCMS Method 5. 1H NMR (CDCl3) δ ppm: 9.35 (br. s., 1H), 8.93 (d, J=9.78 Hz, 1H), 7.50 (d, J=9.54 Hz, 1H), 4.26 (d, J=7.34 Hz, 2H), 2.56 (quin, J=7.03 Hz, 1H), 1.58-1.88 (m, 6H), 1.10-1.38 (m, 8H), 1.04 (dt, J=2.81, 12.17 Hz, 1H), 0.59-0.78 (m, 2H), 0.30-0.47 (m, 2H). Example 2 was synthesized in an analogous manner using the indicated Intermediate.
Figure imgf000053_0002
Example 3
A-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(tetrahydro-2J/-pyran-4-yl)propanamide
Figure imgf000053_0001
Step 1
To ethyl 2-(tetrahydro-2H-pyran-4-yl)propanoate (0.255 g, 1.369 mmol) in dioxane (4 mL) was added a solution of LiOH (0.164 g, 6.85 mmol) in water (1 mL). After stirring overnight, the reaction was acidified with 2N HCl and extracted with EtOAc (3X). The combined organic extracts were concentrated to give crude 2-(tetrahydro-2H-pyran-4- yl)propanoic acid (220 mg, 1.391 mmol, recovery: quantitative) as a colorless oil, which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 4.02 (dt, J=4.16, 11.86 Hz, 2H), 3.34-3.47 (m, 2H), 2.32 (quin, J=7.15 Hz, 1H), 1.83 (dtd, J=3.79, 7.87, 11.77 Hz, 1H), 1.56-1.71 (m, 2H), 1.32-1.55 (m, 2H), 1.19 (d, J=7.09 Hz, 3H). Step 2 To 2-(tetrahydro-2H-pyran-4-yl)propanoic acid (58.7 mg, 0.371 mmol) and HATU (141 mg, 0.371 mmol) in DMF (1 mL) was added a solution of 5-(2,4-difluorophenoxy)pyridin- 2-amine (Intermediate 17, Step 2) (55 mg, 0.248 mmol) and DIEA (0.065 mL, 0.371 mmol) in DMF (1 mL). The reaction was stirred at 50 °C overnight, then at 90 °C for 90 min. Additional DIEA (0.065 mL, 0.371 mmol) was added, and heating was continued for 45 min. The mixture was diluted with EtOAc, washed with pH 4 phosphate buffer and brine, dried over Na2SO4, concentrated and purified by silica gel chromatography (12 g cartridge), eluting with 40% EtOAc in heptanes to provide N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(tetrahydro-2H-pyran-4-yl)propenamide (47 mg, 0.130 mmol, 52.4 % yield). LCMS (m/z) 363 (M+H)+, RT= 0.93 min. LCMS Method 5. 1H NMR (CDCl3) δ ppm: 8.24 (d, J=9.05 Hz, 1H), 7.97-8.14 (m, 2H), 7.26-7.38 (m, 1H), 7.08 (dt, J=5.50, 8.99 Hz, 1H), 6.98 (ddd, J=2.93, 7.95, 10.64 Hz, 1H), 6.89 (dddd, J=1.71, 2.93, 7.55, 9.08 Hz, 1H), 3.89-4.09 (m, 2H), 3.29-3.48 (m, 2H), 2.07-2.24 (m, 1H), 1.81-1.96 (m, 1H), 1.69-1.80 (m, 1H), 1.58-1.69 (m, 1H), 1.29-1.51 (m, 2H), 1.17-1.29 (m, 3H). Example 4 N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4-oxocyclohexyl)propanamide
Figure imgf000054_0001
Step 1 To ethyl 2-(1,4-dioxaspiro[4.5]decan-8-yl)acetate (500 mg, 2.190 mmol) in THF (4 mL) at -78 °C was added LDA (2M, 1.314 mL, 2.63 mmol), dropwise. After 30 min, iodomethane (0.164 mL, 2.63 mmol) in THF (1 mL) was added dropwise, and the mixture was stirred for 20 min and allowed to warm to rt. After stirring overnight, the reaction was quenched with NH4Cl(aq) solution and diluted with EtOAc. The organic layer was isolated, washed with NaHCO3(aq) and brine, dried over sodium sulfate and concentrated to provide crude ethyl 2-(1,4-dioxaspiro[4.5]decan-8-yl)propanoate (478 mg, 1.97 mmol, recovery: 90 %) as an amber oil, which was used without further purification. 1H NMR (CHLOROFORM-d) δ ppm: 4.14 (qd, J=7.1, 3.2 Hz, 2H), 3.91-3.95 (m, 4H), 2.28 (t, J=7.1 Hz, 1H), 1.71-1.81 (m, 3H), 1.50-1.66 (m, 4H), 1.30-1.41 (m, 2H), 1.23-1.28 (m, 3H), 1.13 (d, J=6.8 Hz, 3H). Step 2 To ethyl 2-(1,4-dioxaspiro[4.5]decan-8-yl)propanoate (0.48 g, 1.98 mmol) in EtOH (6 mL) was added NaOH(aq) (5N, 1.98 mL, 9.90 mmol). The reaction was heated to 90 °C for 90 min, and then at 40 °C overnight. The mixture was concentrated to remove volatile organics, diluted with water and washed with Et2O (2X). The aqueous layer was acidified with 6N HCl and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give crude 2-(1,4-dioxaspiro[4.5]decan-8-yl)propanoic acid (356 mg, 1.66 mmol, recovery: 84%) as an amber oil, which was used without further purification. 1H NMR (CHLOROFORM-d) δ ppm: 3.93-3.98 (m, 4H), 2.36 (t, J=7.1 Hz, 1H), 1.66-1.85 (m, 5H), 1.57 (s, 4H), 1.18 (d, J=7.3 Hz, 3H). Step 3 To 2-(1,4-dioxaspiro[4.5]decan-8-yl)propanoic acid (0.48 g, 2.240 mmol) in THF (3 mL) was added HCl(aq) (1M, 3.36 mL, 3.36 mmol), and the reaction was stirred for 3 h at 60 °C and then allowed to cool to rt. After stirring overnight, the mixture was concentrated to remove volatile organics, diluted with brine and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give crude 2-(4- oxocyclohexyl)propanoic acid (270 mg, 1.59 mmol, recovery: 71 %) as a pale amber oil, which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 2.31-2.51 (m, 5H), 2.02-2.16 (m, 3H), 1.46-1.65 (m, 2H), 1.21-1.26 (m, 3H). Step 4 To 2-(4-oxocyclohexyl)propanoic acid (92 mg, 0.540 mmol) and HATU (205 mg, 0.540 mmol) in DMF (0.9 mL) was added a solution of 5-(2,4-difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (80 mg, 0.360 mmol) and DIEA (0.094 mL, 0.540 mmol) in DMF (0.9 mL). The reaction was stirred at 60 °C for 24 h, diluted with EtOAc, washed with pH 4 phosphate buffer (2X) and brine, dried over Na2SO4, concentrated and purified by silica gel chromatography (12 g cartridge), eluting with 55% EtOAc in heptanes to provide N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4-oxocyclohexyl)propanamide (59 mg, 0.158 mmol, 43.8 % yield). LCMS (m/z) 375 (M+H)+, RT= 0.93 min. LCMS Method 5. 1H NMR (CDCl3) δ ppm: 8.24 (d, J=9.05 Hz, 1H), 8.04 (d, J=2.93 Hz, 2H), 7.24-7.36 (m, 1H), 7.08 (dt, J=5.38, 8.93 Hz, 1H), 6.99 (ddd, J=2.93, 8.01, 10.58 Hz, 1H), 6.89 (dddd, J=1.71, 2.93, 7.58, 9.05 Hz, 1H), 2.31-2.52 (m, 4H), 2.01-2.31 (m, 4H), 1.41-1.63 (m, 2H), 1.26-1.38 (m, 3H). Examples 5 and 6 Ex.5: (R)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-((1s,4S)-4- hydroxycyclohexyl)propanamide and Ex.6: (R)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)- 2-((1r,4R)-4-hydroxycyclohexyl)propanamide
Figure imgf000056_0001
Ethanol (3 ml) was added to a mixture of N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4- oxocyclohexyl)propanamide (Example 4) (177 mg, 0.473 mmol) and NaBH4 (96.5 mg, 2.55 mmol) at 24 °C. The reaction was stirred overnight, and an additional portion NaBH4 was added. After stirring overnight again, LiBH4 (30.9 mg, 1.418 mmol) was then added and the reaction was stirred for another 2 h, quenched with NH4Cl(aq) and concentrated. This material was chirally separated (column: ChiralPak IG, 20x250mm, 5 micron; flow rate: 20mL/min, solvents: 85:15 AcCN: MeOH [0.1% isopropylamine] for the first 9 minutes, then 50:50 AcCN: MeOH [0.1% isopropylamine], and returning to starting conditions at 19 minutes) to provide four stereoisomers of N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(4-hydroxycyclohexyl)propenamide with retention times of 7.16, 8.04, 10.62 and 11.36 min. Recovered were: Isomer 1 (1.9 mg, 5.05 µmol, recovery: 1%) at retention time of 7.16 min; and Isomer 2 (8.3 mg, 0.022 mmol, recovery: 5%) at retention time of 8.04 minutes. Isomer 1: LCMS (m/z) 377 (M+H)+, retention time: 0.90 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 8.31 (d, J=9.29 Hz, 1H), 8.22-8.27 (m, 1H), 7.98-8.04 (m, 1H), 7.33-7.39 (m, 1H), 7.04-7.13 (m, 1H), 6.96-7.04 (m, 1H), 6.87-6.94 (m, 1H), 3.98- 4.08 (m, 1H), 2.21-2.29 (m, 1H), 1.74-1.87 (m, 3H), 1.54-1.72 (m, 5H), 1.39-1.54 (m, 2H), 1.27 (d, J=6.85 Hz, 3H). Isomer 2: LCMS (m/z) 377 (M+H)+, retention time: 0.87 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 8.26 (d, J=9.29 Hz, 1H), 8.02-8.05 (m, 1H), 7.98-8.01 (m, 1H), 7.30-7.35 (m, 1H), 7.04-7.12 (m, 1H), 6.96-7.03 (m, 1H), 6.86-6.93 (m, 1H), 3.52- 3.62 (m, 1H), 2.09-2.19 (m, 1H), 1.88-2.09 (m, 3H), 1.77-1.86 (m, 1H), 1.52-1.66 (m, 2H), 1.36 (br s, 2H), 1.23-1.26 (m, 3H), 1.01-1.22 (m, 2H). Example 7 (R)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(4,4-difluorocyclohexyl)propanamide
Figure imgf000057_0001
Step 1 4,4-Difluorocyclohexanone (1.34 g, 9.99 mmol) and ethyl 2- (triphenylphosphoranylidene)acetate (3.83 g, 10.99 mmol) in toluene (30 mL) were stirred at 100 °C for 16 h, concentrated and purified over silica, eluting with 20% EtOAc in hexanes to provide ethyl 2-(4,4-difluorocyclohexylidene)acetate (1.9 g, 9.29 mmol, recovery: 93 %) as a colorless oil. 1H NMR (CHLOROFORM-d) δ: 5.75 (s, 1H), 4.18 (q, J=7.3 Hz, 2H), 3.02-3.10 (m, 2H), 2.38-2.47 (m, 2H), 1.97-2.14 (m, 4H), 1.30 (t, J=7.1 Hz, 3H). Step 2 Ethyl 2-(4,4-difluorocyclohexylidene)acetate (1.87 g, 9.16 mmol), methanol (60 mL) and palladium on carbon (370 mg, 0.348 mmol) (10% w/w, 50% wet) were stirred under an atmosphere of H2 for 16 h, filtered through Celite (rinsing with EtOAc) and concentrated to give crude 5-(pyridin-3-yloxy)pyridin-2-amine (1.81 g, 8.78 mmol, recovery: 96%) as a colorless oil, which was used without purification. 1H NMR (CHLOROFORM-d) δ ppm: 4.16 (q, J=7.2 Hz, 2H), 2.27 (d, J=6.8 Hz, 2H), 2.09 (td, J=7.1, 3.4 Hz, 2H), 1.90 (br d, J=3.9 Hz, 1H), 1.79-1.87 (m, 3H), 1.65-1.78 (m, 1H), 1.35 (br dd, J=12.0, 3.2 Hz, 2H), 1.28 (t, J=7.1 Hz, 3H). Step 3 To ethyl 2-(4,4-difluorocyclohexyl)acetate (250 mg, 1.212 mmol) in THF (3 mL) at -78 °C was added LDA (2M, 1.212 mL, 2.424 mmol), dropwise. After 30 min, iodomethane (0.303 mL, 4.85 mmol)) in THF (0.5 mL) was added dropwise, and the reaction was stirred for 20 min, allowed to warm to rt and stirred overnight. The reaction was quenched with NH4Cl(aq) solution and diluted with EtOAc. The organic layer was isolated, washed with NaHCO3(aq) and brine, dried over sodium sulfate and concentrated to provide crude ethyl 2-(4,4-difluorocyclohexyl)propanoate (282 mg, 1.28 mmol, recovery: quantitative) as an amber oil, which was used without further purification. NMR (400 MHz, CDCl3) δ ppm 4.09-4.22 (m, 2H), 2.32 (quin, J=7.09 Hz, 1H), 2.11 (ttd, J=3.55, 7.01, 17.29 Hz, 2H), 1.75-1.87 (m, 2H), 1.55-1.74 (m, 3H), 1.32-1.49 (m, 2H), 1.23-1.31 (m, 3H), 1.16 (d, J=7.09 Hz, 3H). Step 4 To ethyl 2-(4,4-difluorocyclohexyl)propanoate (0.267 g, 1.212 mmol) in dioxane (5 mL) was added a solution of LiOH (0.145 g, 6.06 mmol) in water (1.2 mL). The reaction was stirred overnight, acidified with 2N HCl and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give partially hydrolyzed product. This material was taken up in EtOH (4 mL), treated with NaOH(aq) (5M, 1.212 mL, 6.06 mmol) and heated to 70 °C for 2.5 h. The mixture was concentrated to remove volatile organics, acidified and extracted with EtOAc (3X). The combined organics were dried and concentrated to give crude 2-(4,4-difluorocyclohexyl)propanoic acid (188 mg, 0.978 mmol, recovery: 81%) as a tan solid, which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 2.39 (quin, J=7.03 Hz, 1H), 2.06-2.20 (m, 2H), 1.61- 1.89 (m, 5H), 1.30-1.55 (m, 2H), 1.21 (d, J=7.09 Hz, 3H). Step 5 To 2-(4,4-difluorocyclohexyl)propanoic acid (63.5 mg, 0.331 mmol) and HATU (126 mg, 0.331 mmol) in DMF (0.7 mL) was added 6-(cyclopropylmethoxy)pyridazin-3-amine (39 mg, 0.236 mmol) (Intermediate 1, Step 1) (80 mg, 0.360 mmol) and DIEA (0.058 mL, 0.331 mmol), washing down walls of the vessel with DMF (0.5 mL). The reaction was stirred at 60 °C for 18 h, diluted with EtOAc, washed with pH 4 phosphate buffer (2X) and brine, dried over Na2SO4, concentrated and purified by silica gel chromatography (12 g cartridge), eluting with 40% EtOAc in heptanes to provide 41 mg of a white solid. This material was chirally separated (column: AD-H, 20x250mm, 5 micron; flow rate: 20 mL/min, solvents: 50:50 AcCN: MeOH) to provide two stereoisomers of N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(4-oxocyclohexyl)propanamide with retention times of 10.107 and 16.565 min. The second peak (16.565 min) was collected to give (R)-N-(6- (cyclopropylmethoxy)pyridazin-3-yl)-2-(4,4-difluorocyclohexyl)propanamide, 13.89 mg. LCMS (m/z) 340 (M+H)+, RT= 0.96 min. LCMS Method 5. 1H NMR (CDCl3) δ ppm: 10.40 (s, 1H), 8.54 (d, J=9.54 Hz, 1H), 7.10 (d, J=9.54 Hz, 1H), 4.12-4.39 (m, 2H), 2.68- 2.89 (m, 1H), 2.02-2.25 (m, 2H), 1.97 (d, J=12.23 Hz, 1H), 1.60-1.89 (m, 5H), 1.29-1.57 (m, 2H), 1.27 (d, J=6.85 Hz, 3H), 0.59-0.78 (m, 2H), 0.25-0.49 (m, 2H). Example 8 was synthesized in an analogous manner using the designated Intermediate in Step 5.
Figure imgf000060_0001
Example 9 N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(3-(3-oxopiperazin-1-yl)piperidin-1- yl)propanamide
Figure imgf000061_0001
To tert-butyl 3-oxopiperidine-1-carboxylate (850 mg, 4.27 mmol), piperazin-2-one (427 mg, 4.27 mmol) and acetic acid (0.366 mL, 6.40 mmol) in THF (12 mL) was added sodium triacetoxyborohydride (2260 mg, 10.66 mmol). After stirring over a weekend, the reaction was concentrated to remove most of the THF, water was added and the mixture was extracted with EtOAc (6X). The combined organics were washed with brine, dried over sodium sulfate, filtered, concentrated and purified by silica gel chromatography (ISCO 80 g Gold column), eluting with 0-10% MeOH in DCM to provide tert-butyl 3-(3- oxopiperazin-1-yl)piperidine-1-carboxylate (90 mg, 0.318 mmol, recovery: 7 %) as a light yellow foam. LCMS (m/z) 284 (M+H)+, retention time: 0.67 min, LC/MS Method 3. 1H NMR (CHLOROFORM-d) δ: 5.97 (br m, 1H), 3.86 (br m, 3H), 3.38 (br s, 4H), 2.85 (br m, 4H), 2.38 (br s, 1H), 1.60-2.02 (m, 4H). Step 2 Hydrogen chloride (4M, 1.588 mL, 6.35 mmol) was added to tert-butyl 3-(3-oxopiperazin- 1-yl)piperidine-1-carboxylate (90 mg, 0.318 mmol) in MeOH (2 mL). After stirring overnight, the reaction was concentrated to provide crude 4-(piperidin-3-yl)piperazin-2-one dihydrochloride (81 mg, 0.316 mmol, recovery: quantitative) as a yellow sticky oil, which was used without purification. LCMS (m/z) 184 (M+H)+, retention time: 0.30 min, LC/MS Method 3. Step 3 To 4-(piperidin-3-yl)piperazin-2-one dihydrochloride (40 mg, 0.156 mmol), 2-bromo-N-(5- (2,4-difluorophenoxy)pyridin-2-yl)propanamide (Intermediate 17) (55.8 mg, 0.156 mmol) and TEA (0.065 mL, 0.468 mmol) in DMA (1.5 mL), silver nitrate (26.5 mg, 0.156 mmol) was added. The reaction was heated to 40 °C overnight, diluted with water and extracted with ethyl acetate (4X). The combined organics were washed with 5% LiCl and brine, dried over sodium sulfate, filtered, concentrated and purified by silica gel chromatography (ISCO 80 g Gold column), eluting with 0-8% MeOH in DCM to provide N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(3-(3-oxopiperazin-1-yl)piperidin-1-yl)propanamide (35 mg, 0.076 mmol, recovery: 49 %) as a fluffy white solid. LCMS (m/z) 460 (M+H)+, retention time: 0.93-0.95 min, LC/MS Method 3. 1H NMR (400 MHz, MeOH-d4) δ ppm 8.17 (d, J=9.05 Hz, 1H), 8.06 (d, J=2.93 Hz, 1H), 7.41-7.45 (M, 1H), 7.15-7.29 (m, 2H), 7.02 (d, J=1.22 Hz, 1H), 3.41 (dd, J=6.85, 5.38 Hz, 1H), 3.24-3.32 (m, 4 H) 2.92-3.06 (m, 1H), 2.66-2.89 (m, 4 H) 2.42 (s, 1H), 2.23 (br. s., 1H), 1.94-2.04 (m, 1H), 1.82-1.91 (m, 1H), 1.61-1.79 (m, 1H), 1.33-1.43 (m, 1H), 1.32 (dd, J=6.97, 2.32 Hz, 3H). Example 10 (2S)-2-((5R)-3,5-dihydroxy-3-(trifluoromethyl)piperidin-1-yl)-N-(5-fluoropyridin-2- yl)propanamide
Figure imgf000062_0001
Step 1 To (2S,4R)-4-hydroxypyrrolidine-2-carboxylic acid (15.74 g, 120 mmol) in MeOH (240 ml) cooled to 0 °C was added SOCl2 (13.14 ml, 180 mmol), dropwise. The reaction was heated to 60 °C until complete by TLC, then concentrated to give crude methyl (2S,4R)-4- hydroxypyrrolidine-2-carboxylate (17.2 g, 118 mmol, recovery 99 %) as a white solid, which was used without purification. 1H NMR (400 MHz, D2O) δ ppm 4.55-4.63 (m, 2H), 3.75 (s, 3H), 3.42 (dd, J=12.72, 3.91 Hz, 1H), 3.23-3.35 (m, 1H), 2.39 (ddt, J=14.12, 7.64, 1.83, 1.83 Hz, 1H), 2.19 (ddd, J=14.37, 10.45, 4.28 Hz, 1H). Step 2 To methyl (2S,4R)-4-hydroxypyrrolidine-2-carboxylate (22.72 g, 157 mmol) in DCM (626 ml) was added triethylamine (43.6 ml, 313 mmol) followed by benzyl bromide (37.2 ml, 313 mmol), and the reaction was refluxed at 65 °C overnight. After cooling to 4 °C, NaOH(aq) (5M, 200 mL) was added until the pH reached 12-14. The layers were separated, and the aqueous phase was extracted with DCM (2 X 100 mL). The organic layers were combined, and about 200 mL of DCM was removed in vacuo to reduce the volume. The organic phase was neutralized with HCl(aq) (1.0 M, 200 mL), the layers were separated, and the organic phase was extracted with HCl (1.0 M, 50 mL). The combined aqueous layers were neutralized with sat’d aq NaHCO3 (100 mL), with ice cooling, and the pH was adjusted to 12-14 by adding solid K2CO3. The aqueous layer was extracted with diethyl ether (3 X 100 mL), and the combined organic extracts were dried over MgSO4 and concentrated to give crude methyl (2S,4R)-1-benzyl-4-hydroxypyrrolidine-2-carboxylate (23 g, 98 mmol, recovery: 63 %) as a pale yellow oil, which was used without further purification. LCMS (m/z) 236 (M+H)+, retention time: 0.34 min, LC/MS Method 5. Step 3 To methyl (2S,4R)-1-benzyl-4-hydroxypyrrolidine-2-carboxylate (23 g, 98 mmol) in DCM (489 ml) was added tert-butyldiphenylchlorosilane (25.1 ml, 98 mmol). The reaction was cooled to 0 °C, and triethylamine (13.63 ml, 98 mmol) was added, dropwise, followed by DMAP (2.389 g, 19.55 mmol). The mixture was allowed to warm to rt, then stirred overnight and treated with water (200 mL). The aqueous layer was isolated and extracted with EtOAc (200 mL). The combined organic extracts were dried over Na2SO4 and purified over silica, eluting with 19:1 hexanes: ethyl acetate to give methyl (2S,4R)-1- benzyl-4-((tert-butyldiphenylsilyl)oxy)pyrrolidine-2-carboxylate (36 g, 74.5 mmol, recovery: 76 %) as a clear oil. LCMS (m/z) 474 (M+H)+, retention time: 1.194 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 7.65 (ddd, J=10.9, 8.0, 1.6 Hz, 4H), 7.36-7.50 (m, 6H), 7.28-7.36 (m, 5H), 4.48 (dt, J=10.6, 5.1 Hz, 1H), 3.94 (d, J=13.0 Hz, 1H), 3.68 (br d, J=13.0 Hz, 1H), 3.63 (s, 3H), 3.20 (br dd, J=9.8, 5.6 Hz, 1H), 2.55 (dd, J=10.0, 4.6 Hz, 1H), 2.03-2.13 (m, 2H), 1.06-1.12 (m, 9H). Step 4 To a suspension of LiAlH4 (52.8 ml, 106 mmol) in THF (100 ml) at 0 °C was added a solution of methyl (2S,4R)-1-benzyl-4-((tert-butyldiphenylsilyl)oxy)pyrrolidine-2- carboxylate (25 g, 52.8 mmol) in THF (100 ml), dropwise. After 10 min, the reaction was heated to reflux (80 °C) for 2 h, then cooled to 0 °C. Water (4 mL), 3.75M NaOH solution (4 mL), and additional water (12 mL) were successively added. The mixture was filtered through Celite, rinsing with THF. The filtrate was concentrated to provide crude ((2S,4R)-1-benzyl-4-((tert-butyldiphenylsilyl)oxy)pyrrolidin-2-yl)methanol (21.2 g, 47.6 mmol, recovery: 90 %), which was used without further purification. LCMS (m/z) 446 (M+H)+, retention time: 1.09 min, LC/MS Method 5. Step 5 Trifluoroacetic anhydride (2.044 ml, 14.47 mmol) was added dropwise to ((2S,4R)-1- benzyl-4-((tert-butyldiphenylsilyl)oxy)pyrrolidin-2-yl)methanol (4.3 g, 9.65 mmol) in THF (80 ml) at -78 °C. After 3 h, triethylamine (5.38 ml, 38.6 mmol) was added dropwise, and after 15 min the reaction was refluxed at 75 °C for 20 h. After addition of sodium hydroxide (1 M, 31.8 ml, 31.8 mmol), the mixture was stirred for 3 h and extracted with DCM. The organic layer was dried over MgSO4, concentrated and purified by flash chromatography, eluting with 10-50% EtOAc in hexanes to give (3R,5R)-1-benzyl-5-((tert- butyldiphenylsilyl)oxy)piperidin-3-ol (3.84 g, 8.62 mmol, recovery: 89 %) as a light yellow oil. LCMS (m/z) 446 (M+H)+, retention time: 1.05 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 7.60 - 7.64 (m, 4H), 7.37-7.41 (m, 8H), 7.21-7.35 (m, 3H), 4.03-4.11 (m, 1H), 3.94 (br s, 1H), 3.48 (s, 2H), 2.27 (br d, J=10.27 Hz, 2H), 1.97- 2.08 (m, 2H), 1.47-1.56 (m, 1H), 1.24-1.35 (m, 1H), 1.04 (s, 9H). Step 6 To oxalyl chloride (0.50 mL, 5.71 mmol) in DCM (15 mL) at -78°C was added dimethyl sulfoxide (0.80 mL, 11.27 mmol), dropwise. After 10 minutes a solution of (3R,5R)-1- benzyl-5-((tert-butyldiphenylsilyl)oxy)piperidin-3-ol (1.21 g, 2.71 mmol) in DCM (5 mL) was added dropwise. After 20 minutes, triethylamine (3.0 mL, 21.52 mmol) was added, and after 5 min, the cooling bath was removed. After 30 minutes. the mixture was poured into water and extracted with DCM (2 X). The combined organic extracts were washed with brine, dried over sodium sulfate, concentrated and purified over silica (40 g), eluting with 0-20% ethyl acetate in heptane to provide (R)-1-benzyl-5-((tert- butyldiphenylsilyl)oxy)piperidin-3-one (815 mg, 1.837 mmol, recovery: 68%) as a yellow oil. LCMS (m/z) 444 (M+H)+, retention time: 1.70 min, LC/MS Method 3. 1H NMR (400 MHz, CDCl3) δ ppm 7.61 (d, J=6.1 Hz, 5H), 7.34-7.48 (m, 8H), 7.23 (br. s., 2H), 3.56 (br. s., 2H), 3.04-3.13 (m, 1H), 2.84-2.95 (m, 2H), 2.59-2.69 (m, 2H), 2.38-2.52 (m, 2H), 1.05 (s, 9H). Step 7 To (R)-1-benzyl-5-((tert-butyldiphenylsilyl)oxy)piperidin-3-one (800 mg, 1.803 mmol) in THF (15 mL) at 0°C was added trimethyl(trifluoromethyl)silane (0.60 mL, 4.06 mmol), followed by cesium fluoride (50.0 mg, 0.329 mmol). After 10 minutes, the reaction was allowed to warm to rt. After 30 minutes. the mixture was poured into water and extracted with EtOAc (2 X). The combined organic extracts were washed with brine, dried over sodium sulfate, concentrated and purified over silica (40 g), eluting with 0-20% ethyl acetate in heptane to provide (5R)-1-benzyl-5-((tert-butyldiphenylsilyl)oxy)-3- (trifluoromethyl)-3-((trimethylsilyl)oxy)piperidine (793 mg, 1.354 mmol, recovery: 75%) as a yellow oil. LCMS (m/z) 586 (M+H)+, retention time: 1.97 min, LC/MS Method 3. Step 8 To (5R)-1-benzyl-5-((tert-butyldiphenylsilyl)oxy)-3-(trifluoromethyl)-3- ((trimethylsilyl)oxy)piperidine (100 mg, 0.171 mmol) in EtOH (3 mL), under a nitrogen atmosphere, was added 10% palladium on carbon (20 mg, 0.019 mmol). The reaction vessel was fitted with a hydrogen-filled balloon, evacuated and purged with hydrogen (3X), then stirred under a hydrogen atmosphere overnight. The reaction vessel was evacuated and purged with nitrogen, additional 10% palladium on carbon (20 mg, 0.019 mmol) was added, and the reaction vessel was evacuated and purged with hydrogen (3X), then stirred under a hydrogen atmosphere overnight. The reaction was filtered through Celite, and concentrated to afford crude (5R)-5-((tert-butyldiphenylsilyl)oxy)-3- (trifluoromethyl)-3-((trimethylsilyl)oxy)piperidine (79 mg, 0.135 mmol, recovery: 79 %) as a pale yellow oil, which was used without purification. LCMS (m/z) 496 (M+H)+, retention time: 1.29 min, LC/MS Method 5. Step 9 To (R)-2-bromo-N-(5-fluoropyridin-2-yl)propanamide (Intermediate 4) (35 mg, 0.142 mmol) in DMA (1 mL) was added (5R)-5-((tertbutyldiphenylsilyl)oxy)-3- (trifluoromethyl)-3-((trimethylsilyl)oxy)piperidine (64 mg, 0.129 mmol) and triethylamine (0.020 mL, 0.143 mmol), followed by silver nitrate (25 mg, 0.147 mmol). The reaction was heated at 40 °C for 3.5 h, then at 60 °C over the weekend. Additional (R)-2-bromo-N- (5-fluoropyridin-2-yl)propanamide (11 mg, 0.045 mmol) and silver nitrate (9 mg, 0.053 mmol) were added, and the reaction was stirred at 60 °C 5 h, poured into water and extracted with EtOAc (2X). The combined organics were washed with brine, dried over sodium sulfate and concentrated to afford crude (2S)-2-((5R)-5-((tert- butyldiphenylsilyl)oxy)-3-(trifluoromethyl)-3-((trimethylsilyl)oxy)piperidin-1-yl)-N-(5- fluoropyridin-2-yl)propanamide (104 mg, 0.157 mmol, recovery: quantitative) as a dark yellow oil, which was used without further purification. LCMS (m/z) 662 (M+H)+, retention time: 1.84 min, LC/MS Method 5. Step 10 To crude (2S)-2-((5R)-5-((tert-butyldiphenylsilyl)oxy)-3-(trifluoromethyl)-3- ((trimethylsilyl)oxy)piperidin-1-yl)-N-(5-fluoropyridin-2-yl)propanamide (85 mg, 0.128 mmol) in THF (1 mL) at 0 °C was added tetra-n-butylammonium fluoride (1M in THF, 0.30 mL, 0.300 mmol), and the mixture was allowed to warm slowly to rt. After 1.5 h, additional tetra-n-butylammonium fluoride (0.30 mL) was added, and stirring was continued overnight. The reaction was poured into water and extracted with EtOAc (2X). The combined organics were washed with brine, dried over sodium sulfate, concentrated and purified by MDAP HPLC (XSELECT CSH C18 column), eluting with 15-55% AcCN in water (with 10 mM ammonium bicarbonate adjusted to pH 10 with ammonia) to afford (2S)-2-((5R)-3,5-dihydroxy-3-(trifluoromethyl)piperidin-1-yl)-N-(5-fluoropyridin-2- yl)propanamide (18 mg, 0.051 mmol, purity: 98 % recovery: 40 %) as a beige solid. LCMS (m/z) 352 (M+H)+, retention time: 0.73 and 0.78 min, LC/MS Method 3. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.36 (s, 1H), 8.31-8.35 (m, 1H), 8.17 (dd, J=9.0, 4.2 Hz, 1H), 7.76 (td, J=8.7, 3.2 Hz, 1H), 4.88-5.04 (m, 1H), 3.82-3.93 (m, 1H), 3.46-3.62 (m, 1H), 2.98 (br dd, J=10.8, 4.4 Hz, 1H), 2.66-2.76 (m, 1H), 2.25-2.48 (m, 2H), 1.90-2.16 (m, 2H), 1.55-1.69 (m, 1H), 1.48 (br d, J=10.8 Hz, 1H), 1.21 (d, J=6.8 Hz, 2H). Example 11 (2S)-N-(5-fluoropyridin-2-yl)-2-(3-hydroxy-3-methylpiperidin-1-yl)propanamide
Figure imgf000067_0001
To 3-methylpiperidin-3-ol (36.7 mg, 0.319 mmol), (R)-2-bromo-N-(5-fluoropyridin-2- yl)propanamide (Intermediate 4) (55.8 mg, 0.156 mmol) and TEA (0.036 mL, 0.255 mmol) in DMA (2 mL), silver nitrate (43.3 mg, 0.255 mmol) was added, and the reaction was heated to 40 °C for 15 h. The mixture was filtered, diluted with ethyl acetate, washed with water and brine, concentrated and purified by silica gel chromatography (ISCO 12 g Gold column), eluting with 0-60% (3:1 EtOAc: EtOH) in heptanes to provide (2S)-N-(5- fluoropyridin-2-yl)-2-(3-hydroxy-3-methylpiperidin-1-yl)propanamide (67 mg, 0.226 mmol, recovery: 89 %). LCMS (m/z) 282 (M+H)+, retention time: 0.37 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 9.75 (br s, 0.5H), 9.53 (br s, 0.5H), 8.19- 8.29 (m, 1H), 8.13 (dd, J=2.93, 1.47 Hz, 1H), 7.43 (dddd, J=9.05, 7.58, 2.93, 1.47 Hz, 1H), 3.30 (dq, J=17.91, 7.07 Hz, 1H), 2.58-2.81 (m, 1H), 2.37-2.57 (m, 2H), 2.17-2.30 (m, 1H), 1.80-2.04 (m, 2H), 1.60-1.75 (m, 2H), 1.34-1.45 (m, 1H), 1.31 (dd, J=7.09, 6.11 Hz, 3H), 1.25 (d, J=6.36 Hz, 3H).
