CA2069312A1 - Carboxyalkyl dipeptide inhibitors of endopeptidases - Google Patents

Abstract

Carboxyalkyl dipeptide inhibitors of endopeptidases of formula (I) or pharmaceutically acceptable salt thereof, wherein R1 is H, alkyl, arylalkyl or aryl; R2 is H, alkyl, alkenyl or alkynyl, wherein the alkyl portion is substituted with 0-3 substituents independently selected from the group consisting of hydroxy, alkoxy, alkoxyalkoxy, alkylthio, aryl, alkoxyalkylthio, arylalkoxy and arylalkylthio; R3 and R4 are independently alkyl or arylalkyl; or R3 and R4 together with the carbon to which they are attached form an optionally substituted 5-, 6- or 7-membered ring wherein said ring comprises 0 to 1 heteroatoms selected from the group consisting of sulfur and oxygen; R5 is H, alkyl, alkoxyalkyl, alkylthioalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, arylalkoxyalkyl or arylalkylthioalkyl; R6 is hydroxy, alkoxy, or R5; R7 is hydroxy, alkoxy, aryloxy, arylalkoxy, amino, alkylamino or dialkylamino; m is 0 or 1; and n is 0, 1, 2, or 3, use of the compounds, alone or in combination with an ACE inhibitor or an ANF, in the treatment of cardiovascular disorders such as hypertension, congestive heart failure, edema and renal insufficiency, use of the compounds in the treatment of pain conditions, and pharmaceutical compositions containing said compounds are disclosed.

Description

WO 91tO5796 Pcr/usgo/o~64o 2Q`5~31~

CARBOXYALKYL DIPEPT~DE
INHIBITORS OF ENDOPEPTIDASES

BACXGROUND OF THE INVENTION
The present invention relates to carboxyalkyl dipeptide inhibitors of endopeptidases useful in t~e treatment of cardiovascular disorders and pain conditions.
Cardiovascular conditions which may be treated with compounds of th~ present invention include hypertension, congestive heart ailure, edema and renal insufficiency.
Human hypertension represents a disease of multiple etiologies. Included among these is a sodium and volume dependent low renin form of hypertension.
Drugs that act to control one aspect of hypertension will not necessarily be effective in controlling another.
Enkephalin is a natural opiate receptor agonist which is known to produce a profound analgesia when injected into the brain ventricle of rats. It is also known in the art that enkephalin is acted upon by a group of enzymes known as enkephalinases or endopeptidases, which are also naturally occurring, and is inactivated thereby.
~ variety of compounds are known as endopaptidase inhibitors useul a~ anaigesics and/or in 2 0 ~ ~ 3 1 ~ -2- PCT/US9o/05~0 the treatment of hypertension. For example, European Patent Application 274,234, publis~ed July 13, 1988, discloses, inter ~lia, spiro-cubstituted glutaramide diuretic compounds of the formula ~ 2 3-6 HOOC-CIHCHa C ~0 ~ 2)1-3 wherein R5 in thQ cited patent may be a variety o~ al~yl or amino derivativQs or a hetQrocyclic.
U~S. Patent 4,513,009~ issued April 23, 1985,.
discloses, inter alia, alpha amino acid derivatives of the formula ( CH2 ) R2 Il 0-1 wherein Rl is preferably hydrogen or phenyl and R2 is preferably ~ydrogen, alkyl, benzyl or benzyloxyalkyl.
The compounds are said to ~ave enkep~alinase inhibiting and hypotensive activity.
U.S. Patent 4,610,816, issued September 9, 1986, discloses, inter alia, s~bstituted dipeptide enXephalinase~inhibitors of the formula Rl ~3 ~4 H00C-CH-NH-CH-CO-NH-~CH2)o 2-CH-C~

whQrein Rl and R3 are pre~erably phenylethyl and ~4 is preferably hydrogen, methyl or benzyl.
Similarly, German Patent Application 3,819,539, publis~ed December 22, 1988, discloses, inter alia, carboxyalkyl compounds of the formula WO91/0~796 PCT/US90/0~640 2~5~312 HOOC-CH-NH-CH-C-NH-IH-~CH2)o 5C-OH

wherein Rl and R8 are preferably bensyl and R5 is preferably hydrogen or lower alkyl~
It has recently been discovered that the ~eart secr~tes a series of~peptide hormones calle~ atrial natriurQtic f~actors tANF) which help~to regulat~ blood pressure, blood volu~e and tha ~xcretion o~ water, sodium and potassium. ANF wQr~ found to produce a short-term rQduction in blood pressurQ and to bQ useful in thQ
treatment of congQstive heart failurQ. See P. Needleman Qt al, ~Atriopeptin: A Cardiac HormonQ Intimately Involved in Fluid, Electrolyte and Blood-Pressure Homostasis~, N~ En~l. J~ Med., 314, 13 (1986) pp. 828-834, and M. Cantin et al in ~The Heart as an Endocrine Gland~, Scientific American, 2 (1986) pg. 76-81.
A class of drugs known to be effective in treating some types of hypertension is ACE inhibitors, which compounds are useful in blocXing the rise in blood pressure caused by increases in vascular resistance and fluid volume d~e to the formation of angiotensin II from angiotensin I. For a review of ACE Inhibitors, see M.
Wyvratt and A. Patchett, ~Recent Develop~ents in the Design of Angiotensin Converting Enzyme Inhibitors~ in Med. Res. Rev. Vol. 5, No. 4 (1985) pp. 483-531.

