WO2005075469A1

WO2005075469A1 - Thiazolyl-hydroxamic acids and thiadiazolyl-hydroxamic acids, and use thereof for treating diseases associated with histone deacetylase enzymatic activity

Info

Publication number: WO2005075469A1
Application number: PCT/GB2005/000282
Authority: WO
Inventors: Walter Bordogna; Jonathan Mark Sutton; George Hynd; Hazel Joan Dyke; Stephen Price; Neil Victor Harris; Mathew Iain Andrew Gill
Original assignee: Argenta Discovery Limited
Priority date: 2004-02-04
Filing date: 2005-01-27
Publication date: 2005-08-18
Also published as: GB0402496D0

Abstract

A compound of formula: (I) in which A represents optionally substituted monocyclic heteroaryl or phenyl; B represents optionally substituted heteroaryl, aryl, aryl-fused-heterocycloalkyl, heteroaryl-fused-cycloalkyl, heteroaryl-fused-heterocycloalkyl or aryl-fused-cycloalkyl, or B represents H when L represents a single bond; L represents a single bond, alkylene, (CH2)nX(CH2)m, (CH2)nX(CH2)pY(CH2)m; Q represents N or CR2; T represents N or CR2, provided that Q and T do not both represent CR2 simultaneously; X represents -O-, -NR3-, -CO-, -SO2-, -NR3C0-, -NR3SO2-, -CONR3-, -SO2NR3-, -NR1CONR1-; Y represents -NR3- or -O-; Rl represents H or alkyl; R2 represents hydrogen, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, CN; R3 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, or alkyl substituted by -OR4, -NR5R6, -NR6COR7, -NR6SO2R7, -CONR5R6 or -SO2NR5R6; R4 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl; R5 represents H or alkyl; R6 represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl or NR5R6 represents a cyclic amine; R7 represents alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl; n represents 0-3; m represents 0-3; p represents 1-3; and corresponding N-oxides, pharmaceutically acceptable salts, solvates and prodrugs thereof; and use to treat a disease in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease.

Description

THIAZOLYL-HYDROXAMIC ACIDS AND THIADIAZOLYL-HYDROXAMIC ACIDS, AND USE THEREOF FOR TREATING DISEASES ASSOCIATED WITH HISTONE DEACETYLASE ENZYMATIC ACTIVITY

This invention relates to substituted thiazolyl-hydroxamic acids and thiadiazolyl- hydroxamic acids, their preparation and pharmaceutical compositions containing these compounds for treating diseases associated with histone deacetylase enzymatic activity.

In eukaryotic cells, DNA is tightly associated with histones to form a compact complex called chromatin. The histones, generally highly conserved across eukaryotic species, constitute a family of proteins which are rich in basic amino acids that contact the phosphate groups of DNA.

There are different types of histones, including HI, H2A, H2B, H3 and H4. Four pairs of each of H2A, H2B, H3 and H4 together form a disk-shaped octomeric protein core, around which DNA is wound (with the basic amino acids of the histones interacting with the negatively charged phosphate groups of the DNA ) to form a nucleosome. Approximately 146 base pairs of DNA wrap around a histone core to make up a nucleosome particle, the repeating structural motif of chromatin.

Histone deacetylases (HDACs) are part of transcriptional corepressor complexes and play key roles in regulating chromatin structure. Three different classes of human HDACs have been defined based on their homology to HDACs found in Saccharomyces cerevisiae. Class I HDACs (HDAC1, 2, 3, and 8) are related to the yeast transcriptional regulator RPD3. Class II HDACs (HDAC4, 5, 6, 1, 9, and 10) are similar to HDAl, another deacetylase in yeast. Class III HDACs are related to the yeast silencing protein SIR2 and are dependent on NAD for enzymatic activity.

Reversible acetylation of histones is a major regulator of gene expression that acts by altering accessibility of transcription factors to DNA. In normal cells, histone deacetylase (HDAC) and histone acetyltransferases (HATs) together control the level of acetylation of histones to maintain a balance. Histone acetylation has a key role in transcriptional activation, whereas deacetylation of histones correlates with the transcriptional repression and silencing of genes [for a review of histone deacetylation see Kouzarides Curr. Opin. Genet. Dev., 9:40-48 (1999); Johnstone RW Nat. Rev. Drug Discov., 1:287-299 (2002)]. Genetic repression may have an important role in neuronal ageing, atrophy and degenerative diseases.

Moreover, histone deacetylases have been shown to regulate the activity of non-histone proteins through the modification of their acetylation level. These include steroid receptors such as estrogen and androgen receptors [Wang et al, J. Biol. Chem., 276:18375-83 (2001), Gaughan et al, J. Biol. Chem., 277: 25904-13 (2002)], transcription factors such as p53, E2F and myoD [Luo et al, Nature, 408:377-381 (2000); Ito et al, EMBO J, 19:1176-1179 (2001); Sartorelli et al, Mol. Cell, 4:725-734 (1999)], and cytoplasmic proteins such as α- tubulin [Hubbert et al, Nature, 417:455-458 (2002)].

There are currently several known inhibitors, both natural and synthetic, of HDAC. Some natural inhibitors include: (i) trapoxin B; (ii) trichostatin A [Yoshida and Beppu, Exper. Cell Res. , 177:122-131 (1988)]; and (iii) chlamydocin. Synthetic inhibitors include suberoyl anilide hydroxamic acid [Richon et al, Proc. Natl. Acad. Sci. USA, 95: 3003-3007 (1998)] and phenylbutyrate [Johnstone RΨ Nat. Rev. Drug Discov., 1:287-299 (2002)].

Trichostatin A has been shown to cause arrest of rat fibroblasts at both G] and G phases of the cell cycle, implicating HDAC in cell cycle regulation [Yoshida and Beppu, Exper. Cell Res., 177:122-131 (1988)]. Trichostatin A and suberoyl anilide hydroxamic acid have been shown to inhibit cell growth, induce terminal differentiation and prevent the formation of tumors in mice [Johnstone RW Nat. Rev. Drug Discov., 1:287-299 (2002)]. Trapoxin, trichostatin, and depudecin have been used to study gene regulation by HDAC- mediated chromatin remodeling [Christian A. Hassig, Stuart L. Schreiber, Curr. Opinion in Chem. Biol, 1997, 1, 300-308; Christian A. Hassig, Jeffrey K. Tong, Stuart L. Schreiber, Chem. & Biol, 1997, 4, 783-789; Christian A. Hassig, Jeffrey K. Tong, Tracey C. Fleischer, Takashi Owa, Phyllis Grable, Donald E. Ayer, Stuart L. Schreiber, Proc. Natl Acad. Scl, U.S.A., 1998, 95, 3519-3524; Ho Jeong Kwon, Takashi Owa, Christian A. Hassig, Junichi Shimada, Stuart L. Schreiber, Proc. Natl. Acad. Sci, U.S.A. 1998, 95, 3356-3361]. It is an objective of the present invention to provide inhibitors of histone deacetylase.

Thus, in one aspect, the present invention provides compounds of formula (I):

(I)

in which

A represents optionally substituted monocyclic heteroaryl or phenyl;

B represents optionally substituted heteroaryl, aryl, aryl-fused-heterocycloalkyl, heteroaryl-fused-cycloalkyl, heteroaryl-fused-heterocycloalkyl or aryl-fused-cycloalkyl, or B represents H when L represents a single bond;

L represents a single bond, alkylene, (CH₂)_nX(CH₂)_m, (CH₂)_nX(CH₂)_p Y(CH₂)_m;

Q represents N or CR²;

T represents N or CR , provided that Q and T do not both represent CR simultaneously;

X represents -O-, -NR³-, -CO-, -SO₂-, -NR³CO-, -NR³SO₂-, -CONR³-, -SO₂NR³-, N^CONR¹-;

Y represents -NR³- or -O-;

R¹ represents H or alkyl;

R represents hydrogen, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, CN;

R³ represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, or alkyl substituted by -OR⁴, -NR R⁶, -NR⁶COR⁷, -NR⁶SO₂R⁷, -CONR⁵R⁶ or -SO₂NR⁵R⁶; R⁴ represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl;

R⁵ represents H or alkyl;

R⁶ represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl

or NR R represents a cyclic amine;

R⁷ represents alkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl;

n represents 0-3 ; m represents 0-3; p represents 1-3;

and corresponding N-oxides, pharmaceutically acceptable salts, solvates and prodrugs of such compounds.

A second aspect of the invention is a pharmaceutical composition comprising a compound of formula (I) or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof, in admixture with a pharmaceutically acceptable carrier or excipient.

A third aspect of the invention is a compound of formula (I) or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof for use in therapy.

A fourth aspect of the invention is the use of a compound of formula (I), or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof, in the manufacture of a medicament for the treatment of a disease in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease. A fifth aspect of the invention is a method for treating a disease in a patient in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease, which method comprises administering to the patient a therapeutically effective amount of compound of formula (I) or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof.

A sixth aspect of the invention is a method of inhibiting histone deacetylase in a cell, comprising contacting a cell in which inhibition of histone deacetylase is desired with a compound of formula (I) or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof.

A seventh aspect of the invention is a method of preparing a compound of formula (I) or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof.

An eighth aspect of the invention is a method of making a pharmaceutical composition comprising combining a compound of formula (I), or an N-oxide, pharmaceutically acceptable salt, solvate or prodrug thereof, with a pharmaceutically acceptable carrier or excipient.

For purposes of the present invention, the following definitions as used throughout the description of the invention shall be understood to have the following meanings:

"Compounds of the invention", and equivalent expressions, are meant to embrace compounds of general formula (I) as hereinbefore described, their N-oxides, their prodrugs, their pharmaceutically acceptable salts and their solvates, where the context so permits.

"Histone deacetylase" and "HDAC" are intended to refer to any one of a family of enzymes that remove acetyl groups from lysine residues of proteins including, but not limited to, histones, transcription factors, steroid receptors and tubulin. Unless otherwise indicated the term histone is meant to refer to any histone protein, including HI, H2A, H2B, H3, H4 and H5 from any species. In one preferred embodiment the histone deacetylase is a human HDAC, including, but not limited to, HDAC-1, HDAC-2, HDAC- 3, HDAC-4, HDAC-5, HDAC-6, HDAC-7, HDAC-8, HDAC-9, and HDAC-10. In another preferred embodiment the histone deacetylase is derived from a protozoal or fungal source.