Example 12 2-(3-(1,1-dioxidothiomorpholino)piperidin-1-yl)-N-(5-(4-fluorophenoxy)pyrazin-2- yl)propanamide
Figure imgf000068_0001
Step 1 tert-Butyl 3-oxopiperidine-1-carboxylate (1 g, 5.02 mmol) and thiomorpholine 1,1-dioxide (1.018 g, 7.53 mmol) were stirred in DCE (20 mL) for 5 minutes, followed by addition of acetic acid (0.287 mL, 5.02 mmol) and sodium triacetoxyborohydride (3.19 g, 15.06 mmol). After stirring overnight, the reaction was quenched with 1N sodium hydroxide until the aqueous layer was slightly basic (approximately pH 8). The mixture was extracted with ethyl acetate, concentrated and purified by column chromatography (40 g silica Gold), eluting with 0-20% MeOH in DCM to provide tert-butyl 3-(1,1- dioxidothiomorpholino)piperidine-1-carboxylate (1.047 g, 3.12 mmol, recovery: 62 %) as a yellow oil. LCMS (m/z) 319 (M+H)+ retention time: 0.78 min, LC/MS Method 3. 1H NMR (DMSO-d6) δ: 3.75 (br s, 2H), 3.55-3.66 (m, 2H), 3.35-3.42 (m, 2H), 3.03 (br dd, J=19.3, 6.1 Hz, 4H), 2.79 (br s, 1H), 1.76-1.84 (m, 2H), 1.59-1.67 (m, 2H), 1.41 (br s, 9H). Step 2 tert-Butyl 3-(1,1-dioxidothiomorpholino)piperidine-1-carboxylate (100 mg, 0.314 mmol) was stirred in TFA (1 mL) for 30 min, diluted with DCM and toluene, concentrated and azeotroped with toluene (2X) to yield crude 4-(piperidin-3-yl)thiomorpholine 1,1-dioxide, trifluoroacetic acid salt (137 mg, 0.330 mmol, recovery: 96%) as a bright yellow oil, which was used without purification. 1H NMR (400 MHz, MeOH-d4) δ ppm 5.49 (s, 1H), 4.01 (dt, J=5.26, 2.51 Hz, 1H), 3.45-3.81 (m, 2H), 2.89-3.21 (m, 8H), 1.63-2.17 (m, 6H). Step 3 A mixture of 2-bromo-N-(5-(4-fluorophenoxy)pyrazin-2-yl)propanamide (Intermediate 21) (100 mg, 0.294 mmol), 4-(piperidin-3-yl)thiomorpholine 1,1-dioxide, TFA salt (102 mg, 0.307 mmol), and TEA (0.246 mL, 1.764 mmol) in DMA (2 mL) was stirred at 40 °C overnight. The mixture was diluted with ethyl acetate, washed with brine (2X), dried over sodium sulfate, concentrated and purified by MDAP chromatography, eluting with 15-50% AcCN in water, to provide (1,1-dioxidothiomorpholino)piperidin-1-yl)-N-(5-(4- fluorophenoxy)pyrazin-2-yl)propanamide (20 mg, 0.040 mmol, 13.53 % yield) as a yellow oil. LCMS (m/z) 478 (M+H)+, retention time: 1.01 min, LC/MS Method 3. 1H NMR (METHANOL-d4) δ: 8.90-8.97 (m, 1H), 8.18 (d, J=1.5 Hz, 1H), 7.14-7.23 (m, 4H), 3.42 (quin, J=7.2 Hz, 1H), 3.33 (dt, J=3.3, 1.5 Hz, 2H), 3.11-3.17 (m, 4H), 3.05-3.09 (m, 4H), 2.73-3.00 (m, 4H), 1.80-1.97 (m, 2H), 1.58-1.74 (m, 1H), 1.35-1.48 (m, 1H), 1.31 (d, J=7.3 Hz, 3H). Examples 13 and 14 were synthesized in an analogous manner using the designated Intermediate in Step 3.
Figure imgf000069_0001
Figure imgf000070_0001
Example 15 Isopropyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2-yl)amino)-1-oxopropan-2-yl)piperidine- 1 carboxylate
Figure imgf000071_0001
Step 1 To ethyl 2-(piperidin-4-yl)acetate hydrochloride (1.246 g, 6 mmol) suspended in EtOAc (15 mL) was added sodium carbonate solution (25 mL). After stirring until clear, the organic layer was isolated, dried over Na2SO4 and filtered. To the filtrate was added triethylamine (1.004 mL, 7.20 mmol), and the reaction was cooled in an ice bath. Over 25 minutes, isopropyl carbonochloridate (7.20 mL, 7.20 mmol) was added, and the mixture was stirred at rt. After 3 h, the reaction was quenched with water and washed with pH 4 phosphate buffer, sodium bicarbonate solution and brine. The organic layer was dried over Na2SO4 and concentrated to give crude isopropyl 4-(2-ethoxy-2-oxoethyl)piperidine-1- carboxylate (1.01 g, 3.92 mmol, recovery: 65 %), which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 4.91 (td, J=6.24, 12.47 Hz, 1H), 4.14 (q, J=7.25 Hz, 4H), 2.76 (t, J=12.35 Hz, 2H), 2.24 (d, J=7.09 Hz, 2H), 1.96 (td, J=3.67, 7.34 Hz, 1H), 1.71 (d, J=12.96 Hz, 2H), 1.21-1.33 (m, 9H), 1.17 (dd, J=3.79, 12.35 Hz, 2H). Step 2 To isopropyl 4-(2-ethoxy-2-oxoethyl)piperidine-1-carboxylate (1.00 g, 3.89 mmol) in THF (10 mL) at -78 °C was added LDA (2M, 2.332 mL, 4.66 mmol), dropwise. After 20 min, iodomethane (0.292 mL, 4.66 mmol) in THF (1 mL) was added dropwise, and the reaction was stirred for 20 min, allowed to warm to rt and stirred overnight. The reaction was quenched with NH4Cl(aq) solution and diluted with EtOAc. The organic layer was isolated, washed with NaHCO3(aq) and brine, dried over sodium sulfate, concentrated and purified over silica, eluting with 6% MeOH in DCM to provide isopropyl 4-(1-ethoxy-1- oxopropan-2-yl)piperidine-1-carboxylate (481 mg, 1.773 mmol, recovery: 46%) as a colorless oil. NMR (400 MHz, CDCl3) δ ppm 4.90 (td, J=6.24, 12.47 Hz, 1H), 4.07-4.18 (m, 3H), 2.70 (t, J=12.47 Hz, 2H), 2.27 (t, J=7.21 Hz, 1H), 1.63-1.77 (m, 2H), 1.58 (d, J=12.96 Hz, 1H), 1.18-1.32 (m, 11H), 1.13 (d, J=7.09 Hz, 4H). Step 3 To isopropyl 4-(1-ethoxy-1-oxopropan-2-yl)piperidine-1-carboxylate (0.20 g, 0.737 mmol) in EtOH (4 mL) was added NaOH(aq) (5N, 0.737 mL, 3.69 mmol). The reaction was heated to 60 °C 1 h, aged in a refrigerator overnight, concentrated, acidified to pH 1 and extracted with EtOAc (3X). The combined organics were dried over sodium sulfate and concentrated to give crude 2-(1-(isopropoxycarbonyl)piperidin-4-yl)propanoic acid (216 mg, 0.888 mmol, recovery: quantitative) as a colorless oil, which was used without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 4.92 (td, J=6.24, 12.47 Hz, 1H), 4.07- 4.29 (m, 2H), 2.72 (t, J=12.72 Hz, 2H), 2.33 (t, J=7.09 Hz, 1H), 1.61-1.83 (m, 3H), 1.21- 1.36 (m, 7H), 1.18 (d, J=7.09 Hz, 3H). Step 4 To 2-(1-(isopropoxycarbonyl)piperidin-4-yl)propanoic acid (104 mg, 0.428 mmol) and HATU (163 mg, 0.428 mmol) in DMF (1.2 mL) was added 5-(2,4- difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (68 mg, 0.306 mmol) and DIEA (0.075 mL, 0.428 mmol). The reaction was heated at 60 °C for 18 h, diluted with EtOAc, washed with pH 4 phosphate buffer and brine, dried over Na2SO4, concentrated and purified by silica gel chromatography (24 g cartridge), eluting with 55% EtOAc in heptanes to provide isopropyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2-yl)amino)-1- oxopropan-2-yl)piperidine-1-carboxylate (69.5 mg, 0.155 mmol, 50.7 % yield). LCMS (m/z) 448 (M+H)+, retention time: 1.13 min, LC/MS Method 5. 1H NMR (400 MHz, CDCl3) δ ppm 8.16-8.31 (m, 2H), 8.03 (d, J=2.93 Hz, 1H), 7.30 (dd, J=3.18, 9.29 Hz, 1H), 7.07 (dt, J=5.38, 9.05 Hz, 1H), 6.98 (ddd, J=2.93, 8.13, 10.70 Hz, 1H), 6.83-6.93 (m, 1H), 4.91 (td, J=6.24, 12.47 Hz, 1H), 4.03-4.32 (m, 2H), 2.71 (br. s., 2H), 2.09-2.23 (m, 1H), 1.70 (d, J=12.96 Hz, 1H), 1.19-1.37 (m, 12H), 1.15 (dd, J=4.16, 12.96 Hz, 1H). Example 16 N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(1-(2,2,2-trifluoroacetyl)piperidin-4- yl)propanamide
Figure imgf000073_0001
Step 1 Hexamethyldisilazide (1M in THF, 10.69 ml, 10.69 mmol) was added dropwise to MeI (0.668 ml, 10.69 mmol) and tert-butyl 4-(2-ethoxy-2-oxoethyl)piperidine-1-carboxylate (2.637 g, 9.72 mmol) in THF (15 ml) at -15 °C. The reaction was stirred overnight, and lithium diisopropylamide (2M in THF/heptane/ethylbenzene, 2.91 ml, 5.83 mmol) was added, followed by MeI (0.9 ml, 14.39 mmol) about 3 h later. The reaction was stirred overnight, then allowed to come to 24 °C. After stirring another night, the reaction was quenched with NH4Cl(aq), and the THF was evaporated off before extracting with EtOAc. The organic layer was adsorbed onto silica and purified via normal phase chromotography, eluting with 0-100% EtOAc in heptanes to give tert-butyl 4-(1-ethoxy-1-oxopropan-2- yl)piperidine-1-carboxylate (2027.3 mg, 5.26 mmol, 54.1 % yield). LCMS (m/z) 186 (M+H-BOC)+, retention time: 1.10 min, LC/MS Method 5. Step 2 A mixture of LiOH (1M, 25.9 ml, 25.9 mmol) and tert-butyl 4-(1-ethoxy-1-oxopropan-2- yl)piperidine-1-carboxylate (740 mg, 2.59 mmol) in dioxane (10 ml) was stirred overnight, quenched with NH4Cl and a small amount of 10% citric acid, and extracted with EtOAc. The organic layer was dried over NaHCO3 and concentrated to give crude 2-(1-(tert- butoxycarbonyl)piperidin-4-yl)propanoic acid (717.6 mg, 2.79 mmol, 108 % yield), which was used without purification. NMR (400 MHz, CDCl3) δ ppm 4.09-4.22 (m, 2H), 2.63- 2.79 (m, 2H), 2.29-2.40 (m, 1H), 1.60-1.84 (m, 3H), 1.48 (s, 9 H) 1.22-1.35 (m, 2H), 1.16- 1.22 (m, 3 H). Step 3 A solution of DIEA (0.295 ml, 1.688 mmol) and 5-(2,4-difluorophenoxy)pyridin-2-amine (Intermediate 17, Step 2) (250 mg, 1.125 mmol) in DMF (0.5 ml) was added to 2-(1-(tert- butoxycarbonyl)piperidin-4-yl)propanoic acid (434 mg, 1.688 mmol) and HATU (701 mg, 1.844 mmol) in DMF (0.5 ml), and the reaction was heated to 60°C. After 18 h, the mixture was diluted with EtOAc, washed with potassium phosphate pH 4 buffer and brine, adsorbed onto silica and purified via normal phase chromotography, eluting with 0-100% EtOAc in heptane. Both product and carbanate intermediate eluted together, and the fractions with both peaks were concentrated. The mixture was used as starting material for a repeat of the reaction with the same conditions to give tert-butyl 4-(1-((5-(2,4- difluorophenoxy)pyridin-2-yl)amino)-1-oxopropan-2-yl)piperidine-1-carboxylate (359.3 mg, 0.779 mmol, 69.2 % yield). LCMS (m/z) 462 (M+H)+, retention time: 1.19 min, LC/MS Method 5. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.46 (s, 1H), 8.13 (d, J=1.47 Hz, 1H), 8.12 (d, J=3.91 Hz, 1H), 7.43-7.56 (m, 2H), 7.24-7.35 (m, 1H), 7.09-7.15 (m, 1H), 3.86-4.01 (m, 2H), 2.60-2.76 (m, 2H), 2.40-2.48 (m, 1H), 1.68-1.81 (m, 1H), 1.57- 1.67 (m, 1H), 1.48-1.54 (m, 1H), 1.35-1.44 (m, 9 H) 1.09-1.24 (m, 1H), 1.04-1.09 (m, 3H), 0.92-1.04 (m, 1 H). Step 4 TFA (2 ml, 26.0 mmol) was added to tert-butyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2- yl)amino)-1-oxopropan-2-yl)piperidine-1-carboxylate (345 mg, 0.748 mmol) in CHCl3 (1.5 mL). After 20 minutes, the reaction was concentrated and partitioned between DCM and NaHCO3(aq). The DCM layer was concentrated to give crude N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(piperidin-4-yl)propanamide which was used without purification. LCMS (m/z) 362 (M+H)+, retention time: 0.67 min, LC/MS Method 5. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.51 (s, 1H), 8.25-8.04 (m, 2H), 7.64-7.46 (m, 2H), 7.30 (td, J=9.3, 5.4 Hz, 1H), 7.21-7.05 (m, 1H), 3.22-3.04 (m, 2H), 2.79-2.57 (m, 2H), 2.49-2.44 (m, 1H), 1.81 (br d, J=13.7 Hz, 1H), 1.75-1.52 (m, 2H), 1.32 (br dd, J=12.2, 3.4 Hz, 1H), 1.26-1.14 (m, 1H), 1.07 (d, J=6.8 Hz, 3H). Step 5 Trifluoroacetic anhydride (14.36 μl, 0.102 mmol) was added to DIEA (48.4 μl, 0.277 mmol) and N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(piperidin-4-yl)propanamide (33.4mg, 0.092 mmol) in CHCl3 (308 μl) at 0 °C. The reaction was allowed to come to 24 °C for 1 h, then cooled back to 0°C. More trifluoroacetic anhydride (20 μl, 0.142 mmol) was added, and the mixture was brought back 24 °C and stirred overnight. The reaction was purified via MDAP (XSELECT CSH C18 column), eluting with 50-99% AcCN in 10 mM ammonium bicarbonate in H2O (adjusted to pH 10 with ammonia) to give N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-(1-(2,2,2-trifluoroacetyl)piperidin-4-yl)propanamide (10 mg, 0.022 mmol, 23.66 % yield). LCMS (m/z) 458 (M+H)+, retention time: 1.18 min, LC/MS Method 3. 1H NMR (400 MHz, CD3OD) δ ppm 8.08-8.13 (m, 1H), 8.04-8.07 (m, 1H), 7.39 (dd, J=9.05, 3.18 Hz, 1H), 7.13-7.26 (m, 2H), 7.01 (dddd, J=9.29, 7.83, 2.93, 1.96 Hz, 1H), 4.43-4.58 (m, 1H), 3.98-4.12 (m, 1H), 3.17-3.31 (m, 1H), 2.86 (br d, J=12.72 Hz, 1H), 2.40 (br t, J=7.09 Hz, 1H), 1.79-2.05 (m, 3H), 1.25-1.45 (m, 2H), 1.20-1.25 (m, 3H). Example 17 (2S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(5-methyl-1,3,4-oxadiazol-2- yl)piperidin-1-yl)propanamide
Figure imgf000075_0001
To (R)-2-bromo-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)propanamide (Intermediate 1) (100 mg, 0.333 mmol) in DMA (1 mL) was added 2-methyl-5-(piperidin-3-yl)-1,3,4- oxadiazole hydrochloride (70 mg, 0.344 mmol) and triethylamine (0.10 mL, 0.717 mmol), followed by silver nitrate (57 mg, 0.336 mmol). The mixture was heated at 40°C for 4 h, poured into water and extracted twice with EtOAc. The combined organic layers were washed with brine, dried over Na2SO4, filtered, concentrated and purified over silica gel (12 g RediSep Gold), eluting with 0-10% MeOH in DCM. Product-containing fractions were collected and repurified over silica (12 g RediSep Gold), eluting with 0-50% EtOAc in heptane to provide (2S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(5-methyl- 1,3,4-oxadiazol-2-yl)piperidin-1-yl)propanamide (84 mg, 0.217 mmol, 65 % yield) as a yellow oil. LCMS (m/z) 387 (M+H)+, retention time: 0.51 min, LC/MS Method 5. 1H NMR (METHANOL-d4) δ ppm: 8.37 (dd, J=4.49.5 Hz, 1H), 7.21 (d, J=9.5 Hz, 1H), 4.27 (dd, J=2.0, 7.1 Hz, 2H), 3.44-3.55 (m, 1H), 3.08-3.17 (m, 1H), 2.78-2.85 (m,2H), 2.58-2.74 (m, 2H), 2.50 (d, J=9.3 Hz, 3H), 2.08-2.15 (m, 1H), 1.75-1.96 (m, 3H), 1.34 (dd, J=1.7, 7.1 Hz, 4H), 0.61-0.67 (m, 2H), 0.40 (s, 2H). Examples 18-20 were synthesized in an analogous manner, using the indicated commercially available amine.
Figure imgf000076_0001
Figure imgf000077_0001
Figure imgf000078_0001
Example 21a and 21b Ex.21a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3-hydroxy-3- (trifluoromethyl)pyrrolidin-1-yl)propanamide or Ex.21b: (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1- yl)propanamide
Figure imgf000079_0001
A mixture of 3-(trifluoromethyl)pyrrolidin-3-ol hydrochloride (450 mg, 2.36 mmol, 1.0 eq), TEA (1.9 g, 18.85 mmol, 8.0 eq), KI (377 mg, 2.36 mmol, 1.0 eq) and 2-bromo- N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (702 mg, 2.36 mmol, 1.0 eq) in THF (10 mL) was stirred for 12 h at 60 °C, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 2). The combined organic phases were washed with brine (100 mL), dried over Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:3) to give 450 mg product as light yellow oil. This material was chirally separated (column: CHIRALPAK IA, 2 x 25 cm, 5 µm, flow rate: 18 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 90:10) to provide three peaks with retention times of 14.635, 16.662 and 19.660 min. The first peak (14.365 min) was collected to give 65.0 mg (purity: 98.4%, yield: 7%) of (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1- yl)propanamide or (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3- (trifluoromethyl)pyrrolidin-1-yl)propanamide as a white solid. LCMS (m/z) 374 (M+H)+, retention time: 1.47 min, LC/MS Method 9. 1H NMR (METHANOL-d4) δ ppm: 8.01 (d, J=9.2 Hz, 1H), 7.98 (d, J=3.2 Hz, 1H), 7.40 (dd, J=9.2, 2.8 Hz, 1H), 3.87 (d, J=7.2 Hz, 2H), 3.30-3.21 (m, 1H), 3.13-2.95 (m, 2H), 2.85-2.73 (m, 2H), 2.33-2.25 (m, 1H), 2.01- 1.95 (m, 1H), 1.41 (d, J=6.8 Hz, 3H), 1.28-1.22 (m, 1H), 0.63-0.61 (m, 2H), 0.39-0.35 (m, 2H). Examples 22 and 23 were synthesized in an analogous manner using the designated Intermediate.
Figure imgf000080_0001
Figure imgf000081_0001
Example 24 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3- (trifluoromethyl)piperidin-1-yl)propanamide
Figure imgf000082_0001
A mixture of 3-(trifluoromethyl)piperidin-3-ol hydrochloride (200 mg, 1.18 mmol, 1.0 eq), TEA (590 mg, 5.90 mmol, 5.0 eq) and (R)-2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide (Intermediate 3) (351 mg, 1.18 mmol, 1.0 eq) in THF (10 mL) was stirred for 12 h at 40 °C, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 2). The combined organic phases were dried over Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:4) to give 200 mg pure product as light yellow oil. This material was chirally separated (column: CHIRALPAK IA, 2 x 25 cm, 5 µm, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH 70:30) to provide four peaks with retention times of 4.311, 5.142, 5.857 and 9.50 min. The third peak (5.857 min) was collected to give 40.0 mg (purity: 97.2%, yield: 9%) of (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3- (trifluoromethyl)piperidin-1-yl)propanamide as a white solid. LCMS (m/z) 388 (M+H)+, retention time: 1.69 min, LC/MS Method 9. 1H NMR (METHANOL-d4) δ ppm: 7.99-7.97 (m, 2H), 7.40 (dd, J=9.2, 2.8 Hz, 1H), 3.87 (d, J=6.4 Hz, 2H), 3.35-3.31 (m, 1H), 2.85-2.81 (m, 2H), 2.43-2.37 (m, 2H), 2.08-1.96 (m, 1H), 1.86-1.80 (m, 1H), 1.70-1.60 (m, 2H), 1.29 (d, J=6.8 Hz, 3H), 1.26-1.24 (m, 1H), 0.64-0.60 (m, 2H), 0.38-0.34 (m, 2H). Vibration circular dichroism (VCD): Inspection of VCD data in the analysis range indicated that the VCD difference spectrum obtained by subtracting the VCD spectrum of the two stereoisomers differing at the trifluoromethyl position when compared with the VCD difference spectrum of the calculated VCD of fs1ss minus that of fs2sr is a good match with experimentally determined values. Therefore the absolute configuration of the chiral center alpha to the trifluoromethyl group was confirmed to be (R). The confidence limit for this assignment was estimated to be 100% based on the current database that includes 88 previous correct assignments for different chiral structures. The IR spectrum of the sample was compared with the IR spectrum calculated for the various Models. Again, the model spectrum is in good qualitative agreement with experimental results, confirming the overall structure of this sample (i.e., its molecular connectivity) and providing additional support for satisfactory coverage of its solution phase conformational space by the computational analysis.
Examples 25-28 were synthesized in an analogous manner using the designated Intermediate.
Figure imgf000083_0001
Figure imgf000084_0001
Figure imgf000085_0002
Example 29
A-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(piperidin-l-yl)propanamide
Figure imgf000085_0001
A mixture of 2-bromo-A-(5-cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate
3) (100 mg, 0.34 mmol, 1.0 eq) in THF (5 mL) under nitrogen was treated with piperidine (200 uL, 2.0 mmol, 5.9 eq) and the reaction mixture was heated at 45 °C for 3 days. The mixture was concentrated under reduced pressure and diluted with EtOAc and water. The organic layer was separated, washed with brine, dried over sodium sulfate, filtered and concentrated. The resulting residue was purified by reverse phase HPLC (Column: Xselect CSH Prep OBD C18 Column 30* 150mm, 5mm; Mobile Phase A: water (10 mmol/L NH4HCO3 and 0.075% NH4OH), Mobile Phase B: MeCN; Flow rate: 40 mL/min; Gradient: 50% B to 99% B in 9 min; Rt: 9.54 min) to give 82 mg (purity: 100%, 79% yield) of N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(piperidin-1-yl)propanamide. LCMS (ES, m/z): 304 [M+H]+, retention time: 1.19 min, LC/MS Method 3. 1H NMR: (400 MHz, DMSO-d6) δ 9.90 (s, 1H), 8.12-7.92 (m, 2H), 7.51-7.36 (m, 1H), 3.86 (d, J=7.3 Hz, 2H), 3.45-3.24 (m, 1H), 2.56-2.40 (m, 4H), 1.66-1.35 (m, 5H), 1.28-1.17 (m, 1H), 1.15 (d, J=7.3 Hz, 2H), 0.76-0.48 (m, 2H), 0.41-0.19 (m, 2H). Example 30 was synthesized in an analogous manner using the designated Intermediate
Figure imgf000086_0001
Figure imgf000087_0002
Example 31 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide
Figure imgf000087_0001
To 4,4-difluoropiperidine hydrochloride (173 mg, 1.1 mmol, 1.1 eq) in THF (10 mL) were added 2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (298 mg, 1.0 mmol, 1.0 eq) and TEA (606 mg, 6.0 mmol, 6.0 eq). The reaction was stirred for 15 h at 60 oC, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over Na2SO4 and concentrated. The product was purified by reverse phase column (XBridge Prep C18 OBD), eluting with 42-60% AcCN in water (10 mm/L NH4HCO3) to give 220 mg of product. This material was chirally separated (column: CHIRALPAK IG, 2 x 25 cm, 5 µm, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: IPA, A:B 80:20) to provide two peaks with retention times of 10.683 and 13.142 min. The second peak (13.142 min) was collected to give 30 mg (purity: 99.4%, yield: 9%) of (S)-N- (5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide as a light yellow oil. LCMS: (ES, m/s) 340 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ 8.07 (d, J=9.0 Hz, 1H), 7.97 (d, J=3.0 Hz, 1H), 7.41 (dd, J=9.0, 3.0 Hz, 1H), 3.87 (d, J=6.9 Hz, 2H), 3.45-3.40 (m, 1H), 2.78-2.64 (m, 4H), 2.15-2.02 (m, 4H), 1.30 (d, J=6.9 Hz, 3H), 1.27-1.21 (m, 1H), 0.65-0.59 (m, 2H), 0.38-0.33 (m, 2H). Examples 32-33 was synthesized in an analogous manner using the designated Intermediate.
Figure imgf000088_0001
Figure imgf000089_0002
Example 34 (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1- yl)propanamide
Figure imgf000089_0001
Step 1 To tert-butyl 4,4-difluoro-3-hydroxypiperidine-1-carboxylate (source: Shanghai AQBioPharma Co. Ltd ) (200 mg, 0.84 mmol, 1.0 eq) in DCM (6 mL) was added TFA (2 mL). After 1 h, the reaction was concentrated to give 116 mg of crude 4,4- difluoropiperidin-3-ol as light yellow oil, which was used without purification. LCMS: (ES, m/s) 138 [M+H]+. 1H NMR (400 MHz, CD3OD) δ ppm: 4.10-4.06 (m, 1H), 3.45- 3.37 (m, 2H), 3.35-3.30 (m, 1H), 3.24-3.16 (m, 1H), 2.65-2.45 (m, 1H), 2.25-2.15 (m, 1H). Step 2 To 4,4-difluoropiperidin-3-ol (as free base) (116 mg, 0.84 mmol, 1.0 eq) and (R)-2-bromo- N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (252 mg, 0.84 mmol, 1.0 eq) in THF (10 mL) was added TEA (0.68 g, 6.75 mmol, 8.0 eq). After 20 h, the reaction was quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 2). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (1:3) to give 130 mg product as light yellow oil. This material was chirally separated (column: CHIRALPAK IG, 2 x 25 cm, 5 µm, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 1:1) to provide four peaks with retention times of 3.818, 4.793, 8.356 and 10.830 min. The third peak (8.356 min) was collected to give 34 mg (purity: 98.6%, yield: 11%) of rel-(2S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoro-3- hydroxypiperidin-1-yl)propanamide as light yellow oil. LCMS (ES, m/s): 356 [M+H]+. 1H NMR (400 MHz, CD3OD) δ ppm: 8.03-7.97 (m, 2H), 7.40 (dd, J = 9.0, 3.0 Hz, 1H), 3.89-3.82 (m, 3H), 3.46-3.38 (m, 1H), 2.81-2.63 (m, 4H), 2.32-2.21 (m, 1H), 2.08-1.97 (m, 1H), 1.30-1.20 (m, 4H), 0.65-0.59 (m, 2H), 0.38-0.33 (m, 2H). Examples 35-39 were synthesized in an analogous manner using the designated Intermediate in Step 2.
Figure imgf000090_0001
Figure imgf000091_0001
Figure imgf000092_0001
Figure imgf000093_0002
Example 40a and 40b Ex.40a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-(trifluoromethyl)piperidin- 1-yl)propanamide or Ex.40b: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3- (trifluoromethyl)piperidin-1-yl)propanamide
Figure imgf000093_0001
To (R)-2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (100 mg, 0.34 mmol, 1.0 eq) in THF (10 mL) was added 3- (trifluoromethyl)piperidine (62 mg, 0.40 mmol, 1.2 eq) and TEA (136 mg, 1.34 mmol, 4.0 eq), and the mixture was stirred at 60 oC for 2 days. The reaction was filtered, concentrated and purified by Prep-TLC (ethyl acetate : petroleum ether = 1 : 8) to give 120 mg product as light yellow oil. This material was chirally separated (column: Chiral Pak AD - H, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide two peaks with retention times of 16.220 and 21.447 min. The first peak (16.220 min) was collected and further chirally separated (column: CHIRALPAK IA, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 6.060 and 7.216 min. The second peak (7.216 min) was collected to give 30 mg (purity: 98.2%, yield: 20%) of (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2- ((R)-3-(trifluoromethyl)piperidin-1-yl)propanamide or (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3-(trifluoromethyl)piperidin-1-yl)propanamide as a white solid. LCMS (m/z) 372 (M+H)+, retention time: 0.782 min, LC/MS Method 4. 1H NMR (METHANOL-d4) δ ppm: 8.07 (d, J=8.8 Hz, 1H), 7.97 (d, J=2.8 Hz, 1H), 7.41 (dd, J=9.2, 3.2 Hz, 1H), 3.88 (d, J=7.2 Hz, 2H), 3.40-3.35 (m, 1H), 2.98-2.86 (m, 2H), 2.60-2.54 (m, 1H), 2.43-2.37 (m, 1H), 2.25-2.19 (m, 1H), 2.00-1.96 (m, 1H), 1.86-1.73 (m, 2H), 1.40 -1.33 (m, 1H), 1.29 (d, J=7.2 Hz, 3H), 1.27-1.21 (m, 1H), 0.65-0.60 (m, 2H), 0.38-0.34 (m, 2H). Example 41 was synthesized in an analogous manner using the designated Intermediate:
Figure imgf000094_0001
Figure imgf000095_0002
Example 42
(5)-A-(5-chloropyridin-2-yl)-2-(4-fluoropiperidin-l-yl)propanamide
Figure imgf000095_0001
A mixture of 2-bromo-A-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (100 mg, 0.38 mmol, 1.0 eq), 4-fluoropiperidine hydrochloride (107 mg, 0.77 mmol, 2.0 eq) and TEA (771 mg, 7.63 mmol, 20.0 eq) in THF (8 mL) was stirred for 16 h at 60 °C, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The organic phases were washed with brine (100 mL), dried over sodium sulfate, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (3:7) to give 60 mg product as a white solid. This material was chirally separated (column: CHIRALPAK IG, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: IP A, A:B 9: 1) to provide two peaks with retention times of 10.304 and 12.781 min. The second peak (12.781 min) was collected to give(5)-A-(5-chloropyridin-2-yl)-2-(4- fluoropiperidin-l-yl)propanamide (10.9 mg, yield: 18.2%, purity: 99.5%, ee%: 99.8%) as white solid. LCMS (m/z) 286 (M+H)+, retention time: 1.652 min, LC/MS Method 9. 'H NMR (CDCL) 5 ppm: 9.77 (s, 1H), 8.24-8.22 (m, 2H), 7.65 (dd, J=2.4, 9.2 Hz 1H), 4.80- 4.68 (m, 1H), 3.29-3.26 (m, 1H), 2.82-2.80 (m, 1H), 2.70-2.66 (m, 1H), 2.54-2.47 (m, 2H), 2.01-1.59 (m, 4H), 1.31 (d, J=7.2 Hz, 3H). Example 43a and 43b Ex.43a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-fluoropiperidin-1-yl)propanamide or Ex. 43b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-fluoropiperidin-1-yl)propanamide
Figure imgf000096_0001
A mixture of 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (150 mg, 0.57 mmol, 1.0 eq), 3-fluoropiperidine hydrochloride (160 mg, 1.15 mmol, 2.0 eq) and TEA (1.20 g, 11.88 mmol, 20.0 eq) in THF (10 mL) was stirred for 16 h at 60 oC, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The organic phases were washed with brine (100 mL), dried over sodium sulfate, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (3:7) to give 85 mg product as white solid. This material was chirally separated (column: CHIRALPAK IF, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: IPA, A:B 9:1) to provide four peaks with retention times of 12.241, 13.567, 15.426 and 19.242 min. The second peak (13.567 min) was collected to give (S)- N-(5-chloropyridin-2-yl)-2-((S)-3-fluoropiperidin-1-yl)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((R)-3-fluoropiperidin-1-yl)propanamide (15.3 mg, yield: 18.2%, purity: 99.8%, ee%: 97.3%) as white solid. LCMS (m/z) 286 (M+H)+, retention time: 1.691 min, LC/MS Method 9. 1H NMR (CDCl3) δ ppm: 9.73 (s, 1H), 8.25-8.21 (m, 2H), 7.65 (dd, J=2.4, 8.8 Hz, 1H), 4.79-4.66 (m, 1H), 3.30-3.28 (m, 1H), 2.86-2.81 (m, 1H), 2.58-2.52 (m, 3H), 1.95-1.88 (m, 2H), 1.76-1.65 (m, 2H), 1.32 (d, J=6.8 Hz, 3H). Example 44 was synthesized in an analogous manner using the designated Intermediate
Figure imgf000097_0001
Example 45a and 45b Ex.45a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(trifluoromethyl)piperidin-1- yl)propanamide or Ex.45b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-4,4-difluoro-3- (trifluoromethyl)piperidin-1-yl)propanamide
Figure imgf000098_0001
Step 1 A mixture of 1-benzylpiperidin-4-one (10.0 g, 52.8 mmol, 1.0 eq), TEA (8.84 mL, 63.4 mmol, 1.2 eq), chlorotriethylsilane (9.56 g, 63.4 mmol, 1.2 eq) and sodium iodide (9.50 g, 63.4 mmol, 1.2 eq) in acetonitrile (80 mL) was stirred for 12 h at 25 oC, poured into H2O (200 mL) and extracted with ethyl acetate (200 mL x 2). The organic layers were combined, washed with brine (400 mL x 2), dried over Na2SO4, filtered, concentrated and purified via a silica gel column, eluting with ethyl acetate : petroleum ether (0:100 to 25: 75 over 25 min) to give 15.0 g (purity: 95%, yield: 89%) 1-benzyl-4-((triethylsilyl)oxy)- 1,2,3,6-tetrahydropyridine as a yellow oil. LCMS (m/z) 304 (M+H)+, retention time 0.956 minutes, LCMS Method 22. 1H NMR (CD3OD) δ ppm: 7.37-7.25 (m, 5H), 4.81-4.79 (m, 1H), 3.59 (s, 2H), 2.99-2.97 (m, 2H), 2.65-2.62 (m, 2H), 2.19-2.15 (m, 2H), 1.03-0.98 (m, 9H), 0.73-0.67 (m, 6H). Step 2 To a sealed tube containing trifluoromethyl iodide (6.45 g, 32.9 mmol, 10.0 eq) at -90 oC was added 1-benzyl-4-((triethylsilyl)oxy)-1,2,3,6-tetrahydropyridine (1.0 g, 3.29 mmol, 1.0 eq), acetonitrile (15.0 mL), Ru(bpy)3Cl2.6H2O (0.12 g, 0.16 mmol, 0.05 eq), sodium bicarbonate (0.55 g, 6.58 mmol, 2.0 eq) and H2O (0.09 mL, 4.94 mmol, 1.5 eq). The sealed tube was closed, and the mixture was stirred for 40 h at 25 oC while exposed to a 40 W fluorescent lamp under N2 atmosphere. The reaction was filtered, concentrated and purified over a silica gel column to give 144 mg (purity: 90%, yield: 19%) of 1-benzyl-3- (trifluoromethyl)piperidin-4-one as a light yellow oil. LCMS (ES, m/s): 258 [M+H]+, retention time 1.192 minutes, LCMS Method 26.