SUMMARY OF THE INVENTION
NOVQ1 compounds of the present invention are represented by the formula R2 R3 R4 R15 l6 RlO-fi-CH-NH~ -~-NH-(CH)~-(CH2)n-CH- ICI-R7 O O O

~ ~ S ~ 3 ~ ~ -4- PCT/US90/0~0 wherein R1 is H, alkyl, arylalkyl or aryl;
R2 is H, alkyl, al~enyl or alkynyl, wherein the alkyl portion is substituted wit~ 0-3 substituents independently selected from the group consisting of hydroxy, alkoxy, alkoxyalXoxy, alkylthio, aryl, alkoxyalkylthio, arylalkoxy and arylaiXylthio;

R3 and~R4 are independently alkyl or arylalkyl; or R3 and R4 togethe~ with the carbon to which they are a~tached form a 5-, 6- or ~membQred rinq whQrein said ring comprises O to ~ hetQroatoms selQcted from the group consisting of sulfur and oxygen, wh~rain said ring is unsubstituted or is substit~ted on a carbon atom ring member by an alkyl or aryl group, or wherein said ring is substituted by a fused ben2ene ring;
R5 is H, alkyl, alkoxyalkyl, alkylthioalkyl, aryl, aryl-alkyl, heteroaryl, heteroarylal~yl, arylal~oxyalkyl or arylalkylthioalkyl;
R6 is H, hydroxy, alkoxy, alkyl, alkoxyalkyl, alkylthioalkyl, arylalkoxyalkyl, arylalkylthioalkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl;
R~ is hydroxy, alkoxy, aryloxy, arylalkoxy, amino, alkylamino or dialkylamino;
m is O or 1, n is 0, 1, 2 or 3;
or a pharmaceutically acceptable salt thereof.
~ A preferred group of compounds of the present invention is that wherein R2 is arylalXyl, especially phenylethyl. Another preferred group is that wherein R3 and R4 together with the carbon to which they are attached form a 5-, 6- or 7-membered ring, especially a carbocyclic ring; especially preferred is a 5-membered ring~ Still another pre~erred group in that wherein R5 is hydrogen, R6 is hydroxy, m is 1 and n ~s zero.

WO 91/OS79fi 2 ~ S 9 3 1 2 PC~tUSgo/0~640 Other preferred compounds of formula I are those wherein Rl is hydrogen or benzyl. Similarly, R7 is preferably ~ydroxy, ethoxy or ~enzyloxy~
T~e invention also relates to the treatment of cardiovascular diseases with a combination of a carboxyalkyl dipeptide of the prese~nt invention and an atrial natriuretic factor (ANF) or with a combination of a carboxyalkyl dipeptide of the present invQntion and an angiotensin converting enzyme (ACE) inhibitor.
Oth~r as~ects of the invention relatQ to pharmaceutical compositions comprising a carboxyalkyl dipaptide of this invention, alone or in combination with an ANF or an ~CE inhibitor, and to mathods of treatment o~ cardiovascular diseases comprising administer~nq a carboxyalkyl dipeptide of this invention, alone or in combination with an ANF or an ACE inhibitor, to a mammal in need of such treatment.
Still another aspect of this invention relates to a method of treating pain conditions by ~ministering a carboxyalXyl dipeptide of this invention, thereby inhibiting the action of endopeptidases in a mammal and eliciting an analgesic effect~ Analgesic pharmaceutical compositions comprising said carboxyalkyl dipeptide compounds are also contemplated.

DETAILED DESCRIPTION
As used herein, the term "alkyl~ means straight or branched lower alkyl chains of 1 to 6 carbon atoms;
~talXenyl~t similarly means lower alkenyl chalns of 2 to 6 carbon atoms; "alkynyl~' means lower alkynyl chains of 2 to 6 carbon atoms; and "alkoxy" similarly means lower alkoxy chains of 1 to 6 carbon atoms.
"Aryl~' means a phenyl or naphthyl ring; a phenyl or napht~yl r~ng substituted with 1-3 substituents selected ~rom the group consisting of alkyl, hydroxy, WO91/05~s6 2~69~ PCT/US90/0;~0 alkoxy, halo, trifluoromethyl, phenyl, phenoxy and phenylthio; or a phenyl ring wherein adjacent alkyl or alkyl and alkoxy substituents form a 5- or 6-membered ring (for example indanyl, dihydrobenzofuranyl, 1,2,3,4-tetrahydronaphthyl and isochromanyl~.
~ Heteroaryl~ means mono-cyclic or ~ussd ring bicyclic aromatic groups having 5 to 10 ring members wherein 1-2 ring members are independently selected ~rom ~he group consisting of oxygQn, nitrogen and sulfur and where~n 1-3 carbon ring membQrs may be substituted with substi~uents as defined above for aryl~ Examples of he~eroaryl groups are ~uranyl, thienyl, pyrrolyl, benzofuranyl, thianaphthenyl, indolyl and pyridyl.
All positional isomers of the aryl and hetaroayl groups are contemplated, e~g~ 2-pyridyl and 3-pyridyl, Q-naphthyl and ~-naphthyl.
Halo means fluoro, chloro, bromo or iodo radicals.
Compounds of the invention can form pharmaceutically acceptable salts with organic and inorganic acids. Examples of suitable acids for salt formation are hydrochloric, sulfuric, phosphoric, acetic, citric, oxalic, malonic, salicylic, malic, fumaric, succinic, ascorbic, maleic, methanesulfonic and other mineral and carboxylic acids well known to those in the art.
Certain compounds of the invention are acidic e.g., those compounds which possess a carboxyl group.
These compounds ~orm pharmaceutically acceptable salts with inorganic and organic bases. Examples of such salts are the sodium, potassium, calcium and aluminum salts.
Also included are salts formed with pharmaceutically acceptable amines such as ammonia, alkyl amines, hydroxy alkyl amines, N-methylglucamine and the like.