"Patient" includes both human and other mammals.

For purposes of the present invention, the following chemical terms as used above, and throughout the description of the invention, and unless otherwise indicated, shall be understood to have the following meanings:

"Acyl" means a -CO-alkyl group in which the alkyl group is as described herein. Exemplary acyl groups include -COCH₃ and -COCH(CH₃)₂.

"Acylamino" means a -NR-acyl group in which R and acyl are as described herein. Exemplary acylamino groups include -NHCOCH₃ and -N(CH₃)COCH₃.

"Alkoxy" and "alkyloxy" means an -O-alkyl group in which alkyl is as defined below. Exemplary alkoxy groups include methoxy and ethoxy.

"Alkoxycarbonyl" means a -COO-alkyl group in which alkyl is as defined below. Exemplary alkoxycarbonyl groups include methoxycarbonyl and ethoxycarbonyl.

"Alkyl" as a group or part of a group refers to a straight or branched chain saturated hydrocarbon group having from 1 to 12, preferably 1 to 6, carbon atoms, in the chain. Exemplary alkyl groups include methyl, ethyl, 1-propyl and 2-propyl.

"Alkylamino" means a -NH-alkyl group in which alkyl is as defined above. Exemplary alkylamino groups include methylamino and ethylamino.

"Alkylene means an -alkyl- group in which alkyl is as defined previously. Exemplary alkylene groups include -CH₂-, -(CH₂)₂ and -C(CH₃)HCH₂-.

"Alkylsufinyl" means a -SO-alkyl group in which alkyl is as defined above. Exemplary alkylsulfinyl groups include methylsulfinyl and ethylsulfinyl. "Alkylsufonyl" means a -SO2~alkyl group in which alkyl is as defined above. Exemplary alkylsulfonyl groups include methylsulfonyl and ethylsulfonyl.

"Alkylthio" means a -S-alkyl group in which alkyl is as defined above. Exemplary alkylthio groups include methylthio and ethylthio.

"Aminoacyl" means a -CO-NRR group in which R is as herein described. Exemplary aminoacyl groups include -CONH₂ and -CONHCH₃.

"Aminoalkyl" means an alkyl-NH₂ group in which alkyl is as previously described. Exemplary aminoalkyl groups include -CH NH₂.

"Aminosulfonyl" means a -SO₂-NRR group in which R is as herein described. Exemplary aminosulfonyl groups include -SO NH and -SO₂NHCH₃.

"Aryl" as a group or part of a group denotes an optionally substituted monocyclic or multicyclic aromatic carbocyclic moiety of from 6 to 14 carbon atoms, preferably from 6 to 10 carbon atoms, such as phenyl or naphthyl, and in one embodiment preferably phenyl. The aryl group may be substituted by one or more substituent groups.

"Arylalkyl" means an aryl-alkyl- group in which the aryl and alkyl moieties are as previously described. Preferred arylalkyl groups contain a Cj_4 alkyl moiety. Exemplary arylalkyl groups include benzyl, phenethyl and naphthlenemethyl.

"Arylalkyloxy" means an aryl-alkyloxy- group in which the aryl and alkyloxy moieties are as previously described. Preferred arylalkyloxy groups contain a C_j_4 alkyl moiety.

Exemplary arylalkyl groups include benzyloxy.

"Aryl-fused-cycloalkyr' means a monocyclic aryl ring, such as phenyl, fused to a cycloalkyl group, in which the aryl and cycloalkyl are as described herein. Exemplary aryl- fused-cycloalkyl groups include tetrahydronaphthyl and indanyl. The aryl and cycloalkyl rings may each be sustitued by one or more substituent groups. The aryl-fused-cycloalkyl group may be attached to the remainder of the compound of formula (I) by any available carbon atom.

"Aryl-fused-heterocycloalkyl" means a monocyclic aryl ring, such as phenyl, fused to a heterocycloalkyl group, in which the aryl and heterocycloalkyl are as described herein. Exemplary aryl-fused-heterocycloalkyl groups include tetrahydroquinolinyl, indolinyl, benzodioxinyl, benxodioxolyl, dihydrobenzofuranyl and isoindolonyl. The aryl and heterocycloalkyl rings may each be sustitued by one or more substituent groups. The aryl- fused-heterocycloalkyl group may be attached to the remainder of the compound of formula (I) by any available carbon or nitrogen atom.

"Aryloxy" means an -O-aryl group in which aryl is described above. Exemplary aryloxy groups include phenoxy.

"Cyclic amine" means an optionally substituted 3 to 8 membered monocyclic cycloalkyl ring system where one of the ring carbon atoms is replaced by nitrogen, and which may optionally contain an additional heteroatom selected from O, S or NR (where R is as described herein). Exemplary cyclic amines include pyrrolidine, piperidine, morpholine, piperazine and N-methylpiperazine. The cyclic amine group may be substituted by one or more substituent groups.

"Cycloalkyl" means an optionally substituted saturated monocyclic or bicyclic ring system of from 3 to 12 carbon atoms, preferably from 3 to 8 carbon atoms, and more preferably from 3 to 6 carbon atoms. Exemplary monocyclic cycloalkyl rings include cyclopropyl, cyclopentyl, cyclohexyl and cycloheptyl. The cycloalkyl group may be substituted by one or more substituent groups.

"Cycloalkylalkyl" means a cycloalkyl-alkyl- group in which the cycloalkyl and alkyl moieties are as previously described. Exemplary monocyclic cycloalkylalkyl groups include cyclopropylmethyl, cyclopentylmethyl, cyclohexylmethyl and cycloheptylmethyl.

"Dialkylamino" means a -Ν(alkyl)2 group in which alkyl is as defined above. Exemplary dialkylamino groups include dimethylamino and diethylamino. "Halo" or "halogen" means fluoro, chloro, bromo, or iodo. Preferred are fluoro or chloro.

"Haloalkoxy" means an -O-alkyl group in which the alkyl is substituted by one or more halogen atoms. Exemplary haloalkyl groups include trifluoromethoxy and difluoromethoxy.

"Haloalkyl" means an alkyl group which is substituted by one or more halo atoms. Exemplary haloalkyl groups include trifluoromethyl.

"Heteroaryl" as a group or part of a group denotes an optionally substituted aromatic monocyclic or multicyclic organic moiety of from 5 to 14 ring atoms, preferably from 5 to 10 ring atoms, in which one or more of the ring atoms is/are element(s) other than carbon, for example nitrogen, oxygen or sulfur. Examples of such groups include benzimidazolyl, benzoxazolyl, benzothiazolyl, benzofuranyl, benzothienyl, furyl, imidazolyl, indolyl, indolizinyl, isoxazolyl, isoquinolinyl, isothiazolyl, oxazolyl, oxadiazolyl, pyrazinyl, pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, tetrazolyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl and triazolyi groups. The heteroaryl group may be substituted by one or more substituent groups. The heteroaryl group may be attached to the remainder of the compound of formula (I) by any available carbon or nitrogen atom.

"Heteroarylalkyl" means a heteroaryl-alkyl- group in which the heteroaryl and alkyl moieties are as previously described. Preferred heteroarylalkyl groups contain a lower alkyl moiety. Exemplary heteroarylalkyl groups include pyridylmethyl.

"Heteroarylalkyloxy" means a heteroaryl-alkyloxy- group in which the heteroaryl and alkyloxy moieties are as previously described. Preferred heteroarylalkyloxy groups contain a lower alkyl moiety. Exemplary heteroarylalkyloxy groups include pyridylmethyloxy.

"Heteroaryloxy" means a heteroaryloxy- group in which the heteroaryl is as previously described. Exemplary heteroaryloxy groups include pyridyloxy. "Heteroaryl-fused-cycloalkyl" means a monocyclic heteroaryl group, such as pyridyl or furanyl, fused to a cycloalkyl group, in which heteroaryl and cycloalkyl are as previously described. Exemplary heteroaryl-fused-cycloalkyl groups include tetrahydroquinolinyl and tetrahydrobenzofuranyl. The heteroaryl and cycloalkyl rings may each be sustitued by one or more substituent groups. The heteroaryl-fused-cycloalkyl group may be attached to the remainder of the compound of formula (I) by any available carbon or nitrogen atom.

"Heteroaryl-fused-heterocycloalkyl" means a monocyclic heteroaryl group, such as pyridyl or furanyl, fused to a heterocycloalkyl group, in which heteroaryl and heterocycloalkyl are as previously described. Exemplary heteroaryl-fused-heterocycloalkyl groups include dihydrodioxinopyridinyl, dihydropyrrolopyridinyl, dihydrofuranopyridinyl and dioxolopyridinyl. The heteroaryl and heterocycloalkyl rings may each be sustitued by one or more substituents groups. The heteroaryl-fused-heterocycloalkyl group may be attached to the remainder of the compound of formula (I) by any available carbon or nitrogen atom.

"Heterocycloalkyl" means: (i) an optionally substituted cycloalkyl group of from 4 to 8 ring members which contains one or more heteroatoms selected from O, S or NR; (ii) a cycloalkyl group of from 4 to 8 ring members which contains CONR and CONRCO (examples of such groups include succinimidyl and 2-oxopyrrolidinyl). The heterocycloalkyl group may be substituted by one or more substituent groups. The heterocycloalkyl group may be attached to the remainder of the compound of formula (I) by any available carbon or nitrogen atom.

"Heterocycloalkylalkyl" means a heterocycloalkyl-alkyl- group in which the heterocycloalkyl and alkyl moieties are as previously described.

"Lower alkyl" as a group means unless otherwise specified, an aliphatic hydrocarbon group which may be straight or branched having 1 to 4 carbon atoms in the chain, i.e. methyl, ethyl, propyl ("propyl or 'propyl) or butyl ("butyl, 'butyl or ^lbutyl).

"R" means hydrogen, alkyl, arylalkyl, cycloalkyl, cycloalkylalkyl, heteroarylalkyl, heteroaryl or aryl. "Sulfonyl" means a -SO₂-alkyl group in which alkyl is as described herein. Exemplary sulfonyl groups include methanesulfonyl.