Figure imgf000099_0001
NMR (400 MHz, CDCl3) δ ppm: 7.41-7.30 (m, 5H), 3.75-3.65 (m, 2H), 3.41-3.30 (m, 2H), 3.12-3.07 (m, 1H), 2.68-2.46 (m, 4H). Step 3 To 1-benzyl-3-(trifluoromethyl)piperidin-4-one (2.2 g, 8.55 mmol, 1.0 eq) in DCM (30 mL) at 0 oC was added DAST (2.26 mL, 17.10 mmol, 2.0 eq). The mixture was stirred for 13 h at room temperature, poured into H2O (50 mL) and extracted with DCM (50 mL x 2). The combined organic phases were dried over Na2SO4, filtered, concentrated and purified by Prep-TLC with ethyl acetate :hexane (1:6) to give 410 mg (purity: 50%, yield: 9%) of 1- benzyl-4,4-difluoro-3-(trifluoromethyl)piperidine as light yellow oil. LCMS (ES, m/s): 280 [M+H]+, 0.635 minutes, LCMS Method 27. 1H NMR (CDCl3) δ ppm: 7.39-7.31 (m, 5H), 3.69-3.57 (m, 2H), 3.05-3.03 (m, 1H), 2.89-2.71 (m, 2H), 2.57-2.37 (m, 2H), 2.22- 1.95 (m, 2H). Step 4 A mixture of 1-benzyl-4,4-difluoro-3-(trifluoromethyl)piperidine (400 mg, 1.43 mmol, 1.0 eq), and Pd/C (152 mg, 10%) in MeOH (15.0 mL) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen. The reaction was stirred 1 h at room temperature under an atmosphere of hydrogen (balloon) and filtered. HCl (0.5 mL, 12.0 mol/L in H2O) was added to the filtrate. The resulting solution was stirred for 0.5 h at room temperature and concentrated to give 300 mg (purity: 60%, yield: 56%) of 4,4-difluoro-3- (trifluoromethyl)piperidine hydrochloride as a red oil, which was used without purification. LCMS (ES, m/s): 190 [M+H]+, retention time 0.736 minutes, LCMS Method 22. 1H NMR: (400 MHz, DMSO-d6) δ 5.50-5.10 (m, 1H), 4.00-3.92 (m, 1H), 3.75-3.65 (m, 1H), 3.55-3.45 (m, 1H), 3.30-3.00 (m, 2H), 2.44-2.35 (m, 2H). Step 5 A mixture of (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (374 mg, 1.42 mmol, 1.2 eq), 4,4-difluoro-3-(trifluoromethyl)piperidine HCl salt (268 mg, 1.20 mmol, 1.0 eq), TEA (1.98 mL, 14.19 mmol, 10.0 eq) and silver(I) nitrate (241 mg, 1.42 mmol, 1.0 eq) in DMA (4.0 mL) was stirred for 12 h at 40 oC, poured into H2O (20 mL) and extracted with ethyl acetate (20 mL x 3). The organic layers were combined, washed with brine (60 mL x 3), dried over Na2SO4, concentrated and purified over a silica gel column, eluting with 0-10% ethyl acetate in petroleum ether to give 120 mg product as a yellow oil. This material was chirally separated (column: CHIRALPAK IA, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 4:1) to provide four peaks with retention times of 6.750, 7.920, 9.935 and 14.668 min. The first peak (6.750 min) was collected to give 20 mg (purity: 97.1%, yield: 4%) (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(trifluoromethyl)piperidin-1- yl)propanamide or (S)-N-(5-chloropyridin-2-yl)-2-((R)-4,4-difluoro-3- (trifluoromethyl)piperidin-1-yl)propanamide as a yellow oil. LCMS (ES, m/s): 372 [M+H]+ retention time: 1.841 min, LC/MS Method 9. 1H NMR (CD3OD) δ ppm: 8.29 (d, J=2.4 Hz, 1H), 8.19 (d, J=8.8 Hz, 1H), 7.81 (dd, J=8.8, 2.4 Hz, 1H), 3.58-3.52 (m, 1H), 3.29-3.16 (m, 1H), 3.07-3.03 (m, 1H), 2.94-2.91 (m, 1H), 2.77-2.67 (m, 2H), 2.25-2.14 (m, 2H), 1.32 (d, J=7.2 Hz, 3H). Example 46a and 46b Ex.46a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methoxy-3-(trifluoromethyl)piperidin-1- yl)propanamide or Ex.46b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-methoxy-3- (trifluoromethyl)piperidin-1-yl)propanamide
Figure imgf000100_0001
A mixture of 3-methoxy-3-(trifluoromethyl)piperidine hydrochloride (200 mg, 0.91 mmol, 1.0 eq), (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (238 mg, 0.91 mmol, 1.0 eq) and triethylamine (460 mg, 4.55 mmol, 5.0 eq) in tetrahydrofuran (5 mL) was stirred for 12 h at 40 oC, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 2). The combined organic phases were dried over anhydrous sodium sulfate, concentrated and purified by Prep-HPLC (Column: XSelect CSH Prep C18 OBD), eluting with 35-45% AcCN in water (0.1% FA) to give 120 mg pure product as a yellow oil. This material was chirally separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: IPA, A:B 9:1) to provide four peaks with retention times of 4.301, 9.409, 13.575 and 15.758 min. The first peak (4.301 min) was collected and further separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 11.125 and 13.034 min. The first peak (11.125 min) was collected to give 19.0 mg (purity: 99%, yield: 6%) of (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methoxy-3-(trifluoromethyl)piperidin-1- yl)propanamide or (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-methoxy-3- (trifluoromethyl)piperidin-1-yl)propanamide as a white solid. LCMS (ES, m/s): 366 [M+H]+ retention time: 1.943 min, LC/MS Method 9. 1H NMR (300 MHz, CD3OD) δ ppm: 8.29 (d, J=2.4 Hz, 1H), 8.17 (d, J=9.2 Hz, 1H), 7.80-7.77 (m, 1H), 3.52-3.46 (m, 4H), 2.88-2.83 (m, 2H), 2.59-2.52 (m, 1H), 2.46 (d, J=12.0 Hz, 1H), 2.16-2.12 (m, 1H), 1.96- 1.87 (m, 1H), 1.73-1.69 (m, 1H), 1.62-1.58 (m, 1H), 1.30 (d, J=7.2 Hz, 3H). Example 47 (S)-N-(5-chloropyridin-2-yl)-2-(3,3-difluoropiperidin-1-yl)propanamide
Figure imgf000101_0001
A mixture of 3,3-difluoropiperidine hydrochloride (181 mg, 1.15 mmol, 2.0 eq), 2-bromo- N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (150 mg, 0.57 mmol, 1.0 eq) and triethylamine (1.20 g, 11.88 mmol, 20.0 eq) in tetrahydrofuran (8 mL) was stirred for 48 h at 60 oC, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over sodium sulfate, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum (1:4) to give 45 mg pure product as a white solid. This material was chirally separated (column: CHIRALPAK IG, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 10.33 and 12.637 min. The second peak (12.637 min) was collected to give (S)-N-(5-chloropyridin-2-yl)-2-(3,3- difluoropiperidin-1-yl)propanamide (12.1 mg, yield: 27%, purity: 99.6%, ee%: 99.7%) as a white solid. LCMS (ES, m/s): 304 [M+H]+ retention time: 1.724 min, LC/MS Method 9. 1H NMR (400 MHz, CDCl3) δ ppm: 9.69 (s, 1H), 8.26-8.20 (m, 2H), 7.67-7.64 (m, 1H), 3.42-3.37 (m, 1H), 2.86-2.69 (m, 2H), 2.66-2.61 (m, 2H), 2.02-1.83 (m, 4H), 1.32 (d, J=7.2 Hz, 3H). Examples 48-49 was synthesized in an analogous manner using the designated Intermediate:
Figure imgf000102_0001
101
Figure imgf000103_0001
Example 50a and 50b Ex.50a: (S)-2-((S)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.50b: (S)-2-((R)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
Figure imgf000104_0001
Step 1 To methyl 3,3,3-trifluoro-2-oxopropanoate (10 g, 64 mmol, 1eq) in DCM (100 mL) was added NH2Boc (7.5 g, 64 mmol, 1eq). After 72 h, the mixture was concentrated to give methyl 2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-hydroxypropanoate as a yellow solid, which was used without purification. LCMS (ES, m/s): 274 [M+H]+ .
Figure imgf000104_0002
(400 MHz, DMSO-d6) δ ppm 8.62 (s, 1H), 6.13 (s, 1H), 3.73 (s, 3H), 1.36 (s, 9H). Step 2 To methyl 2-((tert-butoxycarbonyl)amino)-3,3,3-trifluoro-2-hydroxypropanoate (11.4 g, 42 mmol, 1 eq) in diethyl ether (50 mL) was added trifluoroacetic anhydride (8.7 g, 42 mmol, 1 eq). After cooling to 0 oC for 1.5 h, pyridine (6.6 g, 84 mmol, 2 eq) was added slowly. After 2 h at 0 oC, the reaction was filtered and concentrated to give 9 g (purity: 70%, yield: 84 %) of methyl (Z)-2-((tert-butoxycarbonyl)imino)-3,3,3-trifluoropropanoate as a yellow oil, which was used without purification. LCMS (ES, m/s): 256 [M+H]+ . 1H NMR: (300 MHz, DMSO-d6) δ ppm 3.93 (s, 3H), 1.51 (s, 9H). Step 3 To prop-2-yn-1-amine (10 g, 0.18 mol, 1 eq) and triethylamine (54 g, 0.54 mol, 3 eq) in DCM (200 mL) at 0 oC was added chlorotrimethylsilane (39 g, 0.36 mol, 2 eq), dropwise. The mixture was stirred 16 h at room temperature, quenched with water (300 mL) and extracted with ethyl acetate (200 mL x 3). The organic layers were combined, washed with brine (200 mL), dried over sodium sulfate and concentrated to give 15 g crude 1,1,1- trimethyl-N-(prop-2-yn-1-yl)-N-(trimethylsilyl)silanamine as a brown oil, which was used without purification. LCMS (ES, m/s): 200 [M+H]+ . 1H NMR (300 MHz, DMSO-d6) δ ppm 3.48 (s, 2H), 3.01 (s, 1H), 0.11 (s, 18H). Step 4 To 1,1,1-trimethyl-N-(prop-2-yn-1-yl)-N-(trimethylsilyl)silanamine (8.3 g, 42 mmol, 1.2 eq) in THF (100 mL) at -78 oC was added n-BuLi (17 mL, 42 mmol, 2.5 M in hexane, 1.2 eq), dropwise. After 10 min, a solution of methyl (Z)-2-((tert-butoxycarbonyl)imino)- 3,3,3-trifluoropropanoate (9 g, 35 mmol, 1 eq) in THF (10 mL) was added dropwise. The resulting mixture was stirred 3 h at room temperature, quenched with saturated ammonium chloride aqueous solution (500 mL) and extracted with ethyl acetate (200 mL x 3). The organic layers were combined, washed with brine, concentrated and purified over silica gel, eluting with methanol : dichloromethane (1:10) to give 5 g (purity: 90%, yield: 46 %) methyl 5-amino-2-((tert-butoxycarbonyl)amino)-2-(trifluoromethyl)pent-3-ynoate as a yellow solid. LCMS (ES, m/s): 311 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 8.63 (s, 1H), 3.73 (s, 3H), 3.34 (s, 2H), 1.75 (s, 2H), 1.37 (s, 9H). Step 5 A mixture of 5-amino-2-((tert-butoxycarbonyl)amino)-2-(trifluoromethyl)pent-3-ynoate (5 g, 16.1 mmol, 1 eq) and Pd/C (2 g, wet 10%) in methanol (20 mL) was stirred at room temperature for 4 h under an H2 atmosphere (2 atm), filtered and concentrated to give 4 g (purity: 90%, yield: 89 %) of tert-butyl (2-oxo-3-(trifluoromethyl)piperidin-3-yl)carbamate as yellow solid, which was used without purification. LCMS (ES, m/s): 283 [M+H]+. 1H NMR: (300 MHz, DMSO-d6) δ ppm 8.01 (s, 1H), 7.37 (s, 1H), 3.26 -3.04 (m, 2H), 2.34- 2.24 (m, 1H), 2.17-2.08 (m, 1H), 1.79-1.73 (m, 2H), 1.36 (s, 9H). Step 6 tert-Butyl (2-oxo-3-(trifluoromethyl)piperidin-3-yl)carbamate (1.5 g, 5.3 mmol, 1 eq) in borane (40 mL, 1M in THF) was stirred at room temperature for 48 h, quenched with methanol (20 mL) at 0 oC and concentrated to give 1.5 g crude 3- (trifluoromethyl)piperidin-3-amine as a yellow oil, which was used without purification. LCMS (ES, m/s): 169 [M+H]+. 1H NMR: (300 MHz, DMSO-d6) δ ppm 4.09 (s, 2H), 3.36-3.34 (m, 2H), 2.96-2.89 (m, 1H), 2.84-2.76 (m, 2H), 2.29-2.24 (m, 1H), 1.88-1.71 (m, 1H), 1.57-1.52 (m, 1H), 1.45 -1.36 (m, 1H). Step 7 A mixture of 3-(trifluoromethyl)piperidin-3-amine (1.7 g, 10.1 mmol, 13 eq), (R)-2-bromo- N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (200 mg, 0.76 mmol, 1 eq) and triethylamine (230 mg, 2.3 mmol, 3 eq) in THF (5 mL) was stirred at 40 oC for 48 h, diluted with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The organic layers were combined, washed with brine, dried over Na2SO4, concentrated and purified over silica gel column, eluting with ethyl acetate : petroleum (1:1) to give 100 mg of a yellow oil. This material was chirally separated (column: CHIRAL ART Cellulose-SBS, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 7.825 and 9.158 min. The first peak (7.825 min) was collected to give 8 mg (yield: 16 %) of (S)-2- ((S)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide or (S)-2-((R)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide as a white solid. LCMS (m/z) 351 (M+H)+, retention time: 1.153 min, LC/MS Method 8. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.48 (s, 1H), 8.37 (d, J=2.4 Hz, 1H), 8.13 (d, J=8.8 Hz, 1H), 7.92 (dd, J=8.8, 2.4 Hz, 1H), 3.51-3.46 (m, 1H), 2.79 (d, J=11.2 Hz, 1H), 2.56 (d, J=11.2 Hz, 1H), 2.30-2.27(m, 2H), 1.88-1.80 (m, 1H), 1.56-1.50 (m, 3H), 1.16 (d, J=6.8 Hz, 3H). Example 51a and 51b Ex.51a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methylpiperidin-1-yl)propanamide or Ex. 51b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-methylpiperidin-1-yl)propanamide
Figure imgf000107_0001
A mixture of (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (100 mg, 0.38 mmol, 1.0 eq) and 3-methylpiperidine (189 mg, 1.91 mmol, 5.0 eq) in toluene (5 mL) was stirred at room temperature for 48 hours, concentrated and purified by preparative TLC (ethyl acetate : petroleum ether = 1:4) to give the racemic product (60 mg) as white solid. This material was chirally separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 6.745 and 8.605 min. The first peak (6.745 min) was collected to give 11.2 mg (yield: 10.4%, purity: 99%, ee%: 99%) (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methylpiperidin-1-yl)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((R)-3-methylpiperidin-1-yl)propanamide as a white solid. LCMS (ES, m/s): 282 [M+H]+ retention time: 2.021 min, LC/MS Method 9. 1H NMR (300 MHz, CDCl3) δ ppm: 9.91 (s, 1H), 8.23 (dd, J= 2.7, 5.7 Hz, 2H), 7.70-7.64 (m, 1H), 3.25-3.22 (m, 1H), 2.76-2.71 (m, 2H), 2.64-2.61 (m, 1H), 1.82 – 1.67 (m, 5H), 1.28 (d, J= 7.2 Hz, 3H), 0.88 (d, J= 6.3 Hz, 4H). Example 52a and 52b Ex.52a: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3,3-difluoro-4-hydroxypyrrolidin-1- yl)propanamide or Ex.52b: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3,3-difluoro-4- hydroxypyrrolidin-1-yl)propanamide
Figure imgf000108_0001
A mixture of 4,4-difluoropyrrolidin-3-ol (165.5 mg, 1.345 mmol, 1.0 eq), (A)-2-bromo-A- (5-chloropyridin-2-yl)propanamide (Intermediate 5) (356.5 mg, 1.345 mmol, 1.0 eq) and TEA (1.3 g, 13.45 mmol, 10.0 eq) in THF (5 mL) was stirred at 40 °C for 15 h, quenched with H2O (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified over a silica gel column, eluting with 0-30% ethyl acetate in petroleum ether to give product as a yellow oil. This material was chirally separated (column: CHIRALPAK IA, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9: 1) to provide two peaks with retention times of 6.843 and 8.147 min. The first peak (6.484 min) was collected to give 44 mg (yield: 11%) of (5)-A-(5-chloropyridin-2-yl)-2-((5)-3,3-difluoro-4- hydroxypyrrolidin-l-yl)propanamide or (5)-A-(5-chloropyridin-2-yl)-2-((A)-3,3-difluoro-4- hydroxypyrrolidin-l-yl)propanamide as a white solid. LCMS (ES, m/s): 306 [M+H]+ retention time: 2.570 min, LC/MS Method 12. XH NMR (400 MHz, CD3OD) 5 ppm: 8.29- 8.28 (m, 1H), 8.15 (d, J=8.8 Hz, 1H), 7.81-7.79 (m, 1H), 4.24-4.17 (m, 1H), 3.35-3.31 (m, 1H), 3.24-3.17 (m, 2H), 3.15-3.02 (m, 1H), 2.69-2.64 (m, 1H), 1.35 (d, J=6.8 Hz, 3H).
Example 53a and 53b
Ex. 53a: (5)-A-(5-chloropyridin-2-yl)-2-((A)-3-(oxazol-2-yl)piperidin-l-yl)propanamide or
Ex. 53b: (5)-7V-(5-chloropyridin-2-yl)-2-((5)-3-(oxazol-2-yl)piperidin-l-yl)propanamide
Figure imgf000109_0001
Step 1
To l-((benzyloxy)carbonyl)piperidine-3-carboxylic acid (5.00 g, 19.01 mmol, 1.0 eq), EDCI (5.45 g, 28.52 mmol, 1.5 eq) and HOBT (3.85 g, 28.52 mmol, 1.5 eq) in dichloromethane (100 mL) was added 2,2-dimethoxyethan-l -amine (2.40 g, 22.81 mmol, 1.2 eq) and TEA (5.76 g, 57.03 mmol, 3.0 eq). The reaction mixture was stirred at room temperature for 16 h, diluted with di chloromethane (200 mL), washed with water (200 mL x 2) and brine (400 mL), dried over sodium sulfate and concentrated to give benzyl 3 -((2,2- dimethoxyethyl)carbamoyl)piperidine-l-carboxylate (6.5 g, yield: 83%, purity: 85% ) as a yellow oil, which was used without further purification. LCMS: (ES, m/s) 351 [M+H]+.
'H NMR: (300 MHz, CD3OD) 5 ppm 7.37-7.31 (m, 5H), 5.12 (s, 2H), 4.41-4.38 (m, 1H), 4.16-4.05 (m, 2H), 3.36 (s, 6H), 3.29-3.27 (m, 2H), 3.02-2.89 (m, 2H), 2.39-2.37 (m, 1H), 2.02-1.90 (m, 1H), 1.75-1.71 (m, 2H), 1.59-1.55 (m, 1H). Step 2
To benzyl 3-((2,2-dimethoxyethyl)carbamoyl)piperidine-l-carboxylate (3.00 g, 8.57 mmol, 1.0 eq) in acetone (25 mL) was added HC1 (3N, 20 mL), dropwise. After 19 h, the reaction was concentrated, diluted with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The organic phases were washed with saturated aqueous NaHCO3 (300 mL x 2) and brine (300 mL x 2), dried over sodium sulfate, concentrated and loaded onto a silica gel column (100 - 200 mesh, 80 g), eluting with 0-100% ethyl acetate in petroleum ether to give benzyl 3-((2-oxoethyl)carbamoyl)piperidine-1-carboxylate (800 mg, yield: 31%, purity: 98%) as a yellow oil. LCMS (ES, m/s): 305 [M+H]+ . 1H NMR: (300 MHz, CD3OD) δ ppm 7.38-7.32 (m, 5H), 5.14 (s, 2H), 4.17-4.05 (m, 2H), 3.26-3.22 (m, 2H), 3.08-2.92 (m, 2H), 2.40-2.35 (m, 1H), 1.93-1.91 (m, 1H), 1.75-1.67 (m, 2H), 1.53-1.50 (m, 1H). Step 3 To benzyl 3-((2-oxoethyl)carbamoyl)piperidine-1-carboxylate (700 mg, 2.30 mmol, 1.0 eq) in dichloromethane (50 mL) was added Cl3CCCl3 (1032 mg, 4.59 mmol, 2.0 eq), PPh3 (1207 mg, 4.59 mmol, 2.0 eq) and TEA (4651 mg, 4.59 mmol, 2.0 eq). The reaction was stirred for 36 hours, diluted with dichloromethane (100 mL), washed with water (100 mL x 2) and brine (100 mL x 2), dried over sodium sulfate, concentrated and purified by preparative TLC with ethyl acetate : petroleum ether (1:1) to give benzyl 3-(oxazol-2- yl)piperidine-1-carboxylate (150 mg, yield, 23 %, purity: 95%) as yellow oil. LCMS (ES, m/s): 287 [M+H]+ . 1H NMR: (300 MHz, CD3OD) δ ppm 7.58-7.56 (m, 1H), 7.39-7.33 (m, 5H), 7.06-7.04 (m, 1H), 5.21-5.15 (m, 2H), 4.38-4.32 (m, 1H), 4.12-4.08 (m, 1H), 3.20- 2.94 (m, 3H), 2.25-2.21 (m, 1H), 1.91-1.75 (m, 2H), 1.32-1.28 (m, 1H). Step 4 A mixture of benzyl 3-(oxazol-2-yl)piperidine-1-carboxylate (140 mg, 0.49 mmol, 1.00 eq) and Pd/C (10%, 70 mg) in methanol (10 mL) was stirred under hydrogen for 2 h, filtered and concentrated to give 2-(piperidin-3-yl)oxazole (70 mg, yield: 75%, purity: 80%) as a yellow oil, which was used without purification. LCMS (ES, m/s): 153 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ ppm 7.86-7.84 (m, 1H), 7.11-7.10 (m, 1H), 3.01-2.99 (m, 2H), 2.87-2.79 (m, 1H), 2.69-2.60 (m, 1H), 2.19-2.13 (m, 1H), 1.85-1.58 (m, 3H), 1.35- 1.31 (m, 1H). Step 5 To 2-(piperidin-3-yl)oxazole (70 mg, 0.5 mmol, 1.0 eq) and (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (121 mg, 0.5 mmol, 1.0 eq) in THF (10 mL) was added TEA (233 mg, 2.5 mmol, 5.0 eq). The reaction was stirred at 40 °C for 48 h, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic extracts were washed with brine (200 mL), dried over sodium sulfate, concentrated and purified by preparative TLC with ethyl acetate : petroleum ether (1:3) to give 58 mg of product. This material was chirally separated (column: CHIRALPAK IG, 5X25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 1:1) to provide two peaks with retention times of 7.313 and 7.966 min. The first peak (7.313 min) was collected to give (S)-N-(5-chloropyridin-2-yl)- 2-((R)-3-(oxazol-2-yl)piperidin-1-yl)propanamide or (S)-N-(5-chloropyridin-2-yl)-2-((S)-3- (oxazol-2-yl)piperidin-1-yl)propanamide (6.6 mg, yield: 4%, purity: 99%, ee%: 100%) as a white solid. LCMS (m/z) 335 (M+H)+, retention time: 0.848 min, LC/MS Method 24. 1H NMR (400 MHz, CD3OD) δ ppm 8.27 (dd, J=0.6, 2.7 Hz, 1H), 8.17 (dd, J=0.6, 9.0 Hz, 1H), 7.81-7.77 (m, 2H), 7.09-7.08 (m, 1H), 3.43-3.36 (m, 1H), 3.25-3.16 (m, 1H), 3.07- 3.02 (m, 1H), 2.80-2.75 (m, 1H), 2.65-2.51 (m, 2H), 2.09-2.03 (m, 1H), 1.87-1.65 (m, 3H), 1.30 (d, J=7.2 Hz, 3H). Example 54a and 54b Ex.54a: (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-(oxazol-4-yl)piperidin-1-yl)propanamide or Ex.54b: (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-(oxazol-4-yl)piperidin-1-yl)propanamide
Figure imgf000112_0001
Step 1 To 1-(piperidin-3-yl)ethan-1-one hydrochloride salt (1.00 g, 6.25 mmol, 1.0 eq) and TEA (3.10 g, 30.69 mmol, 5.0 eq) in DCM (50 mL) at 0 oC was added benzyl carbonochloridate (1.25 g, 7.50 mmol, 1.2 eq), dropwise. The resulting solution was stirred at room temperature for 16 h, poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic phases were dried with Na2SO4, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum (3:7) to give benzyl 3- acetylpiperidine-1-carboxylate (1.1 g, yield: 68 %, purity: 100%) as colorless oil. LCMS: (ES, m/s) 262 [M+H]+. 1H NMR: (300 MHz, DMSO-d6) δ ppm 7.40-7.28 (m, 5H), 5.07 (s, 2H), 3.98-3.75 (m, 2H), 3.05-2.90 (m, 2H), 2.55-2.49 (m, 1H), 2.11 (s, 3H), 1.97- 1.93(m, 1H), 1.66-1.61 (m, 1H), 1.47-1.40 (m, 2H). Step 2 To benzyl 3-acetylpiperidine-1-carboxylate (1.00 g, 3.83 mmol, 1.00 eq) in MeOH (100 mL) at -5 oC was added Br2 (636 mg, 4.02 mmol, 1.05 eq), dropwise. The reaction was stirred at room temperature for 16 h, poured into water (200 mL) and concentrated to remove MeOH. The aqueous was extracted with ethyl acetate (200 mL x 3). The combined organic extracts were washed with brine (500 mL x 2), dried over sodium sulfate, concentrated and purified via preparative TLC with ethyl acetate : petroleum ether (1:7) to give benzyl 3-(2-bromoacetyl)piperidine-1-carboxylate (650 mg, yield: 50 %, purity: 90%) as light yellow oil. LCMS (ES, m/s): 340 [M+H]+ . 1H NMR: (400 MHz, CDCl3) δ ppm 7.43-7.32 (m, 5H), 5.19 (s, 2H), 4.19-3.98 (m, 4H), 3.05-2.96 (m, 2H), 2.06- 2.02 (m, 1H), 1.79-1.53 (m, 4H). Step 3 A mixture of benzyl 3-(2-bromoacetyl)piperidine-1-carboxylate (500 mg, 1.47 mmol, 1.00 eq) and formamide (5 mL) was stirred at 90 oC for 1 h. Formic acid (1.5 mL) was added, and after 3 h the mixture was poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3). The organic phases were washed with brine (200 mL x 2), dried over sodium sulfate, concentrated and purified by C18 (120 g) column chromatography, eluting with 30-80% AcCN in water (0.1%, FA) to give benzyl 3-(oxazol-4-yl)piperidine-1-carboxylate (180 mg, yield: 43 %, purity: 100%) as yellow oil. LCMS (ES, m/s): 287 [M+H]+ . 1H NMR: (400 MHz, CDCl3-d) δ ppm 7.85 (s, 1H), 7.47 (s, 1H), 7.39-7.32 (m, 5H), 5.32-5.13 (m, 2H), 4.51-4.02 (m, 2H), 3.13-3.00 (m, 2H), 2.81-2.78 (m, 1H), 2.11-2.07 (m, 2H), 1.75-1.60 (m, 2H). Step 4 A mixture of benzyl 3-(oxazol-4-yl)piperidine-1-carboxylate (180 mg, 0.67 mmol, 1.00 eq) and Pd/C (10%, 100 mg) in MeOH (15 mL) was stirred for 3 h under an atmosphere of hydrogen, filtered and concentrated to give 4-(piperidin-3-yl)oxazole (90 mg, yield: 90 %, purity: 95%) as yellow oil, which was used without purification. LCMS (ES, m/s): 153 [M+H]+. 1H NMR: (400 MHz, CDCl3) δ ppm 7.83 (s, 1H), 7.43 (s, 1H), 3.34-3.30 (m, 1H), 3.10-3.06 (m, 1H), 2.77-2.63 (m, 5H), 2.10-2.08 (m, 1H), 1.77-1.75 (m, 1H). Step 5 A mixture of 4-(piperidin-3-yl)oxazole (90 mg, 0.59 mmol, 1.0 eq), (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (155 mg, 0.59 mmol, 1.0 eq) and TEA (598 mg, 5.88 mmol, 10.0 eq) in THF (8 mL) was stirred for 18 h at 40 oC, quenched with water (80 mL) and extracted with ethyl acetate (80 mL x 3). The organic phases were washed with brine (100 mL), dried over sodium sulfate, concentrated and purified via preparative TLC with ethyl acetate : petroleum ether (1:1) to give 120 mg product as a colorless oil. This material was chirally separated (column: CHIRALPAK IF, 2X25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 85:15) to provide two peaks with retention times of 11.281 and 16.295 min. The first peak (11.281 min) was collected to give (S)-N-(5-chloropyridin-2-yl)-2-((R)-3- (oxazol-4-yl)piperidin-1-yl)propanamide or (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-(oxazol- 4-yl)piperidin-1-yl)propanamide (25 mg, yield: 13 %, purity: 98%, ee%: 100%) as colorless oil. LCMS (m/z) 335 (M+H)+, retention time: 1.584 min, LC/MS Method 7. 1H NMR (400 MHz, CDCl3) δ ppm 9.88 (s, 1H), 8.24-8.24 (m, 2H), 7.81 (s, 1H), 7.64 (dd, J=2.6, 4.4 Hz, 1H), 7.44 (s, 1H), 3.32-3.27 (m, 1H), 3.01-2.92 (m, 2H), 2.81-2.78 (m, 1H), 2.53-2.46 (m, 1H), 2.35-2.30 (m, 1H), 2.06-2.02 (m, 1H), 1.87-1.73 (m, 2H), 1.55-1.50 (m, 1H), 1.31 (d, J=7.2 Hz, 3H). Example 55a and 55b Ex.55a: (S)-2-((R)-3-(1,2,4-oxadiazol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.55b: (S)-2-((S)-3-(1,2,4-oxadiazol-3-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
Figure imgf000114_0001
A mixture of the HCl salt of 3-(piperidin-3-yl)-1,2,4-oxadiazole (200 mg, 1.05 mmol, 1.0 eq), (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Interemediate 5) (277 mg, 1.05 mmol, 1.0 eq) and TEA (1069 mg, 10.58 mmol, 10.0 eq) was stirred for 18 h at 40 oC, quenched with water (80 mL) and extracted with ethyl acetate (80 mL x 3). The organic phases were washed with brine (100 mL), dried over sodium sulfate, concentrated and purified via preparative TLC with ethyl acetate : petroleum ether (1:1) to give 200 mg of a colorless oil. This material was chirally separated (column: CHIRALPAK IF, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 10.966 and 13.873 min. The second peak (13.873 min) was collected to give (S)-2-((R)-3-(1,2,4-oxadiazol-3- yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide or (S)-2-((S)-3-(1,2,4-oxadiazol-3- yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (30 mg, yield: 8 %, purity: 95%, ee%: 100%) as colorless oil. LCMS (ES, m/s): 336 [M+H]+ retention time: 1.591 min, LC/MS Method 7. 1H NMR (400 MHz, CDCl3) δ ppm: 9.87 (s, 1H), 8.65 (s, 1H), 8.25- 8.24 (m, 1H), 8.22 (s, 1H), 7.65 (dd, J=2.8, 8.8 Hz, 1H), 3.41-3.28 (m, 2H), 3.05-3.03 (m, 1H), 2.86-2.72 (m, 2H), 2.46-2.43 (m, 1H), 2.09-2.08 (m, 1H), 1.97-1.91 (m, 1H), 1.79- 1.71 (m, 2H), 1.32 (d, J=6.8 Hz, 3H). Example 56 (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5- yl)piperidin-1-yl)propanamide
Figure imgf000115_0001
Step 1 A mixture of 1-benzyl 3-methyl 4-oxopiperidine-1,3-dicarboxylate (20.0 g, 68.73 mmol, 1.0 eq) and TsOH (2 g, 11.6 mmol, 0.2 eq) and ethane-1,2-diol (22.0 g, 354.83 mmol, 5.0 eq) in toluene (500 mL) was heated to reflux under a Dean-Stark apparatus. After 26 h, the reaction was cooled to room temperature, quenched with water (500 mL) and extracted with ethyl acetate (500 mL x 3). The combined organic phases were washed with brine (500 mL), dried with Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:3) to give 16.0 g (purity: 70%, yield: 69%) of 8-benzyl 6- methyl 1,4-dioxa-8-azaspiro[4.5]decane-6,8-dicarboxylate as a light yellow oil. LCMS: (ES, m/s) 336 [M+H]+. NMR not reported. Step 2 To 8-benzyl 6-methyl 1,4-dioxa-8-azaspiro[4.5]decane-6,8-dicarboxylate (16.0 g, 47.80 mmol, 1.0 eq) in MeOH (300 mL) and H2O (150 mL) at 25 °C was added NaOH (5.73 g, 143.3 mmol, 3.0 eq). After 16 h, the organic solvent was removed under vacuum, and the reaction was diluted with water (100 mL). The pH was adjusted to 3 with 1 M HCl, and the mixture was extracted with ethyl acetate (300 mL x 2). The combined organic phases were dried over Na2SO4 and concentrated to give 13.5 g (purity: 70%, yield: 88%) of 8- ((benzyloxy)carbonyl)-1,4-dioxa-8-azaspiro[4.5]decane-6-carboxylic acid as yellow oil, which was used without purification. LCMS (ES, m/s): 322 [M+H]+ . Step 3 To 8-((benzyloxy)carbonyl)-1,4-dioxa-8-azaspiro[4.5]decane-6-carboxylic acid (13.50 g, 42.10 mmol, 1.0 eq) in DMF (100 mL) at 25 oC was added HATU (19.19 g, 50.50 mmol, 1.2 eq) and DIEA (16.40 g, 127.2 mmol, 3.0 eq). After 30 min, NH4Cl (4.46 g, 84.20 mmol, 2.0 eq) was added. The mixture was stirred at room temperature for 3 h, quenched with water (300 mL) and extracted with ethyl acetate (300 mL x 3). The combined organic phases were washed with brine (500 mL x 3), dried over Na2SO4, concentrated and purified over silica gel, eluting with methanol : dichloromethane (1:10) to give 13.2 g (purity: 60%, yield: 95%) of benzyl 6-carbamoyl-1,4-dioxa-8-azaspiro[4.5]decane-8- carboxylate as a light yellow oil. LCMS (ES, m/s): 321 [M+H]+ . Step 4 A mixture of benzyl 6-carbamoyl-1,4-dioxa-8-azaspiro[4.5]decane-8-carboxylate (13.20 g, 41.30 mmol, 1.0 eq) in DMF-DMA (250 mL) was stirred at 110 oC for 3 h, concentrated under vacuum, then dissolved in AcOH (200 mL). N2H4·H2O (80 %, 15 mL) was added, and the reaction was stirred at 90 oC. After 15 h, the mixture was concentrated, dissolved in ethyl acetate (300 mL), washed with NaHCO3 (300 mL, sat., aq.), dried over Na2SO4, concentrated and purified over silica gel, eluting with methanol : dichloromethane (1:20) to give 12.0 g (purity: 60%, yield: 85%) benzyl 6-(1H-1,2,4-triazol-3-yl)-1,4-dioxa-8- azaspiro[4.5]decane-8-carboxylate as a yellow oil. LCMS (ES, m/s): 345 [M+H]+. NMR not reported. Step 5 To benzyl 6-(1H-1,2,4-triazol-3-yl)-1,4-dioxa-8-azaspiro[4.5]decane-8-carboxylate (10.0 g, 29.10 mmol, 1.0 eq) in DMF (100 mL) at 0 oC was added NaH (1.75 g, 43.70 mmol, 1.5 eq, 60%), in portions. After 30 min, benzyl chloride (5.44 g, 34.9 mmol, 1.2 eq) was added dropwise, and the resulting mixture was stirred at 25 oC. After 15 h, the reaction was quenched with ice water (300 mL) and exacted with ethyl acetate (300 mL x 2). The combined organic phases were washed with brine (500 mL x 3), dried with Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 11.2 g (purity: 40%, yield: 83%) of benzyl 6-(1-(4-methoxybenzyl)-1H-1,2,4- triazol-3-yl)-1,4-dioxa-8-azaspiro[4.5]decane-8-carboxylate as a yellow oil. LCMS (ES, m/s): 465 [M+H]+. NMR not reported. Step 6 To benzyl 6-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)-1,4-dioxa-8- azaspiro[4.5]decane-8-carboxylate (9.0 g, 19.44 mmol, 1.0 eq) in acetone (150 mL) and H2O (75 mL) was added TsOH (16.65 g, 92.2 mmol, 5.0 eq), and the mixture was stirred at 95 °C. After 15 h, the reaction was concentrated, diluted with ethyl acetate (200 mL), washed with NaHCO3 (150 mL, sat., aq.) and saturated brine (200 mL), dried over Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 5.3 g (purity: 86%, yield: 65%) of benzyl 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol- 3-yl)-4-oxopiperidine-1-carboxylate as a yellow oil. LCMS (ES, m/s): 421 [M+H]+. NMR not reported. Step 7 To benzyl 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)-4-oxopiperidine-1-carboxylate (5.80 g, 13.81 mmol, 1.0 eq) in DCM (100 mL) at 0 oC was added DAST (8.89 g, 55.24 mmol, 4.0 eq) in DCM (150 mL), dropwise. The reaction was stirred at room temperature overnight, quenched with ice water (150 mL) and exacted with DCM (150 mL x 2). The combined organic phases were washed with brine (300 mL), dried over Na2SO4, concentrated and purified over silica gel, eluting with methanol : dichloromethane (1:20) to give 4.3 g (purity: 50%, yield: 70%) of benzyl 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H- 1,2,4-triazol-3-yl)piperidine-1-carboxylate as yellow oil. LCMS PH-CSX-51481-002-192- 7 (ES, m/s): 443 [M+H]+. NMR not reported. Step 8 A mixture of benzyl 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)piperidine- 1-carboxylate (3.3 g, 7.46 mmol) and palladium hydroxide on carbon (5.24 g, 7.46 mmol) in methanol (60 mL) was stirred under hydrogen at 25°C for 2 h, filtered, concentrated and purified over C18 silica (120 g column), eluting with 5-95% AcCN in water (10 mM NH4HCO3) to afford 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)piperidine (1.7 g, 2.51 mmol, 33.7 % yield) as a colorless oil. LCMS (m/z) 309 (M+H)+, retention time: 0.567 min, LC/MS Method 27. 1H NMR (400 MHz, CDCl3) δ ppm 7.91 (s, 1H), 7.14-7.23 (m, 2H), 6.91-6.94 (m, 2H), 5.26 (s, 2H), 3.83 (s, 3H), 3.45-3.49 (m, 1H), 3.34- 3.43 (m, 2H), 3.24-3.33 (m, 2H), 2.18-2.22 (m, 1H), 1.95-1.99 (m, 1H). Step 9 To 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-3-yl)piperidine (1.7 g, 5.51 mmol) in DCM (2 mL) was added TFA (2 mL). The reaction was stirred at 40°C overnight and concentrated to give 4,4-difluoro-3-(1H-1,2,4-triazol-3-yl)piperidine (900 mg, 3.20 mmol, 58.1 % yield) as a yellow oil, which was used without purification. LCMS (m/z) 189 (M+H)+, retention time: 0.245 min, LC/MS Method 28. Step 10 To 4,4-difluoro-3-(1H-1,2,4-triazol-3-yl)piperidine (300 mg, 1.594 mmol) in THF (5 mL), was added (R)-2-bromo-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)propanamide (Intermediate 1) (479 mg, 1.594 mmol) and TEA (0.222 mL, 1.594 mmol). The reaction was stirred at 40 °C for 13 h, diluted with water (25 mL) and extracted with EtOAc (3 X 25 mL). The combined organics were washed with brine (25 mL), dried over sodium sulfate, concentrated and purified by reverse-phase HPLC (XBridge Shield RP18 OBD Column), eluting with 20-25% AcCN in water (10 mM NH4HCO3 + 0.1%NH3.H2O) to give 110 mg of a white solid. This material was chirally separated (column: CHIRALPAK IF-3, 4.6X50 mm, 3um, flow rate: 1 mL/min, solvent: MTBE [0.1%DEA]: EtOH 90:10) to provide two peaks with retention times of 7.38 and 10.03 min. The first peak (7.38 min) was collected to give (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-4,4-difluoro-3- (1H-1,2,4-triazol-5-yl)piperidin-1-yl)propanamide (30 mg, 0.073 mmol, 4.60 % yield) as a white solid. LCMS (m/z) 408 (M+H)+, retention time: 1.308 min, LC/MS Method 9. 1H NMR (400 MHz, CD3OD) δ ppm 13.94 (s, 1H), 10.99 (s, 1H), 8.46 (s, 1H), 8.24 (d, J=9.6Hz, 1H), 7.26 (d, J=9.6Hz, 1H), 4.17-4.26 (m, 2H), 3.66 (d, J=6.8Hz, 2H), 3.03 (s, 1H), 2.91-2.96 (m, 2H), 2.67-2.72 (m, 1H), 2.07-2.22 (m, 2H), 1.27-1.30 (m, 4H), 0.55- 0.58 (m, 2H), 0.35-0.38 (m, 2H). Examples 57-60 were synthesized in an analogous manner using the designated Intermediate in Step 10.