WO91/0~796 PCT/VS90/0~0 -~- 2Q~3~2 The salts may be formed by conventional means, as by reacting the free acid or base forms of t~e product with one or more equivalents of the appropriate base or acid in a solvent or medium in which the salt i8 insoluble, or in a solvent such as water which is thQn removed in vacuo or by freeze-drying or by exc~anging the cations of an ~xisting salt for another cation on a suitablQ ion exchange resin~
Compounds of formula I havQ a~ l~ast one asymmetrical carbon atom and ther~forQ include various stereoisomQrs. ThQ invention includQs all such isomers both in pur~ form and in admixture, including racemic mixtures ~
An aspect of the present in~ention described above relates to the combination of a compound of ~ormula I with an ANF. As indicated by Needleman et al., a number of ANF have been isolated so far, all having the same core seguence of 17 amino acids within a cysteine disul~ide bridge, but having different N-termini lengths. These peptides represent N-terminal truncated fragments (21-48 amino acids) of a common preprohormone tl~l and 152 amino acids for man and rats, respectively).
Human, porcine and bovine carboxy-terminal 28-amino acid peptides are identical and differ from similar pep~ides in rats and mice in that the former contain a methionine group at position 12 while the latter contain isoleucine. Various synthetic analogs of naturally occurring ANF's also have been found to have comparable biological activity. Examples of ANF~s contemplated for use in t~is invention are o human AP 21 (atriopeptin I), o human AP 28, o human AP 23 (atriopeptin II or APII), ~
human AP 24, Q human AP 25, o hu~an~AP 26, o human AP 33, and the corresponding rat sequence of each of the above wherein Met 12 is Ile. See Table 1 for a comparison of the peptides.

WO 91/057~6 ~ 8- PCl'tVS90/0~640 S~L~
~W
~CPSI~)I! ~

2 ~ b 26 ~ c - S
S~ r~
Another aspect of the invention is the administration of a combination of an ACE inhibitor and a co~pound of ~ormula I.
Examples of ACE inhibitors are those disclosed in the article by Wyvratt et al., cited above, and in t~e following U~S. patents: U.S. Patents 4,105,776, 4,468,519, 4,555,506, 4,374,82g, 4,462,943, 4,470,973, 4,470,972, 4,350,704, 4,256,761, 4,344,949, 4,508,729, 4,512,924, 4,410,520 and 4,374,847, all incorporated herein by reference; and the following foreign patents or published patent applications:

British Specification No. 2095682 published October 6, 1982 discloses N-substituted-N-carboxyalkyl a~ino carboxyl alXyl glycine derivatives which are said to be angiotensin converting enzyme inhibitors and have the formula ~ Rb b ~ ~ N ~ COR9 a3 WO91/05796 PCT/US90/0~0 20~3 ~ ~

either (A~ R~ and Rgb are OH, 1-6C alkoxy, 2-6C alkonyloxy, di-~1-6C alkyl)amino-~1-6C) alkoxy, 1-6C hydroxy alkoxy, acylamino-(1-6C)alkQxy, acyloxy-(l-6C)alkoxy, aryloxy; aryloxy~ 6C)alkoxy, NH2, mono-or di~ 6C alkyl)amino, ~ydroxy amino or aryl~
6C)alXylamino;
~ R5b, R7b and R8b are 1-20C alkyl, 2-20C alkonyl, 2-20C alkynyl, aryl, aryl-(1-6C) alkyl having 7-12C
or heterocyclyl-~1-6C)al~yl hdving ?-12C;
R6b is cycloalkyl, polycycloalkyl, partly saturated cycloalkyl or polycycloalkyl, cycloalkyl-tl-6C)alkyl having 3-20C, 6-lOC aryl, aryl-(1-6C)alkyl, aryl-(2-6C)alkenyl or aryl-(2-6C) alkynyl; or R2b and R3b together wit~ t~e C and N atoms to which they are attached or R3b and R5b together with the N
and C atoms to which they are attached form an N-heterocycle containing 3-5C or 2-4C and a S atom;
all alkyl, alkonyl and alkynyl are optionally substituted by OH, 1-6C alkoxy, thio(sic), 1-6C
alkylthio, NH2, mono- or di(1-6C alkyl)amino, halogen or N02,~
all 'cycloalkyl' groups (including poly and partially unsaturated) are optionally substituted by halogen, 1-6C hydroxy alkyl, 1-6C alkoxy, amino-~l-6C alkyl)amino, di-(1-6C alkyl)amino, SH, 1-6C
al~ylthio, N02 or CF3; and aryl groups are optionally substituted by OH, 1-6C
alkoxy, NH2, mono- or di-(1-6C alkyl) amino, SH, 1-6C alXylthio, 1-6C hydroxy alkyl, 1-6C aminoalkyl, ~V09ltos7s6 ~Q~3~2 ~o PCT/USgo/o~o 1-6C thioalkyl, N02, halogen, CF3, OC~2o, ureido or ~uanid~no; or (B) Rb and Rgb are H or 1-6C alkoxy;
Rlb and R2b are H, 1-6C alkyl, aryl-~1-6C) alkyl having 7-12C or heterocyclyl-(1-6C) alkyl having 6-12C;
R3b-R5b, R7~ and R8b are H or 1-6C alkyl;
R6b is cycloalkyl, polycycloalkyl, partly saturated cycloalkyl or~polycycloalkyl, cycloalkyl-(1-6~) alkyl having 3-20C, aryl or aryl-~1-6C) alXyl; and aryl has 6-lOC and is optionally substitute~ by 1-6C
alkyl, 2-6C alkonyl, 2-6C alkynyl, OH, 1-6C alkoxy, NH2, mono- or di-tl-6C alkyl~ amino, SH, l-~C
alkylthio, l-6C hydroxy alkyl, 1-6C aminoalkyl, 1-6C
thioalkyl, N02, halogen, CF3, OCH20, ureido or guanidino;