"Sulfonylamino" means a -NR-sulfonyl group in which R and sulfonyl are as described herein. Exemplary sulfonylamino groups include -NHSO CH₃.

"Pharmaceutically acceptable salt" means a physiologically or toxicologically tolerable salt and include, when appropriate, pharmaceutically acceptable base addition salts and pharmaceutically acceptable acid addition salts. For example (i) where a compound of the invention contains one or more acidic groups, for example carboxy groups, pharmaceutically acceptable base addition salts that may be formed include sodium, potassium, calcium, magnesium and ammonium salts, or salts with organic amines, such as, diethylamine, N-methyl-glucamine, diethanolamine or amino acids (e.g. lysine) and the like; (ii) where a compound of the invention contains a basic group, such as an amino group, pharmaceutically acceptable acid addition salts that may be formed include hydrochlorides, hydrobromides, phosphates, acetates, citrates, lactates, tartrates, malonates, methanesulphonates and the like.

"Prodrug" means a compound which is convertible in vivo by metabolic means (e.g. by hydrolysis, reduction or oxidation) to a compound of formula (I). For example an ester prodrug of a compound of formula (I) containing a hydroxy group may be convertible by hydrolysis in vivo to the parent molecule. Suitable esters of compounds of formula (I) containing a hydroxy group, are for example acetates, citrates, lactates, tartrates, malonates, oxalates, salicylates, propionates, succinates, fumarates, maleates, methylene-bis-β-hydroxynaphthoates, gentisates, isethionates, di-_jP-toluoyltartrates, methanesulphonates, ethanesulphonates, benzenesulphonates, p-toluenesulphonates, cyclohexylsulphamates and quinates. As another example an ester prodrug of a compound of formula (I) containing a carboxy group may be convertible by hydrolysis in vivo to the parent molecule [Examples of ester prodrugs are those described by F. J. Leinweber, Drug Metab. Res., 18:379 (1987)]. "Saturated" pertains to compounds and/or groups which do not have any carbon-carbon double bonds or carbon-carbon triple bonds.

The cyclic groups referred to above, namely, aryl, heteroaryl, cycloalkyl, aryl-fused- cycloalkyl, heteroaryl-fused-cycloalkyl, heterocycloalkyl, aryl-fused-heterocycloalkyl, heteroaryl-fused-heterocycloalkyl and cyclic amine may be substituted by one or more substituent groups. Suitable optional substituent groups include acyl (e.g. -COCH3), alkoxy (e,g, -OCH3), alkoxycarbonyl (e.g. -COOCH3), alkylamino (e.g. -NHCH3), alkylsulfinyl (e.g. -SOCH3), alkylsulfonyl (e.g. -SO CH₃), alkylthio (e.g. -SCH3), -NH₂, aminoalkyl (e.g. -CH₂NH₂)_? arylalkyl (e.g. -CH₂Ph or -CH₂-CH₂-Ph), cyano, dialkylamino (e.g. -N(CH3)₂), halo, haloalkoxy (e.g. -OCF3 or -OCHF₂), haloalkyl (e.g.

-CF3), alkyl (e.g. -CH3 or -CH2CH3), -OH, -CHO, -NO₂, aryl (optionally substituted with alkoxy, haloalkoxy, halogen, alkyl or haloalkyl), heteroaryl (optionally substituted with alkoxy, haloalkoxy, halogen, alkyl or haloalkyl), heterocycloalkyl, aminoacyl (e.g. - CONH₂, -CONHCH₃), aminosulfonyl (e.g. -SO₂NH₂, -SO₂NHCH₃), acylamino (e.g. - NHCOCH₃), sulfonylamino (e.g. -NHSO₂CH₃), heteroarylalkyl, cyclic amine (e.g. morpholine), aryloxy, heteroaryloxy, arylalkyloxy (e.g. benzyloxy) and heteroarylalkyloxy.

Compounds of the invention may exist in one or more geometrical, optical, enantiomeric, diastereomeric and tautomeric forms, including but not limited to cis- and transforms, E- and Z-forms, R-, S- and meso-forms, keto-, and enol-forms. Unless otherwise stated a reference to a particular compound includes all such isomeric forms, including racemic and other mixtures thereof. Where appropriate such isomers can be separated from their mixtures by the application or adaptation of known methods (e.g. chromatographic techniques and recrystallisation techniques). Where appropriate such isomers may be prepared by the application of adaptation of known methods (e.g. asymmetric synthesis).

With reference to formula (I) above, particular and preferred embodiments are described below. In one embodiment, the group A is a monocyclic heteroaryl group, preferably containing 5 or 6 ring atoms. Preferably, the heteroatom(s) is/are selected from N, O and S atoms, and preferably from N atom(s). Preferably, there are one or two ring heteroatoms. In a preferred embodiment, A is selected from monocyclic heteroaryl groups containing 5 or 6 ring atoms including one or two nitrogen heteroatoms. Preferably, A is selected from pyrazolyl, imidazolyl, pyridinyl and pyrimidinyl. In one embodiment, A is selected from pyrazolyl, pyridinyl and pyrimidinyl. The group A may be substituted or unsubstituted, and in one embodiment, A is unsubstituted. In an alternative embodiment, A is substituted and in this embodiment one or two substituent groups may be present. The substituent groups are preferably selected from alkyl, alkoxy, haloalkyl, haloalkoxy, halogen and CN. In a preferred embodiment, A is selected from pyrazolyl, imidazolyl, pyridinyl and pyrimidinyl optionally substituted with a substituent chosen from alkyl, alkoxy, haloalkyl, haloalkoxy, halogen and CN.

In one embodiment, R³ is selected from H and alkyl. In one embodiment, R⁴ is selected from H and alkyl. In one embodiment, R⁵ is selected from H and alkyl. In one embodiment, R is selected from H and alkyl. In one embodiment, R is selected from H and alkyl.

In one embodiment, Q represents N and T represents CR . In an alternative embodiment, Q represents CR² and T represents N. In a third embodiment, Q and T both represent N.

In one embodiment, n is 0, 1 or 2; in a further embodiment n is 0 or 1; and in a further embodiment n is 1. In one embodiment, m is 2 or 3. In an alternative embodiment, m is 1 or 2. In a further embodiment, m is 2. In one embodiment, p is 1 or 2, and in a further embodiment p is 1.

The present invention provides compounds that inhibit HDAC activity according to the tests described in the literature and in the Biological Activity section of this document. The therapeutic application of these compounds is pertinent to any disease that is known to be at least in part mediated by HDAC activity or whose symptoms are known to be alleviated by HDAC inhibitors (such as Trichostatin-A, suberoyl anilide hydroxamic acid, Trapoxin and depudecin). For example, these compounds could be beneficial for the treatment of cancer, psoriasis, fibroproliferative disorders (e.g. liver fϊbrosis), smooth muscle cell proliferation disorders (e.g. arteriosclerosis, restenosis), cardiomyocyte hypertrophy (e.g congestive heart failure), inflammatory diseases and conditions treatable by immune modulation (e.g. rheumatoid arthritis, autoimmune diabetes, lupus, allergies), neurodegenerative disorders (e.g. Huntington's disease), diseases involving angiogenesis (e.g. cancer, psoriasis, rheumatoid arthritis, retinal diseases such as diabetic retinopathy, age-related macular degeneration, interstitial keratitis, rubeotic glaucoma), fungal and parasitic infections (e.g. malaria, protozoal infections), haematopoietic disorders (e.g. anaemia, sickle cell anaemia, thalassemϊa) and conditions treatable by modulation of nuclear receptor activity (e.g. by increasing progesterone receptor activity to prevent premature parturition).

Thus, in one embodiment, the present invention is intended for the treatment of diseases caused by increased cell proliferation. These include, but are not limited to, primary and metastatic cancers of different origin (including those triggered by viral infections such as EBV, HIV, hepatitis B and C and KSHN), fϊbrosis of the liver, lung, kidney, heart and skin caused by myofibroblasts proliferation and increased production of extracellular matrix proteins [Νiki et al, Hepatology, 29:858-67 (1999)], inflammatory diseases and cardiomyocyte hypertrophy [Lu et al, PΝAS, 97: 4070-4075 (2000)].

In another embodiment, the invention is also aimed at the treatment of protozoal infections including, but not limited to, malaria, toxoplasmosis and coccidiosis.

In another embodiment, the invention is aimed at the treatment of diseases caused by expanded polyglutamine repeats resulting in histone hypoacetylation including, but not limited to, neurodegenerative disorders such as Huntington's disease.

The compounds of formula (I) may be used or administered in combination with one or more additional drug(s) and/or procedures (such as radiotherapy in the case of cancer) useful in the treatment of the disorders mentioned above, the components being in the same formulation or in separate formulations for administration simultaneously or sequentially. The additional drug(s) may or may not be HDAC inhbitors. The thiazolyl-hydroxamic acids and thiadiazolyl hydroxamic acids of the present invention may be prepared, for example, by the application or adaptation of methods described herein. They may also be prepared by known organic synthesis methods for example those described by R. C. Larock in Comprehensive Organic Transformations, NCH publishers, 1989. They may also be prepared by appropriate adaptation of any of the methods described in US patent 5,840,698 or those described by Campbell et al, Bioorg. Med. Chem. Lett. 1998, 8, 1157-1162 or Levin et al Bioorg. Med. Chem Lett. 1998, 8, 1163- 1168.

It may be necessary to protect reactive functional groups (e.g. hydroxy, amino, thio or carboxy) in intermediates used in the preparation of compounds of formula (I) to avoid their unwanted participation in a reaction leading to the formation of compounds of formula (I). Conventional protecting groups, for example those described by T. W. Greene and P. G. M. Wuts in "Protective Groups in Organic Chemistry" John Wiley and Sons. 1999, may be used. In the reaction schemes provided below, all definitions of A, B, L, R to R are to be understood to include such protected functional groups.