Figure imgf000119_0001
Figure imgf000120_0001
Figure imgf000121_0001
Figure imgf000122_0002
Example 61
(5)-A-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((, )-4,4-difluoro-3-(lH-pyrazol-5- yl)piperidin- 1 -yl)propanamide
Figure imgf000122_0001
Step 1
To 3-bromo-lH-pyrazole (25.00 g, 170.24 mmol, 1.0 eq) in DMF (100 mL) at 0 °C was added sodium hydride (8.22 g, 205.50 mmol, 1.2 eq, 60%). After 30 min, PMBC1 (32.05 g, 205.45 mmol 1.2 eq) was added, and the mixture was stirred at room temperature. After 6 h, the reaction was quenched with water (500 mL) and extracted with ethyl acetate (800 mL x 2). The organic phases were washed with brine (500 mL), dried over anhydrous sodium sulfate, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum (1 :9) to give 42 g (yield: 92%, purity: 94%) of 3-bromo-l-(4-methoxybenzyl)- IH-pyrazole as a yellow oil. LCMS: (ES, m/s) 267 [M+H]+. NMR not reported. Step 2 To potassium tert-butoxide (2.70 g, 28.09 mmol, 2.5 eq) in THF (20 mL) was added tri- tert-butylphosphane (2.26 g, 1.12 mmol, 0.1 eq, 10 wt% in hexanes) and palladium (II) acetate (252 mg, 1.12 mmol, 0.1 eq). After 10 min, tert-butyl 4-oxopiperidine-1- carboxylate (3.35 g, 16.85 mmol, 1.5 eq) and 3-bromo-1-(4-methoxybenzyl)-1H-pyrazole (3.00 g, 11.23 mmol, 1.0 eq) were added. The reaction was stirred at 35 °C for 12 hours, quenched with water (500 mL) and extracted with ethyl acetate (500 mL x 3). The combined organic extracts were dried over sodium sulfate, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:10) to give 50 g (crude) of tert- butyl 3-(1-(4-methoxybenzyl)-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate as a yellow oil. LCMS (ES, m/s): 386 [M+H]+ . NMR not reported. Step 3 To tert-butyl 3-(1-(4-methoxybenzyl)-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate (50.00 g, 129.87 mmol, 1.0 eq) in dichloromethane (400 mL) at 0 °C was added DAST (41.82 g, 259.74 mmol, 2.0 eq), dropwise, and the mixture was stirred at room temperature for 10 h. The reaction was quenched with water (500 mL) and extracted with dichloromethane (500 mL x 3). The combined extracts were dried over magnesium sulfate, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum (1:3) to give 1.5 g (yield: 33 % (two steps), purity: 61%) tert-butyl 4,4-difluoro-3-(1-(4- methoxybenzyl)-1H-pyrazol-3-yl)piperidine-1-carboxylate as a light yellow oil. LCMS (ES, m/s): 408 [M+H]+ . NMR not reported. Step 4 A solution of tert-butyl 4,4-difluoro-3-(1-(4-methoxybenzyl)-1H-pyrazol-3-yl)piperidine- 1-carboxylate (450 mg, 1.11 mmol, 1.0 eq) in trifluoroacetic acid (10 mL) was stirred at 100 °C for 10 h. The solvent was removed to give 450 mg crude 4,4-difluoro-3-(1H- pyrazol-5-yl)piperidine TFA salt, as a yellow oil which was used without purification. LCMS (ES, m/s): 187 [M+H]+. Step 5 To 4,4-difluoro-3-(1H-pyrazol-3-yl)piperidine (free base) (450 mg, 2.41 mmol, 1.0 eq) in THF (10 mL) was added triethylamine (729 mg, 7.22 mmol, 3.0 eq), potassium iodide (399 mg, 2.41 mmol, 1.0 eq) and 2-bromo-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (1.08 g, 3.61 mmol, 1.5 eq). The mixture was stirred at 60 °C for 10 h, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic extracts were dried over sodium sulfate, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum (1:3) to give 80 mg of a white solid. This material was chirally separated (column: CHIRALPAK ID-3, 2 x 25 cm, 5 µm, flow rate: 20 mL/min; Mobile phase A: hex: DCM = 5:1, Mobile phase B: IPA, A:B 85:15) to provide three peaks with retention times of 9.901, 12.146 and 18.417 min. The third peak (18.417 min) was collected to give 10 mg (yield: 12.5%, purity: 99.2%, ee%: 99.4%) of (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide as an off white solid. LCMS (m/z) 406 (M+H)+, retention time: 1.538 min, LC/MS Method 9. 1H NMR (400 MHz, DMSO-d6) δ ppm 12.79 (br, 1H), 10.28 (br, 1H), 8.07-8.00 (m, 2H), 7.72-7.63 (m, 1H), 7.51-7.40 (m, 1H), 6.24-6.18 (m, 1H), 3.86 (d, J=7.2 Hz, 2H), 3.61-3.58 (m, 1H), 3.42-3.45 (m, 1H), 2.97-2.95 (m, 2H), 2.68-2.66 (m, 2H), 2.17-2.00 (m, 2H), 1.23-1.19 (m, 4H), 0.58-0.55 (m, 2H), 0.34-0.31 (m, 2H). Examples 62-64 were synthesized in an analogous manner using the designated Intermediate in Step 5
Figure imgf000124_0001
Figure imgf000125_0001
Figure imgf000126_0002
Example 65 (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide
Figure imgf000126_0001
Step 1 To 1-(piperidin-3-yl)ethenone hydrochloride (2.0 g, 12.22 mmol) in THF (50 mL) at 0 °C was added DIPEA (5.34 mL, 30.6 mmol), followed by benzyl carbonochloridate (1.919 mL, 13.44 mmol), dropwise. The mixture was stirred at 0 °C for 1 hour, warmed to RT overnight, diluted with water and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column, EtOAc in hexanes 0-50%) to afford benzyl 3-acetylpiperidine-1-carboxylate (2.31 g, 8.84 mmol, 72.3 % yield) as a colorless oil. LCMS: (ES, m/s) 262 [M+H]+. 1H NMR (400 MHz, DMSO- d6) δ ppm: 7.21-7.45 (m, 5H), 4.95-5.16 (m, 2H), 3.95 (br d, J=12.0 Hz, 1H), 3.78 (br d, J=13.0 Hz, 1H), 2.79-3.14 (m, 2H), 2.51-2.59 (m, 1H), 2.11 (s, 3H), 1.89-1.99 (m, 1H), 1.58-1.69 (m, 1H), 1.31-1.52 (m, 2H) Step 2 To benzyl 3-acetylpiperidine-1-carboxylate (2.3 g, 8.80 mmol) in DMF (20 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (3.15 g, 26.4 mmol). The mixture was heated at 130 °C for 6 hours and concentrated. The residue was dissolved in ethanol (20.00 mL), and con. HCl (0.5 mL, 5.92 mmol) was added dropwise. After 10 min, hydrazine monohydrate (9.2 mL, 188 mmol) was added, and the resulting mixture was refluxed overnight, concentrated, diluted with water and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 60 mL/min, MeOH in DCM, 0-10%) to afford benzyl 3-(1H-pyrazol-5- yl)piperidine-1-carboxylate (1.95 g, 6.83 mmol, 78 % yield) as a colorless oil. For chiral separation, 6 g material was purified via Chiral SFC purification (Column: Chiralpak AY, 20x250mm, 5u; Co-Solvent:: 25% MeOH; Total flowrate: 50 g/min). The fractions of peak 1 were collected and concentrated to afford 3.06 g of benzyl (S)-3-(1H-pyrazol-5- yl)piperidine-1-carboxylate. The absolute configuration was assigned based on VCD analysis. LCMS (ES, m/s): 286 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.24- 7.67 (m, 6H), 6.09 (br s, 1H), 5.03-5.13 (m, 2H), 4.03-4.20 (m, 1H), 3.96 (br d, J=13.2 Hz, 1H), 2.64-3.04 (m, 3H), 1.95-2.06 (m, 1H), 1.37-1.75 (m, 3H). Step 3 To benzyl (S)-3-(1H-pyrazol-5-yl)piperidine-1-carboxylate (1.95 g, 6.83 mmol) in ethanol (20 mL) under N2 was added Pd/C, 10% (0.073 g, 0.683 mmol), and the mixture was hydrogenated under an H2 balloon overnight, filtered through Celite and concentrated to afford (S)-3-(1H-pyrazol-5-yl)piperidine (1.03 g, 6.81 mmol, 100 % yield) as a colorless oil, which was used without purification. LCMS (ES, m/s): 152 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.42 (br s, 1H), 6.01 (d, J=1.7 Hz, 1H), 3.05 (br d, J=10.8 Hz, 1H), 2.88 (br d, J=12.2 Hz, 1H), 2.67 (tt, J=10.8, 3.9 Hz, 1H), 2.38-2.48 (m, 2H), 1.89-2.02 (m, 1H), 1.55-1.65 (m, 1H), 1.36-1.53 (m, 2H). Step 4 To (S)-3-(1H-pyrazol-5-yl)piperidine (91 mg, 0.602 mmol) and (R)-2-bromo-N-(5- (cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (180 mg, 0.602 mmol) in DMSO (4.0 mL) was added triethylamine (0.335 mL, 2.407 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column, EtOAc in DCM, 40-90%) to afford (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)propanamide (193 mg, 0.496 mmol, 82 % yield) as an off white solid. LCMS (ES, m/s): 370 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.28-12.70 (m, 1H), 9.92-10.02 (m, 1H), 7.94-8.10 (m, 2H), 7.42 (dd, J=9.0, 3.2 Hz, 2H), 6.05 (d, J=1.5 Hz, 1H), 3.85 (d, J=7.1 Hz, 2H), 3.44 (q, J=6.8 Hz, 1H), 2.75-2.96 (m, 3H), 2.35 (td, J=11.2, 2.4 Hz, 1H), 2.17-2.28 (m, 1H), 1.88-1.97 (m, 1H), 1.68-1.78 (m, 1H), 1.52-1.67 (m, 1H), 1.31-1.46 (m, 1H), 1.11-1.26 (m, 4H), 0.51-0.62 (m, 2H), 0.25-0.38 (m, 2H). Examples 66-75 were synthesized in an analogous manner using the designated Intermediate in Step 4.
Figure imgf000128_0001
Figure imgf000129_0001
Figure imgf000130_0001
Figure imgf000131_0001
Figure imgf000132_0001
Figure imgf000133_0001
Figure imgf000134_0001
Figure imgf000135_0001
Figure imgf000136_0001
Figure imgf000137_0002
Example 76 (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(propylamino)pyridin-2-yl)propanamide
Figure imgf000137_0001
Step 1 To 3-(1H-pyrazol-5-yl)piperidine (Example 65, Step 3 racemate) (95 mg, 0.626 mmol) and tert-butyl (R)-(6-(2-bromopropanamido)pyridin-3-yl)(propyl)carbamate (Intermediate 14) (220 mg, 0.570 mmol) in DMSO (4.0 mL) was added triethylamine (0.318 mL, 2.278 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in DCM 30-80%) to afford tert-butyl (6-((2S)-2-(3-(1H- pyrazol-5-yl)piperidin-1-yl)propanamido)pyridin-3-yl)(propyl)carbamate (220 mg, 0.482 mmol, 85 % yield) as an off white solid. LCMS: (ES, m/s) 458 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.38-12.63 (m, 1H), 10.16-10.26 (m, 1H), 8.20 (dd, J=5.5, 2.5 Hz, 1H), 8.10 (d, J=9.0 Hz, 1H), 7.65-7.73 (m, 1H), 7.26-7.63 (m, 1H), 6.01-6.12 (m, 1H), 3.44-3.58 (m, 3H), 2.70-3.06 (m, 3H), 2.31-2.44 (m, 1H), 2.14-2.29 (m, 1H), 1.89-1.97 (m, 1H), 1.67-1.78 (m, 1H), 1.53-1.66 (m, 1H), 1.39-1.49 (m, 3H), 1.36 (br s, 9H), 1.18 (d, J=6.5 Hz, 3H), 0.82 (td, J=7.4, 2.0 Hz, 3H). Step 2 A mixture of tert-butyl (6-((2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamido)pyridin-3-yl)(propyl)carbamate (220 mg, 0.482 mmol) and TFA (4.0 mL, 51.9 mmol) was stirred for 1 hour, concentrated and made basic with sat. NaHCO3. The mixture was extracted with EtOAc (3X), washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in DCM 60-90%) to afford (2S)-2-(3-(1H-pyrazol-5- yl)piperidin-1-yl)-N-(5-(propylamino)pyridin-2-yl)propanamide (118 mg, 0.314 mmol, 65.3 % yield) as an off white solid. LCMS (ES, m/s): 357 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.38-12.64 (m, 1H), 9.70 (d, J=6.0 Hz, 1H), 7.83 (d, J=9.0 Hz, 1H), 7.67 (dd, J=4.8, 2.8 Hz, 1H), 7.26-7.62 (m, 1H), 6.95-7.03 (m, 1H), 6.06 (br s, 1H), 5.63 (td, J=5.6, 1.9 Hz, 1H), 3.36-3.43 (m, 1H), 2.68-3.04 (m, 5H), 2.29-2.42 (m, 1H), 2.10-2.27 (m, 1H), 1.93 (br d, J=11.8 Hz, 1H), 1.67-1.77 (m, 1H), 1.49-1.63 (m, 3H), 1.30-1.44 (m, 1H), 1.15 (d, J=6.8 Hz, 3H), 0.93 (td, J=7.4, 1.3 Hz, 3H). Example 77 (S)-N-(5-chloropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((3R,5R)-3-methyl-5-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (1:1 mix)
Figure imgf000139_0001
Step 1 To 1H-pyrazole-3-boronic acid (1.27 g, 11.11 mmol) and 3-bromo-5-methylpyridine (1.50 g, 8.55 mmol) in dioxane (68 mL) were added 1M aqueous cesium fluoride (3.93 g, 25.64 mmol), Pd2dba3 (577 mg, 0.60 mmol), and S-Phos (537 mg, 1.28 mmol) under argon. The mixture was stirred in a pressure proof vessel for 16-20 hours at 100 °C, concentrated and purified by column chromatography, eluting with 0-5 % MeOH in CHCl3, to yield 3- methyl-5-(1H-pyrazol-5-yl)pyridine (757 mg, 56 %). LCMS: (ES, m/s) 160 [M+H]+. NMR not reported. Step 2 3-Methyl-5-(1H-pyrazol-5-yl)pyridine (240 mg, 1.51 mmol) was dissolved in MeOH (76 mL) and TFA (0.23 mL), and the mixture was hydrogenated using an H-Cube (70 mm CatCart of 5 % Rh/Al2O3, 100 °C, 50 bar, 0.5 mL/min). The collected material was concentrated, and the crude product was purified by prep HPLC (conditions not reported) to afford trans-3-methyl-5-(1H-pyrazol-5-yl)piperidine (145 mg, 58 %) as a yellow oil. LCMS: (ES, m/s) 167 [M+H]+. 1H NMR (300 MHz, MeOD-d4) δ ppm: 7.66 (d, 1H), 6.28 (d, 1H), 3.64-3.69 (m, 1H), 3.39-3.42 (m, 1H), 3.23-3.33 (m, 2H), 2.75-2.82 (m, 1H), 1.95- 2.14(m, 2H), 1.66-1.75 (m, 1H), 1.02 (s, 3H). Step 3 To (trans)-3-methyl-5-(1H-pyrazol-5-yl)piperidine (128 mg, 0.775 mmol) and (R)-2- bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (225 mg, 0.852 mmol) in DMSO (4.0 mL) was added triethylamine (0.216 mL, 1.549 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column, EtOAc in DCM 40-90%) to afford (S)-N-(5-chloropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-pyrazol- 5-yl)piperidin-1-yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((3R,5R)-3-methyl-5- (1H-pyrazol-5-yl)piperidin-1-yl)propanamide (1:1 mix) (67 mg, 0.183 mmol, 23.62 % yield) as an off white solid. LCMS: (ES, m/s) 348 [M+H]+. 1H NMR (400 MHz, DMSO- d6) δ ppm: 8.35-8.44 (m, 1H), 8.12-8.19 (m, 1H), 7.85-7.94 (m, 1H), 7.27-7.63 (m, 1H), 6.11 (br d, J=11.0 Hz, 1H), 3.38-3.55 (m, 1H), 3.03-3.19 (m, 1H), 2.52-2.82 (m, 3H), 2.13- 2.30 (m, 1H), 1.67-1.94 (m, 2H), 1.41-1.56 (m, 1H), 1.17 (dd, J=7.0, 3.3 Hz, 3H), 0.99 (br dd, J=12.3, 6.7 Hz, 3H). Example 78a and 78b Ex.78a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-(2- hydroxyethyl)-1H-pyrazol-3-yl)piperidin-1-yl)propanamide or Ex.78b: (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-(2-hydroxyethyl)-1H-pyrazol- 3-yl)piperidin-1-yl)propanamide
Figure imgf000140_0001
Step 1 To (2S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoro-3-(1H-pyrazol-3- yl)piperidin-1-yl)propanamide (Example 61) (490 mg, 1.21 mmol, 1.0 eq) in DMF (10 mL) was added (2-bromoethoxy)(tert-butyl)dimethylsilane (323 mg, 1.45 mmol, 1.2 eq) and CS2CO3 (668 mg.4.84 mmol, 4.0 eq). After 2 h, the reaction was quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 2). The organic phases were combined, washed with brine (100 mL x 3), dried over Na2SO4, concentrated and purified via a silica gel column, eluting with ethyl acetate : petroleum (1:10) to give 0.35 g (purity: 67%, yield: 51%) of (2S)-2-(3-(1-(2-(tert-butyldimethylsilyloxy)ethyl)-1H-pyrazol-3-yl)-4,4- difluoropiperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide as light yellow oil. LCMS: (ES, m/s) 564 [M+H]+. NMR not reported. Step 2 To (2S)-2-(3-(1-(2-(tert-butyldimethylsilyloxy)ethyl)-1H-pyrazol-3-yl)-4,4- difluoropiperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)propanamide (370 mg, 0.66 mmol, 1.0 eq) in THF (10 mL) at 0 °C was added TBAF (1.0 mol/L, 3.3 mL, 3.29 mmol). The mixture was stirred for 2 h at room temperature, quenched with NH4Cl (50 mL) and extracted with ethyl acetate (50 mL x 2). The organic phases were combined, washed with brine (100 mL x 3), dried over Na2SO4, concentrated and purified over a silica gel column, eluting with methanol : dichloromethane (1: 20) to give 100 mg pure product as a light-yellow oil. This material was chirally separated (column: CHIRAL ART Cellulose - SB, 2 x 25 cm, 5 µm, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide four peaks with retention times of 14.926, 17.919, 20.788 and 33.897 min. The third peak (20.788 min) was collected to give 22 mg (purity: 99.9%, yield: 7%) of (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)- 4,4-difluoro-3-(1-(2-hydroxyethyl)-1H-pyrazol-3-yl)piperidin-1-yl)propanamide or (S)-N- (5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-(2-hydroxyethyl)-1H- pyrazol-3-yl)piperidin-1-yl)propanamide as a white solid. LCMS (ES, m/s): 450 [M+H]+. 1H NMR (400 MHz, CD3OD) δ ppm: 8.03 (d, J=8.8 Hz, 1H), 7.98 (d, J=2.8 Hz, 1H), 7.57 (d, J=2.4 Hz, 1H), 7.41-7.38 (m, 1H), 6.28 (s, 1H), 4.19-4.16 (m, 2H), 3.88-3.82 (m, 4H), 3.59-3.47 (m, 2H), 3.06-2.92 (m, 3H), 2.69-2.61 (m, 1H), 2.29-2.18 (m, 2H), 1.33 (d, J=6.8 Hz, 3H), 1.27-1.22 (m, 1H), 0.64-0.60 (m, 2H), 0.38-0.34 (m, 2H). Example 79 (S)-N-(5-chloropyridin-2-yl)-2-((3S,4S)-4-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide
Figure imgf000142_0001
Step 1 To 1H-pyrazole-3-boronic acid (1.27 g, 11.11 mmol) and 3-bromo-4-methylpyridine (1.50 g, 8.55 mmol) in dioxane (69 mL) were added 1M aqueous cesium fluoride (3.93 g, 25.64 mmol), Pd2dba3 (577 mg, 0.60 mmol), and S-Phos (537 mg, 1.28 mmol) under argon. The mixture was stirred in a pressure proof vessel for 16-20 hours at 100 °C, concentrated and purified by column chromatography, eluting with 0-5 % MeOH in CHCl3. The white product was clarified on activated charcoal to give 4-methyl-3-(1H-pyrazol-5-yl)pyridine (1.36 g, 57 %). LCMS: (ES, m/s) 161 [M+H]+. NMR not reported. Step 2 4-Methyl-3-(1H-pyrazol-5-yl)pyridine (600 mg, 3.77 mmol) was dissolved in MeOH (189 mL) and TFA (0.58 mL), and the reaction was hydrogenated using an H-Cube (116 mm CatCart of 5 % Ru/C, 140 °C, 50 bar, 0.5 mL/min). The collected material was concentrated, purified by prep HPLC (conditions not reported) and combined with another batch of material to afford cis-4-methyl-3-(1H-pyrazol-5-yl)piperidine (780 mg, 4.72 mmol) as an oil. LCMS: (ES, m/s) 167 [M+H]+. 1H NMR (300 MHz, MeOD-d4) δ ppm: 7.64 (d, 1H), 6.22 (d, 1H), 3.52-3.58 (m, 1H), 3.37-3.45 (m, 2H), 3.26 (m, 1H), 3.17 (m, 1H), 2.18 (m, 1H), 1.73 (m, 2H), 0.97 (s, 3H). Step 3 To (cis)-4-methyl-3-(1H-pyrazol-5-yl)piperidine (180 mg, 1.089 mmol) and (R)-2-bromo- N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (316 mg, 1.198 mmol) in DMSO (4.0 mL) was added triethylamine (0.304 mL, 2.179 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column), eluting with 60- 90% EtOAc in DCM to afford 353 mg of an off white solid. For chiral separation, 332 mg material was purified via Chiral SFC purification (Column: Chiralpak IG, 20x250mm, 5u; Co-Solvent:: 25% EtOH; Total flowrate: 50 g/min). The fractions of peak 1 were collected and concentrated to afford (S)-N-(5-chloropyridin-2-yl)-2-((3S,4S)-4-methyl-3-(1H- pyrazol-5-yl)piperidin-1-yl)propanamide (98.4 mg, 0.269 mmol, 28.2 % yield) as an off white solid. LCMS: (ES, m/s) 348 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.17-12.47 (m, 1H), 10.33-11.30 (m, 1H), 8.33-8.49 (m, 1H), 8.14 (br d, J=8.6 Hz, 1H), 7.90 (dd, J=8.8, 2.7 Hz, 1H), 7.27-7.64 (m, 1H), 6.16 (d, J=1.7 Hz, 1H), 3.45 (q, J=6.4 Hz, 1H), 3.00 (br s, 1H), 2.56-2.90 (m, 3H), 2.26-2.46 (m, 1H), 1.78-1.92 (m, 1H), 1.31-1.64 (m, 2H), 1.19 (br d, J=5.6 Hz, 3H), 0.68 (br d, J=6.6 Hz, 3H). Example 80 (S)-2-((S)-3-(1H-pyrrol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide
Figure imgf000143_0001
Step 1 To tert-butyl 3-oxopiperidine-1-carboxylate (10 g, 50 mmol, 1.0 eq) in THF (200 mL) at - 78 oC was added LiHMDS (60 ml, 60 mmol, 1.2 eq, 1 M in tetrahydrofuran), dropwise. After 70 min, HMPA (17.4 ml, 100 mmol, 2.0 eq) was added dropwise, followed after 15 min by dropwise addition of PhNTf2 (21.4 g, 60 mmol, 1.2 eq) in THF (80 mL). The temperature was increased to room temperature naturally, and the reaction mixture was stirred for 13 h, quenched with water (200 mL) and extracted with ethyl acetate (500 mL × 3). The combined organic extracts were dried over anhydrous sodium sulfate, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (1:10) to give 8 g (purity: 70%, yield: 48%) of tert-butyl 5-(((trifluoromethyl)sulfonyl)oxy)-3,6- dihydropyridine-1(2H)-carboxylate as a yellow oil. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.15-7.09 (m, 1H), 4.04-3.98 (m, 1H), 3.45-3.36 (m, 3H), 2.40-2.37 (m, 2H), 1.42 (s, 9H). Step 2 A mixture of tert-butyl 5-(((trifluoromethyl)sulfonyl)oxy)-3,6-dihydropyridine-1(2H)- carboxylate (5.5 g, 16.6 mmol, 1.0 eq), (1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl)boronic acid (5.25 g, 24.9 mmol, 1.5 eq), Pd(dppf)Cl2 (1.22 g, 1.66 mmol, 0.1 eq) and Na2CO3 (3.52 g, 33.2 mmol, 2.0 eq) in dioxane (160 mL) and water (40 mL) was evacuated and flushed with nitrogen three times, stirred at 90 °C for 12 h, filtered, concentrated and diluted with water (100 mL). The reaction was extracted with ethyl acetate (100 mL × 3), dried over anhydrous sodium sulfate, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1:10) to give 4 g (purity: 92%, yield: 69%) tert-butyl 5-(1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl)-3,6-dihydropyridine-1(2H)- carboxylate as a yellow oil. LCMS (ES, m/s): 349 [M+H]+ . 1H NMR: (400 MHz, DMSO- d6) δ ppm 7.48-7.11 (m, 2H), 6.30-6.04 (m, 2H), 3.92 -3.89 (m, 1H), 3.47-3.41 (m, 1H), 2.21-2.11 (m, 2H), 1.82 -1.79 (m, 2H), 1.50 (s, 9H), 1.37 (s, 9H). Step 3 A mixture of tert-butyl 5-(1-(tert-butoxycarbonyl)-1H-pyrrol-2-yl)-3,6-dihydropyridine- 1(2H)-carboxylate (4 g, 11.5 mmol, 1.0 eq), tetrahydrofuran (20 mL) and CH3ONa (20 mL, 30% in methanol) was stirred for 1 h, concentrated, diluted with water (100 mL) and extracted with ethyl acetate (100 mL × 3). The combined extracts were dried over anhydrous sodium sulfate, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1:5) to give 1.1 g (purity: 90%, yield: 39%) tert-butyl 5- (1H-pyrrol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate as a yellow oil. LCMS (ES, m/s): 249 [M+H]+ . Step 4 A mixture of tert-butyl 5-(1H-pyrrol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.1 g, 4.4 mmol, 1.0 eq), methanol (20 mL) and Pd(OH)2/C (110 mg, 0.2 eq) was evacuated and flushed three times with hydrogen, stirred 2 h under hydrogen, filtered, concentrated and purified over a silica gel column, eluting with methanol : dichloromethane (1:10) to give 673 mg (purity: 95%, yield: 61%) tert-butyl 3-(1H-pyrrol-2-yl)piperidine-1-carboxylate as a yellow solid. LCMS (ES, m/s): 251 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 10.63 (s, 1H), 6.61-6.55 (m, 1H), 5.91 -5.89 (m, 1H), 5.79-5.77 (m, 1H), 4.05-3.88 (m, 2H), 3.34-3.32 (m, 1H), 2.80-2.65 (m, 2H), 1.98-1.95 (m, 1H), 1.69-1.65 (m, 2H), 1.60- 1.46 (m, 1H), 1.41 (s, 9H). Step 5 To tert-butyl 3-(1H-pyrrol-2-yl)piperidine-1-carboxylate (673 mg, 2.69 mmol, 1.0 eq) in DMF (15 mL) at 0 oC was added NaH (215 mg, 5.38 mmol, 2.0 eq, 60%). After 30 min, 4- methylbenzenesulfonyl chloride (615 mg, 3.23 mmol, 1.2 eq) was added, and the mixture was stirred at room temperature for 2 h, quenched with water (20 mL) and extracted with ethyl acetate (100 mL × 3). The combined organic extracts were washed with brine (200 mL × 5), dried over anhydrous sodium sulfate, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1:5) to give 860 mg (purity: 95%, yield: 79%) of tert-butyl 3-(1-tosyl-1H-pyrrol-2-yl)piperidine-1-carboxylate as a yellow oil. Step 6 A mixture of tert-butyl 3-(1-tosyl-1H-pyrrol-2-yl)piperidine-1-carboxylate (849 mg, 2.1 mmol, 1.0 eq), dichloromethane (8 mL) and TFA (2 mL) was stirred for 0.5 h and concentrated to give 606 mg (purity: 90%, yield: 95%) 5-(1-tosyl-1H-pyrrol-2-yl)-1,2,3,6- tetrahydropyridine as a yellow solid, which was used without purification. LCMS (ES, m/s): 305 [M+H]+. Step 7 A mixture of 5-(1-tosyl-1H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine (as a free base) (606 mg, 2 mmol, 1.0 eq), 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (1.05 g, 4 mmol, 2.0 eq) and TEA (2.02 g, 20 mml, 10.0 eq) in tetrahydrofuran (10 mL) was stirred at 40 oC for 12 h, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1: 2) to give 628 mg (purity: 95%, yield: 65%) N-(5- chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-2-yl)piperidin-1-yl)propanamide as a white solid. LCMS (ES, m/s): 487 [M+H]+. 1H NMR: (300 MHz, DMSO-d6) δ ppm 10.24 (s, 1H), 8.40 (t, J=2.8 Hz, 1H), 8.13 (t, J=8.4 Hz, 1H), 7.95-7.89 (m, 1H), 7.72-7.58 (m, 2H), 7.39 (d, J=8.1 Hz, 1H), 7.35-7.25 (m, 2H), 6.27-6.23 (m, 1H), 6.17-6.15 (m, 1H), 3.50-3.28 (m, 2H), 3.14 -3.11 (m, 1H), 2.85-2.66 (m, 2H), 2.31 (d, J=6.0 Hz, 3H), 2.19-1.93 (m, 1H), 1.64-1.50 (m, 3H), 1.23 -1.16 (m, 1H), 1.09 (d, J=6.9 Hz, 3H). Step 8 A mixture of N-(5-chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-2-yl)piperidin-1- yl)propanamide (520 mg, 1.07 mmol, 1.0 eq) and TBAF (25 mL, 1M in tetrahydrofuran) was stirred at 50 oC for 72 h, concentrated, diluted with water (50 mL) and extracted with ethyl acetate (50 mL × 3). The combined organic extracts were washed with brine (100 mL × 8), dried over sodium sulfate, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1:1) to give 168 mg of a white solid. This material was chirally separated (column: CHIRAL ART Cellulose-SBS-5um, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 9.744 and 13.259 min. The second peak (13.259 min) was collected and further chirally separated (column: CHIRAL PAK IF, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 95:5) to provide two peaks with retention times of 10.904 and 12.886 min. The second peak (12.886 min) was collected to give 20 mg (purity: 99%, yield: 5.6%) of (S)-2-((S)-3-(1H-pyrrol-2-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide as a white solid. LCMS (m/z) 333 (M+H)+, retention time: 0.989 min, LC/MS Method 9. 1H NMR (300 MHz, DMSO-d6) δ ppm 10.54 (br, 1H), 10.27 (s, 1H), 8.37-8.36 (m, 1H), 8.17-8.14 (m, 1H), 7.94-7.90 (m, 1H), 6.55-6.52 (m, 1H), 5.87-5.84 (m, 1H), 5.74-5.70 (m, 1H), 3.52-3.45 (m, 1H), 2.93-2.73 (m, 3H), 2.34-2.27 (m, 1H), 2.19-2.12 (m, 1H), 1.93-1.89 (m, 1H), 1.75-1.70 (m, 1H), 1.65-1.53 (m, 1H), 1.40- 1.24 (m, 1H), 1.18 (d, J=7.2 Hz, 3H). Example 81a and 81b Ex.81a: (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-methyl-1H- pyrazol-3-yl)piperidin-1-yl)propanamide or Ex.81b: (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-methyl-1H-pyrazol-3- yl)piperidin-1-yl)propanamide
Figure imgf000147_0001