European Patent Application 0 050 800 published May 5, 1982 discloses carboxy alkyl dipeptides deri~atives which are said to be angiotensin converting enzyme inhibitors and have the formula Rlc R3C R4C R5C o RC-C -~ -NH - ~ - C--~ C C R6c l2c B 1 7c or a pharmaceutically acceptable salt thereof, wherein Rc and R6C are the same or different and are hydroxy, lower alkoxy, lower alkonyloxy, dilower alkylamino lower alkoxy, acylamino lower alkoxy, acyloxy lower alkoxy, aryloxy, aryllower alkoxy, amino, lower alkylamino, dilower alkylamino, hydroxy amino, aryllower alkylamino, or substituted aryloxy or substituted aryllower alkoxy wherein the substituent is methyl, halo or methoxy; RlC

WO 91/~796 -1 PCT/l~s90/0~640 2~6931 ~
is hydrogen, alkyl of fro~ 1 to 10 carbon atoms, substituted lower alkyl wherein t~e substituent is hydroxy, lower alkoxy, aryloxy, substituted aryloxy, heteroaryloxy, substituted ~eteroaryloxy, amino, lower alkylamino, diloweralkylamino, acylamino, arylamino, substituted arylamino, guan~dino, i~idazolyl, indolyl,~
lower alkyl~hio, arylthio, substituted arylthio, carboxy, carbamoyl, lower alkoxy carboxyl, a~yl, substit~ted aryl, aralkyloxy, substitut~d aralkyloxy, aralkylthio or substituted aralkylthio, wherein thQ aryl or heteroaryl portion of said substituted aryloxy, heteroaryloxy, ~rylamino, arylthio, aryl, aralXyloxy, aralXylthio group is substitutQd with a group selected from halo, lower al~yl, hydroxy, lower alXoxy, amino, aminomethyl, carboxyl, cyano, or sul~amoyl; R2C and R7c are the same or different and are hydrogen or lower alkyl; R3c is hydrogen, lower alXyl, phenyl lower alkyl, aminoethylphenyl lower alkyl, hydroxyphenyl lower alkyl, hydroxy lower alkyl, acylamino lower alkyl, amino lower alkyl, dimethylamino lower alkyl, guanidino lower alkyl, imidazolyl lower alkyl, indolyl lower alkyl, or lower alkyl thio lower alkyl; R4c and R5c are the same or different and are hydrogen, lower alkyl or zc, or R4c and R5c taXen toget~er form a group represented by Qc, p , vc yc, Dc or EC, wherein;
zc is R8CXlC X2CR9c ~~
( CH2 ) pc wherein xlC and X2C independent o~ each other are 0, S or CH2, R8C and ~9c independent of each other are lower alkyl, lower alkonyl, lower alkynyl, cycloalkyl having 3 wo9l/os7s6 ~ Q ~ ~ 3 ~2 -12- PCT/US90/o;~O
to 8 carbon atoms, hydroxy lower al~yl, or -(CH2)nCAr~, wherein nc is o, 1, 2 or 3 and ArC is unsubstituted or substituted phenyl, furyl, thienyl or pyridyl, wherein said substituted phenyl, furyl, thienyl or pyridyl groups are substituted with at least one group that is independently selected from Cl to C~ alXyl, lower alkoxy, lower alkylthio, halo, CF3 and hydroxy, or R8C and R9c ta~en together form a~bridge WC, wh~rQin wC is a single bond or a methylene bridge or a substitutQd methylene brid~e when at least one of xlC and X2C is methylenQ, or wc is an alkylQnQ or substituted alkylQna bridge h~vin~ 2 or ~ carbon atoms, said substituted methylene bridge or said substituted alkylene bridge having one or two substituents selected from lower alXyl, aryl and aryl lower alkyl groups, and pc is O, 1 or 2; with the proviso that a~ least one of R4c and R5c is zc, with the proviso that if R4c is zc and pc is O then XlC and X2C must both be methylene, and with the proviso that if xlC and X2C
are both methylene then R8C and R9c must form an ~lkylene bridge WC;
QC iS

R8 cx~2 CR9C

( CH2~ ~ CH2 ) qC

wherein R8C R9C, XlC and X2C are as defined above, pc is O, 1 or 2, qc is O, 1 or 2, with the proviso that the sum of pc and gc must be 1, 2 or 3, with the proviso that if pc is O then XlC and X2C must be methylene, and with the proviso that if XlC and X2C are methylene then R3c and R9c taken toget~er form a bridge WC, wherein wC is as definad above;