Preparation of compounds of formula (I) One method for the preparation of compounds of formula (I) is the deprotection of compounds of formula (II), in which R^a is a suitable protecting group. Suitable protecting groups include benzyl, 'butyloxycarbonyl, dimethyrbutylsilyl, tetrahydropyranyl and Wang polystyrene resin. The reactions carried out depend on the nature of the protecting group, for example if the protecting group is benzyl, the reaction carried out is a hydrogenolysis in an inert solvent such as an alcohol like methanol or ethanol, in the presence of a noble metal catalyst such as palladium on a suitable carrier such as carbon or barium sulfate, at an appropriate temperature and pressure, such as ambient temperature and pressure. When the protecting group is tetrahydropyranyl or Wang polystyrene resin, the reaction is carried out in the presence of an acid, at a temperature between -20°C and 60°C, preferably between 0°C and ambient temperature. The acid may be a solution of hydrochloric acid in an inert solvent such as diethyl ether or dioxane, or trifluoroacetic acid in dichloromethane. Alternatively, when the protecting group is a silyl group, the reaction is carried out in the presence of a fluoride source such as tetrabutylammonium fluoride in an inert solvent such as dichloromethane.

(II) Compounds of formula (II) can be obtained from compounds of formula (III) by reaction with an appropriately protected hydroxylamine, such as O-(tetrahydro-2H-pyran-2- yl)hydroxylamine, O-benzylhydroxylamine, O-Wang hydroxylamine polystyrene resin or O-(dimethyl tylsilyl)hydroxylamine. For example, reaction of compounds of formula (III) with O-(tetrahydro-2H-pyran-2-yl)hydroxylamine is conveniently carried out using an activating agent such as O-(7-azabenzotriazol-l-yl)-NNN'N'-tetramethyluronium hexafluorophosphate and a base such as diisopropylethylamine in a suitable solvent such as NN-dimethylformamide at an appropriate temperature such as ambient temperature.

(III) An alternative method for the preparation of compounds of formula (I) involves the reaction of a compound of formula (III) with hydroxylamine. This reaction typically involves the use of an activating agent such as O-(7-azabenzotriazol-l-yl)-NNN',N'- tetramethyluronium hexafluorophosphate (ΗATU) and a base such as diisopropylethylamine in a suitable solvent such as dimethylformamide at an appropriate temperature such as ambient temperature. Alternatively, a compound of formula (III) can be converted to a reactive derivative, such as an acid chloride or mixed anhydride. The reactive intermediate, is then treated with hydroxylamine in a suitable solvent, such as dichloromethane. The reactive intermediate may be used in situ without isolation, or it may be isolated and then treated with hydroxylamine.

Another method for the preparation of compounds of formula (I) involves the reaction of a compound of formula (IV), in which R is a suitable protecting group, such as methyl or ethyl, with hydroxylamine. The reaction may be carried out in the presence of a base, such as potassium hydroxide, in a suitable solvent such as methanol. A co-solvent, such as NN- dimethylacetamide may be used.

(IV)

Compounds of formula (III) may be prepared by hydrolysis of compounds of formula (IN). The hydrolysis may be carried out using a suitable base such as sodium hydroxide, in a protic solvent such as ethanol, at an appropriate temperature, such as ambient temperature. Alternatively, the hydrolysis may be carried out under acidic conditions, for example using concentrated mineral acid, such as concentrated hydrochloric acid.

An alternative method for the preparation of compounds of (III) involves the hydrolysis of compounds of formula (N). The hydrolysis may be carried out using a suitable base, such as sodium hydroxide, in a protic solvent such as ethanol, at an appropriate temperature, such as the reflux temperature of the solvent.

(N)

An additional method for the preparation of compounds of formula (III) involves the use of a compound of formula (NI), in which "hal" means chloro, bromo or iodo. A compound of formula (NI) can be converted into a compound of formula (III) by any suitable method known to those skilled in the art, including the use of a palladium catalysed carbonylation reaction, or a halogen/lithium exchange followed by quenching with carbon dioxide. The carbonylation reaction can be carried out using carbon monoxide in the presence of a suitable catalyst, such as bis(triphenylphosphine) palladium chloride and a suitable base, such as triethylamine in appropriate solvent(s), such as methanol and water. The reaction may be carried out at any appropriate temperature and pressure, such as a temperature of HO C and a pressure of 10 bar. The halogen/lithium exchange reaction may be carried out in the presence of a suitable lithium base, such as "butyl lithium, in an appropriate solvent such as tetrahydrofuran, at an appropriate temperature such as 0°C.

Compounds of formula (VI) may also be used to prepare compounds of fomula (IV) if the carbonylation reaction is carried out in the presence of an alcohol, such as methanol or ethanol. Alternatively, subjection of a compound of formula (VI) to halogen/lithium exchange followed by quenching with a suitable chloroformate, such as ethyl chloroformate, will also provide a compound of formula (IV).

Compounds of formula (V) may be prepared from compounds of formula (VI) by reaction with zinc cyanide in the presence of a palladium (0) catalyst, for example tetrakis (triphenylphospine)palladium (0), in an inert solvent, for example NN- dimethylformamide, at temperatures from about room temperature up to reflux temperature.

Compounds of formula (VI) may be prepared from compounds of formula (VII) by reaction with an appropriate halogenating agent, such as bromine, iodine, N- chlorosuccinimide, N-bromosuccinimide, or N-iodosuccinimide, in an appropriate solvent, such as dichloromethane.

(VII)

Compounds of formula (IV) may be prepared from compounds of formula (VIII), in which R^c represents hydrogen, lower alkyl, or -B(OR^c)₂ represents a cyclic boronate ester, and a compound of formula (IX), in which "hal" and R^b are as previously defined. The reaction may be performed in the presence of a suitable catalyst, such as tetrakis(triphenylphosphine)palladium (0), and a suitable base, such as cesium carbonate, in an appropriate solvent such as NN-dimethylformamide, at a suitable temperature, such as an elevated temperature, such as 80°C. Gr^LPΞP

(VIII) (IX)

In a similar manner, compounds of formula (III) may be prepared from compounds of formula (VIII) and a compound of formula (X), and compounds of formula (V) can be prepared starting from compounds of formula (XI).

(X) (XI)

An alternative method for the preparation of compounds of formula (IV) involves the reaction of a compound of formula (XII), in which hal is as previously defined, with a compound of formula (XIII) in which R and R^c are as previously defined. The reaction may be performed in the presence of a suitable catalyst, such as tetrakis(triphenylphosphine)palladium (0), and a suitable base, such as cesium carbonate, in an appropriate solvent such as NN-dimethylformamide, at a suitable temperature, such as an elevated temperature, such as 80°C.

(XII) (XIII)

In a similar manner, compounds of formula (III) may be prepared from compounds of formula (XII) and a compound of formula (XIV), and compounds of formula (V) can be prepared starting from compounds of formula (XV).

(XIV) (XV)

Further methods for forming a chemical bond between A and the thiazolyl or thiadiazolyl ring system to synthesise compounds of formula (II), (III), (IV), (V), (VI) and (VII) will be evident to one skilled in the art. These methods include replacement of any combination of the following: boronic acid or boronate ester (e.g. with a trialkyl tin, or a zinc halide such as zinc iodide, bromide or chloride); halogen (e.g. with a triflate); solvent; catalyst; temperature; or base. A list of examples of alternative biaryl bond forming reactions which could be used are described by Fu et al. J. Am. Chem. Soc, 123: 2719-2724 (2001) and Lemaire et al. Chem. Rev., 102: 1359-1469 (2002), and references therein. It may also be possible to carry out a biaryl bond forming reaction using an appropriately substituted thiazolyl or thiadiazolyl hydroxamic acid, or protected hydroxamic acid.

Compounds of formula (XIII), (XIV) and (XV) may be commercially available, or may be prepared from compounds of formula (IX), (X) or (XI) respectively by conversion to a suitable organometallic reagent, such as a lithium or magnesium reagent and subsequent treatment with a suitable boron reagent, such as trimethylborate. Alternatively, compounds of formula (IX), (X) or (XI) may be treated with a suitable boron reagent, such as bis(pinacolato)diboron, in the presence of a suitable catalyst, such as [1,1'- bis(diphenylphosphino)ferrocene]dichloropalladium, and a suitable base, such as potassium acetate, in an appropriate solvent, such as dioxane, at a suitable temperature, for example room temperature to the reflux temperature of the solvent.

Compounds of formula (IX), (X) and (XI) may be either commercially available, or may be prepared using any suitable method known to those skilled in the art.

Compounds of formula (NIII) may be prepared from compounds of formula (XII) using the procedures described above for the conversion of compounds of formula (IX), (X) or (XI) into compounds of formula (XIII), (XIV) and (XV).

Compounds of formula (XII) may be prepared using any suitable procedure known to those skilled in the art, including standard functional group interconversions. For example primary amine (-NH₂) groups may be alkylated using a reductive aU ylation process employing an aldehyde or a ketone and a borohydride, for example sodium triacetoxyborohydride or sodium cyanoborohydride, in a solvent such as a halσgenated hydrocarbon, for example 1,2-dichloroethane, or an alcohol such as ethanol, where necessary in the presence of an acid such as acetic acid at around ambient temperature. Secondary amine (-NH-) groups may be similarly alkylated employing an aldehyde.

In a further example, primary amine or secondary amine groups may be converted into amide groups (-NHCOR' or -NRCOR') by acylation. Acylation may be achieved by reaction with an appropriate acid chloride in the presence of a base, such as triethylamine, in a suitable solvent, such as dichloromethane, or by reaction with an appropriate carboxylic acid in the presence of a suitable coupling agent such HATU (O-(7- azabenzotriazol-l-y^-NNN^N'-tetramethyluronium hexafluorophosphate) in a suitable solvent such as dichloromethane. Similarly, amine groups may be converted into sulphonamide groups (-ΝHSO₂R' or -NR"SO R') groups by reaction with an appropriate sulphonyl chloride in the presence of a suitable base, such as triethylamine, in a suitable solvent such as dichloromethane. Primary or secondary amine groups can be converted into urea groups (-NHCONR'R" or -NRCONR'R") by reaction with an appropriate isocyanate in the presence of a suitable base such as triethylamine, in a suitable solvent, such as dichloromethane.