Step 1 To t-BuONa (3.16 g, 32.8 mmol, 2.5 eq) in THF (16 mL) at 25 oC were added (t-Bu)3P (10 % in hexane, 2.66 g, 1.32 mmol, 0.1 eq) and Pd(OAc)2 (294 mg, 1.30 mmol, 0.1 eq). After 5 min 3-bromo-1-methyl-1H-pyrazole (2.12 g, 13.2 mmol, 1.0 eq) and tert-butyl 4- oxopiperidine-1-carboxylate (4.0 g, 20.0 mmol, 1.5 eq) were added, and the reaction was stirred at 42 oC. After 18 h the mixture was quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The organic phases were combined, washed with brine (200 mL), dried over anhydrous Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 2.1 g (purity: 61%, yield: 57%) tert-butyl 3-(1-methyl-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate as a yellow oil. LCMS: (ES, m/s) 280 [M+H]+. 1H NMR: (300 MHz, CDCl3-d) δ 7.30-7.29 (m, 1H), 6.11-6.10 (m, 1H), 4.30-4.25 (m, 1H), 3.83 (s, 3H), 3.70-3.50 (m, 2H), 3.20-3.00 (m, 2H), 2.68-2.50 (m, 2H), 1.46 (s, 9H). Step 2 To tert-butyl 3-(1-methyl-1H-pyrazol-3-yl)-4-oxopiperidine-1-carboxylate (1 g, 4.36 mmol, 1.0 eq) in DCM (10 mL) at 0 oC was added DAST (1.40 g, 8.72 mmol, 2.0 eq), dropwise. The reaction was stirred for 18 h at room temperature, quenched with ice water (60 mL) and extracted with DCM (60 mL x 3). The organic phases were combined, dried over Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:3) to give 300 mg (purity: 62%, yield: 23%) tert-butyl 4,4-difluoro-3- (1-methyl-1H-pyrazol-3-yl)piperidine-1-carboxylate as a yellow oil. LCMS (ES, m/s): 302 [M+H]+ . 1H NMR: (300 MHz, CDCl3) δ 7.32-7.30 (m, 1H), 6.21-6.19 (m, 1H), 4.45-4.35 (m, 1H), 3.87 (s, 3H), 3.70-3.45 (m, 2H), 3.20 – 2.95 (m, 2H), 2.70-2.40 (m, 2H), 1.44 (s, 9H). Step 3 To tert-butyl 4,4-difluoro-3-(1-methyl-1H-pyrazol-3-yl)piperidine-1-carboxylate (400 mg, 1.32 mmol, 1.0eq) in DCM (8 mL) at 25 oC was added TFA (2 mL). The reaction was stirred for 2 h and concentrated to give 540 mg crude 4,4-difluoro-3-(1-methyl-1H- pyrazol-3-yl)piperidine as a yellow solid, which was used without purification. LCMS (ES, m/s): 202 [M+H]+ . 1H NMR: (300 MHz, DMSO-d6) δ 7.69-7.65 (m, 1H), 6.24-6.19 (m, 1H), 3.95-3.92 (m, 1H), 3.80 (s, 3H), 3.60-3.50 (m, 2H), 3.20-3.10 (m, 2H), 2.90-2.85 (m, 2H), 2.00-1.92 (m, 1H). Step 4 To 4,4-difluoro-3-(1-methyl-1H-pyrazol-3-yl)piperidine (TFA salt, 340 mg, 1.67 mmol, 1.0 eq) in THF (20 mL) at 25 oC was added (R)-2-bromo-N-(5- (cyclopropylmethoxy)pyridin-2-yl)propanamide (Intermediate 3) (497 mg, 1.67 mmol, 1.0 eq) and TEA (1.35 g, 13.36 mmol, 8.0 eq), and the reaction was stirred at 40 oC. After 16 h, the mixture was quenched with water (30 mL) and extracted with ethyl acetate (30 mL x 3). The organic phases were combined, dried over Na2SO4, concentrated and purified over silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 130 mg product as a white solid. This material was chirally separated (column: CHIRALPAK IE, 2 x 25 cm, 5 µm, flow rate: 18 mL/min; Mobile phase A: hex: DCM = 1:1 [10mm NH3 – MeOH], Mobile phase B: EtOH, A:B 7:3) to provide four peaks with retention times of 4.076, 4.839, 5.051 and 5.369 min. The second peak (4.839 min) was collected to give 14 mg (purity: 95.4%, yield: 2%) of (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4- difluoro-3-(1-methyl-1H-pyrazol-3-yl)piperidin-1-yl)propanamide or (S)-N-(5- (cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-methyl-1H-pyrazol-3- yl)piperidin-1-yl)propanamide as a white solid. LCMS (m/z) 420 (M+H)+, retention time: 1.151 min, LC/MS Method 6. 1H NMR (400 MHz, CD3OD) ppm δ 8.04 (d, J=8.8 Hz, 1H), 7.98 (d, J=3.2 Hz, 1H), 7.48 (d, J=2.4 Hz, 1H), 7.40 (dd, J=9.2, 2.8 Hz, 1H), 6.25 (br, 1H), 3.87 (d, J=6.8 Hz, 2H), 3.85 (s, 3H), 3.55-3.44 (m, 2H), 2.97-2.94 (m, 2H), 2.79-2.74 (m, 2H), 2.30-2.10 (m, 2H), 1.37 (d, J=6.8 Hz, 3H), 1.29-1.21 (m, 1H), 0.64-0.60 (m, 2H), 0.37-0.34 (m, 2H). Example 82 (S)-N-(5-fluoropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-1,2,4-triazol-5-yl)piperidin-1- yl)propanamide
Figure imgf000149_0001
To 1-benzyl 3-methyl 5-hydroxypiperidine-1,3-dicarboxylate (20.0 g, 68.3 mmol, 1.0 eq) in DCM (200 mL) at 0 oC was added Dess-Martin reagent (58.3 g, 136.5 mmol, 2.0 eq). The mixture was stirred for 2.0 h at room temperature, quenched with NaOH (0.5%, 300 mL, aq) and extracted with DCM (300 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum ether (1:1) to give 18.1 g (purity: 91%, yield: 91%) 1-benzyl 3-methyl 5- oxopiperidine-1,3-dicarboxylate as a yellow oil. LCMS: (ES, m/s) 292 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ ppm 7.45-7.30 (m, 5H), 5.15 (s, 2H), 4.40 -4.10 (m, 2H), 3.70-3.68 (m, 3H), 3.10-2.60 (m, 3H), 2.35-2.20 (m, 1H), 1.75-1.60 (m, 1H). Step 2 To methyltriphenylphosphonium bromide (35.3 g, 98.97 mmol, 1.6 eq) in THF (100 mL) at -10 oC was added n-BuLi (2.5 mol/L, 39.6 mL, 98.97 mmol, 1.6 eq). After 30 min, 1- benzyl 3-methyl 5-oxopiperidine-1,3-dicarboxylate (18.0 g, 61.86 mmol, 1.0 eq) in THF (100 mL) was added. After 10 min, the reaction was stirred 3.0 h at room temperature, quenched with NH4Cl (500 mL, aq.) and extracted with ethyl acetate (500 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with ethyl acetate : petroleum ether (1:4) to give 9.2 g (purity: 86%, yield: 51%) 1- benzyl 3-methyl 5-methylenepiperidine-1,3-dicarboxylate as a yellow oil. LCMS (ES, m/s): 290 [M+H]+ . 1H NMR: (300 MHz, CD3OD) δ ppm 7.40-7.30 (m, 5H), 5.13-5.12 (m, 2H), 4.95-4.85 (m, 2H), 4.35-4.00 (m, 2H), 3.77-3.60 (m, 4H), 3.55-3.35 (m, 1H), 2.70- 2.40 (m, 3H). Step 3 To 1-benzyl 3-methyl 5-methylenepiperidine-1,3-dicarboxylate (9.2 g, 31.8 mmol, 1.0 eq) in THF (90 mL), MeOH (30 mL), H2O (30 mL) and NaOH (6.4 g, 159.2 mmol, 5.0 eq) were added. After 5.0 h, the mixture was poured into H2O (200 mL) and washed with ethyl acetate (200 mL). The pH value of the aqueous layer was adjusted to 2 with 4M HCl, and the mixture was extracted with ethyl acetate (300 mL x 3). The combined organic phases were dried over Na2SO4 and concentrated to give 9.0 g (purity: 92%) 1- ((benzyloxy)carbonyl)-5-methylenepiperidine-3-carboxylic acid as yellow oil, which was used without further purification. LCMS (ES, m/s): 276 [M+H]+ . 1H NMR: (400 MHz, CD3OD-d4) δ 7.40-7.30 (m, 5H), 5.14 (s, 2H), 4.92-4.86 (m, 2H), 4.40-4.10 (m, 2H), 3.69- 3.66 (m, 1H), 3.48-3.18 (m, 1H), 2.70-2.40 (m, 3H). Step 4 To 1-((benzyloxy)carbonyl)-5-methylenepiperidine-3-carboxylic acid (10.0 g, 36.4 mmol, 1.0 eq) in DMF (100 mL) were added HATU (20.7 g, 54.5 mmol, 1.5 eq) and DIEA (14.1 g, 109.1 mmol, 3.0 eq). After 0.5 h, NH4Cl (2.89 g, 54.5 mmol, 1.5 eq) was added, and the mixture was stirred for 3 hours. The reaction was quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with methanol : dichloromethane (1:20) to give 6.2 g (purity: 95%, yield: 62%) of benzyl 3-carbamoyl-5- methylenepiperidine-1-carboxylate as an off white solid. LCMS (ES, m/s): 275 [M+H]+. 1H NMR: (300 MHz, DMSO-d6) δ 7.46 (s, 2H), 7.40-7.26 (m, 5H), 5.09 -5.07 (m, 2H), 4.88-4.82 (m, 2H), 3.68-3.30 (m, 3H), 3.20-3.10 (m, 1H), 2.47-2.42 (m, 1H), 2.35-2.25 (m, 2H). Step 5 Benzyl 3-carbamoyl-5-methylenepiperidine-1-carboxylate (6.2 g, 22.6 mmol, 1.0 eq) in DMF-DMA (70 mL) was stirred for 3 hours at 110 oC and concentrated to give 6.3 g crude benzyl (E)-3-(((dimethylamino)methylene)carbamoyl)-5-methylenepiperidine-1- carboxylate as a yellow oil, which was used without purification. LCMS (ES, m/s): 330 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ ppm 7.99 (s, 1H), 7.40-7.30 (m, 5H), 5.14 -5.13 (m, 2H), 4.94-4.84 (m, 2H), 3.65-3.45 (m, 1H), 3.40-3.34 (m, 1H), 3.20-3.05 (m, 1H), 3.00 (s, 3H), 2.92-2.83 (m, 4H), 2.68-2.42 (m, 3H). Step 6 To benzyl (E)-3-(((dimethylamino)methylene)carbamoyl)-5-methylenepiperidine-1- carboxylate (6.3 g, 19.1 mmol, 1.0 eq) in AcOH (60 mL) was added N2H4.H2O (80%, 6 mL), and the mixture was stirred at 90 oC. After 18 h, the reaction was concentrated, diluted with water (300 mL) and extracted with ethyl acetate (300 mL x 3). The combined organic extracts were dried over Na2SO4, concentrated and purified via a silica gel column, eluting with methanol : dichloromethane (1:20) to give 5.0 g (purity: 95%, yield: 87%) benzyl 3-methylene-5-(1H-1,2,4-triazol-5-yl)piperidine-1-carboxylate as yellow solid. LCMS (ES, m/s): 299 [M+H]+. 1H NMR: (400 MHz, CD3OD) δ ppm 8.40 (s, 1H), 7.40- 7.30 (m, 5H), 5.16 -5.14 (m, 2H), 4.97-4.93 (m, 2H), 4.54-4.51 (m, 1H), 4.40-4.36 (m, 1H), 3.70-3.55 (m, 1H), 3.30-3.15 (m, 1H), 3.10-3.00 (m, 1H), 2.93-2.75 (m, 1H), 2.61- 2.55 (m, 1H). Step 7 To benzyl 3-methylene-5-(1H-1,2,4-triazol-5-yl)piperidine-1-carboxylate (4.8 g, 16.1 mmol, 1.0 eq) in DMF (50 mL) at 0 oC was added NaH (60%, 966 mg, 24.2 mmol, 1.5 eq), in portions. After 30 min, benzyl chloride (3.8 g, 24.2 mmol, 1.5 eq) was added dropwise, and the reaction was stirred at room temperature. After 2 h, the mixture was quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with ethyl acetate : petroleum ether (1:1) to give 6.2 g (purity: 90%, yield: 92%) benzyl 3-(1-(4- methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylenepiperidine-1-carboxylate as a yellow oil. LCMS PH-CSX-51481-002-192-7 (ES, m/s): 419 [M+H]+. 1H NMR: (300 MHz, CDCl3) δ ppm 7.89-7.86 (m, 1H), 7.45-7.20 (m, 7H), 6.95-6.85 (m, 2H), 5.30-5.10 (m, 4H), 4.97-4.93 (m, 2H), 4.60-4.40 (m, 2H), 3.82 (s, 3H), 3.60-3.45 (m, 1H), 3.28-2.90 (m, 1H), 2.83-2.72 (m, 1H), 2.60-2.40 (m, 1H), 2.61-2.55 (m, 1H). Step 8 A mixture of benzyl 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5- methylenepiperidine-1-carboxylate (3.0 g, 7.17 mmol, 1.0 eq) and Pd/C (300 mg) in MeOH (30 mL) was stirred for 15 h under an H2 atmosphere, filtered and concentrated to give 2.0 g crude 3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylpiperidine as yellow oil, which was used without purification. LCMS (m/z) 287 (M+H)+. 1H NMR (300 MHz, CDCl3) δ ppm 7.85-7.83 (m, 1H), 7.24-7.20 (m, 2H), 6.93-6.89 (m, 2H), 5.21 (s, 2H), 3.82 (s, 3H), 3.40-3.35 (m, 1H), 3.15-2.90 (m, 4H), 2.80-2.75 (m, 1H), 2.20-2.14 (m, 1H), 1.80-1.60 (m, 2H), 0.94-0.88 (m, 3H). Step 9 To 3-(1-(4-Methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylpiperidine (2.0 g, 7.0 mmol, 1.0 eq) in THF (50 mL) were added (R)-2-Bromo-N-(5-fluoropyridin-2-yl)propanamide (Intermediate 4) (1.72 g, 7.0 mmol, 1.0 eq) and TEA (7.0 g, 70.0 mmol, 10.0 eq), and the mixture was stirred at 40 oC. After 72 h, the reaction was quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with methanol : dichloromethane (1:10) to give 1.8 g (purity: 86%, yield: 57%) (2S)-N-(5-fluoropyridin-2- yl)-2-(3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5-methylpiperidin-1-yl)propanamide as yellow oil. LCMS (m/z) 453 (M+H)+. 1H NMR: (400 MHz, CD3OD) δ ppm 8.35 (d, J=10.0 Hz, 1H), 8.22-8.19 (m, 2H), 7.66-7.58 (m, 1H), 7.28-7.22 (m, 2H), 6.94-6.88 (m, 2H), 5.27 (d, J=6.4 Hz, 2H), 3.79 (d, J=2.8 Hz, 3H), 3.45-3.40 (m, 1H), 3.25-3.02 (m, 3H), 2.90-2.60 (m, 2H), 2.35-2.25 (m, 1H), 2.16-2.05 (m, 2H), 1.28-1.20 (m, 3H), 0.99-0.96 (m, 3H). Step 10 (2S)-N-(5-Fluoropyridin-2-yl)-2-(3-(1-(4-methoxybenzyl)-1H-1,2,4-triazol-5-yl)-5- methylpiperidin-1-yl)propanamide (1.8 g, 3.98 mmol, 1.0 eq) in TFA (20 mL) was stirred for 48 h at 70 oC, concentrated, and dissolved in water (30 mL). The pH of the mixture was adjusted to 8 - 9 with NaHCO3 (aq., sat.), and the mixture was extracted with DCM (50 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified via silica gel, eluting with methanol : dichloromethane (1:20) to give 200 mg product as yellow solid. This material was chirally separated (column: Chiral PAK ID - 2, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide three peaks with retention times of 10.037, 12.259 and 17.548 min. The first peak (10.037 min) was collected further chirally separated (column: CHIRALPAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide two peaks with retention times of 15.100 and 18.300 min. The first peak (15.100 min) was collected to give 20 mg (purity: 98.8%, yield: 2%) (S)-N-(5-fluoropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-1,2,4-triazol-5-yl)piperidin-1- yl)propanamide as white solid. LCMS (m/z) 333 (M+H)+, retention time: 1.248 min, LC/MS Method 9. 1H NMR (400 MHz, CD3OD) δ ppm 8.46-7.91 (m, 3H), 7.60-7.55 (m, 1H), 3.35-3.33 (m, 1H), 3.16-3.05 (m, 1H), 2.91-2.60 (m, 2H), 2.22-2.00 (m, 2H), 1.98- 1.65 (m, 1H), 1.61 -1.43 (m, 1H), 1.37-1.25 (m, 4H), 1.00 (d, J=6.8 Hz, 3H). Example 83 (S)-2-((R)-3-(1H-pyrrol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide
Figure imgf000154_0001
Step 1 To 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-(triisopropylsilyl)-1H-pyrrole (3.0 g, 8.6 mmol, 1.0 eq) in THF (30 mL) at 0 oC was added TBAF (1 mol/L, 9.0 mL, 9.0 mmol), dropwise. The reaction was stirred for 2 h at 25 oC, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The organic layers were combined, washed with brine (200 mL), dried over Na2SO4, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum ether (1:3) to give 1.3 g (purity: 51%, yield: 79%) of 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole as a white solid. LCMS (m/z) 194 (M+H)+. 1H NMR (300 MHz, CD3OD) δ ppm 7.16-7.15 (m, 1H), 6.78-6.77 (m, 1H), 6.39-6.38 (m, 1H), 1.31 (s, 12H). Step 2 To 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole (4.5 g, 23.0 mmol, 1.0 eq) in dioxane (60 mL) was added tert-butyl 5-(((trifluoromethyl)sulfonyl)oxy)-3,6- dihydropyridine-1(2H)-carboxylate (Example 80, Step 1) (7.72 g, 23.0 mmol, 1.0 eq), Na2CO3 (7.41 g, 70.0 mmol, 3.0 eq) and Pd(dppf)Cl2 (3.41 g, 4.6 mmol, 0.2 eq). The reaction was evacuated and flushed with nitrogen three times, stirred for 15 h at 80 oC, quenched with water (200 mL) and extracted with ethyl acetate (200 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified over a silica gel column, eluting with ethyl acetate/petroleum (1:1) to give 1.66 g (purity: 75%, yield: 28%) of tert-butyl 5-(1H-pyrrol-3-yl)-3,6-dihydropyridine-1(2H)-carboxylate as a yellow solid. LCMS (ES, m/s): 249 [M+H]+ . 1H NMR: (400 MHz, CD3OD) δ ppm 7.30-7.24 (m, 1H), 7.17-7.15 (m, 1H), 6.78-6.75 (m, 1H), 6.40-6.38 (m, 1H), 3.60-3.50 (m, 2H), 2.38- 2.18 (m, 2H), 1.95-1.89 (m, 2H), 1.32 (s, 9H). Step 3 A mixture of tert-butyl 5-(1H-pyrrol-3-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.66 g, 6.69 mmol, 1.0 eq) and Pd(OH)2/C (200 mg, 20%) in MeOH (20 mL) was stirred for 15 h under an atmosphere of hydrogen, filtered and concentrated go give 1.24 g (purity: 40%, yield: 74%) of tert-butyl 3-(1H-pyrrol-3-yl)piperidine-1-carboxylate as a yellow solid, which was used without purification. LCMS (ES, m/s): 251 [M+H]+ . 1H NMR: (300 MHz, CD3OD) δ 7.16-7.15 (m, 1H), 6.78-6.76 (m, 1H), 6.39-6.37 (m, 1H), 3.85-3.55 (m, 2H), 2.90-2.49 (m, 3H), 2.40-2.20 (m, 1H), 2.15-1.95 (m, 2H), 1.76-1.65 (m, 1H), 1.47 (s, 9H). Step 4 To tert-butyl 3-(1H-pyrrol-3-yl)piperidine-1-carboxylate (1.24 g, 4.96 mmol, 1.0 eq) in DMF (20 mL) at 0 oC was added NaH (476 mg, 11.9 mmol). After 30 min, TsCl (1.13 g, 5.95 mmol, 1.2 eq) was added. The reaction was stirred for 6 h at room temperature, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The organic layers were combined, washed with brine (150 mL x 3), dried over Na2SO4, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum (1:10) to give 750 mg (purity: 30%, yield: 37%) of tert-butyl 3-(1-tosyl-1H-pyrrol-3-yl)piperidine-1- carboxylate as a yellow oil. LCMS (ES, m/s): 427 [M+H]+. 1H NMR: (400 MHz, CD3OD) δ ppm 7.94-7.76 (m, 2H), 7.42-7.35 (m, 2H), 7.25-7.20 (m, 1H), 7.18-7.15 (m, 1H), 6.32-6.27 (m, 1H), 4.05-3.90 (m, 2H), 3.70-3.55 (m, 1H), 3.45-3.35 (m, 1H), 3.01- 2.72 (m, 1H), 2.64-2.50 (m, 1H), 2.43 (s, 3H), 2.36-2.25 (m, 1H), 2.10-1.95 (m, 1H), 1.75- 1.60 (m, 1H), 1.48-1.47 (m, 9H). Step 5 To tert-butyl 3-(1-tosyl-1H-pyrrol-3-yl)piperidine-1-carboxylate (700 mg 1.73 mmol, 1.0 eq) in DCM (10 mL) was added TFA (3 mL). The reaction was stirred for 1 h at 25 oC and concentrated to give 526 mg (purity: 45%) 3-(1-tosyl-1H-pyrrol-3-yl)piperidine as a yellow oil, which was used without purification. LCMS (ES, m/s): 305 [M+H]+. 1H NMR: (400 MHz, CD3OD) δ ppm 7.94-7.76 (m, 2H), 7.42-7.35 (m, 2H), 7.25-7.20 (m, 1H), 7.18-7.15 (m, 1H), 6.32-6.27 (m, 1H), 3.46-3.35 (m, 2H), 3.01-2.95 (m, 2H), 2.43 (s, 3H), 2.36-2.28 (m, 1H), 2.10-1.98 (m, 2H), 1.85-1.60 (m, 2H). Step 6 A mixture of 3-(1-tosyl-1H-pyrrol-3-yl)piperidine (as free base) (527 mg, 1.73 mmol, 1.0 eq), 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (454 mg, 1.73 mmol, 1.0 eq), TEA (1.40 g, 13.86 mmol, 8.0 eq) and KI (287 mg, 1.73 mmol, 1.0 eq) in THF (20 mL) was stirred for 15 h at 60 oC, quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum (1:4) to give 240 mg (purity: 77%, yield: 28%) N-(5-chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-3- yl)piperidin-1-yl)propanamide as a yellow solid. LCMS (ES, m/s): 487 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ 8.30-8.28 (m, 1H), 8.21-8.18 (m, 1H), 7.85-7.76 (m, 3H), 7.39-7.35 (m, 2H), 7.14-7.11 (m, 1H), 7.04-7.00 (m, 1H), 6.28-6.25 (m, 1H), 3.66-3.54 (m, 1H), 2.91-2.72 (m, 3H), 2.45-2.34 (m, 4H), 2.00-1.90 (m, 2H), 1.85-1.75 (m, 3H), 1.32- 1.29 (m, 3H). Step 7 N-(5-Chloropyridin-2-yl)-2-(3-(1-tosyl-1H-pyrrol-3-yl)piperidin-1-yl)propanamide (240 mg, 0.49 mmol, 1.0 eq) in TBAF (20 mL, 1.0 mol/L in THF) was stirred for 35 h at 50 oC, quenched with NH4Cl (50 mL, aq., sat.) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified by Prep- HPLC (XBridge Prep C18 OBD column), eluting with 5-55% AcCN in water (10 mmol/L NH4HCO3) to give 60 mg of a white solid. This material was chirally separated (columnCHIRAL ART Cellulose - SB, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 4:1) to provide two peaks with retention times of 5.126 and 6.771 min. The first peak (5.126 min) was further chirally separated (column: CHIRAL PAK IG, 20x250 mm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 85:15) to provide two peaks with retention times of 10.141 and 11.277 min. The second peak (11.277 min) was collected to give 2.8 mg (purity: 99.7%, yield: 2%) of (S)-2-((R)-3-(1H- pyrrol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide as a white solid. LCMS (m/z) 333 (M+H)+, retention time: 1.801 min, LC/MS Method 9. 1H NMR (400 MHz, CD3OD) δ ppm 8.30-8.29 (m, 1H), 8.18 (d, J=8.8 Hz, 1H), 7.82 (dd, J=8.8, 2.4 Hz, 1H), 6.63-6.62 (m, 1H), 6.57 (s, 1H), 6.01-5.99 (m, 1H), 3.59-3.37 (m, 1H), 3.15-2.96 (m, 1H), 2.93-2.80 (m, 1H), 2.70-2.46 (m, 1H), 2.45-2.12 (m, 1H), 2.05-1.96 (m, 1H), 1.90-1.73 (m, 2H), 1.52-1.28 (m, 5H). Example 84 (2S)-N-(5-chloropyridin-2-yl)-2-(3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidin-1- yl)propanamide
Figure imgf000157_0001
Step 1 To 4-bromo-1H-pyrazole (2.00 g, 13.61 mmol) and 1-(chloromethyl)-4-methoxybenzene (2.77 g, 17.69 mmol) in DMSO (40 mL) was added K2CO3 (5.64 g, 40.8 mmol). After 4 hours, the mixture was diluted with water and extracted with DCM (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-30% EtOAc in hexanes to afford 4-bromo-1-(4-methoxybenzyl)-1H- pyrazole (3.62 g, 13.55 mmol, 100 % yield) as a colorless oil. 1H NMR (400 MHz, DMSO-d6) δ ppm: 8.03 (d, J=0.7 Hz, 1H), 7.53 (d, J=0.7 Hz, 1H), 7.22 (d, J=8.8 Hz, 2H), 6.90 (d, J=8.8 Hz, 2H), 5.22 (s, 2H), 3.73 (s, 3H). Step 2 To tert-butyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.5 g, 4.85 mmol), Na2CO3 (1.028 g, 9.70 mmol) and 4-bromo-1-(4- methoxybenzyl)-1H-pyrazole (1.944 g, 7.28 mmol) in water (5.00 mL) and dioxane (15.0 mL) was added PdCl2(dppf)-CH2Cl2adduct (0.396 g, 0.485 mmol). The resulting mixture was heated to 95 °C for 3 hours, cooled to RT, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert-butyl 5-(1-(4- methoxybenzyl)-1H-pyrazol-4-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.80 g, 4.87 mmol, 100 % yield) as a light yellow oil. LCMS (ES, m/s): 370 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.87 (s, 1H), 7.59 (d, J=0.7 Hz, 1H), 7.14-7.24 (m, 2H), 6.85-6.94 (m, 2H), 6.06 (br s, 1H), 5.19 (s, 2H), 4.02 (s, 2H), 3.72 (s, 3H), 3.42 (br t, J=5.6 Hz, 2H), 2.11-2.22 (m, 2H), 1.42 (s, 9H). Step 3 To tert-butyl 5-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.80 g, 4.87 mmol) in ethanol (10 mL) under N2 was added Pd/C, 10% (0.052 g, 0.487 mmol). The mixture was hydrogenated under an H2 balloon overnight, filtered through Celite, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert-butyl 3-(1-(4- methoxybenzyl)-1H-pyrazol-4-yl)piperidine-1-carboxylate (1.52 g, 4.09 mmol, 84 % yield) as a colorless wax. LCMS (ES, m/s): 372 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.60 (s, 1H), 7.33 (s, 1H), 7.14-7.22 (m, 2H), 6.82-6.94 (m, 2H), 5.16 (s, 2H), 3.87- 3.98 (m, 1H), 3.81 (br d, J=13.2 Hz, 1H), 3.72 (s, 3H), 2.73-2.85 (m, 1H), 2.50-2.58 (m, 2H), 1.88-1.96 (m, 1H), 1.57-1.65 (m, 1H), 1.39-1.50 (m, 2H), 1.38 (s, 9H). Step 4 A mixture of tert-butyl 3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidine-1-carboxylate (1.52 g, 4.09 mmol) and TFA (5.0 mL, 64.9 mmol) was stirred at RT for 30 min, heated at 50 °C overnight, cooled to RT, concentrated and treated carefully with sat. NaHCO3 until basic. The mixture was extracted with DCM (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered and concentrated to afford 3-(1-(4- methoxybenzyl)-1H-pyrazol-4-yl)piperidine (1.12 g, 4.13 mmol, 101 % yield) as a light yellow wax, which was used without purification. LCMS (ES, m/s): 272 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.61 (s, 1H), 7.33 (d, J=0.7 Hz, 1H), 7.15-7.21 (m, 2H), 6.86-6.91 (m, 2H), 5.16 (s, 2H), 3.72 (s, 3H), 3.18 (br dd, J=11.9, 1.3 Hz, 1H), 3.07 (br d, J=11.7 Hz, 1H), 2.54-2.74 (m, 3H), 1.89-1.96 (m, 1H), 1.66-1.76 (m, 1H), 1.50-1.64 (m, 1H), 1.36-1.48 (m, 1H). Step 5 To 3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidine (200 mg, 0.737 mmol) and (R)-2- bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (194 mg, 0.737 mmol) in DMSO (5 mL) was added DIPEA (0.515 mL, 2.95 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column), eluting with 30- 80% EtOAc in hexanes to afford (2S)-N-(5-chloropyridin-2-yl)-2-(3-(1-(4- methoxybenzyl)-1H-pyrazol-4-yl)piperidin-1-yl)propanamide (140 mg, 0.293 mmol, 39.8 % yield) as an off white solid. LCMS (ES, m/s): 454 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 10.24 (s, 1H), 8.36 (dd, J=3.5, 2.8 Hz, 1H), 8.13 (d, J=9.0 Hz, 1H), 7.91 (ddd, J=8.9, 2.6, 1.2 Hz, 1H), 7.58 (s, 1H), 7.30 (d, J=6.6 Hz, 1H), 7.12-7.22 (m, 2H), 6.82- 6.91 (m, 2H), 5.14 (d, J=7.8 Hz, 2H), 3.72 (d, J=4.2 Hz, 3H), 3.43-3.55 (m, 1H), 2.61-2.98 (m, 3H), 2.23-2.39 (m, 1H), 2.09-2.22 (m, 1H), 1.84-1.93 (m, 1H), 1.65-1.74 (m, 1H), 1.48-1.63 (m, 1H), 1.16 (dd, J=6.8, 4.2 Hz, 3H). Example 85 (S)-2-((S)-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-propylpyridin-2-yl)propanamide
Figure imgf000160_0001
Step 1 To 3-(1H-1,2,4-triazol-5-yl)pyridine (1.0 g, 6.84 mmol) and potassium carbonate (1.891 g, 13.68 mmol) in DMF (25 mL) was added (2-(chloromethoxy)ethyl)trimethylsilane (2.427 mL, 13.68 mmol). After 72 h, the reaction was poured into ethyl acetate (250 mL), washed with water (250 mL) and brine, dried over MgSO4, concentrated and purified by silica gel chromatography, eluting with ethyl acetate to afford 3-(1-((2- (trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5-yl)pyridine (1.83 g, 6.62 mmol, 97 % yield). LCMS (m/z) 277 (M+H)+, retention time: 0.99 min, LC/MS Method 3. 1H NMR (DMSO-d6) δ ppm: 9.19 (d, J=2.0 Hz, 1H), 8.87 (s, 1H), 8.65 (dd, J=5.0, 1.5 Hz, 1H), 8.34 (d, J=8.0 Hz, 1H), 7.53 (dd, J=8.0, 4.8 Hz, 1H), 5.59 (s, 2H), 3.64 (t, J=8.0 Hz, 2H), 0.88 (t, J=8.0 Hz, 2H), -0.03 (s, 9H). Step 2 To 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5-yl)pyridine (1.83 g, 6.62 mmol) in methanol (50 mL) was added acetic acid (0.758 mL, 13.24 mmol) followed by palladium hydroxide (20% on carbon) (2.324 g, 3.31 mmol). The reaction was evacuated and purged with hydrogen several times, then stirred overnight under a balloon of hydrogen. The mixture was filtered through Celite, concentrated, treated with 10% aq K2CO3 (30 mL) and extracted with 15% IPA/DCM (2 x 80 mL). The combined organic layers were dried over MgSO4 and concentrated to afford the title compound 3-(1-((2- (trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5-yl)piperidine (1.49 g, 5.28 mmol, 80 % yield), which was used without purification. LCMS (ES, m/s): 283 [M+H]+, retention time: 0.90 min, LC/MS Method 3. Step 3 To 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5-yl)piperidine (313 mg, 1.106 mmol) and (R)-2-bromo-N-(5-propylpyridin-2-yl)propanamide (Intermediate 15) (250 mg, 0.922 mmol) in DMSO (3 mL) was added triethylamine (0.321 mL, 2.305 mmol). After stirring overnight, the reaction was poured into ethyl acetate (30 mL), washed with water (30 mL) and brine, dried over MgSO4, concentrated and purified by silica gel chromatography eluting with 0-15% ethanol in ethyl acetate to afford (2S)-N-(5- propylpyridin-2-yl)-2-(3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol-5- yl)piperidin-1-yl)propanamide in quantitative yield. LCMS (ES, m/s): 473 [M+H]+, retention time: 0.81 min, LC/MS Method 2. 1H NMR (DMSO-d6) δ ppm: 10.06 (d, J=5.8 Hz, 1H), 8.55 (d, J=3.5 Hz, 1H), 8.13-8.18 (m, 1H), 8.03 (d, J=8.3 Hz, 1H), 7.63 (dd, J=8.3, 2.3 Hz, 1H), 3.41-3.59 (m, 4H), 3.01-3.08 (m, 1H), 2.88-3.00 (m, 2H), 2.71-2.84 (m, 1H), 2.68 (br s, 1H), 2.35-2.46 (m, 1H), 2.17-2.35 (m, 1H), 1.49-1.66 (m, 5H), 1.15-1.18 (m, 4H), 0.89 (t, J=7.4 Hz, 3H), 0.80 (dt, J=11.8, 7.9 Hz, 2H), -0.09 (d, J=17.3 Hz, 9H). Step 4 (2S)-N-(5-Propylpyridin-2-yl)-2-(3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-1,2,4-triazol- 5-yl)piperidin-1-yl)propanamide (436 mg, 0.922 mmol) and TFA (4.3 mL, 55.3 mmol) were stirred for 1 h and concentrated. The residue was dissolved in 15% IPA/DCM (30 mL), washed with sat. NaHCO3 solution (20 mL), dried over MgSO4 and concentrated. This material was chirally separated (Lux Amylose 2 / Chiraltech AY, eluting with 95:5 acetonitrile: methanol with 0.1% isopropylamine), collecting the first peak to give (S)-2- ((S)-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-propylpyridin-2-yl)propanamide (92 mg, 0.255 mmol, 27.7 % yield). LCMS (ES, m/s): 343 [M+H]+ retention time: 0.88 min, LC/MS Method 3. 1H NMR (400 MHz, DMSO-d6) δ ppm: 13.68 (br. s., 1H), 10.10 (s, 1H), 8.15 (d, J=2.0 Hz, 1H), 8.04 (d, J=8.4Hz, 1H), 7.64 (dd, J=8.5, 2.4Hz, 1H), 3.49 (q, J=6.6 Hz, 1H), 2.98 (d, J=8.6 Hz, 1H), 2.80 (br. s., 1H), 2.35-2.47 (m, 6 H), 1.97 (d, J=15.5 Hz, 1H), 1.71 (br. s., 1H), 1.58 (dq, J=14.9, 7.4Hz, 4H), 1.13-1.23 (m, 3H), 0.89 (t, J=7.2Hz, 3H). Example 86 was synthesized in an analogous manner using the designated Intermediate in Step 3.