PCT/US90/0~0 WO91/05796 -13~ 3 1 2 vc is R8CX~c X2CR9c ( CH2~ CH2 ) gC

w~Qrein R8c ~9c, xlc and X2C are as defined above, pc is 0, 1 or 2 and qc is 0, 1 or 2, with the proviso that the sum of pc and qc is 1, 2 or 3, with the proviso that i~
x~c and X2C are CH2 then R8C and R9c taken together form a bridge WC, wherein wC is as defined above;
uc is /wc ~2c - ( C~2 ) pC ( CH2 ) qC
wherein wC is as defined above (except that wC may also be a methylene bridge when XlC and X2C are oxygen or sulfur), xlC and X2C are as de~ined above, pc is o, 1 or 2, qc is 0, 1 or 2, with the proviso that the sum of pc and qc is 1 or 2, and with the proviso that if pc is 0, XlC must be CH2;
yC is ( CH2 ) ac ( H2 ) bC

WO91/05796 ~ 3~ -14- PCTIUS90/0~0 wherein Gc is oxygen, sulfur or CH2, ac is 2, 3 or 4 and bc is 1, 2, 3, 4 or 5, with the proviso that t~e sum of ac and bc is 5, 6 or 7 or Gc is CH2, ac is O, 1, 2 or 3, bc is O, 1, 2 or 3 with the proviso that the sum of ac and bc is 1, 2 or 3, with the proviso that the sum of aC and ~c may be 1, 2 or 3 only if ~lc is lower alkyl substituted with aralXylthio or aralkyloxy;

Dc is ( CH2~CH2 ) tC

( CH2 ) j c CH2 ) kC

wherein Fc is o or S, j c is o, 1 or 2 and kC-is 0, 1 or 2, with the proviso that the sum of jc and kc must be 1, 2 or 3, and mc is 1, 2 or 3 and tc is 1, 2 or 3, with the proviso that the sum of mc and tc must be 2, 3 or 4;
Ec is ( CH2 ~ hC \?CH2 ) Sc ( CH2~ --\H2 ) vc wherein Lc is O or S, UC is 0, 1 or 2 and VC is 0, 1 or 2, with the proviso that the sum of UC and VC must be 1 or 2, and ~c is 1 or 2 and 5c is 1 or 2, with t~e proviso that the sum of hc and 5c must be 2 or 3;

W091/05796 -15- ~ 0 ~ ~ 3 ~ ~

European Patent Application 0 079 522 published May 25, 1983 discloses N-carboxymethyl(amidino) lysyl-proline compounds which are said to be angiotensin converting enzyme inhibitors and have the formula where R2d Rld -CH _ NH- Cl - CO---N - CH (~)d COORd H ~oORd R2d R3d Rld~ CH NH--C-- CO ~ N ~Ia)d COORd H IHR14d I ooRd wherein:
Rd and R2d are independently hydrogen; loweralkyl;
aralkyl; or aryl;
Rld is hydrogen; branched or straight chain Cl_l2 alkyl and alkonyl; C3-Cg cycloalXyl and benzofused alkyl; substituted loweralkyl where the substituents are halo, ~ydroxy loweralkoxy, aryloxy, amino, mono-or diloweralkylamino, acylamino, arylamino, guanidino, ~ercapto, loweralkylthio, arylthio, carboxy, carboxamido, or loweralkoxycarbonyl; aryl;
substituted aryl where the substituents are loweralkyl, loweralkoxy, or halo; arloweralkyl;
arloweralkenyl; heteroarloweralkyl;
heteroarloweralkenyl, substituted arloweralkyl, substituted arloweralkenyl, substituted heteroarloweralkyl, or substituted heteroarloweralkenyl where the aryl and heteroaryl substituents are halo, dihalo, loweralkyl, hydroxy, loweralkoxy, amino, aminoloweralkyl, acylamino, WO9l/05796 ~93~ ~ -16- PCT/US90/05~0 mono- or diloweralkylamino, carboxyl, haloloweralkyl, nitro, cyano, or sulfonam~do, and where the loweralkyl portion of arloweralkyl may be substituted by amino, acylamino, or hydroxyl;

d d d '~f~
cooRd ~ ~CB) ~ OOC ~.

-N~ ~d '~A

~ ~
COO~

where:
xd and yd taken together are -CH2-CH2-;
O O O
-CH-S-; -C-CH2-; -CH2 -~ 0-; - C-S-;

oR4d O R~d R~d C~2 CH ; -~-N-; or -CH2-C-RSd;
R4d is ~ydrogen; loweralkyl; aryl; substituted aryl;
RSd is ~ydrogen; loweral~yl; aryl` or substituted aryl;
nd is 1 to 3;
is a~sent; -CH2-; or -C-;

W09tt0~796 ~ ~ 6 9 3 1 7 PCT/US90/0~0 zd is -(C~2)md, where md is O to 2, provided that md may not be O and Wd may noe be absent at the same time; and R6d ~5 hydrogen; loweralkyl; halo; or oR4d;

~2d is (CH2)r 8d-- (CH2)Sd--NR~dRlSd where rd and ~d are indQp~nd~ntly O to 3;
Bd ~s absent; -O-; -S-; or -NR8d;
wharQ ~8d is hydrog~n; loweralkyl; alkanoyl; or aroyl; and R7d iS NRlld NRlld N _ Jd _c_R9d; -~-NHRlOd; or _l -where R9d is loweralkyl; aralkyl; aryl; heteroaryl; or heteroarloweralXyl and these groups substituted by hydroxy, lower alkoxy or halo; carboxyl;
carboxamido; nitromethenyl.
RlOd is hydrogen; loweralkyl; aryl; or amidino;
Rlld hydrogen; loweralXyl; cyano; amidino; aryl; aroyl;
loweralXanoyl; _~_NHR13d;