An amine (-NH₂) may be obtained by reduction of a nitro (-NO₂) group, for example by catalytic hydrogenation, using for example hydrogen in the presence of a metal catalyst, for example palladium on a support such as carbon in a solvent such as ethyl acetate or an alcohol e.g. methanol. Alternatively, the transformation may be carried out by cjhemical reduction using for example a metal, e.g. tin or iron, in the presence of an acid such as hydrochloric acid.

In a further example, amine (-CH₂NH₂) groups may be obtained by reduction of nitriles (- CN), for example by catalytic hydrogenation using for example hydrogen in the presence of a metal catalyst, for example palladium on a support such as carbon, or Raney nickel, in a solvent such as an ether e.g. a cyclic ether such as tetrahydrofuran, at a temperature from -78°C to the reflux temperature of the solvent. In a further example, amine (-NH₂) groups may be obtained from carboxylic acid groups (- CO₂H) by conversion to the conesponding acyl azide (-CON ), Curtius reanangement and hydrolysis of the resultant isocyanate (-N=C=O).

Aldehyde groups (-CHO) may be converted to amine groups (-CH₂NR'R")) by -reductive amination employing an amine and a borohydride, for example sodium triacetoxyborohydride or sodium cyanoborohydride, in a solvent such as a halogenated hydrocarbon, for example dichloromethane, or an alcohol such as ethanol, where necessary in the presence of an acid such as acetic acid at around ambient temperature.

In a further example, aldehyde groups may be converted into alkenyl groups (-CH=CHR') by the use of a Wittig or Wadsworth-Emmons reaction using an appropriate phosphorane or phosphonate under standard conditions known to those skilled in the art.

Aldehyde groups may be obtained by reduction of ester groups (such as -CO₂Et) or nitrϊles (-CN) using diisobutylaluminium hydride in a suitable solvent such as toluene. Alternatively, aldehyde groups may be obtained by the oxidation of alcohol groups using any suitable oxidising agent known to those skilled in the art.

Ester groups (-CO₂R') may be converted into the corresponding acid group (-CO₂H) by acid- or base-catalused hydrolysis, depending on the nature of R. If R is t-butyl, acid- catalysed hydrolysis can be achieved for example by treatment with an organic acid such as trifiuoroacetic acid in an aqueous solvent, or by treatment with an inorganic acid such as hydrochloric acid in an aqueous solvent.

Carboxylic acid groups (-CO₂H) may be converted into amides (-CONHR' or -CONR'R") by reaction with an appropriate amine in the presence of a suitable coupling agent, such as HATU, in a suitable solvent such as dichloromethane.

In a further example, carboxylic acids may be homologated by one carbon (i.e -CO₂H to - CH₂CO₂H) by conversion to the conesponding acid chloride (-COC1) followed by Arndt- Eistert synthesis. In a further example, -OH groups may be generated from the conesponding ester (e.g. - CO₂R'), or aldehyde (-CHO) by reduction, using for example a complex metal hydride such as lithium aluminium hydride in diethyl ether or^" tetrahydrofuran, or sodium borohydride in a solvent such as methanol. Alternatively, an alcohol may be prepared by reduction of the conesponding acid (-CO₂H), using for example lithium aluminium hydride in a solvent such as tetrahydrofuran, or by using borane in a solvent such as tetrahydrofuran.

Alcohol groups may be converted into leaving groups, such as halogen atoms or sulfonyloxy groups such as an alkylsulfonyloxy, e.g. trifluoromethylsulfonyloxy or arylsulfonyloxy, e.g. j^-toluenesulfonyloxy group using conditions known to those skilled in the art. For example, an alcohol may be reacted with thionyl chloride in a halogenated hydrocarbon (e.g. dichloromethane) to yield the conesponding chloride. A base (e.g. triethylamine) may also be used in the reaction.

In another example, alcohol or phenol groups may be converted to ether groups by coupling a phenol with an alcohol in a solvent such as tetrahydrofuran in the presence of a phosphine, e.g. triphenylphosphine and an activator such as diethyl-, diisopropyl, or dimethylazodicarboxylate. Alternatively ether groups may be prepared by deprotonation of an alcohol, using a suitable base e.g. sodium hydride followed by subsequent addition of an alkylating agent, such as an alkyl halide.

Aromatic halogen substituents in the compounds may be subjected to halogen-metal exchange by treatment with a base, for example a lithium base such as "butyl or 'butyl lithium, optionally at a low temperature, e.g. around -78°C, in a solvent such as tetrahydrofuran, and then quenched with an electrophile to introduce a desired substituent. Thus, for example, a formyl group may be introduced by using NN-dimethylformamide as the electrophile. Aromatic halogen substituents may alternatively be subjected to metal (e.g. palladium or copper) catalysed reactions, to introduce, for example, acid, ester, cyano, amide, aryl, heteraryl, alkenyl, alkynyl, thio- or amino substituents. Suitable procedures which may be employed include those described by Heck, Suzuki, Stille, Buchwald or Hartwig. Aromatic halogen substituents may also undergo nucleophilic displacement following reaction with an appropriate nucleophile such as an amine or an alcohol. Advantageously, such a reaction may be carried out at elevated temperature in the presence of microwave inadiation.

As another example, compounds of formula (I) in which A is heteroaryl containing an N-oxide group (e.g. pyridine-N-oxide) may be prepared by oxidation of compounds of formula (I) in which A is the conesponding non-oxidised he^~teroaryl.

It will be appreciated by those skilled in the art that the functional group interconversions described above may be carried out at any suitable stage of the synthesis. Thus, for example, compounds of formula (V) may be prepared from compounds of formula (XVIII) or formula (XIX) using standard functional group interconversions such as those described above.

(XVIII) (XIX)

For the purpose of illustration, a typical synthetic sequence is provided in Schemes

Scheme 1 The compositions of the present invention may be formulated in a conventional manner using one or more pharmaceutically acceptable carriers or ^"excipients. Thus, the active compounds of the invention may be formulated for oral, buccal, intranasal, parenteral (e.g. intravenous, intramuscular or subcutaneous) transdermal or rectal administration or in a form suitable for administration by inhalation or insufflation.

For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpynolidone or hydroxypropylmethylcellulose); fillers (e.g. lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium starch glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art.

Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g. sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g. lecithin or acacia); non-aqueous vehicles (e.g. almond oil, oily esters or ethyl alcohol); and preservatives (e.g. methyl or propyl p-hydroxybenzoates or sorbic acid).

For buccal administration the composition may take the form of tablets or lozenges formulated in conventional manner.

The active compounds of the invention may be formulated for parenteral administration by injection, including using conventional catheterization techniques or infusion. Formulations for injection may be presented in unit dosage form (e.g. in ampoules or in multi-dose containers, with an added preservative). The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulating agents such as suspending, stabilising and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, (e.g. sterile pyrogen-free water), before use.

The active compounds of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, (e.g. containing conventional suppository bases such as cocoa butter or other glycerides).

For intranasal administration or administration by inhalation, the active compounds of the invention are conveniently delivered in the form of a solution or suspension from a pump spray container that is squeezed or pumped by the patient or as an aerosol spray presentation from a pressurized container or a nebulizer, with the use of a suitable propellant, (e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas). In the case of a pressurized aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurized container or nebulizer may contain a solution or suspension of the active compound. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.

A proposed dose of the active compounds of the invention for oral, parenteral or buccal administration to the average adult human for the treatment of the conditions refened to above is 0.1 to 500 mg of the active ingredient per unit dose which could be administered, for example, 1 to 4 times per day.

The invention will now be described in detail with reference to the following examples. It will be appreciated that the invention is described by way of example only and modification of detail may be made without departing from the scope of the invention.

EXPERIMENTAL

General experimental detail

All reactions were canied out under an inert atmosphere of nitrogen. Where products were purified by chromatography the stationary phase used was an Isolute^® flash silica-gel cartridge. An applied pressure of nitrogen of ~ 10 psi was used to accelerate column elution. Thin layer chromatography (TLC) was carried out on aluminium foil plates coated with silica gel containing a fluorescent indicator (254 mn), (e.g. Fluka 60778). Organic solutions were dried over magnesium sulphate unless otherwise specified. TLC analysis was performed on Fluka aluminium-backed silica gel/TLC cards (20 x 20 cm) with layer thickness 0.2 mm, cut to size.

1H NMR system

400MHz 1H nuclear magnetic resonance spectra (NMR) were recorded at ambient temperature using a Varian Unity Inova (400MHz) spectrometer with a triple resonance 5mm probe. In the NMR, chemical shifts (δ) are expressed in ppm relative to tetramethylsilane. The following abbreviations have been used: br = broad signal, s = singlet, d = doublet, dd = double doublet, ddd = double double doublet, dt = double triplet, t = triplet.

LCMS system

High Pressure Liquid Chromatography - Mass Spectrometry (LCMS) experiments to determine retention times (Rj) and associated mass ions were performed using one of the following methods:

Method A; Experiments performed on a Finnigan TSQ700 spectrometer with positive ion electrospray and single wavelength UV 254 nm detection using a Higgins Clipeus C18 5 μm 100 x 3.0 mm column and a 2 ml / minute flow rate. The initial solvent system was 95% water containing 0.1% formic acid (solvent A) and 5% acetonitrile containing 0.1% formic acid (solvent B) for the first minute followed by a gradient up to 5% solvent A and 95% solvent B over the next 14 minutes. The final solvent system was held constant for a further 2 minutes.

Method B; Experiments performed on a Micromass Platform LC spectrometer with positive and negative ion electrospray and ELS/Diode anay detection using a Phenomenex Luna C18 (2) 30 x 4.6 mm column and a 2 ml / minute flow rate. The solvent system was 95% solvent A and 5% solvent B for the first 0.50 minutes followed by a gradient up to 5% solvent A and 95% solvent B over the next 4 minutes. The final solvent system was held constant for a further 0.50 minutes. HPLC system

Reverse-phase High Pressure Liquid Chromatography (HPLC) purification was performed using a Genesis HPLC Column (Ref. 16R10985, 100 mm x 22.5 mm) containing C18-7 μm 120 A silica, eluting with a gradient of acetonitrile (containing 0.1% trifluoroacetic acid) in water (containing 0.1% trifluoroacetic acid) at a flow rate of 5 ml/min. The starting gradient was 10% acetonitrile, and was increased at a rate of 1% per minute up to 50% acetonitrile/water unless otherwise stated. UV detection at 230 nm used unless otherwise stated.