Figure imgf000162_0001
Example 87 (2S)-2-(3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide
Figure imgf000163_0001
Step 1 A mixture of benzyl 3-carbamoylpiperidine-1-carboxylate (2.0 g, 7.62 mmol) and 1,1- dimethoxy-N,N-dimethylmethanamine (10.0 mL, 75 mmol) was heated at 100 °C for 3 h, concentrated and dissolved in acetic acid (10 mL). Hydrazine monohydrate (3.74 mL, 76 mmol) was added, and the resulting mixture was heated at 100 °C for 2 hours, cooled to RT and concentrated. The residue was diluted with water/sat. NaHCO3 and extracted with EtOAc (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 60 mL/min, MeOH/DCM, 0-10%) to afford benzyl 3-(1H-1,2,4- triazol-5-yl)piperidine-1-carboxylate (1.97 g, 6.88 mmol, 90 % yield) as a colorless oil. LCMS (m/z) 287 (M+H)+. 1H NMR (DMSO-d6) δ ppm: 13.65-13.84 (m, 1H), 8.10-8.25 (m, 1H), 7.28-7.41 (m, 5H), 5.03-5.12 (m, 2H), 4.21 (br s, 1H), 3.90-4.02 (m, 1H), 3.26- 3.43 (m, 1H), 2.78-2.97 (m, 2H), 2.04-2.13 (m, 1H), 1.61-1.78 (m, 2H), 1.41-1.55 (m, 1H). Step 2 To benzyl 3-(1H-1,2,4-triazol-5-yl)piperidine-1-carboxylate (1.97 g, 6.88 mmol) in ethanol (10 mL) under N2 was added Pd/C, 10% (0.073 g, 0.688 mmol). The mixture was hydrogenated under an H2 balloon overnight, filtered through Celite and concentrated to afford 3-(1H-1,2,4-triazol-5-yl)piperidine (1.05 g, 6.90 mmol, 100 % yield) as an off white solid, which was used without purification. LCMS (ES, m/s): 153 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 8.01 (s, 1H), 3.09 (br d, J=11.8 Hz, 1H), 2.88 (br d, J=12.0 Hz, 1H), 2.80 (tt, J=10.6, 3.9 Hz, 1H), 2.56-2.66 (m, 1H), 2.40-2.48 (m, 1H), 1.94-2.04 (m, 1H), 1.53-1.67 (m, 2H), 1.35-1.52 (m, 1H). Step 3 To 3-(1H-1,2,4-triazol-5-yl)piperidine (131 mg, 0.860 mmol) and (R)-1-((5-chloropyridin- 2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (305 mg, 0.860 mmol) in DMSO (6 mL) was added DIEA (0.300 mL, 1.719 mmol). The mixture was stirred for 2 days, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, MeOH/DCM 30-80%) to afford (2S)-2-(3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide (285 mg, 0.809 mmol, 94 % yield) as an off white solid. LCMS (ES, m/s): 335 [M+H]+. 1H NMR (DMSO-d6) δ ppm: 13.37-13.88 (m, 1H), 10.28- 10.62 (m, 1H), 8.38 (dd, J=6.4, 2.6 Hz, 1H), 8.14 (d, J=9.0 Hz, 1H), 8.00-8.11 (m, 1H), 7.91 (dd, J=8.9, 2.6 Hz, 1H), 3.52 (quin, J=7.0 Hz, 1H), 2.90-3.07 (m, 2H), 2.68-2.84 (m, 1H), 2.36-2.47 (m, 1H), 2.22-2.31 (m, 1H), 1.90-1.99 (m, 1H), 1.67-1.77 (m, 1H), 1.47- 1.65 (m, 2H), 1.18 (dd, J=6.9, 3.1 Hz, 3H). Example 88a and 88b Ex.88a: (S)-2-((R)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.88b: (S)-2-((S)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
Figure imgf000164_0001
Step 1 To 4-bromo-1H-pyrazole (2.00 g, 13.61 mmol) in THF (50 mL) was added NaH (0.653 g, 16.33 mmol). After 30 min, the reaction was cooled to 0 °C, and SEM-Cl (3.14 mL, 17.69 mmol) was added, dropwise. The resulting mixture was stirred for 4 hours while warming up to RT, quenched with sat NH4Cl and extracted with EtOAc (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford 4-bromo-1-((2- (trimethylsilyl)ethoxy)methyl)-1H-pyrazole (3.76 g, 13.56 mmol, 100 % yield) as a colorless oil. LCMS (m/z) 277 (M+H)+. 1H NMR (DMSO-d6) δ ppm: 8.15 (d, J=0.7 Hz, 1H), 7.63 (d, J=0.7 Hz, 1H), 5.37 (s, 2H), 3.48-3.56 (m, 2H), 0.77-0.88 (m, 2H), -0.05 (s, 9H). Step 2 To tert-butyl 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.50 g, 4.85 mmol), Na2CO3 (1.028 g, 9.70 mmol) and 4-bromo-1-((2- (trimethylsilyl)ethoxy)methyl)-1H-pyrazole (2.017 g, 7.28 mmol) in water (5.00 mL) and dioxane (15.0 mL) was added PdCl2(dppf)-CH2Cl2adduct (0.396 g, 0.485 mmol). The resulting mixture was heated to 95 °C for 3 hours, cooled to RT, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert- butyl 5-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-4-yl)-3,6-dihydropyridine-1(2H)- carboxylate (1.68 g, 4.43 mmol, 91 % yield) as a light yellow oil. LCMS (ES, m/s): 380 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.95 (s, 1H), 7.70 (s, 1H), 6.13 (br s, 1H), 5.35 (s, 2H), 4.04 (br d, J=2.0 Hz, 2H), 3.46-3.60 (m, 2H), 3.44 (br t, J=5.5 Hz, 2H), 2.18 (br d, J=3.9 Hz, 2H), 1.42 (s, 9H), 0.74-0.90 (m, 2H), -0.05 (s, 9H). Step 3 To tert-butyl 5-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-4-yl)-3,6- dihydropyridine-1(2H)-carboxylate (1.68 g, 4.43 mmol) in ethanol (10 mL) under N2 was added Pd/C, 10% (0.047 g, 0.443 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-40% EtOAc in hexanes to afford tert-butyl 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol- 4-yl)piperidine-1-carboxylate (1.69 g, 4.43 mmol, 100 % yield) as a colorless wax. LCMS (ES, m/s): 382 [M+H]+. 1H NMR (DMSO-d6) δ ppm: 7.71 (s, 1H), 7.42 (s, 1H), 5.32 (s, 2H), 3.87-4.03 (m, 1H), 3.78-3.86 (m, 1H), 3.44-3.55 (m, 2H), 2.67-2.92 (m, 2H), 2.52- 2.62 (m, 1H), 1.89-1.99 (m, 1H), 1.57-1.68 (m, 1H), 1.41-1.56 (m, 2H), 1.39 (s, 9H), 0.75- 0.83 (m, 2H), -0.06 (s, 9H). Step 4 A mixture of tert-butyl 3-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrazol-4- yl)piperidine-1-carboxylate (350 mg, 0.917 mmol) and TFA (3.0 mL, 38.9 mmol) was stirred for 3 hours and concentrated to afford 3-(1H-pyrazol-4-yl)piperidine, trifluoroacetic acid salt (243 mg, 0.916 mmol, 100 % yield) as a colorless wax, which was used without purification. LCMS (ES, m/s): 152 [M+H]+. Step 5 To 3-(1H-pyrazol-4-yl)piperidine, trifluoroacetic acid salt (243 mg, 0.916 mmol) and (R)- 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (241 mg, 0.916 mmol) in DMSO (5 mL) was added DIEA (0.640 mL, 3.66 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via RPHPLC (HPLC conditions: Waters Xbridge C1820x100mm; solvent A: water+0.1% NH4OH, B: acetonitrile gradient: 10-50% B; Flowrate:18 mL/min; Gradient time: 12 min) to afford (S)-2-((R)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or (S)-2-((S)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide (37.5 mg, 0.107 mmol, 11.65 % yield) as an off white solid. LCMS (ES, m/s): 334 [M+H]+. 1H NMR (DMSO-d6) δ ppm: 12.45-12.61 (m, 1H), 10.25 (s, 1H), 8.36 (dd, J=2.7, 0.7 Hz, 1H), 8.11-8.17 (m, 1H), 7.91 (dd, J=8.9, 2.6 Hz, 1H), 7.46-7.58 (m, 1H), 7.29-7.39 (m, 1H), 3.48 (q, J=7.0 Hz, 1H), 2.79-2.92 (m, 2H), 2.63-2.75 (m, 1H), 2.29-2.39 (m, 1H), 2.13 (t, J=10.8 Hz, 1H), 1.85-1.94 (m, 1H), 1.67-1.75 (m, 1H), 1.53- 1.66 (m, 1H), 1.22-1.35 (m, 1H), 1.18 (d, J=6.8 Hz, 3H). Examples 89 and 90 Ex.89: (S)-N-(5-chloropyridin-2-yl)-2-((3S,3'S)-6'-oxo-[3,3'-bipiperidin]-1- yl)propanamide and Ex.90: (S)-N-(5-chloropyridin-2-yl)-2-((3S,3'R)-6'-oxo-[3,3'- bipiperidin]-1-yl)propanamide
Figure imgf000167_0001
Step 1 To 2-(benzyloxy)-5-bromopyridine (1.00 g, 3.80 mmol, 1.0 eq) and tert-butyl 5-(4,4,5,5- tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate (1.41 g, 4.56 mmol, 1.2 eq) in dioxane/water (50 mL, 4/1) were added Pd(dppf)Cl2 (621 mg, 0.85 mmol, 0.2 eq) and sodium carbonate (1.21 g, 11.40 mmol, 3.0 eq). The reaction was flushed with nitrogen and stirred at 60 oC. After 16 h, the mixture was quenched with water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic extracts were dried over sodium sulfate, concentrated and purified over a silica gel column, eluting with 0— 10% ethyl acetate in petroleum ether to give 1.35 g (yield: 97 %, purity: 96%) of tert-butyl 6'-(benzyloxy)-5,6-dihydro-[3,3'-bipyridine]-1(2H)-carboxylate as yellow syrup. LCMS (ES, m/s): 367 [M+H]+ . Step 2 A mixture of tert-butyl 6'-(benzyloxy)-5,6-dihydro-[3,3'-bipyridine]-1(2H)-carboxylate (1.20 g, 3.28 mmol, 1.0 eq) and Pd/C (10%, 1.20 g) in methanol (15 mL) was evacuated and flushed three times with nitrogen, followed by flushing with hydrogen. The reaction was stirred for 16 h at 60 oC under 40 atm hydrogen, filtered, concentrated and purified over a C18 column, eluting with 5-95% AcCN in water (10 mmol/L NH4HCO3) to give 900 mg (yield: 97%, purity: 100%) of tert-butyl 6'-oxo-[3,3'-bipiperidine]-1-carboxylate as a light yellow solid. LCMS (ES, m/s): 565 [M+H]+ . Step 3 To tert-butyl 6'-oxo-[3,3'-bipiperidine]-1-carboxylate (900 mg, 3.19 mmol, 1.0 eq) in dioxane (10 mL) was added HCl (8 mL, 4M in dioxane), dropwise. After 18 h the reaction was concentrated to give 600 mg crude [3,3'-bipiperidin]-6-one as a white solid, which was used without purification. LCMS (ES, m/s): 183 [M+H]+ . Step 4 A mixture of [3,3'-bipiperidin]-6-one (as free base) (300 mg, 1.65 mmol, 1.0 eq), (R)-2- bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (522 mg, 1.98 mmol, 1.2 eq) and triethylamine (833 mg, 8.35 mmol, 5.0 eq) in tetrahydrofuran (20 mL) was stirred for 16 h at 40 oC, poured into water (80 mL) and extracted with ethyl acetate (80 mL x 3). The combined organic phases were dried over sodium sulfate, concentrated and purified by prep-TLC (methanol /dichloromethane = 1/20) to give 300 mg of a light yellow solid. This material was chirally separated (column: CHIRAL ART Cellulose-SB, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex, Mobile Phase B: EtOH, A:B 1:1) to provide three peaks with retention times of 10.294, 11.622 and 33.97 min. The second peak (11.622 min) was collected and further chirally separated (column: CHIRALPAK IG-03, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex: DCM = 5:1, Mobile Phase B: EtOH, A:B 1:1) to provide two peaks with retention times of 22.514 and 25.99 min, (S)-N- (5-chloropyridin-2-yl)-2-((3S,3'S)-6'-oxo-[3,3'-bipiperidin]-1-yl)propanamide and (S)-N-(5- chloropyridin-2-yl)-2-((3S,3'R)-6'-oxo-[3,3'-bipiperidin]-1-yl)propanamide. Peak one (22.51 min): LCMS (ES, m/s): 365 [M+H]+ retention time: 0.676 min, LC/MS Method 16. 1H NMR (300 MHz, DMSO-d6) δ ppm: 10.19 (s, 1H), 8.37 (d, J=2.4 Hz, 1H), 8.13 (d, J=8.7 Hz, 1H), 7.94-7.90 (m, 1H), 7.38 (s, 1H), 3.49-3.46 (m, 1H), 3.16-3.12 (m, 1H), 2.90-2.59 (m, 3H), 2.18-2.07 (m, 4H), 1.79-1.65 (m, 3H), 1.50-1.29 (m, 4H), 1.18- 1.16 (m, 3H), 1.04-0.97 (m, 1H). Peak two (25.99 min): LCMS (ES, m/s): 365 [M+H]+ retention time: 0.673 min, LC/MS Method 22. 1H NMR (300 MHz, DMSO-d6) δ ppm: 10.20 (s, 1H), 8.36 (d, J=3.5, 1H), 8.13 (d, J=9.0 Hz, 1H), 7.92 (dd, J=2.7, 9.0 Hz, 1H), 7.39 (d, J=2.7 Hz, 1H), 3.49-3.47 (m, 1H), 3.26-3.15 (m, 1H), 2.90-2.88 (m, 2H), 2.65-2.61 (m, 1H), 2.17-2.07 (m, 4H), 1.88- 1.65 (m, 3H), 1.62-1.39 (m, 4H), 1.14 (d, J=6.9 Hz, 3H), 1.09-1.00 (m, 1H). Examples 91 and 92 Ex.91: (S)-2-((3S,3'R)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide and Ex.92: (S)-2-((3S,3'S)-4,4-difluoro-6'- oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide
Figure imgf000169_0001
Step 1 To sodium tert-butoxide (278.1 g, 2894 mmol) in THF (2.15 L) were added tert-butyl 4- oxopiperidine-1-carboxylate (287.7 g, 1444 mmol) and 5-bromo-2-methoxypyridine (180.1 g, 958 mmol), using THF (250 mL) to rinse. The mixture was evacuated and back-filled with nitrogen (3x), then XPhos (45.7 g, 96 mmol) and palladium(II) acetate (10.75 g, 47.9 mmol) were added, using THF (0.35 L) to rinse. The reaction was heated to 45 °C for 22 h, cooled to 0 °C, and quenched slowly with water (1.575 L) and brine (675 mL). EtOAc (2.3 L) was added, and the mixture was agitated for 10 min. The layers were separated, and the aqueous layer was extracted with EtOAc (2 X 1.35 L). The combined organics were washed with brine (900 mL), concentrated and purified by column chromatography, eluting with 15-75% EtOAc in heptane to provide tert-butyl 3-(6-methoxypyridin-3-yl)-4- oxopiperidine-1-carboxylate (210 g, 685 mmol, purity: 84 %, recovery: 74 %). LCMS (m/z) 307 (M+H)+, retention time: 0.91 min, LC/MS Method 3.1H NMR: (400 MHz, CDCl3) δ ppm 7.99 (d, J=2.4 Hz, 1H), 7.41 (dd, J=8.8, 2.4 Hz, 1H), 6.77 (d, J=8.8 Hz, 1H), 4.24-4.39 (m, 2H), 3.95 (s, 3H), 3.69 (dd, J=10.5, 6.1 Hz, 1H), 3.43 (ddd, J=13.3, 10.1, 4.4 Hz, 2H), 2.53-2.65 (m, 2H), 1.53 (s, 9H). Step 2 To XtalFluor-E (199 g, 868 mmol) in DCM (585 mL) at -1.1 °C was slowly added a solution of triethylamine trihydrofluoride (140 g, 868 mmol) and pyridine (34.3 g, 434 mmol) in DCM (414 mL), followed by a solution of tert-butyl 3-(6-methoxypyridin-3-yl)- 4-oxopiperidine-1-carboxylate (133 g, 434 mmol) in DCM (794 mL). The reaction was warmed to 25 °C and after 3 h slowly poured into a stirred sat’d NaHCO3 sol’n cooled to - 5 °C. The mixture was warmed to 25 °C, the layers were separated, and the aqueous layer was extracted with DCM (2 X 1.3 L). The combined organics were dried over sodium sulfate, concentrated and purified by column chromatography, eluting with 5-45% EtOAc in heptane to provide tert-butyl 4,4-difluoro-3-(6-methoxypyridin-3-yl)piperidine-1- carboxylate (64.37 g, 196 mmol, purity: 90 %, recovery: 45 %). LCMS (m/z) 328 (M+H)+, retention time: 1.02 min, LC/MS Method 5. 1H NMR: (400 MHz, CDCl3) δ ppm 8.09 (d, J=2.45 Hz, 1H), 7.54 (br d, J=8.31 Hz, 1H), 6.74 (d, J=8.31 Hz, 1H), 4.19-4.38 (m, 3H), 3.94 (s, 3H), 2.85-3.19 (m, 2H), 1.87-2.09 (m, 2H), 1.42-1.55 (m, 9H). Step 3 To a 48% aqueous solution of hydrobromic acid (40.9 mL, 361 mmol) was added a solution of tert-butyl 4,4-difluoro-3-(6-methoxypyridin-3-yl)piperidine-1-carboxylate (12.6 g, 38.4 mmol) in toluene (40 mL), dropwise. The reaction was stirred at 95 °C overnight, concentrated, taken up in 2-MeTHF (100 mL) and treated with a 3M solution of hydrochloric acid in cyclopentylmethyl ether (CPME) (130 mL). Dilution to approximately 250 mL total volume with 2-methyltetrahydrofuran, sonication of the gel- salt/organic mixture for approximately five minutes and subsequent stirring at room temperature for 30 minutes afforded a thick pale green suspension. The suspended solids were then collected by suction filtration and dried. This material was subjected to chiral resolution, after neutralization with isopropylamine before injection, via Agilent semi-prep 1200 through an AD-H column (5 microns-20 mm x 250 mm), eluting with 70:30 AcCN: MeOH at 45 ml/min. The enantiomers eluted at 3.981 min and 8.269 min. The first-eluting isomer (3.981 min) was stirred in AcCN (250 mL) at 60 °C with activated charcoal (3 g) for 90 min. The mixture was filtered through Celite, concentrated, and the residue was triturated with AcCN to provide (S)-5-(4,4-difluoropiperidin-3-yl)pyridin-2(1H)-one (2.568 g, 11.87 mmol, recovery: 31 %) as a light tan solid. LCMS (m/z) 215 (M+H)+, retention time: 0.39 min, LC/MS Method 3. 1H NMR (400 MHz, MeOH-d4) δ ppm 7.60 (ddd, J=9.54, 2.69, 0.98 Hz, 1H), 7.37 (d, J=2.45 Hz, 1H), 6.53 (d, J=8.80 Hz, 1H), 3.05- 3.23 (m, 2H), 2.92-3.05 (m, 2H), 2.86 (td, J=13.21, 2.93 Hz, 1H), 1.84-2.21 (m, 2H). Step 4 (S)-5-(4,4-difluoropiperidin-3-yl)pyridin-2(1H)-one (500 mg, 2.334 mmol) was dissolved in methanol (10 mL) and platinum(IV) oxide (106 mg, 0.467 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. The reaction was stirred at room temperature for 40 h. The reaction was filtered through Celite and solid was washed by methanol (3 X 10 mL). The filtrate was combined and concentrated in vacuo to give (S)-4',4'-difluoro-[3,3'-bipiperidin]-6-one (480 mg, 2.199 mmol, 94 % yield). LCMS: (ES, m/z): 219.2 [M+H]+.1H NMR (400 MHz, METHANOL-d4) δ ppm 3.36 - 3.52 (m, 1 H) 3.08 - 3.29 (m, 3 H) 2.74 - 2.85 (m, 1 H) 2.65 (t, J=12.47 Hz, 1 H) 2.29 - 2.42 (m, 2 H) 1.50 - 2.26 (m, 6 H). Step 5 To a solution of (R)-2-bromo-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (Intermediate 17) (196 mg, 0.550 mmol) in DMA (2 ml) was added (S)-4',4'-difluoro-[3,3'- bipiperidin]-6-one (120 mg, 0.550 mmol) followed by TEA (0.230 mL, 1.650 mmol) and silver nitrate (187 mg, 1.100 mmol). The mixture was stirred at rt overnight. The reaction mixture was diluted with EtOAc (10 mL) and then filtered to remove silver salts. The filtrate was then concentrated in vacuo to ~2 mL solution (DMA). The sample was purified by reverse phase XSelect CSH Prep C185μM OBD (Gradient 30% to 85% B over 19min, flow rate 40 mL/min, A: Water with 0.1% Formic Acid /B: Acetonitrile with 0.1% Formic Acid) to obtain (S)-2-((S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide (36.2 mg, 0.072 mmol, 13.05 % yield) as a mixture of 2 diastereomers. 25 mg of this mixture was chirally separated (Column: IC (5 microns - 20 mm x 250 mm), flow rate: 20mL/min, solvents: 40:60 Heptane: Ethanol, modifier: 0.1% isopropylamine) to provide two pure stereoisomers at retention times of 8.4 min and 10.5 min, (S)-2-((3S,3'R)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5- (2,4-difluorophenoxy)pyridin-2-yl)propanamide and (S)-2-((3S,3'S)-4,4-difluoro-6'-oxo- [3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide. Peak one (8.4 min) (9.67 mg): LCMS (ES, m/s): 495.1 [M+H]+, rt = 1.06 min, Method 3, 1H NMR (400 MHz, DMSO-d6) δ ppm 10.27 (s, 1 H) 8.14 (d, J=2.93 Hz, 1 H) 8.09 (d, J=8.80 Hz, 1 H) 7.45 - 7.56 (m, 2 H) 7.42 (d, J=3.42 Hz, 1 H) 7.30 (td, J=9.29, 5.87 Hz, 1 H) 7.09 - 7.16 (m, 1 H) 3.60 (q, J=6.85 Hz, 1 H) 3.17 (br d, J=11.25 Hz, 1 H) 2.83 - 3.03 (m, 2 H) 2.76 (br d, J=12.23 Hz, 1 H) 2.35 - 2.47 (m, 2 H) 2.14 - 2.21 (m, 2 H) 1.85 - 2.11 (m, 5 H) 1.57 - 1.71 (m, 1 H) 1.17 (d, J=6.85 Hz, 3 H). Peak two (10.5 min) (13.46 mg): LCMS (ES, m/s): 495.1 [M+H]+, rt = 1.05 min, Method 3, 1H NMR (400 MHz, DMSO-d6) δ ppm 10.28 (s, 1 H) 8.15 (d, J=2.93 Hz, 1 H) 8.10 (d, J=8.80 Hz, 1 H) 7.48 - 7.54 (m, 2 H) 7.43 (d, J=3.42 Hz, 1 H) 7.31 (td, J=9.29, 5.38 Hz, 1 H) 7.11 - 7.16 (m, 1 H) 3.63 (q, J=6.85 Hz, 1 H) 3.26 (br d, J=12.23 Hz, 1 H) 2.97 - 3.08 (m, 2 H) 2.77 (br d, J=11.25 Hz, 1 H) 2.37 - 2.46 (m, 2 H) 2.08 - 2.17 (m, 2 H) 1.81 - 2.07 (m, 5 H) 1.40 - 1.50 (m, 1 H) 1.18 (d, J=6.85 Hz, 3 H). Examples 93-97 were synthesized in an analogous manner, using the designated Intermediate in Step 5.
Figure imgf000172_0001
Figure imgf000173_0001
Figure imgf000174_0001
Figure imgf000175_0001
Example 98 (2S)-2-(4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide
Figure imgf000176_0001
Step 1
A degassed solution of tert-butyl 4-oxopiperidine-l -carboxylate (5.66 g, 28.4 mmol) and sodium tert-butoxide (5.46 g, 56.8 mmol) in Tetrahydrofuran (THF) (60 ml) under nitrogen was treated with 2-(benzyloxy)-5-bromopyridine (5 g, 18.93 mmol) followed by XPhos (1.805 g, 3.79 mmol) and then palladium(II) acetate (0.425 g, 1.893 mmol) and the reaction mixture was heated at 50 °C overnight. The reaction mixture was diluted with water and extracted 3x with EtOAc. The combined organic extracts were washed with brine, dried over sodium sulfate and concentrated. The resulting residue was purified by silica gel column chromatography (ISCO 120 gram column, EtOAc/Heptane 0% to 50%) to afford tert-butyl 3 -(6-(benzyloxy )pyri din-3 -yl)-4-oxopiperi dine- 1 -carboxylate (5684 mg, 13.52 mmol, 71.4 % yield) as a dark yellow oil. LCMS: (ES, m/z): 383 [M+H]+. Step 2 XtalFluor-E (6210 mg, 27.1 mmol) was dissolved in Dichloromethane (DCM) (30 mL) and chilled with an ice batch. In an separate vial, triethylamine trihydrofluoride (4.42 mL, 27.1 mmol) and pyridine (1.097 mL, 13.56 mmol) were dissolved in Dichloromethane (DCM) (15 mL) and the mixture was then slowly added into reaction. The mixture was stirred in icebath for 20 min. tert-butyl 3-(6-(benzyloxy)pyridin-3-yl)-4-oxopiperidine-1-carboxylate (5186 mg, 13.56 mmol) in Dichloromethane (DCM) (15 mL) was then slowly added to the reaction. The reaction was then stirred for 30 min with icebath and additional 3h at room temperature. The reaction was chilled in an icebath.100 mL sat. NaHCO3 solution was slowly added to reaction mixture, followed by 100 mL DCM. The ending point pH ~8. Layers were separated and aqueous layer was extracted by DCM (2 X 100 mL). The combined organic layer was washed by brine and dried over Na2SO4. The solution was filtered and concentrated in vacuo. The crude product was purified by ISCO 220 silica column (EtOAc/Heptane 0% to 30%) to give tert-butyl 3-(6-(benzyloxy)pyridin-3-yl)-4,4- difluoropiperidine-1-carboxylate (1061 mg, 2.62 mmol, 19.35 % yield). LCMS: (ES, m/z): 405.3 [M+H]+. Step 3 tert-butyl 3-(6-(benzyloxy)pyridin-3-yl)-4,4-difluoropiperidine-1-carboxylate (1.16 g, 2.87 mmol) was dissolved in Methanol (15 mL) and Pd-C (0.305 g, 0.287 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. After one hour of reaction, LCMS showed all starting material was consumed and desired product was formed. The reaction was filtered through Celite and solid was washed by methanol (3 X 10mL). The filtrate was combined and concentrated in vacuo to give tert-butyl 4,4-difluoro-3-(6-oxo-1,6-dihydropyridin-3- yl)piperidine-1-carboxylate (900 mg, 2.86 mmol, 100 % yield). LCMS: (ES, m/z): 315.2 [M+H]+.1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.46 (br d, J=9.29 Hz, 1 H) 7.37 (s, 1 H) 6.60 (d, J=9.29 Hz, 1 H) 4.21 (br s, 2 H) 3.08 (br s, 2 H) 2.76 - 2.92 (m, 1 H) 2.07 - 2.21 (m, 1 H) 1.84 - 2.05 (m, 1 H) 1.48 (s, 9 H). Step 4 tert-butyl 4,4-difluoro-3-(6-oxo-1,6-dihydropyridin-3-yl)piperidine-1-carboxylate (460 mg, 1.463 mmol) and cesium carbonate (715 mg, 2.195 mmol) was dissolved in N,N- Dimethylformamide (DMF) (6.5 mL).2,2,2-trifluoroethyl trifluoromethanesulfonate (0.316 mL, 2.195 mmol) was then added to the reaction. The reaction was stirred at room temperature for 1h. The reaction was then diluted with EtOAc (100 mL) and the organic layer was washed with water (20 mL) and brine (20 mL). After drying with Na2SO4, the organic layer was filtered and concentrated in vacuo. The crude product was purified by ISCO 40g silica column (EtOAc/Heptane 0% to 80%) to give tert-butyl 4,4-difluoro-3-(6- oxo-1-(2,2,2-trifluoroethyl)-1,6-dihydropyridin-3-yl)piperidine-1-carboxylate (240 mg, 0.606 mmol, 41.4 % yield). LCMS: (ES, m/z): 397.4 [M+H]+.1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.34 (d, J=9.53 Hz, 1 H) 7.18 - 7.25 (m, 1 H) 6.62 (d, J=9.29 Hz, 1 H) 4.54 - 4.69 (m, 2 H) 4.08 - 4.28 (m, 2 H) 3.05 - 3.21 (m, 2 H) 2.76 - 2.90 (m, 1 H) 2.09 - 2.22 (m, 1 H) 1.86 - 2.03 (m, 1 H) 1.49 (s, 9 H). Step 5 tert-butyl 4,4-difluoro-3-(6-oxo-1-(2,2,2-trifluoroethyl)-1,6-dihydropyridin-3- yl)piperidine-1-carboxylate (330 mg, 0.833 mmol) was dissolved in Methanol (10 mL) and Pd-C (89 mg, 0.083 mmol) was then added to the reaction. The reaction was purged with hydrogen and the hydrogenation was conducted with hydrogen balloon. After one hour of reaction, LCMS showed all starting material was consumed and desired product was formed. The reaction was filtered through Celite and solid was washed by methanol (3 X 10mL). The filtrate was combined and concentrated in vacuo to give tert-butyl 4,4- difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidine]-1-carboxylate (300 mg, 0.749 mmol, 90 % yield). LCMS: (ES, m/z): 345.3 [M+H-tBu]+. Step 6 To tert-butyl 4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidine]-1-carboxylate (300 mg, 0.749 mmol) was added HCl in dioxane (3 mL, 12.00 mmol). After stirring at room temperature for 2h, The organic solvents were removed in vacuo to give 4',4'- difluoro-1-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-6-one, Hydrochloride (250 mg, 0.742 mmol, 99 % yield). The product was used in next step without purification. LCMS: (ES, m/z): 301.2 [M+H]+. Step 7 To a solution of (R)-2-bromo-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (140 mg, 0.392 mmol) (Intermediate 17) in DMA (2 ml) was added 4',4'-difluoro-1-(2,2,2- trifluoroethyl)-[3,3'-bipiperidin]-6-one, hydrochloride (132 mg, 0.392 mmol) followed by TEA (0.219 mL, 1.568 mmol) and silver nitrate (133 mg, 0.784 mmol). The mixture was stirred at rt overnight. The reaction mixture was filtered to remove some silver salts. The filtrate was diluted with EtOAc and washed with satd. K2CO3 solution. The organic phase was washed 1x with a mix of satd. K2CO3 solution and brine, then dried over Na2SO4, filtered and concentrated. The sample was purified by reverse phase C18 AQ 100g Gold (Gradient 50% to 80% B over 19min, flow rate 60 mL/min, A: Water with 10mM Ammonium Bicarb and 0.075% Ammonium Hydroxide/B: Acetonitrile) and obtained (2S)-2-(4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide (107 mg, 0.180 mmol, 45.9 % yield) (mixture of 4 diastereomers). LCMS (ES, m/s): 577.3 [M+H]+, rt = 1.20-1.30 min, Method 3,
Figure imgf000179_0001
NMR (400 MHz, DMSO-d6) δ ppm 10.17 - 10.43 (m, 1 H) 7.94 - 8.24 (m, 2 H) 7.42 - 7.61 (m, 2 H) 7.23 - 7.41 (m, 1 H) 7.07 - 7.20 (m, 1 H) 3.43 - 4.30 (m, 3 H) 3.21 - 3.43 (m, 4 H) 2.55 - 3.07 (m, 2 H) 2.24 - 2.49 (m, 4 H) 1.63 - 2.24 (m, 4 H) 1.42 - 1.62 (m, 1 H) 1.11 - 1.28 (m, 2 H). Example 99 was synthesized in an analogous manner, using the designated Intermediate in Step 7.