-~-oR13d; -NO2; -SO2NH2;

or So2R13d;
R12d is hydrogen; loweralkyl; halo; aralXyl; amino;
cyano; mono- or diloweralkylamino; or oR4d;
R13d is hydrogen; loweralkyl; or aryl;
R15d is hydrogen; lower alkyl; aralkyl; or aryl;

W091/OS796 ~ 18- PCT/US~O/O~O

12d -c-~ constitute a basic heterocycle of 5 or 6 ato~s or benzofused analogs t~ereof and optionally containing 1-3 N atoms, an oxygen, a sulfur, an S-O, or an S02 group optionally substituted by amino, lower alkyl amino, diloweralkyl amino, lower alkoxy, or aralkyl groups;
R3d is C3-8 cycloalXyl and benzofused C3_8 cycloalkyl;
perhydrobenzofused C3_a cycloalkyl; aryl;
substituted aryl; ~eteraryl; substituted heteroaryl;
R14d is ~ydrogen or lowaralXyl; and, a pharmaceutically acceptable salt therQo~;

European Patent 79022 published May 18, 1983 discloses N-amino acyl-azabicyclooctane carboxylic acid d~rivatives which have t~e formula xe- C- CH2- CH NH CH - CO - N
ze COOR2e Rle HOO ~

hydrogen atoms at ring positions 1 and S are cis to each other and the 3-carboxy group ~as the endo orientation;
Rle is H, allyI, vinyl or the side chain o~ an optionally protected naturally occurring ~-amino acid;
R2e is H, 1-6C alXyl, 2-6C alXonyl or aryl(l-4C
alXyl);
Ye~is H or 0~ and ze is H, or ye and ze together oxyg~n;
X~ is 1-6C alkyl, 2-6C alkonyl, 5-9C cycloalkyl, 6-12C aryl (optionally substituted by one to three 1-WO91/05796 -19- 2 ~ 6 ~ /usgo/o;~o 4C alkyl or alkoxy, OH, halo, nitro, amino ~optionally substituted by one or two 1-4C alkyl), or methylenedioxy) or indol-3-yl);
European Patent 46953 published March lO, 1982 discloses N-amino acyl-indolinQ and tetrahydro isoquinoline carboxylic acids which are angiotensin coverting enzyme inhibitors and ha~e t~e formula COOH

N ~
~ H2)nf CO-C~Rlf-NH-C~R2fCOOR3f nf is 0 or 1;

Af 3 is a benzene or cyclohexane ring:

Rlf and R2f are each 1-6C alkyl, 2-6C alkonyl, 5-7C
cycloalkyl, 5-7C cycloalkanyl, 7-12C
cycloalkylalkyl, optionally partially hydrogenated 6-lOC aryl, 7-14C aralkyl or 5-7 membered monocyclic or 8-10 membered bicyclic ~eterocyclyl containing 1 or 2 S or O and/or 1-4N atoms; all Rlf and R2f groups are optionally substituted, -R3f is H, 1-6C alkyl, 2-6C alXonyl or 7-14C aralkyl.

The following Table II lists ACE inhibitors preferred for use in thQ combination of th_s invention.

WO 91/05796 Pcr/~lS90/05640 ~,96~3~ PREFERRED ACE INHIBI~ORS

fOORl R2 o R-C~I-NH -C~-C-R3 ~ R -- Rl R2 ~R3 splraF~ril ~6~5~2C~2- Ee 1~3 -~ H
e~alapr ~1 C6H5CH2CH~- Et Q~3 prolyl ramlpril C6H5CH2~2_ Et c~3 -N~

perindopril ~3~2CH2 Et C83 ~1 irx3O1april C6H5~2cH2- Et CH3 (~
lysinc~r il C6~5CH2~2_ ~2 (~2) ~~ prolyl ~' .
quinapril C~ 2~2~ 3 -N--C~

pen~ril ~I3 Et CEI3 -~

cilaza~ril C6H5CH2~2- H C~--C-R3 , ~N~?
2~

WO 91/0~796 -21- PCI`/US90/0~64o 2QS~3~ ~

ç~3 ~
C~2 ~2-~-R2 R Rl captcpril ~ prolyl S~6H5 20~r~pril C6HSCO~
P
pivalopril (CH3~3C-C- -N-CH2~XX~
~2 R-~H

R
~03)2 fosinqpril ~R5-(CR2)~ ~C~-CH2CH3 ~5 ThQ compounds of the present invention can be produced by ~ethods known to t~ose skilled in the art, for example by one or more of the methods and subroutes described below. Reactive groups not involved in the condensations described below, e.g., amino, carboxy, etc., may be protected by methods standard in peptide chemistry prior to the coupling reactions and subsequently deprotected to obtain the desired WO91/0~796 ~QS~3 ~ -22- PCTIUS90/05~0 products. In the formulae in t~e following description of the processes, Rl, R2, R3, R4, R5, R6 and R7 are as defined above for Formula I, including suitable protection where applicable.