Microwave system

Microwave experiments were carried out using a Personal Chemistry Smith Synthesizer™, which uses a single-mode resonator and dynamic field tuning, both of which give reproducibility and control. Temperature from 40-250 °C can be achieved, and pressures of up to 20 bar can be reached. Two types of vial are available for this processor; 0.5-2.0 mL and 2.0-5.0 mL.

Compounds have been named using Beilstein Autonom software.

Example 1:

2-Pyridin-2-yl-thiazole-5-carboxylic acid hydroxyamide.HCl

To a solution of 2-pyridin-2-yl-thiazole-5-carboxylic acid (tetrahydro-pyran-2-yloxy)- amide (Reference example 1), (31 mg, 0.10 mmol) in dichloromethane (3 mL) was added 4 M HC1 in dioxane (0.1 mL, 0.40 mmol). The reaction mixture was stined for 1 hour then treated with diethylether and the precipitate collected by centrifugation. Further trituration with diethylether allowed isolation of the required product, 2-pyridin-2-yl-thiazole-5- carboxylic acid hydroxyamide hydrochloride. (25 mg, 97%) as an off white powder. 1H NMR (d₆-DMSO)): 11.48 (br s, 1H), 10.72 (s br, 1H), 8.67 (d, 1H), 8.37 (s, 1H), 8.16 (d, 1H), 8.00 (dt, 1H), 7.55 (ddd, 1H). LCMS (Method A): R_T = 3.57 minutes; 222 (M+H)+.

Example 2A: 2-[5-(Benzylamino-methyl)-pyridin-2-yl]-thiazole-5-carboxylic acid hydroxyamide

To a solution of benzyl-{6-[5-(tetrahydro-pyran-2-yloxycarbamoyl)-thiazol-2-yl]-pyridin- 3-ylmethyl}-carbamic acid tert-butyl ester (Reference example 4A), (315 mg, 0.60 mmol) in dioxane (5 mL) was added 4 M HC1 in dioxane (5 mL, 20 mmol). The reaction mixture was stined for 3 hours and the resultant precipitate was collected by filtration. The crude product was purified by preparative HPLC following the general HPLC method described above to afford 2-[5-(benzylamino-methyl -pyridin-2-yl]-thiazole-5-carboxylic acid hydroxyamide as a white crystalline solid (trifluoroacetic acid salt; 64 mg, 20%). *H NMR (d₆-DMSO)): 11.50 (br s, 1H), 9.35 (s br, 3H,), 8.75 (dd, 1H), 8.39 (s, 1H), 8.23 (d, 1H), 8.11 (dd, 1H), 7.53-7.41 (m, 5H), 4.34 (br s, 2H), 4.26 (br s, 2H). LCMS (Method A): R_τ

= 5.67 minutes; 341 (M+H)⁺.

Example 2B:

2-[5-(Phenethylamino-methyl -pyridin-2-yl]-thiazole-5-carboxylic acid hydroxyamide

To a solution of phenethyl-{6-[5-(tetrahydro-pyran-2-yloxycarbamoyl)-thiazol-2-yl]- pyridin-3-ylmethyl}-carbamic acid tert-butyl ester (Reference example 4B), (205 mg, 0.38 mmol) in dioxane (4 mL) was added 4 M HC1 in dioxane (4 mL, 16 mmol). The reaction mixture was stined for 18 hours and then treated with 4 M HC1 in dioxane (5 mL) and warmed to 50 °C for 3 hours. The resultant precipitate was collected by filtration and purified by preparative HPLC following the general HPLC method described above to afford 2-[5-(phenethylylamino-methyl -pyridin-2-yl]-thiazole-5-carboxylic acid hvdroxyl amide as a white crystalline solid (trifluoroacetic acid salt; 67 mg, 30%). *H NMR (d₆- DMSO)): 11.51 (br s, IH), 9.38 (s br, IH,), 9.06 (br s, 2H), 8.75 (dd, IH), 8.39 (s, IH),

8.24 (d, IH), 8.11 (dd, IH), 7.38-7.32 (m, 2H), 7.30-7.25 (m, 3H), 4.32 (br s, 2H), 3.23 (m,

2H), 2.96 (m, 2H). LCMS (Method A): R_T = 5.25 minutes; 355 (M+H)+.

Example 3 2-(l -Ouinolin-3-ylmethyl-lH-imidazol-4-yl -thiazole-5-carboxylic acid hydroxyamide

The title compound was synthesized from 2-(l-quinolin-3-ylmethyl-lH-imidazol-4-yl)- thiazole-5 -carboxylic acid (tetrahydro-pyran-2-yloxy)-amide (Reference example 9), (300 mg, 0.69 mmol) in an analogous manner to that described in Reference example 1. Purification by preparative HPLC, eluting from 10% acetonitrile/water (+ 0.1 % TFA) to 90% acetonitrile/water (+ 0.1 % TFA) over 45 minutes gave 2-( 1 -quinolin-3 -ylmethyl- 1 H- imidazol-4-yl -thiazole-5-carboxylic acid hvdroxyl amide as a tan solid (trifluoroacetic acid salt; 50 mg, 19%).!H NMR (d₆-DMSO): 11.29 (s br, IH), 9.03 (s, IH), 8.40 (s, IH), 8.16 (m, IH), 8.10 (m, IH), 8.06 (d, IH), 8.05 (m, IH obscured), 8.03 (d, IH), 7.82 (m,

IH), 7.67 (m, IH), 5.56 (s, 2H). LCMS (Method A): R_τ = 5.53 minutes; 352 (M+H)+.

Reference example 1 2-Pyridin-2-yl-thiazole-5-carboxyIic acid (tetrahydro-pyran-2-yloxy)-amide

A solution of 2-pyridin-2-yl-thiazole-5 -carboxylic acid methyl ester (Reference example 2), (55 mg, 0.25 mmol) in THF (5 mL) was treated with potassium silanolate (192 mg, 1.50 mmol) and allowed to stir for 30 minutes at room temperature. The intermediate potassium salt that precipitated was collected by filtration and washed with THF. The salt was then dissolved in DMF (3 mL) and treated with O-(tetrahydro-pyran-2-yι)- hydroxylamine (Aldrich; 34 mg, 0.29 mmol), O-(7-azabenzotriazol-l-yl)-N,N,N',N'- tetramethyluoronium hexafluorophosphate (Aldrich; 143 mg, 0.38 mmol) and then diisopropylethylamine (130 μL, 0.75 mmol). The resulting mixture was stined at room temperature for 45 minutes then concentrated in vacuo. The residue was partitioned between water (20 mL) and dichloroethane (2 x 20 mL) and the organic extracts passed through a hydrophobic filter prior to being concentrated in vacuo. Further purification by chromatography, gradient eluting from cyclohexane to 60% ethyl acetate in cyclohexane, afforded the title compound 2-pyridin-2-yl-thiazole-5-earboxylic acid (tetrahydro-pyran-2- yloxyVamide (31 mg, 41%) as a gum. *H NMR (CDCI3): 9.33 (s br, IH), 8.62 (d, IH),

8.47 (s br, IH), 8.20 (d, IH), 7.82 (dt, IH), 7.37 (ddd, IH), 5.09 (s br, IH), 4.00 (m, IH), 3.68 (m, IH), 1.99-1.81 (m, 3H), 1.71-1.58 (m, 3H). LCMS (Method B): R = 2.67 minutes; 306 (M+H)+.

Reference example 2

2-Pyridin-2-yl-thiazole-5-carboxylic acid methyl ester

To a cooled (-78 °C) solution of 2-(5-bromo-thiazol-2-yl)-pyridine (Reference example 3), (150 mg, 0.62 mmol) in THF (20 mL) was added n-butyllithium (2.5 M in hexanes; 0.30 mL, 0.75 mmol) under argon. The resulting solution was aged for 10 minutes then allowed to warm to -40 °C and then cooled again to -78 °C. A solution of methylchloroformate (Aldrich; 67 μL, 0.87 mmol) in THF (1 mL) was then added and the resultant mixture aged for 10 minutes prior to warming to room temperature. Saturated ammonium chloride (1.0 mL) was added and the reaction mixture partitioned between water (20 mL) and dichloroethane (2 x 25 mL). The combined organic extracts were passed through a hydrophobic filter and concentrated. Purification by flash chromatography, gradient eluting from 5-15% diethylether in cyclohexane, gave the 2-pyridin-2-yl-thiazole-5-carboxylic acid methyl ester (161 mg, 14%) as an off white solid. !H NMR (CDC1₃): 8.64 (d, IH), 8.47 (s, IH), 8.22 (d, IH), 7.85 (dt, IH), 7.38 (ddd, IH), 3.94 (s, IH). LCMS (Method B): R_T - 3.10 minutes; 221 (M+H)+.

Reference example 3

2-(5-Bromo-thiazol-2-yl)-pyridine

A microwave vial (20 mL) was charged with a solution, in DMF (20 mL), of 2- tributylstannanyl-pyridine (Aldrich; 80%, 2.19g, 4.76 mmol), 2,5-dibromo-thiazole (Aldrich; 2.0 g, 8.23 mmol) and dichlorobis(triphenylphosphine)palladium(II) (395 mg, 0.56 mmol). The resulting mixture was microwave inadiated for 3 minutes at 140 °C then diluted with methanol (20 mL) and applied to an SCX-2 cartridge (70 g; sulphonic acid ion-exchange resin). Elution, first with methanol, allowed removal of DMF and excess stannane, and further elution with 2 M ammonia in methanol afforded the enriched pyridyl- thiazole product. Subsequent flash silica-gel chromatography, gradient eluting from cyclohexane to 20% diethylether in cyclohexane, afforded 2-(5-bromo-thiazol-2-yl)- pyridine (161 mg, 14%) as an amber oil that solidified on standing. ^H NMR (CDCI3):

8.58 (d, IH), 8.10 (d, IH), 7.79 (dt, IH), 7.78 (s, IH), 7.33 (ddd, IH). Reference example 4A

Benzyl-{6-[5-(tetrahydro-pyran-2-yloxycarbamoyl)-thiazol-2-yl]-pyridin-3-ylmethyl}- carbamic acid tert-butyl ester

The title compound was synthesised from 2-{5-[(benzyl-tert-butoxycarbonyl-amino)- methyl]-pyridin-2-yl}-thiazole-5-carboxylic acid methyl ester (Reference example 5A), (260 mg, 0.59 mmol) in an analogous manner to that described in Reference example 1 and gave benzyl-j^f6-[5-(tetrahydro-pyran-2-yloxycarbamoyl)-tlriazol-2-yl]-pyridin-3-ylmethyl} -carbamic acid tert-butyl ester as a tan foam (284 mg, 91%). LCMS (Method B): =

3.99 minutes; 525 (M+H)⁺.