Figure imgf000179_0002
Figure imgf000180_0003
Figure imgf000180_0002
Figure imgf000180_0001
Example 100a and 100b Ex.100a: (S)-2-((R)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.100b: (S)-2-((S)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
Figure imgf000181_0001
Step 1 To tert-butyl 3-hydroxypiperidine-1-carboxylate (3.00 g, 15.93 mmol, 1.0 eq) and TEA (2.26 g, 22.39 mmol, 1.5 eq) in DCM (100 mL) at 0 °C was added MsCl (1.87 g, 16.42 mmol, 1.1 eq), dropwise. The reaction was stirred at room temperature for 2 h, poured into water (300 mL) and extracted with dichloromethane (200 mL x 3). The organic phases were combined, dried over sodium sulfate and concentrated to give tert-butyl 3- ((methylsulfonyl)oxy)piperidine-1-carboxylate (4.0 g, yield: 90%, purity: 99% ) as a yellow oil, which was used without purification. LCMS (ES, m/s): 280 [M+H]+ . 1H NMR: (300 MHz, CDCl3) δ ppm 4.73-4.71 (m, 2H), 3.76-3.62 (m, 2H), 3.49-3.43 (m, 1H), 3.37-3.30 (m, 2H), 3.05 (s, 3H), 2.03-1.70 (m, 2H), 1.47 (s, 9H). Step 2 To 1H-pyrazole (975 mg, 14.29 mmol, 2.0 eq) and DMF (50 mL) at 0 °C was added NaH (60%, 516 mg, 12.9 mmol, 1.8 eq), in portions. The reaction was stirred at room temperature for 1 hour, then tert-butyl 3-((methylsulfonyl)oxy)piperidine-1-carboxylate (200 mg, 7.14 mmol, 1.0 eq) in DMF (10 mL) was added. The mixture was stirred at 100 °C for 16 h, poured into water (400 mL) and extracted with ethyl acetate (300 mL x 3). The combined organic phases were washed with brine (500 mL), dried over sodium sulfate, concentrated and purified via silica gel column, eluting with ethyl acetate : petroleum (1:4) to give tert-butyl 3-(1H-pyrazol-1-yl)piperidine-1-carboxylate (300 mg, yield: 17%, purity: 100%) as yellow oil. LCMS (ES, m/s): 252 [M+H]+ . 1H NMR: (400 MHz, CDCl3) δ ppm 7.55-7.54 (m, 1H), 7.48-7.47 (m, 1H), 6.27-6.25 (m, 1H), 4.34-4.18 (m, 2H), 3.28-3.22 (m, 1H), 2.95-2.89 (m, 1H), 2.22-2.11 (m, 3H), 1.82-1.79 (m, 1H), 1.63-1.60 (m, 1H), 1.48 (s, 9H). Step 3 A mixture of tert-butyl 3-(1H-pyrazol-1-yl)piperidine-1-carboxylate (300 mg, 1.36 mmol, 1.0 eq), dichloromethane (9 mL) and TFA (3 mL) was stirred at rt for 2 h and concentrated to give 3-(1H-pyrazol-1-yl)piperidine as a yellow solid, which was used without purification. LCMS (ES, m/s): 152 [M+H]+. 1H NMR: (400 MHz, CD3OD) δ ppm 7.75- 7.71 (m, 1H), 7.57-7.55 (m, 1H), 6.37-6.35 (m, 1H), 4.73-4.65 (m, 1H), 3.63-3.49 (m, 2H), 3.37-3.35 (m, 1H), 3.25-3.17 (m, 1H), 2.28-2.20 (m, 3H), 1.93-1.79 (m, 1H). Step 4 A mixture of 3-(1H-pyrazol-1-yl)piperidine (as free base) (90 mg, 0.6 mmol, 1.0 eq), (R)- 2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (156 mg, 0.6 mmol, 1.0 eq) and TEA (301 mg, 3.0 mmol, 5.0 eq) in THF (10 mL) was stirred at 40 °C for 24 h, poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3). The combined organic extracts were washed with brine (200 mL), dried over sodium sulfate, concentrated and purified by prep TLC with ethyl acetate : petroleum ether (1:5) to give 120 mg product. This material was chirally separated (column: CHIRALPAK IF, 2x25cm, 5 um, flow rate: 15 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 1:1) to provide two peaks with retention times of 9.739 and 13.144 min. The first peak (9.739 min) was collected to give (S)-2-((R)-3-(1H-pyrazol-1-yl)piperidin-1-yl)- N-(5-chloropyridin-2-yl)propanamide or (S)-2-((S)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N- (5-chloropyridin-2-yl)propanamide (35.5 mg, yield, 18 %, purity: 99%, ee%: 100%) as a white solid. LCMS (ES, m/s): 334 [M+H]+ retention time: 0.910 min, LC/MS Method 23. 1H NMR (300 MHz, CD3OD) δ ppm: 8.29 (d, J=1.8 Hz, 1H), 8.20 (d, J=9.0 Hz, 1H), 7.83- 7.80 (m, 1H), 7.72 (d, J=2.4 Hz, 1H), 7.49 (d, J=0.5 Hz, 1H), 6.29-6.27 (m, 1H), 4.62-4.43 (m, 1H), 3.49-3.42 (m, 1H), 3.12-3.08 (m, 1H), 2.91-2.87 (m, 1H), 2.62-2.48 (m, 2H), 2.17-2.14 (m, 1H), 2.01-1.83 (m, 3H), 1.30 (d, J=6.9 Hz, 3H). Example 101a and 101b Ex.101a: (S)-2-((R)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2- yl)propanamide or Ex.101b: (S)-2-((S)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide
Figure imgf000183_0001
Step 1 To DMF (10 mL) and NaH (60%, 240 mg, 6.00 mmol, 1.0 eq) was added 2H-1,2,3-triazole (412 mg, 5.97 mmol, 1.0 eq). After 30 min, tert-butyl 3-((methylsulfonyl)oxy)piperidine- 1-carboxylate (Example 100, Step 1) (2.00 g, 7.17 mmol, 1.2 eq) in DMF (3 mL) was added dropwise, and the reaction was stirred at 60 oC. After 20 h, the mixture was poured into water (100 mL) and extracted with ethyl acetate (100 mL x 3). The organic phases were washed with brine (200 mL x 2), dried over sodium sulfate, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum (3:7) give tert-butyl 3-(2H- 1,2,3-triazol-2-yl)piperidine-1-carboxylate (340 mg, yield: 22 %, purity: 100%) as colorless oil. LCMS (ES, m/s): 253 [M+H]+ . 1H NMR: (300 MHz, CDCl3) δ ppm 7.28 (s, 2H), 4.62-4.55 (m, 1H), 4.43-4.27 (m, 1H), 4.12-4.02 (m, 1H), 3.36-3.31 (m, 1H), 2.96- 2.86 (m, 1H), 2.34-2.29 (m, 1H), 2.19-2.07 (m, 1H), 1.94-1.87 (m, 1H), 1.71-1.62 (m, 1H), 1.46 (s, 9H). Step 2 To tert-butyl 3-(2H-1,2,3-triazol-2-yl)piperidine-1-carboxylate (340 mg, 1.34 mmol, 1 eq) in dioxane (5 mL) was added HCl (5 mL, 4M in dioxane), dropwise. After 16 h the reaction was concentrated to give 3-(2H-1,2,3-triazol-2-yl)piperidine as colorless oil, which was used without purification. LCMS (ES, m/s): 153 [M+H]+. 1H NMR: (300 MHz, CD3OD) δ ppm 7.80 (s, 2H), 5.03-5.01 (m, 1H), 3.80-3.66 (m, 2H), 3.37-3.23 (m, 2H), 2.35-2.31 (m, 2H), 1.93-1.89 (m, 2H). Step 3 PB67047FF A mixture of 3-(2H-1,2,3-triazol-2-yl)piperidine (as free base) (100 mg, 0.65 mmol, 1.0 eq), (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (172 mg, 0.65 mmol, 1.0 eq) and TEA (664 mg, 6.57 mmol, 10.0 eq) in THF (8 mL), was stirred for 18 h at 40 oC, quenched with water (80 mL) and extracted with ethyl acetate (80 mL x 3). The organic phases were washed with brine (200 mL), dried over sodium sulfate, concentrated and purified via preparative TLC, developed with ethyl acetate : petroleum ether (1:5) to give a white solid. This material was chirally separated (column: CHIRALPAK IF, 2x25cm, 5 um, flow rate: 15 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 7:3) to provide two peaks with retention times of 9.287 and 12.357 min. The first peak (9.287 min) was collected to give (S)-2-((R)-3-(2H-1,2,3- triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide or (S)-2-((S)-3-(2H- 1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (37 mg, yield: 17 %, purity: 100%, ee%: 100%) as colorless oil. LCMS (ES, m/s): 335 [M+H]+ retention time: 1.624 min, LC/MS Method 7. 1H NMR (300 MHz, CDCl3) δ ppm: 9.88 (s, 1H), 8.23-8.22 (m, 2H), 7.69-7.61 (m, 3H), 4.84-4.75 (m, 1H), 3.40-3.33 (m, 1H), 3.19-3.15 (m, 1H), 2.89-2.75 (m, 2H), 2.65-2.57 (m, 1H), 2.29-2.23 (m, 1H), 2.17-2.04 (m, 1H), 2.01- 1.81 (m, 2H), 1.35 (d, J=6.9 Hz, 3H). Example 102 (S)-N-(5-chloropyridin-2-yl)-2-((2R,3R)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2S,3S)-2-methyl-3-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (1:1 mix.)
Figure imgf000185_0001
Step 1 To 1H-pyrazole-3-boronic acid (1.17 g, 10.25 mmol) and 3-bromo-2-methylpyridine (1.50 g, 8.55 mmol) in dioxane (68 mL) were added 1M aqueous cesium fluoride (3.28 g, 21.36 mmol), Pd2dba3 (412 mg, 0.43 mmol), and S-Phos (358 mg, 0.85 mmol), under argon. The mixture was stirred in a pressure-proof vessel for 16-20 hours at 100 °C, diluted with water and extracted with DCM. The organic phase was dried, concentrated, and purified by column chromatography, eluting with 0-10 % MeOH in CHCl3, to give 2-methyl-3-(1H- pyrazol-5-yl)pyridine as a pale yellow solid (893 mg, 66 %). LCMS: (ES, m/s) 161 [M+H]+. Step 2 2-Methyl-3-(1H-pyrazol-5-yl)pyridine (659 mg, 4.14 mmol) in MeOH (207 mL) and TFA (0.64 mL) was hydrogenated using an H-Cube (70 mm CatCart of 5 % Ru/C, 100 °C, 50 bar, 0.5 mL/min). The collected material was concentrated, and the crude product was purified by prep HPLC to afford cis-2-methyl-3-(1H-pyrazol-5-yl)piperidine (830 mg, 5.03 mmol) as a yellow oil. LCMS: (ES, m/s) 167 [M+H]+. 1H NMR (300 MHz, CD3OD) δ ppm: 7.65 (d, 1H), 6.25 (d, 1H), 3.64-3.72 (m, 1H), 3.36-3.45 (m, 2H), 3.10-3.18 (m, 1H), 1.92-2.07 (m, 3H), 1.70-1.77(m, 1H), 1.18 (s, 3H). PB67047FF Step 3 To (cis)-2-methyl-3-(1H-pyrazol-5-yl)piperidine (120 mg, 0.726 mmol) and (R)-2-bromo- N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (211 mg, 0.799 mmol) in DMSO (4.0 mL) was added triethylamine (0.202 mL, 1.452 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column), eluting with 40- 90% EtOAc in DCM to afford (S)-N-(5-chloropyridin-2-yl)-2-((2R,3R)-2-methyl-3-(1H- pyrazol-5-yl)piperidin-1-yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2S,3S)-2- methyl-3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamide (95 mg, 0.259 mmol, 35.7 % yield) as an off white solid. LCMS: (ES, m/s) 348 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.28-12.57 (m, 1H), 10.27-10.55 (m, 1H), 8.35-8.44 (m, 1H), 8.07-8.19 (m, 1H), 7.89-7.99 (m, 1H), 7.22-7.74 (m, 1H), 6.01-6.16 (m, 1H), 3.35-3.60 (m, 1H), 3.06-3.31 (m, 2H), 2.34-2.74 (m, 2H), 1.66-1.84 (m, 3H), 1.41-1.63 (m, 1H), 1.20-1.30 (m, 3H), 0.76 (dd, J=9.3, 6.6 Hz, 3H). Example 103 (S)-N-(5-chloropyridin-2-yl)-2-((2S,3R)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2R,3S)-2-methyl-3-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (1:1 mix.)
Figure imgf000186_0001
Step 1 2-Methyl-3-(1H-pyrazol-5-yl)pyridine (Example 102, Step 1) (893 mg, 5.61 mmol) in MeOH (56 mL) and TFA (0.87 mL) was hydrogenated using an H-Cube (70 mm CatCart of 10 % Pd/C, 80 °C, 50 bar, 1 mL/min). The collected material was concentrated to afford the TFA salt of trans-2-methyl-3-(1H-pyrazol-5-yl)piperidine (520 mg, 3.15 mmol, 56 %) as an oil, which was used without purification. LCMS: (ES, m/s) 167 [M+H]+. 1H NMR (300 MHz, DMSO-d6) δ ppm: 9.03 (br d, 1H), 8.63 (br d, 1H), 7.59 (d, 1H), 6.15 (d, 1H), 3.17-3.30 (m, 2H), 2.91-2.94 (m, 1H), 2.77 (m, 1H), 1.66-1.91 (m, 4H), 1.02 (d, 3H). Step 2 To (trans)-2-methyl-3-(1H-pyrazol-5-yl)piperidine (120 mg, 0.726 mmol) and (R)-2- bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (211 mg, 0.799 mmol) in DMSO (4.0 mL) was added triethylamine (0.202 mL, 1.452 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 40 g silica column), eluting with 40-90% EtOAc in DCM, to afford (S)-N-(5-chloropyridin-2-yl)-2-((2S,3R)-2-methyl- 3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2- ((2R,3S)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamide (79 mg, 0.216 mmol, 29.7 % yield) as an off white solid. LCMS: (ES, m/s) 348 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.28-12.70 (m, 1H), 10.06 (s, 1H), 8.34-8.42 (m, 1H), 8.07-8.18 (m, 1H), 7.88-7.98 (m, 1H), 7.28-7.68 (m, 1H), 6.02-6.10 (m, 1H), 3.63-3.98 (m, 1H), 2.30- 3.00 (m, 4H), 1.45-1.88 (m, 4H), 1.07-1.30 (m, 3H), 0.76-0.99 (m, 3H). Example 104 (2S)-N-(5-chloropyridin-2-yl)-2-(3-(3-hydroxy-1H-pyrazol-5-yl)piperidin-1- yl)propanamide
Figure imgf000188_0001
Step 1 To 1-((benzyloxy)carbonyl)piperidine-3-carboxylic acid (5.0 g, 18.99 mmol) in acetonitrile (60 mL) was added CDI (3.70 g, 22.79 mmol), in portions. After 1 h, potassium 3-ethoxy- 3-oxopropanoate (3.23 g, 18.99 mmol) and magnesium chloride (1.808 g, 18.99 mmol) were added, and the resulting mixture was stirred overnight, concentrated, diluted with water, neutralized with citric acid and extracted with EtOAc (3X). The combined organic extracts were washed with brine (2X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-50% EtOAc in hexanes to afford benzyl 3-(3-ethoxy-3-oxopropanoyl)piperidine-1- carboxylate (4.86 g, 14.58 mmol, 77 % yield) as a colorless oil. LCMS: (ES, m/s) 334 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 7.29-7.40 (m, 5H), 5.07 (d, J=1.5 Hz, 2H), 4.05-4.13 (m, 2H), 3.94-4.01 (m, 1H), 3.79 (br d, J=13.2 Hz, 1H), 3.67 (s, 2H), 2.82- 3.11 (m, 2H), 2.61-2.70 (m, 1H), 1.94-2.02 (m, 1H), 1.60-1.69 (m, 1H), 1.33-1.51 (m, 2H), 1.12-1.23 (m, 3H). Step 2 To benzyl 3-(3-ethoxy-3-oxopropanoyl)piperidine-1-carboxylate (4.86 g, 14.58 mmol) in ethanol (60 mL) was added hydrazine monohydrate (1.095 g, 21.87 mmol), slowly, and the mixture was stirred overnight and concentrated. The residue was purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 30-90% EtOAc in DCM to afford benzyl 3-(3-hydroxy-1H-pyrazol-5-yl)piperidine-1-carboxylate (3.69 g, 12.25 mmol, 84 % yield) as a colorless oil. LCMS (ES, m/s): 302 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.31-7.40 (m, 5H), 5.28 (s, 1H), 5.05-5.10 (m, 2H), 3.99-4.08 (m, 1H), 3.92 (br d, J=13.0 Hz, 1H), 2.76-2.99 (m, 2H), 2.56-2.65 (m, 1H), 1.90-1.98 (m, 1H), 1.62-1.72 (m, 1H), 1.48-1.61 (m, 1H), 1.35-1.47 (m, 1H). Step 3 To benzyl 3-(3-hydroxy-1H-pyrazol-5-yl)piperidine-1-carboxylate (800 mg, 2.65 mmol) in ethanol (30 mL) under N2 was added Pd/C, 10% (28.3 mg, 0.265 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite and concentrated to afford 5-(piperidin-3-yl)-1H-pyrazol-3-ol (416 mg, 2.488 mmol, 94 % yield) as an off white solid, which was used without purification. LCMS (ES, m/s): 168 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 5.21 (s, 1H), 3.25-3.38 (m, 2H), 3.00 (br dd, J=11.7, 1.5 Hz, 1H), 2.86 (br d, J=11.0 Hz, 1H), 2.51-2.57 (m, 1H), 2.36-2.46 (m, 2H), 1.87-1.94 (m, 1H), 1.57 (td, J=5.9, 3.1 Hz, 1H), 1.32-1.47 (m, 2H). Step 4 To 5-(piperidin-3-yl)-1H-pyrazol-3-ol (170 mg, 1.015 mmol) and (R)-1-((5-chloropyridin- 2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (300 mg, 0.846 mmol) in DMSO (4.0 mL) was added DIEA (0.591 mL, 3.38 mmol). After 2 days, the mixture was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 0-15% MeOH in DCM to give partially pure product. This material was further purified via RPHPLC: (Column: Waters Atlantis T320 x 100mm), eluting with AcCN in water to afford (2S)-N-(5-chloropyridin-2-yl)-2-(3-(3-hydroxy-1H-pyrazol-5-yl)piperidin-1- yl)propanamide (126 mg, 0.342 mmol, 40.5 % yield) as an off white solid. LCMS (ES, m/s): 350 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 10.27 (s, 1H), 8.35-8.39 (m, 1H), 8.11-8.17 (m, 1H), 7.92 (ddd, J=8.9, 2.7, 1.1 Hz, 1H), 5.24 (d, J=5.4 Hz, 1H), 3.45- 3.55 (m, 1H), 2.65-3.00 (m, 3H), 2.29-2.39 (m, 1H), 2.13-2.24 (m, 1H), 1.83-1.91 (m, 1H), 1.65-1.74 (m, 1H), 1.45-1.62 (m, 1H), 1.24-1.39 (m, 1H), 1.17 (d, J=6.8 Hz, 3H). Example 105 (2S)-N-(5-chloropyridin-2-yl)-2-(3-(4-methyl-1H-pyrazol-5-yl)piperidin-1-yl)propanamide 670 7
Figure imgf000190_0001
Step 1 To 1-((benzyloxy)carbonyl)piperidine-3-carboxylic acid (5.5 g, 20.89 mmol), N,O- dimethylhydroxylamine hydrochloride (2.445 g, 25.07 mmol), HOBt (4.80 g, 31.3 mmol) and DIEA (10.95 mL, 62.7 mmol) in THF (100 mL) at 0 °C was added EDC (6.01 g, 31.3 mmol), in portions. The mixture was allowed to warm up to RT and stirred overnight. The reaction was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 330 g silica column), eluting with 0- 60% EtOAc in hexanes to afford benzyl 3-(methoxy(methyl)carbamoyl)piperidine-1- carboxylate (6.05 g, 19.75 mmol, 95 % yield) as a colorless oil. LCMS: (ES, m/s) 307 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 7.28-7.41 (m, 5H), 5.02-5.12 (m, 2H), 3.89-4.04 (m, 2H), 3.54-3.72 (m, 3H), 3.07 (br s, 3H), 2.70-2.93 (m, 3H), 1.78-1.86 (m, 1H), 1.63-1.72 (m, 1H), 1.48-1.60 (m, 1H), 1.33-1.46 (m, 1H). Step 2 To benzyl 3-(methoxy(methyl)carbamoyl)piperidine-1-carboxylate (6.05 g, 19.75 mmol) in THF (80 mL) at -78 °C was added ethylmagnesium bromide (3.0 M in ether, 7.90 mL, 23.70 mmol), dropwise, and the mixture was allowed to warm up to RT. After 1 hour, the reaction was quenched with sat. NH4Cl and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-50% EtOAc in hexanes to afford benzyl 3-propionylpiperidine-1- carboxylate (4.91 g, 17.83 mmol, 90 % yield) as a colorless oil. LCMS (ES, m/s): 276 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.28-7.41 (m, 5H), 5.07 (d, J=2.9 Hz, 2H), 3.96 (br d, J=11.7 Hz, 1H), 3.75-3.85 (m, 1H), 2.80-3.08 (m, 2H), 2.51-2.57 (m, 3H), 1.89-1.97 (m, 1H), 1.59-1.68 (m, 1H), 1.32-1.50 (m, 2H), 0.89 (br t, J=7.1 Hz, 3H). Step 3 To benzyl 3-propionylpiperidine-1-carboxylate (4.91 g, 17.83 mmol) in DMF (40 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (6.37 g, 53.5 mmol), and the mixture was heated at 140 °C for 6 h, then concentrated. The residue was dissolved in ethanol (40.0 mL), and con. HCl (1.0 mL, 11.85 mmol) was added dropwise. After 10 min, hydrazine monohydrate (1.749 mL, 35.7 mmol) was added. The reaction was refluxed overnight, cooled to RT, concentrated, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 120 g silica column), eluting with 0-10% MeOH in DCM to afford benzyl 3-(4-methyl-1H-pyrazol-5- yl)piperidine-1-carboxylate (2.34 g, 7.82 mmol, 43.8 % yield) as a colorless oil. LCMS (ES, m/s): 300 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.09-12.45 (m, 1H), 7.12-7.48 (m, 6H), 4.98-5.15 (m, 2H), 4.04 (br d, J=11.5 Hz, 2H), 2.57-3.01 (m, 3H), 1.82- 2.09 (m, 3H), 1.58-1.78 (m, 2H), 1.36-1.53 (m, 1H), 1.19-1.32 (m, 1H). Step 4 To benzyl 3-(4-methyl-1H-pyrazol-5-yl)piperidine-1-carboxylate (2.34 g, 7.82 mmol) in ethanol (30 mL) under N2 was added Pd/C, 10% (0.083 g, 0.782 mmol), and the mixture was hydrogenated under an H2 balloon overnight, filtered through Celite and washed with EtOH. The filtrate was concentrated to afford 3-(4-methyl-1H-pyrazol-5-yl)piperidine (1.30 g, 7.87 mmol, 101 % yield) as a colorless oil, which was used without purification. LCMS (ES, m/s): 166 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.19-7.28 (m, 1H), 3.22-3.39 (m, 1H), 2.91 (br d, J=11.5 Hz, 2H), 2.63-2.73 (m, 1H), 2.42-2.48 (m, 1H), 1.95 (s, 3H), 1.77-1.85 (m, 1H), 1.57-1.66 (m, 2H), 1.38-1.50 (m, 1H). Step 5 To 3-(4-methyl-1H-pyrazol-5-yl)piperidine (138 mg, 0.835 mmol) and (R)-2-bromo-N-(5- chloropyridin-2-yl)propanamide (Intermediate 5) (200 mg, 0.759 mmol) in DMSO (4.0 mL) was added triethylamine (0.423 mL, 3.04 mmol). The mixture was stirred overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column), eluting with 60-90% EtOAc in DCM to afford (2S)-N-(5-chloropyridin-2-yl)-2-(3-(4-methyl-1H-pyrazol-5-yl)piperidin-1- yl)propanamide (218 mg, 0.595 mmol, 78 % yield) as an off white solid. LCMS (ES, m/s): 348 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.03-12.34 (m, 1H), 10.29-10.50 (m, 1H), 8.36-8.41 (m, 1H), 8.11-8.17 (m, 1H), 7.89-7.94 (m, 1H), 7.12-7.41 (m, 1H), 3.50 (q, J=7.0 Hz, 1H), 2.85 (br d, J=11.0 Hz, 2H), 2.70-2.79 (m, 1H), 2.33-2.49 (m, 1H), 2.16- 2.33 (m, 1H), 1.89-1.98 (m, 3H), 1.69-1.85 (m, 2H), 1.43-1.67 (m, 2H), 1.17 (dd, J=7.1, 2.2 Hz, 3H). Example 106 (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide
Figure imgf000192_0001
Step 1 To ethyl piperidine-3-carboxylate (6.0 g, 38.2 mmol) and sodium bicarbonate (12.82 g, 153 mmol) in THF (120 mL) and water (60 mL) at 0 °C was added Cbz-Cl (8.17 mL, 57.2 mmol), dropwise. After stirring at RT overnight, the mixture was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 330 g silica column, 100 mL/min, EtOAc in hexanes 0-30%) to afford 1- benzyl 3-ethyl piperidine-1,3-dicarboxylate (8.66 g, 29.7 mmol, 78 % yield) as a colorless oil. LCMS: (ES, m/s) 292 [M+H]+. 1H NMR: (400 MHz, DMSO-d6) δ ppm 7.28-7.41 (m, 5H), 5.07 (s, 2H), 4.01-4.11 (m, 2H), 3.84-3.99 (m, 1H), 3.61-3.81 (m, 1H), 2.95-3.09 (m, 2H), 2.43-2.49 (m, 1H), 1.91 (br d, J=9.0 Hz, 1H), 1.55-1.68 (m, 2H), 1.32-1.48 (m, 1H), 1.11-1.22 (m, 3H). Step 2 To 1-benzyl 3-ethyl piperidine-1,3-dicarboxylate (8.66 g, 29.7 mmol) in THF (100 mL) at - 78 °C was added LiHMDS (1M in THF, 35.7 mL, 35.7 mmol), dropwise. After 30 min, iodomethane (2.406 mL, 38.6 mmol) was added. After warming to RT overnight, the mixture was quenched with sat. NH4Cl and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 330 g silica column, 100 mL/min, EtOAc in hexanes 0-30%) to afford 1-benzyl 3-ethyl 3-methylpiperidine-1,3- dicarboxylate (9.2 g, 30.1 mmol, quantitative yield) as a colorless oil. LCMS (ES, m/s): 306 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.27-7.40 (m, 5H), 5.01-5.11 (m, 2H), 3.93-4.06 (m, 3H), 3.49-3.64 (m, 1H), 3.04 (m, 2H), 1.90-1.98 (m, 1H), 1.50-1.58 (m, 1H), 1.36-1.48 (m, 2H), 1.10 (br t, J=6.8 Hz, 3H), 1.07 (s, 3H). Step 3 To 1-benzyl 3-ethyl 3-methylpiperidine-1,3-dicarboxylate (9.2 g, 30.1 mmol) in methanol (90 mL) and water (30.0 mL) was added LiOH (1.443 g, 60.3 mmol). After 1 h, the mixture was diluted with water, the MeOH was removed, and the pH was adjusted to approximately 3-4 with 2N HCl. The mixture was extracted EtOAc (3 X), and the combined extracts were washed with brine (2 X), dried over Na2SO4, filtered and concentrated to afford 1-((benzyloxy)carbonyl)-3-methylpiperidine-3-carboxylic acid (8.45 g, 30.5 mmol, quantitative yield) as a colorless oil, which was used without further purification. LCMS (ES, m/s): 278 [M+H]+ . 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.27-7.40 (m, 5H), 5.05 (s, 2H), 3.66-3.92 (m, 1H), 3.45 (br d, J=11.8 Hz, 1H), 3.28-3.36 (m, 1H), 3.11 (br d, J=13.1 Hz, 1H), 1.86-1.96 (m, 1H), 1.36-1.59 (m, 3H), 1.06 (s, 3H). Step 4 To 1-((benzyloxy)carbonyl)-3-methylpiperidine-3-carboxylic acid (5.5 g, 19.83 mmol), N,O-dimethylhydroxylamine hydrochloride (2.322 g, 23.80 mmol), HOBt (4.56 g, 29.7 mmol) and DIEA (10.39 mL, 59.5 mmol) in THF (80 mL) at 0 °C was added EDC (5.70 g, 29.7 mmol), in portions. The mixture was allowed to warm to RT overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 330 g silica column, 100 mL/min, EtOAc in hexanes 0- 60%) to afford benzyl 3-(methoxy(methyl)carbamoyl)-3-methylpiperidine-1-carboxylate (5.16 g, 16.11 mmol, 81 % yield) as a colorless oil. LCMS (ES, m/s): 321 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.29-7.40 (m, 5H), 5.02-5.10 (m, 2H), 3.55-3.74 (m, 4H), 3.37-3.53 (m, 2H), 3.12-3.28 (m, 1H), 3.06 (s, 3H), 1.83-1.91 (m, 1H), 1.59-1.68 (m, 1H), 1.48-1.57 (m, 2H), 1.11 (s, 3H). Step 5 To benzyl 3-(methoxy(methyl)carbamoyl)-3-methylpiperidine-1-carboxylate (5.16 g, 16.11 mmol) in THF (50 mL) at -78 °C was added methylmagnesium bromide in 2-Me-THF (approximately 3.4 M, 5.68 mL, 19.33 mmol), dropwise, and the reaction was allowed to warm to RT. After 1 hour, the mixture was quenched with sat. NH4Cl and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 330 g silica column, 100 mL/min, EtOAc in hexanes 0-50%) to afford benzyl 3-acetyl- 3-methylpiperidine-1-carboxylate (2.78 g, 10.10 mmol, 62.7 % yield) as a colorless oil. LCMS (ES, m/s): 276 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.28-7.34 (m, 5H), 5.06 (s, 2H), 3.86 (br d, J=13.6 Hz, 1H), 3.38-3.52 (m, 1H), 3.06-3.25 (m, 2H), 2.10 (br s, 3H), 1.87-1.97 (m, 1H), 1.46-1.58 (m, 1H), 1.32-1.46 (m, 2H), 1.01 (s, 3H). Step 6 To benzyl 3-acetyl-3-methylpiperidine-1-carboxylate (2.78 g, 10.10 mmol) in DMF (20 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (3.61 g, 30.3 mmol). The mixture was heated at 140 °C for 6 hours and concentrated. The residue was dissolved in ethanol (20 mL), and conc. HCl (0.6 mL, 7.11 mmol) was added dropwise. After 10 min, hydrazine monohydrate (4.95 mL, 101 mmol) was added, and the resulting mixture was refluxed overnight, then concentrated. The residue was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 60 mL/min, MeOH in DCM, 0-10%) to afford benzyl 3-methyl-3- (1H-pyrazol-5-yl)piperidine-1-carboxylate (1.56 g, 5.21 mmol, 51.6 % yield) as a colorless oil. LCMS (ES, m/s): 300 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.43-12.67 (m, 1H), 7.55-7.61 (m, 1H), 7.27-7.41 (m, 5H), 6.00-6.18 (m, 1H), 5.06 (br s, 2H), 3.36- 3.70 (m, 3H), 3.14-3.31 (m, 1H), 1.94-2.05 (m, 1H), 1.39-1.67 (m, 3H), 1.15 (br s, 3H). Step 7 To benzyl 3-methyl-3-(1H-pyrazol-5-yl)piperidine-1-carboxylate (1.56 g, 5.21 mmol) in ethanol (20 mL) under N2 was added Pd/C, 10% (0.055 g, 0.521 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite, washed with EtOH, and concentrated to afford 3-methyl-3-(1H-pyrazol-5-yl)piperidine (0.865 g, 5.23 mmol, 100 % yield) as colorless oil. LCMS (ES, m/s): 166 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.45 (br s, 1H), 6.08 (d, J=2.0 Hz, 1H), 2.60-2.71 (m, 2H), 2.51 (dt, J=3.7, 1.8 Hz, 2H), 1.84-1.95 (m, 1H), 1.53-1.63 (m, 1H), 1.41-1.50 (m, 1H), 1.28-1.39 (m, 1H), 1.18 (s, 3H). Step 8 To 3-methyl-3-(1H-pyrazol-5-yl)piperidine (142 mg, 0.860 mmol) and (R)-1-((5- chloropyridin-2-yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (305 mg, 0.860 mmol) in DMSO (6 mL) was added DIEA (0.300 mL, 1.719 mmol). After 2 days, the mixture was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in DCM 30-80%) to afford (2S)-N-(5-chloropyridin-2-yl)-2-(3-methyl-3-(1H- pyrazol-5-yl)piperidin-1-yl)propanamide (213 mg, 0.582 mmol, 67.7 % yield) as an off white solid. 137 mg of this product was chirally separated via SFC-chiral purification (Column: Chiralpak IA, 20x250mm, 5u; Flowrate: 50 g/min; Cosolvent: 30% IPA; Pressure: 100 Bar) to give two peaks at 5.51 and 6.77 minutes. The second peak (at 6.77 minutes) was collected to give (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methyl-3-(1H- pyrazol-5-yl)piperidin-1-yl)propanamide (56.9 mg, 0.155 mmol, 39.5 % yield) as an off white solid. LCMS (ES, m/s): 348 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.07-12.63 (m, 1H), 10.14-11.06 (m, 1H), 8.34-8.50 (m, 1H), 8.10-8.23 (m, 1H), 7.91 (dd, J=8.8, 2.7 Hz, 1H), 7.25-7.63 (m, 1H), 6.00-6.17 (m, 1H), 3.43 (q, J=6.8 Hz, 1H), 2.68- 2.89 (m, 1H), 2.53-2.64 (m, 1H), 2.35-2.48 (m, 2H), 1.76-1.95 (m, 1H), 1.38-1.68 (m, 3H), 1.21-1.37 (m, 3H), 1.19 (d, J=7.1 Hz, 3H). Example 107 (2S)-2-(3-(1H-pyrazol-5-yl)pyrrolidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide
Figure imgf000196_0001
Step 1 To 1-((benzyloxy)carbonyl)pyrrolidine-3-carboxylic acid (2.1 g, 8.42 mmol), N,O- dimethylhydroxylamine hydrochloride (0.986 g, 10.11 mmol),), HOBt (4.56 g, 29.7 mmol) and DIEA (4.41 mL, 25.3 mmol) in THF (30 mL) at 0 °C was added EDC (2.423 g, 12.64 mmol), in portions. The mixture was allowed to warm to RT overnight, diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in hexanes 20- 70%) to afford benzyl 3-(methoxy(methyl)carbamoyl)pyrrolidine-1-carboxylate (2.0 g, 6.84 mmol, 81 % yield). LCMS (ES, m/s): 293 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.27-7.44 (m, 5H), 5.07 (s, 2H), 3.69 (s, 3H), 3.49-3.60 (m, 1H), 3.34-3.48 (m, 3H), 3.12 (s, 3H), 2.50-2.53 (m, 1H), 2.03-2.13 (m, 1H), 1.88-1.99 (m, 1H). Step 2 To benzyl 3-(methoxy(methyl)carbamoyl)pyrrolidine-1-carboxylate (2.0 g, 6.84 mmol) in THF (30 mL) at -78 °C was added methylmagnesium bromide in 2-Me-THF (approximately 3.4 M, 2.57 mL, 8.21 mmol), dropwise, and the reaction was allowed to warm to RT. After 1 hour, the mixture was quenched with sat. NH4Cl and extracted with EtOAc (3 X). The combined organic extracts were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in hexanes 0-50%) to afford benzyl 3- acetylpyrrolidine-1-carboxylate (1.05 g, 4.25 mmol, 62.1 % yield) as a colorless oil. LCMS (ES, m/s): 248 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.26-7.52 (m, 5H), 5.07 (s, 2H), 3.39-3.53 (m, 2H), 3.20-3.35 (m, 2H), 2.51 (dt, J=3.6, 1.7 Hz, 1H), 2.17 (s, 3H), 2.05-2.14 (m, 1H), 1.87-2.03 (m, 1H). Step 3 To benzyl 3-acetylpyrrolidine-1-carboxylate (1.05 g, 4.25 mmol) in DMF (10 mL) was added 1,1-dimethoxy-N,N-dimethylmethanamine (1.518 g, 12.74 mmol). The mixture was heated at 140 °C for 6 hours and concentrated. The residue was dissolved in ethanol (10 mL), and conc. HCl (0.25 mL, 2.96 mmol) was added dropwise. After 10 min, hydrazine monohydrate (0.625 mL, 12.74 mmol) was added, and the resulting mixture was refluxed overnight, then concentrated. The residue was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 60 mL/min, MeOH in DCM, 0-10%) to afford benzyl 3-(1H- pyrazol-5-yl)pyrrolidine-1-carboxylate (1.05 g, 3.87 mmol, 91 % yield) as a colorless oil. LCMS (ES, m/s): 272 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.54 (br s, 1H), 7.63 (br s, 1H), 7.31-7.40 (m, 5H), 6.15 (br s, 1H), 5.08 (s, 2H), 3.66-3.78 (m, 1H), 3.34- 3.53 (m, 4H), 2.20 (br s, 1H), 1.94-2.01 (m, 1H). Step 4 To benzyl 3-(1H-pyrazol-5-yl)pyrrolidine-1-carboxylate (1.05 g, 3.87 mmol) in ethanol (20 mL) under N2 was added Pd/C, 10% (0.041 g, 0.387 mmol), and the mixture was hydrogenated under an H2 balloon overnight. The reaction was filtered through Celite, washed with EtOH, and concentrated to afford 5-(pyrrolidin-3-yl)-1H-pyrazole (520 mg, 3.79 mmol, 98 % yield) as colorless oil. LCMS (ES, m/s): 138 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 7.45 (s, 1H), 6.05 (d, J=1.7 Hz, 1H), 3.07-3.21 (m, 2H), 2.79-2.94 (m, 2H), 2.65 (dd, J=10.0, 7.1 Hz, 1H), 2.00-2.11 (m, 1H), 1.65-1.77 (m, 1H). Step 5 To 5-(pyrrolidin-3-yl)-1H-pyrazole (100 mg, 0.729 mmol) and (R)-1-((5-chloropyridin-2- yl)amino)-1-oxopropan-2-yl 4-methylbenzenesulfonate (Intermediate 23) (259 mg, 0.729 mmol) in DMSO (6 mL) was added DIEA (0.255 mL, 1.458 mmol). After 2 days, the mixture was diluted with water and extracted with EtOAc (3 X). The combined organic layers were washed with brine (2 X), dried over Na2SO4, filtered, concentrated and purified via normal phase chromatography (Combiflash Rf, 80 g silica column, 65 mL/min, EtOAc in DCM 30-80%) to afford (2S)-2-(3-(1H-pyrazol-5-yl)pyrrolidin-1-yl)-N-(5- chloropyridin-2-yl)propanamide (121 mg, 0.359 mmol, 49.3 % yield) as an off white solid. LCMS (ES, m/s): 320 [M+H]+. 1H NMR (400 MHz, DMSO-d6) δ ppm: 12.41 (br s, 1H), 10.22 (br s, 1H), 8.38 (td, J=1.8, 0.9 Hz, 1H), 8.12-8.17 (m, 1H), 7.92 (dd, J=8.8, 2.7 Hz, 1H), 7.33-7.66 (m, 1H), 6.09 (br s, 1H), 3.37 (br s, 1H), 2.98-3.10 (m, 1H), 2.78 (br t, J=6.8 Hz, 2H), 2.56-2.71 (m, 2H), 2.19 (br s, 1H), 1.79-1.93 (m, 1H), 1.27 (dd, J=6.8, 2.7 Hz, 3H). Example 108a and 108b Ex.108a: (S)-N-(5-chloropyridin-2-yl)-2-((R)-2- (trifluoromethyl)morpholino)propanamide or Ex.108b: (S)-N-(5-chloropyridin-2-yl)-2- ((S)-2-(trifluoromethyl)morpholino)propanamide