Process A~ For the preparation of compounds of formula I, a ketoester (II) is condensed with a dipeptide ~XII) in the presence of a reducing agent:

O ~ R3 R4 ~ 6 R~ 2Nff~ )m~~2)n~ 7 r~uc~r~ ~ I
O o 2gent II III

The ketoester (II) can be condensed with the dipeptide (III) in aqueous solution, optimally near neutrality, or in a suitable organic solvent (for example, CH30H) in the presence of a reducing agent such as sodium cyanoborohydride to give directly the desired compound I. Alternatively, the intermediate Sc~iff base, enamine, or aminol may be catalytically reduced to yield product I, for example, by hydrogen in the presence of palladium on carbon (e.g. lOS palladium on carbon) or of Raney nickel. The ratio of diastereomeric products formed may be altered by choice of catalyst.

Process B: A dipeptide (III) can be alkylated by means of a compound IV:

~2 III I X-CH-COOR

IV

2as~3~ ~
WO91/0579h -23- PCT/US90/0;~0 wherein X is chloro, bromo, iodo, alkylsulfonyloxy, including haloalkylsulfonyloxy (e.g. CF3SO2O-) or arylsulfonyloxy. The reaction can be carried out under basic conditions in water or in an organic solvent.

Process C: An aminoacid V can be condansed with an aminoacid VI

R ~ -NH-~XX~H I H2N~(CH)m-(CH2~n ~ ~X~R7 ~

This reaction is well known from peptide chemistry. The reaction can be carried out in the presence of a condensing agent such as dicyclohexylcarbodiimide (DCC), diphenylphosphoryl azide ~DPPA) or N,N-disuccinimidyl carbonate in an inert solvent such as CH3CN. While, as mentioned above, reactive groups are protected before the coupling reaction is carried out, the carboxy group of compound V can ~e activated via the intermediacy of active esters such as that derived from l-hydroxybenzotriazole, its mixed anhydride tderived from a chlorocarbonic acid ester) or its azide.

Tha starting compounds in this reaction are known compounds and/or can be prepared according to known methods. The compound of formula V can, for èxample, be prèpared by reacting a keto compound II with an amino ester VII:

W09t/05796~s~3 ~ -24- PCT/US90/0~0 II + H2N-~ - COOR8 > V

VII

wherein R8 is an ester protecting group such as t-butyl, according to the conditions described in process A.
Alternatively, compound V can be prapared by condensing VII and IV:
R3 ~ R2 H2N--C--COOR8 + X-C~ OOR
~II IV

under the conditions described for process B above (the radical X being as defined in process B).
It is evident that a compound of formula I
obtained by any one of processes A to C can be transformed into another compound of formula I by methods known in the art.
The above processes can be followed by removing protecting groups by known methods~ Protected carboxy groups e.g~ when -oRl and R7 are for example alkoxy (methoxy, et~oxy, tert. butyloxy), nitrobenzyloxy or benzyloxy, are deprotected by hydrolysis or hydrogenation. For example, reductive cleavage of a benzyl ester of formula I (where R7 is benzyloxy and Rl is alkyl) will yield co~pounds of formula I wherein R1 is alkyl and R7 is hydroxy, and compounds wherein R7 is alkoxy and Rl is benzyl will yield compounds of formula I
wherein Rl is hydrogen and R7 is alkoxy.) ~ydrolysis can be carried out under acidic conditions tusing e.g. a halogen hydracid or trifl~oroacetic acid) or under basic conditions.

WO91/Oa796 -25- 2 Q ~ 9 31 ~CTIUS90/Oa~O
The amino group(s) can be protected by protecting groups such as, for example, formyl, t-butoxycarbonyl, carbobenzyloxy and triphenylmethyl.
These groups can be removed under acidic conditions, e.g.
by means of a halogen hydracid and/or trifluoroacetic acid~
We havQ found that the novel compounds of the present invention are effective in treating cardiovascular disorders such a~ congestive heart ~ailure, edema, rQnal insufficiency and ~arious types of hypQrtension, particularly volume expanded hypertension~ These novel compounds enhancQ both the magnitud~ and duration of the antihypertensive and natriuretic effects of endogQnous ANF~ Administration of a combination of a carboxyalkyl dipeptide and an ACE
inhibitor provides an antihypertensivQ effect greater than either the carboxyalXyl dipeptide or ACE inhibitor alone~ Administration of a combination of a carboxyalkyl dipeptide of formula I and an exogenous ANF or ACE
inhibitor is therefore particularly useful in treating hypertension~
In addition to the compound aspect, the present invention therefore also relates to treating cardiovascular disorders with a carboxyalkyl dipeptide of formula I or with a carboxyalkyl dipeptide of formula I
in combination with an ANF or an ACE inhibitor, which methods comprise administering to a mammal in need of such treatment an amount of the carboxyalkyl dipeptide or an amount of a combination of a carboxyalkyl dipeptide and ANF or ACE inhibitor effective to treat hypertension, congestive heart failure, edema or renal insuffiency~
ThQ drug or combination of drugs is preferably administered in a pharmaceutically acceptable carrier, e~g~ for oral or parenteral administration~ The combinations of drugs m~y be co-administered in a single W09t/05796 ~Q6'~ 26- PCT/US90/0~0 composition, or components of the combination therapy may ~e administered separately. Where the components are administered separately, any convenient combination of dosage forms may be used, e.g. oral carboxyalkyl dipeptide/oral ANF, oral carboxyalkyl dipeptide/
parenteral ACE inhi~itor, parenteral carboxyalkyl dipep~ide/oral ANF, parenteral carboxyalkyl dipeptide/parenteral ACE inhibitox~
Nhen the components o~ a co~bination of a carboxyalkyl dipeptide and ~n ANF are administered separately, it is preferred that the carboxyalkyl dipeptide be administered first.
T~e present invention also relates to a pharmacQutical composition comprising a carboxyalkyl dipeptide for use in treating hypertension, congestive heart failure,edema or renal insufficiency, to a pharmaceutical composition comprising both a carboxyalkyl dipeptide and an ANF and to a pharmaceu~ical composition comprising both a carboxyalkyl dipeptide and an ACE
inhibitor.
The antihypertensive effect of carboxyalkyl dipeptides was determined according to the following procedure:
Nale Spraque Dawley rats weighing 100-150 g were anesthetized with ether and the right kidney was removed. Three pellets containing DOC acetate (desoxycorticosterone acetate, DOCA, 25 mg/pellet) were implanted subcutaneously. Ani~als recovered from surgery, wera maintained on normal rat chow and were allowed }ree access to a fluid of 1% NaCl and 0.2S KCl instead of tap water for a period o~ 17-30 days. This procedure results in a sustained elevation in blood pressure and is a slight modification of published procedures (e.g. Brock et al., 1982) that have been used to produce DOCA salt hypertension in the rat.