Reference example 4B

Phenethyl-{6-[5-(tetrahydro-pyran-2-yloxycarbamoyl)-thiazol-2-yl]-pyridin-3-ylmethyl>- carbamic acid tert-butyl ester

The title compound was synthesised from 2-{5-[(tert-butoxycarbonyl-phenethyl-amino)- methyl]-pyridin-2-yl}-thiazole-5-carboxylic acid methyl ester (Reference example 5B), (175 mg, 0.39 mmol) in an analogous manner to that described in Reference example 1 and gave phenethyl-{6-r5-(tetrahydro-pyran-2-yloxycarbamoyl -thiazol-2-yl]-pyridin-3-ylmeth yl) -carbamic acid tert-butyl ester as a tan foam (205 mg, 98%). LCMS (Method B): R-j; =

4.08 minutes; 539 (M+H)⁺. Reference example 5A

2-{5-[(Benzyl-tert-butoxycarbonyl-amino)-methyl]-pyridin-2-yl}-thiazole-5-carboxylic acid methyl ester

A solution of 2-(5-fonnyl-pyridin-2-yl)-thiazole-5-carboxylic acid methyl ester (Reference example 6), (280 mg, 1.13 mmol) and benzylamine (135 μL, 1.24 mmol) in methanol was stined for 18 hours then treated with sodium borohydride (55 mg, 1.41 mmol). After 1 hour at RT the methanol was removed in vacuo and the residue partitioned between water (50 mL) and dichloromethane (2 x 50 mL) and the combined organic extracts dried (Na₂SO ), filtered and concentrated. The crude amine intermediate was dissolved in dichloromethane (4 mL) and treated with diisopropylethylamine (0.43 mL, 2.48 mmol) followed by a solution, in dichloromethane (0.5 mL), of di-tert-butyl dicarbonate (270 mg, 1.24 mmol). After 45 minutes the reaction mixture was concentrated in vacuo and purified by flash chromatography, loading in dichloromethane and eluting with 10% ethyl acetate/petrol (40-60 °C) to give 2-{5-[(benzyl-tert-butoxycarbonyl-aminoVmethyl]- pyridin-2-yl|-thiazole-5-carboxylic acid methyl ester as a clear oil (259 mg, 52%). LCMS (Method B): Rj = 4.42 minutes; 440 (M+H)⁺.

Reference example 5B

2- { 5-[(tert-ButoxycarbonvI-phenethyl-amino)-methyl]-pyridin-2-yl} -thiazole-5 -carboxylic acid methyl ester

The title compound was synthesised from 2-(5-formyl-pyridin-2-yl)-thiazole-5-carboxylic acid methyl ester (Reference example 6), (280 mg, 1.13 mmol) in an analogous manner to that described in Reference example 5A and gave 2- { 5- [(tert-butoxycarbonyl-phenethyl- aminoVmethyl]-pyridm-2-yl} -thiazole-5 -carboxylic acid methyl ester as a clear oil (175 mg, 35%). LCMS (Method B): RT = 4.55 minutes; 454 (M+H)⁺.

Reference example 6

2-(5-Formyl-pyridin-2-ylVthiazole-5-carboxylic acid methyl ester

A suspension of 2-(5-[l,3]dioxolan-2-yl-pyridin-2-yl)-thiazole-5-carboxylic acid methyl ester (Refrence example 7), (670 mg, 2.29 mmol) in glacial acetic acid (16 mL) was treated with water (4 mL) and stined for 42 hours at RT. The reaction was concentrated and the residue partitioned between aqueous NaHCO₃ (100 mL) and ethyl acetate (3 x 75 mL). The combined organic extracts were washed with brine (100 mL), dried (MgSO₄), filtered and concentrated in vacuo to afford 2-(5-formyl-pyridin-2-yl -thiazole-5-carboxylic acid methyl ester as an oily solid (550 mg, 97%). IH NMR (d₆-CDCl₃)): 10.17 (s, IH), 9.08 (dd, IH), 8.53 (s, IH), 8.40 (d, IH), 8.30 (dd, IH), 3.96 (s, 3H). LCMS (Method B): R_τ =

3.06 minutes; 249 (M+H)+.

Reference example 7

2-(5-[l,3]Dioxolan-2-yl-pyridin-2-ylVthiazole-5-carboxylic acid methyl ester

A solution in toluene (150 L) of 5-[1.3]dioxolan-2-yl-tributylstannanyl-pyridine (Reference example 8), (4.90g, 11.25 mmol), methyl 2-bromothiazole-5-carboxylate (Combi-Blocks; 6.40 g, 28.1 mmol) and triphenylphosphine (302 mg, 1.15 mmol) was purgered via several vacuum/argon flushes. Dichlorobis(triphenylphosphine)palladium(II) (5 mol%, 412 mg, 0.58 mmol) was added and the vacuum/argon purges were repeated. The reaction mixture was heated to reflux for 18 hours then cooled and partitioned between aqueous saturated ammonium chloride (250 mL) and dichloromethane (3 x 150 mL). The combined dichloromethane extracts were dried (Na₂SO ),"fϊltred then concentrated in vacuo. The crude product was purified by flash chromatography on silica-gel, loading in dichloromethane and gradient eluting from 5% ethyl acetate/petrol (40-60 °C) to 20% ethyl acetate/petrol (40-60 °C) to give 2-(5-[1.3]dioxolan-2-yl-pyridin-2-ylVthiazole-5- carboxylic acid methyl ester (700 mg, 21%) as a yellow solid. ^lH NMR (d₆-CDCl₃)): 8.72 (dd, IH), 8.48 (s, IH), 8.23 (dd, IH), 7.93 (dd, IH), 5.92 (s, IH), 4.17-4.06 (m, 4H), 3.94 (s, 3H). LCMS (Method B): R_T = 3.17 minutes; 293 (M+H)⁺.

Reference example 8

5-[1.3]dioxolan-2-yl-tributylstannanyl-pyridine

The title compound was prepared from 2,5-dibromopyridine (Aldrich) using the procedure detailed in Tetrahedron Lett. 1999, 40, 859.

Reference example 9 2-(l -Ouinolin-3-ylmethyl-lH-imidazol-4-ylVthiazole-5-carboxylic acid (tetrahydro-pyran-

2-yloxyVamide

A suspension of 2-(l-qumolin-3-ylmemyl-lH-inήdazol-4-yl)-thiazole-5-carboxylic methyl ester (Reference example 10), (1.9 g, 5.4 mmol) in IMS (30 mL) was treated with 1 M aqueous 5 M NaOH (5 mL) and allowed to stir for 18 hours at RT. The reaction mixture was concentrated and partitioned between water (50 mL) arid ethyl acetate (50 mL). The pH of the aqueous layer was adjusted to 4 via addition of aqueous HCl and then the aqueous layer was extracted with ethyl acetate (2 x 50 mL). The combined organic layer was washed with water (50 mL) and brine (50 mL) prior to drying (Na₂SO₄), filtering and concentrating in vacuo. The crude acid was then dissolved in DMF (20 mL) and treated with O-(tetrahydro-pyran-2-yl)-hydroxylamine (Aldrich; 0.72 g, 6.18 mmol), O-(7- azabenzotriazol-1 -yl)-N,N,N',N'-tetramethyluoroniumhexafluorophosphate. (Aldrich;

2.38 g, 6.18 mmol) and then diisopropylethylamine (2.95 mL, 16.9 mmol). The resulting mixture was stined at room temperature for 3 hours then concentrated in vacuo. The residue was partitioned between water (50 mL) and ethyl acetate (2 x 50 mL) and the organic extracts dried (Na₂SO₄), filtered and concentrated in vacuo. Purification by chromatography, gradient eluting from ethyl acetate to 10% IMS in ethyl acetate, afforded the title compound 2-(l-quinolin-3-ylmethyl-lH-imidazol-4-yl -thiazole-5-carboxylic acid

(tetrahydro-pyran-2-yloxy)-amide (300 mg, 12%) as an amber oil. 1H NMR (d₆-DMSO):

11.75 (s br, IH), 8.98 (d, IH), 8.31 (d, IH), 8.24 (s, IH), 8.06 (d, IH), 8.04 (d, IH), 8.03

(d, IH), 7.99 (d, IH), 7.78 (m, IH), 7.63 (m, IH), 5.53 (s, 2H), 4.97 (s, IH), 4.02 (m, IH), 3.35 (m, IH), 1.72-1.63 (m, 3H), 1.60-1.45 (m, 3H). LCMS (Method B): R_T = 2.36 minutes; 436 (M+H)+.

Reference example 10

2-(l -Ouinolin-3-ylmethyl-lH-imidazol-4-yl)-thiazole-5-carboxylic methyl ester

A mixture of 3-chloromethyl-quinoline hydrochloride (prepared according to J. Chem. Res, Synopes 1991, 5, 110), (1.96g, 9.10 mmol), 2-(H-imidazol-4-yl)-thiazole-5-carboxylic methyl ester (Reference example 11), (1.5 g, 6.1 mmol) and potassium carbonate (4.2 g, 30.5 mmol) in DMF (50 mL) was heated to 80 °C with stining for 24 hours. The reaction mixture was partitioned between water (50 L) and ethyl acetate (3 x 50 mL). The combined organic extract was washed with water (50 mL), brine (50 mL) and concentrated in vacuo. The crude residue was purified by flash chromatography on silica-gel, eluting from ethyl acetate to 5% methanol in ethyl acetate to give 2-( 1 -quinolin-3 -ylmethyl- 1 H- imidazol-4-yl)-thiazole-5 -carboxylic methyl ester (1.48 g, 69%) as an off-white solid. . *H NMR (CDC1₃)): 8.86 (d, IH), 8.32 (s, IH), 8.13 (d, IH), 7.96 (d, IH), 7.81-7.74 (m, 2H), 7.69 (d, IH), 7.64 (d, IH), 7.60 (m, IH), 5.39, (s, 2H), 3.91 (s, 3H). LCMS (Method B): RT = 2.50 minutes; 351 (M+H)⁺.