Figure imgf000198_0001
To 2-(trifluoromethyl)morpholine hydrochloride (100 mg, 0.52 mmol, 1.0 eq) in THF (3 mL) was added (R)-2-bromo-N-(5-chloropyridin-2-yl)propanamide (Intermediate 5) (296 mg, 0.52 mmol) and TEA (423 mg, 4.19 mmo, 8.0 eq). The reaction mixture was stirred for 48 h at 40 oC, quenched with water (50 mL) and extracted with ethyl acetate (50 mL x 3). The combined organic phases were dried over Na2SO4, concentrated and purified over a silica gel column, eluting with ethyl acetate : petroleum (1:3) to give 100 mg of the pure product as a yellow oil. This material was chirally separated (column: CHIRALPAK IG, 2x25cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 4:1) to provide two peaks with retention times of 5.256 and 8.966 min. The first peak (5.256 min) was collected and further chirally separated (column: CHIRALPAK IG, 2x25 cm, 5 um, flow rate: 20 mL/min, Mobile Phase A: Hex [8 mM NH3 in MeOH], Mobile Phase B: EtOH, A:B 9:1) to provide two peaks with retention times of 6.608 and 7.240 min. The first peak (6.608 min) was collected to give 10 mg (purity: 99.4%) of (S)-N-(5- chloropyridin-2-yl)-2-((R)-2-(trifluoromethyl)morpholino)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((S)-2-(trifluoromethyl)morpholino)propanamide as a light yellow oil. LCMS (m/z) 338 (M+H)+, retention time: 1.693 min, LC/MS Method 9. 1H NMR (METHANOL-d4) δ ppm: 8.30-8.29 (m, 1H), 8.18 (d, J=8.8 Hz, 1H), 7.82 (dd, J=8.8, 2.8 Hz, 1H), 4.19-4.11 (m, 1H), 4.00-3.98 (m, 1H), 3.84-3.77 (m, 1H), 3.42-3.34 (m, 1H), 2.94-2.91 (m, 1H), 2.77-2.74 (m, 1H), 2.64-2.59 (m, 1H), 2.41-2.36 (m, 1H), 1.32 (d, J=6.8 Hz, 3H). Example 109 (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-morpholinopropanamide
Figure imgf000199_0001
(R)-2-bromo-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (Intermediate 17) (110 mg, 0.308 mmol) and silver nitrate (52.3 mg, 0.308 mmol) were dissolved in N,N- Dimethylformamide (DMF) (3 mL) at RT. Then added morpholine (0.040 mL, 0.462 mmol) and TEA (0.064 mL, 0.462 mmol). Stirred well then placed into metal block external temp to 35 °C and allowed to stir overnight. Work-up by pouring into EA(50 mls) and stirring then added in 25ml of NH4Cl (sat) and stirred for 10 mins. Separated and back extracted with EA. Combined organics and dried over magnesium sulfate, filtered, and concentrated in vacuo to a residue that was then purified via silica gel column. Using A: Heptane and B: 3 to1 (v/v) EtOAc/EtOH+2%NH4OH and a Gradient of B: 5-30%. Pooled together product fractions and concentrated in vacuo to a afford (S)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)-2-morpholinopropanamide as a sticky solid (45 mg, 0.118 mmol, 38.2 % yield). LCMS (ES, m/s): 364.3 [M+H]+, retention time: 0.63 min, LC/MS Method 5. XH NMR (400 MHz, DMSO-d6) Shift 10.24 - 10.08 (m, 1H), 8.17 - 8.05 (m, 2H), 7.54 - 7.46 (m, 2H), 7.34 - 7.24 (m, 1H), 7.16 - 7.07 (m, 1H), 3.65 - 3.52 (m, 4H), 3.39 (q, J = 6.8 Hz, 1H), 2.59 - 2.53 (m, 2H), 1.18 (d, J = 6.8 Hz, 3H), 2Hs buried under DMSO.
Examples 110-113 were synthesized in an analogous manner using the designated amine.
Figure imgf000200_0001
Figure imgf000201_0001
Figure imgf000202_0002
Figure imgf000202_0001
BIOLOGICAL DATA
Assay Protocol
A Ca2+ mobilization assay was used to assess the activity of the compounds of this invention. A HEK293 cell line with stably expressing human MRGPRX2 and mouse Galphal5 genes was used in the assay. Briefly, cells were seeded into black clear-bottomed 384-well plates at 1.5 x io4 cells/well and culture at 37°C for 24 hours prior to assay. On the day of assay, cells were loaded with Ca2+ indicator dye in 20 pL Hank's buffered saline solution containing 25 mmol/L HEPES, pH 7.2 (assay buffer) supplemented with 2 pmol/L Fluo-4 dye (Molecular Probes), 2.5 mmol/L probenecid (Sigma) & 0.5 mmol/L Brilliant Black (MP Biomedicals). Activation of human MRGPRX2 by a peptide agonist, Cortistatin-14 (PCKNFFWKTFSSCK, Disulfide Bridge: 2-13, TFA salt, GeneScript), was measured on FLIPRTETRA (Molecular Devices) instrument as increased fluorescence intensity (488 nm excitation/530 nm emission) upon receptor binding, leading to G-protein activation and Ca2+ mobilization. An activation dose response curve was produced for Cortistatin-14 to determine the EC50 value of the agonist on the day of assay. Compounds of this invention were prepared as 1 mM or 10 mM solution in DMSO. Serial dilutions of 11 concentrations at 3 -folds were made in DMSO for each compound and then diluted in assay buffer prior to addition onto the dye-loaded cells (final testing concentration range of 100 pmol/L-100 pmol/L for compounds with final 1% DMSO in assay buffer). After 30 min incubation at 37°C, agonist Cortistatin-14 was added to the cell culture at 4xEC50 final concentration. Fluorescence intensity was measured on FLIPRTETRA for compounds’ ability to inhibit agonist mediated MRGPRX2 activation. Dose dependent inhibition curves were fitted in ActivityBase (IDBS) data analysis platform to report a pIC50 value for each individual compound dilution series. The pIC50s for each compound of this invention were averaged to determine a mean value, for a minimum of 2 experiments. For instance, the compounds of Examples 1 – 113 inhibited MRGPRX2 activation in the above method with a pIC50 value between approximately 5 and 9.4. Biological Data The exemplified compounds were tested according to the FLIPRTETRA assay described above and were found to be MrgX2 antagonists with pIC50 > 5. As determined used the above method, the compounds of examples 1-113 exhibited a pIC50 between 5 and 9.4. Examples 8, 24, 30, 33, 49, 57, 61, 77, 92, 94, 95, 98 and 111 exhibited a pIC50 ≥ 8.0. It will be understood that the present invention has been described above purely by way of example, and modification of detail can be made within the scope of the invention. Each feature disclosed in the description, and where appropriate the claims may be provided independently or in any appropriate combination.

Claims

CLAIMS A compound of formula (I)
Figure imgf000204_0001
or a pharmaceutically acceptable salt thereof, wherein: X1 is N or CR5a; X2 is N or CR6a; X3 is N or CR5b X4 is N or CR6b Y is N or CH; Z is SO2, O, C=O, NR12 or C(R2)2; n is 0 or 1; R1 is hydrogen, halogen, (C1-C6)alkyl, -(C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1- C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1-C6)alkyl), -(C1-C6)alkyl-(C3-C8)cycloalkyl, - (C1-C6)alkyl-aryl, 5- or 6-membered heteroaryl(C1-C4)alkyl-, (C3-C8)cycloalkyl, (C2- C6)alkenyl, -(C2-C6)alkenyl-(C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -O-(C2-C6)alkenyl, - O-(C1-C6)alkyl-(C3-C8)cycloalkyl), -O-(C3-C8)cycloalkyl, -O-aryl, -O-heteroaryl, -CO2H, - CO2(C1-C6)alkyl, -CO2(C3-C8)cycloalkyl, -O2C(C1-C6)alkyl, -O2C(C3-C8)cycloalkyl, -NH2, -NH(C1-C6)alkyl, -N((C1-C6)alkyl)((C1-C6)alkyl), aryl, or 5-6 membered heteroaryl, wherein the (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, (C1-C6)alkoxy, -O-aryl, -O- heteroaryl, aryl, or 5-6 membered heteroaryl of R1 is optionally substituted one, two, or three times by R8; each R2 is independently hydrogen, hydroxyl, halogen, or (C1-C6)alkyl; each R3 and R4 is independently selected from hydrogen, -CN (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1-C6)alkoxy, -NH2, -NH(C1-C6)alkyl, -N((C1-C6)alkyl)((C1- C6)alkyl), 5-membered heteroaryl, 5-6 membered heterocycloalkyl or 5-6 membered lactam, wherein the (C1-C6)alkyl, 5-membered heteroaryl, 5-6 membered heterocycloalkyl or 5-6 membered lactam of R3 or R4 is optionally substituted one, two, or three times by R9; each of R5a, R5b, R6a and R6b is independently hydrogen, halogen, (C1-C6)alkyl, - (C1-C6)alkyl-NH2, -(C1-C6)alkyl-NH((C1-C6)alkyl), -(C1-C6)alkyl-N((C1-C6)alkyl)((C1- C6)alkyl), (C2-C6)alkenyl, -NH2, -NH((C1-C6)alkyl), -N((C1-C6)alkyl)((C1-C6)alkyl), - NCH2, or -CHNH; or R1 and R5a or R5b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur, wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, -(C1-C6)alkyl-(C3-C8)cycloalkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; or any of R5a , R5b, R6a and R6b taken together with the atoms to which they are attached, form a 5-, 6-, or 7-membered ring optionally containing one, two, or three heteroatoms independently selected from oxygen, nitrogen, and sulfur; wherein said ring is optionally substituted by one or two substituents independently selected from halogen, (C1-C6)alkyl, halo(C1-C6)alkyl, and (C3-C8)cycloalkyl; each of R7a and R7b is independently selected from hydrogen, halogen, -OH or (C1-C6)alkyl optionally substituted one, two, or three times by halogen; each R8 is independently halogen, (C1-C6)alkyl, (C3-C8)cycloalkyl, -OH, (C1- C6)alkoxy, -O-(C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl, wherein any said (C1- C6)alkyl, (C3-C8)cycloalkyl, aryl, or 5-6 membered heteroaryl is further optionally substituted one, two, or three times by halogen; each R9 is independently halogen, (C1-C6)alkyl, -(C1-C6)alkyl-OH, -(C1-C6)alkyl- O-(C1-C6)alkyl, -(C1-C6)alkyl-aryl, or -OH, wherein any said -(C1-C6)alkyl-aryl is optionally substituted one, two, or three times by (C1-C6)alkoxy; R10 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; R11 is hydrogen, (C1-C6)alkyl, or (C1-C6)alkoxy; and R12 is CO2-(C1-C6 alkyl), C(=O)-(C1-C6 alkyl) optionally substituted with 1, 2 or 3 halogen atoms or SO2-(C1-C6 alkyl). The compound or pharmaceutical salt thereof according to Claim 1, wherein X1 is CR5a. The compound or pharmaceutical salt thereof according to Claim 2, wherein R5a is hydrogen. The compound or pharmaceutical salt thereof according to any preceding claim, wherein X2 is N; and/or wherein X3 is CR5b; and/or wherein R5b is hydrogen; and/or wherein X4 is CR6b; and/or wherein Y is N; and/or wherein Z is C(R2)2; and/or wherein n is 1. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R1 is halogen, (C1-C6)alkyl, (C3-C8)cycloalkyl, -O-(C2-C6)alkenyl, -O-(C1- C6)alkyl-(C3-C8)cycloalkyl, -O-(C3-C8)cycloalkyl, -O-aryl, -O-heteroaryl, -CO2(C1- C6)alkyl or -NH(C1-C6)alkyl wherein the (C1-C6)alkyl, -O-heteroaryl, -O-aryl or aryl of R1 is optionally substituted one, two, or three times by R8. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R1 is O-aryl optionally substituted one, two, or three times by R8; or wherein R1 is O-phenyl substituted one, two, or three times by R8; or wherein R1 is halogen or -O-(C1-C6)alkyl-(C3-C8)cycloalkyl. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R2 is hydrogen, F or CH3; and/or wherein R3 is hydrogen, halogen or OH; and/or wherein R4 is hydrogen, halogen, 5-membered heteroaryl or 5-6 membered lactam. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R7a is hydrogen, OH, halogen or methyl; and/or wherein R7b is hydrogen, OH, halogen or methyl; and/or wherein R7a and R7b are each hydrogen. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R7a is hydrogen and R7b is methyl; and/or wherein R8 is halogen. The compound or pharmaceutical salt thereof according to any preceding claim, wherein R8 is F; and/or wherein R10 is -(C1-C6)alkyl and R11 is H; or wherein R10 is CH3. The compound or pharmaceutical salt thereof according to Claim 1, wherein: R1 is -O-aryl substituted twice with R8, X1 is CR5a, X2 is N, X3 is CR5b, X4 is CR6b, Y is N, Z is C(R2)2, n is 1, R2 is hydrogen or F, R3, R4, R5a, R5b and R6b are each hydrogen, R7a and R7b are each hydrogen, R8 is F, R10 is CH3, and R11 is H; or wherein: R1 is Cl or O-(C1-C6)alkyl-(C3-C8)cycloalkyl, X1 is N or CR5a, X2 is N, X3 is CR5b, X4 is CR6b, Y is N, Z is C(R2)2, n is 1, R2 is F or hydrogen, R3 is hydrogen, R4 is 5-membered heteroaryl, R5a, R5b, R6b is hydrogen, R7a is hydrogen, R7b is hydrogen or CH3, R10 is CH3, and R11 is hydrogen. The compound or pharmaceutical salt thereof according to Claim 1, wherein the compound is selected from the following compounds: 2-cyclohexyl-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)propanamide 2-cyclohexyl-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(tetrahydro-2H-pyran-4-yl)propanamide N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4-oxocyclohexyl)propanamide (R)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-((1s,4S)-4-hydroxycyclohexyl)propanamide (R)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-((1r,4R)-4-hydroxycyclohexyl)propanamide (R)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(4,4-difluorocyclohexyl)propanamide (R)-2-(4,4-difluorocyclohexyl)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(3-(3-oxopiperazin-1-yl)piperidin-1-yl)propanamide (2S)-2-((5R)-3,5-dihydroxy-3-(trifluoromethyl)piperidin-1-yl)-N-(5-fluoropyridin-2- yl)propanamide (2S)-N-(5-fluoropyridin-2-yl)-2-(3-hydroxy-3-methylpiperidin-1-yl)propanamide 2-(3-(1,1-dioxidothiomorpholino)piperidin-1-yl)-N-(5-(4-fluorophenoxy)pyrazin-2- yl)propanamide 2-(3-(1,1-dioxidothiomorpholino)piperidin-1-yl)-N-(5-phenoxypyrazin-2-yl)propanamide N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(1,1-dioxidothiomorpholino)piperidin-1- yl)propanamide Isopropyl 4-(1-((5-(2,4-difluorophenoxy)pyridin-2-yl)amino)-1-oxopropan-2-yl)piperidine-1- carboxylate N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(1-(2,2,2-trifluoroacetyl)piperidin-4-yl)propanamide (2S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(5-methyl-1,3,4-oxadiazol-2-yl)piperidin- 1-yl)propanamide (2S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(5-methyl-1,2,4-oxadiazol-3-yl)piperidin- 1-yl)propanamide (2S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-(3-(4-methylthiazol-2-yl)piperidin-1- yl)propanamide (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1- yl)propenamide, (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)pyrrolidin- 1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1- yl)propenamide, (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1- yl)propanamide (S)-N-(5-fluoropyridin-2-yl)-2-((S)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1-yl)propenamide, (S)-N-(5-fluoropyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1-yl)propenamide, (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)pyrrolidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)piperidin-1- yl)propanamide (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)piperidin-1- yl)propanamide (S)-N-(5-fluoropyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)piperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyrazin-2-yl)-2-((R)-3-hydroxy-3-(trifluoromethyl)piperidin-1- yl)propanamide N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(piperidin-1-yl)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(piperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4,4-difluoropiperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1- yl)propanamide (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1- yl)propanamide 2-(4,4-difluoro-3-hydroxypiperidin-1-yl)-N-(5-phenoxypyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1-yl)propanamide (S)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1-yl)-N-(5-fluoropyridin-2-yl)propanamide (S)-N-(5-cyclopropylpyridin-2-yl)-2-((S)-4,4-difluoro-3-hydroxypiperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-3-(trifluoromethyl)piperidin-1- yl)propenamide, (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-3-(trifluoromethyl)piperidin-1- yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-(trifluoromethyl)piperidin-1-yl)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((S)-3-(trifluoromethyl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-(4-fluoropiperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-fluoropiperidin-1-yl)propanamide (S)-N-(5-chloropyridin- 2-yl)-2-((R)-3-fluoropiperidin-1-yl)propanamide N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(3-fluoropiperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(trifluoromethyl)piperidin-1-yl)propenamide, (S)-N-(5-chloropyridin-2-yl)-2-((R)-4,4-difluoro-3-(trifluoromethyl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methoxy-3-(trifluoromethyl)piperidin-1-yl)propenamide, (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-methoxy-3-(trifluoromethyl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-(3,3-difluoropiperidin-1-yl)propanamide N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-(3,3-difluoropiperidin-1-yl)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(3,3-difluoropiperidin-1-yl)propanamide (S)-2-((S)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propenamide, (S)-2-((R)-3-amino-3-(trifluoromethyl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methylpiperidin-1-yl)propenamide, (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-methylpiperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3,3-difluoro-4-hydroxypyrrolidin-1-yl)propenamide, (S)-N-(5-chloropyridin-2-yl)-2-((R)-3,3-difluoro-4-hydroxypyrrolidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-(oxazol-2-yl)piperidin-1-yl)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((S)-3-(oxazol-2-yl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((R)-3-(oxazol-4-yl)piperidin-1-yl)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((S)-3-(oxazol-4-yl)piperidin-1-yl)propanamide (S)-2-((R)-3-(1,2,4-oxadiazol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propenamide, (S)-2-((S)-3-(1,2,4-oxadiazol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(6-(cyclopropylmethoxy)pyridazin-3-yl)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5- yl)piperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5- yl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5-yl)piperidin-1- yl)propanamide (S)-2-((S)-4,4-difluoro-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-fluoropyridin-2- yl)propanamide 2-(4,4-difluoro-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-phenoxypyridin-2-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide (S)-2-((S)-4,4-difluoro-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-fluoropyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-4,4-difluoro-3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamide (S)-2-((S)-4,4-difluoro-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(pyridin-2-yl)propanamide (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-propoxypyridin-2-yl)propanamide (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-isobutoxypyridin-2-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-ethoxypyridin-2-yl)propanamide (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-fluoropyridin-2-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-methylpyridin-2-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(pyridin-2-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-butoxypyridin-2-yl)propanamide (S)-2-((S)-3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-cyclopropylpyridin-2-yl)propanamide methyl 6-((2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamido)nicotinate (2S)-2-(3-(1H-pyrazol-5-yl)piperidin-1-yl)-N-(5-(propylamino)pyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((3R,5R)-3-methyl-5-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-(2-hydroxyethyl)-1H- pyrazol-3-yl)piperidin-1-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-(2-hydroxyethyl)-1H- pyrazol-3-yl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((3S,4S)-4-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide (S)-2-((S)-3-(1H-pyrrol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((S)-4,4-difluoro-3-(1-methyl-1H-pyrazol-3- yl)piperidin-1-yl)propenamide, (S)-N-(5-(cyclopropylmethoxy)pyridin-2-yl)-2-((R)-4,4-difluoro-3-(1-methyl-1H-pyrazol-3- yl)piperidin-1-yl)propanamide (S)-N-(5-fluoropyridin-2-yl)-2-((3S,5S)-3-methyl-5-(1H-1,2,4-triazol-5-yl)piperidin-1- yl)propanamide (S)-2-((R)-3-(1H-pyrrol-3-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (2S)-N-(5-chloropyridin-2-yl)-2-(3-(1-(4-methoxybenzyl)-1H-pyrazol-4-yl)piperidin-1- yl)propanamide (S)-2-((S)-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-propylpyridin-2-yl)propanamide (S)-2-((S)-3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-(cyclopropylmethoxy)pyridin-2- yl)propanamide (2S)-2-(3-(1H-1,2,4-triazol-5-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-2-((R)-3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-2-((S)- 3-(1H-pyrazol-4-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((3S,3'S)-6'-oxo-[3,3'-bipiperidin]-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((3S,3'R)-6'-oxo-[3,3'-bipiperidin]-1-yl)propanamide (S)-2-((3S,3'R)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyridin-2- yl)propanamide (S)-2-((3S,3'S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyridin-2- yl)propanamide (2S)-2-((3S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-fluoropyridin-2-yl)propanamide (S)-2-((3S,3'R)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyrazin-2- yl)propanamide (S)-2-((3S,3'S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4-difluorophenoxy)pyrazin-2- yl)propanamide 2-((3S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-((3,5-difluoropyridin-2-yl)oxy)pyridin- 2-yl)propanamide 2-((3S)-4,4-difluoro-6'-oxo-[3,3'-bipiperidin]-1-yl)-N-(5-((5-fluoropyridin-2-yl)oxy)pyridin-2- yl)propanamide (2S)-2-(4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-1-yl)-N-(5-(2,4- difluorophenoxy)pyridin-2-yl)propanamide (2S)-2-(4,4-difluoro-6'-oxo-1'-(2,2,2-trifluoroethyl)-[3,3'-bipiperidin]-1-yl)-N-(5-fluoropyridin-2- yl)propanamide (S)-2-((R)-3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-2-((S)- 3-(1H-pyrazol-1-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-2-((R)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propenamide, (S)-2-((S)-3-(2H-1,2,3-triazol-2-yl)piperidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((2R,3R)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2S,3S)-2-methyl-3-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((2S,3R)-2-methyl-3-(1H-pyrazol-5-yl)piperidin-1- yl)propanamide and (S)-N-(5-chloropyridin-2-yl)-2-((2R,3S)-2-methyl-3-(1H-pyrazol-5- yl)piperidin-1-yl)propanamide (2S)-N-(5-chloropyridin-2-yl)-2-(3-(3-hydroxy-1H-pyrazol-5-yl)piperidin-1-yl)propanamide (2S)-N-(5-chloropyridin-2-yl)-2-(3-(4-methyl-1H-pyrazol-5-yl)piperidin-1-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((S)-3-methyl-3-(1H-pyrazol-5-yl)piperidin-1-yl)propanamide (2S)-2-(3-(1H-pyrazol-5-yl)pyrrolidin-1-yl)-N-(5-chloropyridin-2-yl)propanamide (S)-N-(5-chloropyridin-2-yl)-2-((R)-2-(trifluoromethyl)morpholino)propanamide or (S)-N-(5- chloropyridin-2-yl)-2-((S)-2-(trifluoromethyl)morpholino)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-morpholinopropanamide 2-(2,2-difluoromorpholino)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide 2-(3-cyanopiperidin-1-yl)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(4-(methylsulfonyl)piperazin-1-yl)propanamide (S)-N-(5-(2,4-difluorophenoxy)pyridin-2-yl)-2-(1,1-dioxidothiomorpholino)propanamide A pharmaceutical composition comprising the compound or pharmaceutically acceptable salt thereof as defined in any of Claims 1 to 12, and a pharmaceutically acceptable excipient. A method of treating an MrgX2-mediated disease or disorder in a human in need thereof comprising administering to the human a therapeutically effective amount of the compound or pharmaceutically acceptable salt thereof according to any one of Claims 1 to 12 or the pharmaceutical composition according to Claim 13.
15. The method according to Claim 14, wherein the MrgX2-mediated disease or disorder is selected from the group consisting of chronic spontaneous urticaria, prurigo nodularis, irritable bowel syndrome, chronic inducible urticaria, atopic dermatitis, osteoarthritis, rosacea, migraine, pseudo-analphylaxis, mast cell activation syndrome, mastocytosis, pruritus, neurodermatitis, contact urticaria, allergic rhinitis, asthma, acute contact dermatitis, ulcerative colitis, crohns disease, idiopathic chronic cough, rheumatoid arthritis, multiple sclerosis, geographic atrophy, endometriosis, seborrheic dermatitis, psoriasis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, neuropathic itch, periodontitis, autism, abdominal aortic aneurysms, deep vein thrombosis, amyotrophic lateral sclerosis, interstitial cystitis, coronary artery disease, cancer, sickle cell disease, obesity, ulcers..
16. The compound or pharmaceutically acceptable salt thereof according to any one of Claims 1 to 12 or the pharmaceutical composition according to Claim 13 for use in therapy.
17. The compound or pharmaceutically acceptable salt thereof according to any one of Claims 1 to 12 or the pharmaceutical composition according to Claim 13 for use in the treatment of an MrgX2-mediated disease or disorder.
18. The compound or pharmaceutically acceptable salt for use according to Claim 17, wherein the MrgX2 -mediated disease or disorder is selected from the group consisting of chronic spontaneous urticaria, prurigo nodularis, irritable bowel syndrome, chronic inducible urticaria, atopic dermatitis, osteoarthritis, rosacea, migraine, pseudo- analphylaxis, mast cell activation syndrome, mastocytosis, pruritus, neurodermatitis, contact urticaria, allergic rhinitis, asthma, acute contact dermatitis, ulcerative colitis, crohns disease, idiopathic chronic cough, rheumatoid arthritis, multiple sclerosis, geographic atrophy, endometriosis, seborrheic dermatitis, psoriasis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, neuropathic itch, periodontitis, autism, abdominal aortic aneurysms, deep vein thrombosis, amyotrophic lateral sclerosis, interstitial cystitis, coronary artery disease, cancer, sickle cell disease, obesity, ulcers.
19. Use of the compound or pharmaceutically acceptable salt thereof according to any one of Claims 1 to 12, in the manufacture of a medicament for use in the treatment of an MrgX2 -mediated disease or disorder.
20. The use according to Claim 19, wherein the MrgX2 -mediated disease or disorder is chronic spontaneous urticaria, prurigo nodularis, irritable bowel syndrome, chronic inducible urticaria, atopic dermatitis, osteoarthritis, rosacea, migraine, pseudo- analphylaxis, mast cell activation syndrome, mastocytosis, pruritus, neurodermatitis, contact urticaria, allergic rhinitis, asthma, acute contact dermatitis, ulcerative colitis, crohns disease, idiopathic chronic cough, rheumatoid arthritis, multiple sclerosis, geographic atrophy, endometriosis, seborrheic dermatitis, psoriasis, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, neuropathic itch, periodontitis, autism, abdominal aortic aneurysms, deep vein thrombosis, amyotrophic lateral sclerosis, interstitial cystitis, coronary artery disease, cancer, sickle cell disease, obesity, ulcers.
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