Reference example 11

2-(H-Imidazol-4-yl)-thiazole-5-carboxylic methyl ester

A solution of 2-(l-trityl-lH-imidazol-4-yl)-thiazole-5-carboxylic methyl ester (Reference example 12), (4.0 g, 8.86 mmol) in methanol/dichloromethane (100 mL/20 mL) was treated with 10% aqueous HCl (20 mL) and allowed to stir at RT for 18 hours. The reaction mixture was concentrated in vacuo and then triturated with diethyl ether and filtered to afford the product 2-(H-imidazol-4-yl)-thiazole-5-carboxylic methyl ester (1.5 g,

69%) as a white solid. ΪH NMR (d₆.DMSO)): 8.82 (s, IH), 8.52 (s, IH), 8.32 (s, IH), 3.88

(s, 3H). LCMS (Method B): R = 2.66 minutes; 209 (M+H)+.

Reference example 12

2-(l-Trityl-lH-imidazol-4-yl)-thiazole-5-carboxylic methyl ester

A solution in toluene (15 mL) of 4-tributylstannanyl-l-trityl-lH-imidazole (Reference example 13), (3.36 g 5.60 mmol) and methyl 2-bromothiazole-5-carboxylate (Combi- Blocks; 1.1 g, 4.95 mmol) was purged via several vacuum/argon flushes. Tetrakis(tιiphenylphosphine)palladium(0) (5 mol%, 290 mg, 0.25 mmol) was added the vacuum/argon purges repeated. The reaction mixture was heated at reflux for 18 hours then cooled and quenched via addition of saturated aqueous potassium fluoride solution (25 mL). The aqueous layer was extracted with ethyl acetate (3 x 25 mL) and the combined organic extracts washed with water (25 mL) and brine (25 ml) then dried (Na₂SO ), prior to filtering and concentration in vacuo. The crude product was purified by flash chromatography on silica-gel, gradient eluting from 20% ethyl acetate hexane to 20% ethyl acetate/hexane to give 2-(l-trityl-lH-imidazol-4-ylVthiazole-5-carboxylic methyl ester

(900 mg, 40%) as a white solid. !H NMR (CDC1₃)): 8.30 (s, IH), 7.60 (d, IH), 7.50 (d, IH), 7.37-7.34 (m, 9H), 7.18-7.15 (m, 6H), 3.90 (s, 3H). LCMS (Method B): R_T - 4.37 minutes; 452 (M+H)⁺.

Reference example 13

4-Tributylstannanyl- 1 -trityl- 1 H-imidazole

The title compound was prepared from 4-iodo-l-trityl-lH-imidazole (Combi Blocks) using the procedure detailed in Synthesis 1998, 6, 829.

Biological Activity

Compounds are tested for their capacity to inhibit histone deacetylase activity (primary assay) and for their biological effects on growing cells (secondary assay).

Deacetylase Assay

Total lysates from K562 chronic human myelogenous leukemia cells (obtained from American Type Culture Collection, Rockville, MD) are used as source of HDAC activity.

Cells are grown in RPMI media supplied with 10% FCS, harvested by centrifugation, washed once in PBS and resuspended at a density of 24xlθ6/ml in HDA buffer (15mM Potassium phosphate pH 7.5, 5% glycerol, 0.2mM EDTA). After sonication, lysates are centrifuged at lOOOg for 20 minutes and the resulting supernatant is aliquoted and stored at -80°C. Alternatively, commercially available HeLa nuclear extracts (BIOMOL) are used as source of histone deacetylase activity.

The assay was canied out for 30 minutes using 116μM of a fluorescent substrate containing an acetylated lysine residue (BIOMOL). When deacetylation of the lysine occurs, the substrate can react with the added developer producing a fluorophore. The amount of fluorophore produced is proportional to the HDAC activity in the sample and is quantified using a multiwell fluonmeter capable of excitation at 360nm and detection at 450nm.

Compounds are diluted in DMSO prior to addition to assay buffer, the final DMSO concentration in the assay being 1%.

The percent activity of the compounds in reducing histone deacetylase enzymatic activity is calculated as follow:

% activity = { (F^s - B) / (F^c - B) } x 100

where:

F^s is the fluorescence at 450nm in the presence of the tested compound (Sample). F^c is the fluorescence at 450nm in the presence of vehicle 1 % DMSO (Control). B is the fluorescence at 450nm in the absence of enzyme (Background fluorescence)

The IC₅₀ is defined as the concentration at which a given compound achieves 50% activity. IC5₀ values are calculated using the XLfit sof ware package (version 2.0.5).

Secondary Assay

Compounds are tested in a cell proliferation assay using the following cell lines:

MCF-7 human mammary gland adenocarcinoma (ATCC)

MDA-MB-231 human mammary gland adenocarcinoma (ATCC)

Both cell lines are free of Mycoplasma contamination (PCR Mycoplasma Detection Set, Takara). MCF-7 are kept in MEM medium (Gibco) supplemented with 10% FCS and 1% Non Essential Amino Acids at 37°C in a 5% CO humidified incubator. MDA-MB-231 are kept in L-15 (Leibovitz) medium (Gibco) supplemented with 15% FCS at 37°C in a non-modified atmosphere, humidified incubator. Cells are seeded in 96-well plates at a density of 20,000 cells/ml (3,000 cells/well) and after 24h they are exposed to different concentrations of compounds in 0.1% DMSO. Cells are grown for a further 72h, the media is removed and the cells are frozen at -80°C for at least 30 minutes and lysed in a solution containing the CyQUANT dye. This is a fluorescent molecule that specifically binds nucleic acids and whose fluorescence is greatly enhanced upon binding nucleic acids. Therefore the fluorescence intensity is proportional to the number of cells present in each well and can be quantified using a multiwell fmorimeter by measuring the fluorescence of the solution at 520nm.

The percent activity of the compounds in reducing cell number is calculated as follow:

% activity = { (A^s - B) / (A^c - B) } x 100

where:

A^s is the fluorescence at 520nm in the presence of the tested compound (Sample). A^c is the fluorescence at 520nm in the presence of vehicle 0.1% DMSO (Control). B is the fluorescence at 520nm in the absence of cells (Background fluorescence).

The IC₅₀ is defined as the concentration at which a given compound achieves 50% activity. IC₅₀ values are calculated using the XLfit software package (version 2.0.5).

Claims

A compound of formula (I):

(I)

in which

A represents optionally substituted monocyclic heteroaryl or phenyl;

L represents a single bond, alkylene, (CH₂)_nX(CH₂)_m, (CH₂)_nX(CH₂)_pY(CH₂)_m;

Q represents N or CR²;

X represents -O-, -NR³-, -CO-, -SO₂-, -NR³CO-, -NR³SO₂-, -CONR³-, -SO₂NR³-, - NR^ONR¹-;

Y represents -NR³- or -O-

R¹ represents H or alkyl;

R² represents hydrogen, halogen, alkyl, haloalkyl, alkoxy, haloalkoxy, CN;

R represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, or alkyl substituted by -OR⁴, -NR⁵R⁶, -NR⁶COR⁷, -NR⁶SO₂R⁷, -CONR⁵R⁶ or -SO₂NR⁵R⁶; R⁴ represents H, alkyl, arylalkyl, heteroarylalkyl, heterocycloalkylalkyl, cycloalkylalkyl, aryl, heteroaryl, heterocycloalkyl or cycloalkyl;

R⁵ represents H or alkyl;

or NR⁵R represents a cyclic amine;

n represents 0-3; m represents 0-3 ; p represents 1-3;

and conesponding N-oxides, pharmaceutically acceptable salts, solvates and prodrugs of such compounds.

2. A compound according to claim 1 wherein A is optionally substituted pyridinyl, pyrazolyl, imidazolyl or pyrimidinyl.

3. A compound according to either of claims 1 or 2, for use in therapy.

4. The use of a compound according to either of claims 1 or 2 in the manufacture of a medicament for the treatment of a disease in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease.

5. A method for treating a disease in a patient in which inhibition of histone deacetylase can prevent, inhibit or ameliorate the pathology and/or symptomatology of the disease, which method comprises administering to the patient a therapeutically effective amount of a compound according to either of claims 1 or 2.

6. A method or use according to claim 4 or 5 wherein said disease is a disease caused by increased cell proliferation.

7. A method or use according to claim 4 or 5 wherein said disease is cancer, psoriasis, fibroproliferative disorders, smooth muscle cell proliferation disorders, inflammatory diseases and conditions treatable by immune modulation, neurodegenerative disorders, diseases involving angiogenesis, fungal and parasitic infections and haematopoietic disorders.

8. A method or use according to claim 4 or 5 wherein said disease is liver fibrosis, arteriosclerosis, restenosis, rheumatoid arthritis, autoimmune diabetes, lupus, allergies, Huntington's disease, retinal diseases, protozoal infections, anaemia, sickle cell anaemia and thalassemia.

9. A method or use according to claim 8 wherein said protozoal infection is malaria, toxoplasmosis or coccidiosis.

10. A method or use according to claim 8 wherein said retinal disease is diabetic retinopathy, age-related macular degeneration, interstitial keratitis or rubeotic glaucoma.

11. A method or use according to claim 4 or 5 wherein said disease is congestive heart failure due to hypertrophy of cardiac myocytes.

12. A method or use according to claim 4 or 5 wherein said condition is premature parturition caused by decreased progesterone receptor activity.

13. A pharmaceutical composition comprising a compound according to claim 1 or 2 and a pharmaceutically acceptable diluent or excipient.