W091/05796 -27 2 Q ~ ~ 3 1 t~cT/us9o/o~64o on the day of study, animals were again anesthetized with ether and the caudal artery was cannulated for blood pressure measurement. Patency of t~e caudal artery cannula was maintained with a continuous infusion of dextrose in water at a rate of 0~2 ml/hr. Animals were placed into restraining cages where they recovered consciousnQss, Blood pressure was measured from caudal artery cathetQr using a Statham pressure transducer attached to a BecXman oscillographic recorder~ In addition, a cardiovascular monitorinq devicQ ~uxco Electronics, Inc~) and a digital computer wQrQ used to calculate averag~ blood pressures~
A~ter an equilibration period of at least 1.5 hr., animals were dosed subcutaneously ~1 ml/~g) with vehicle (methylcellulose, hereinafter ~C) or carboxyalkyl dipeptide and blood pressure was monitored for the next 4 hours.
A similar procedure can be used to determine the effect of carboxyalkyl dspeptide in combination with ACE inhibitors~
The antihypertensive effect of carboxyalkyl dipeptides in combination with ANF can be determined according to the following procedures:
Male spontaneously hypertensive rats (SHR), 16-18 weeks old, 270-350 g, are anesthetised with ether and the abdominal aorta is cannulated through the tail artery~ The animals are then placed into restrainers to recover from anesthesia (in less than 10 min~) and remain inside throughout the experiments~ Through a pressure transducer (Gould ~23 series) analog blood pressure signals are registered on a Bec~man 612 recorder~ A
Buxco digital computer is used to obtain mean arterial pressures~ Patency of the arterial cannula is maintained with a continuous infusion of 5% dextrose at 0~2 ml/hr~
Animals are allowed a 9o-min equilibration period. The WO 91~05796 ~ 3~ -28- PCTtUSgO/0;~0 animals first ùndergo a challenge with an ANF such a~
atriopeptin II (AP II) or AP28 30 ~g/kg iv and at the end of 60 min. are treated with drug veh~cle or a carboxyalkyl dipeptide subcutaneously. A second ANF
challenge is administered 15 min~ later and blood pressure is monitored for the next 90 min.
The antihypertensivQ effect in SHR of carboxyalkyl dipeptides and A~E in~ibitors, alone and in combination, can be determined as ~ollows:
Animals arQ prepared for blood pressure me~surQmQnt as dQscribed abo~e. AftQr stabilization, animals are dosed subcutaneously or orally with test drugs or placebo and blood pressure is monitored for the next 4 hr.
The compounds having structural formula I have also been found to inhibit the activity of enzymes designated enkephalinases~ ~he compounds are particularly useful for the inhibition of enkephalinase A, which is derived from t~e striata of both rats and humans. In in vitro tests, using test procedures for enkephalinase A
inhibition well known to those skilled in the art, selected compounds having structural formula I have been found to inhibit the activity of the aforementioned enzyme.
Therefore, the present invention also relates to a method of inhibiting the action of enkephalinases in a mammal thereby to elicit an analgesic effect with a compound of formula I, and to analgesic pharmaceutical compositions comprising compounds of formula I.
The compositions of this invention comprise a carboxyalkyl dipeptide or a carboxyàlkyl dipeptide and an ANF or a carboxyalkyl dipeptide and an ACE inhibitor in combination with a pharmaceutically acceptable carrier for administration to mammals. A variety of pharmacèutical forms is suitable, prefexably for oral or parenteral administration, although machanical delivery W~91/05796 PCT/US90/0;~0 ~ass~l~
systems such as transdermal dosage forms are also contemplated.
The daily dose of the compound or combinations of this invention for treatment of hypertension) congestive heart failure, edema or renal insufficiency is as follows: for carboxyalkyl dipeptides alone the typical dosage is 1 to 100 mg/kg of mammalian wQight per day administered in single or dividod dosages; far the combination of carboxyalkyl dip~ptide and an~ANF, tha typical dosage is 1 to 100 mg of carboxyalXyl dip~ptidQ/kg mammalian weight par day in single or divided dosages plus 0~001 to 0.1 mg ANF/kg of mammalian weight per day, in single or divi~ed dosages, and.for the combination of carboxyalkyl dipeptide and an ACE
inhibitor, the typical dosage is 1 to 100 mg of carboxyalkyl dipeptide/kq mammalian weight per day in single or divided dosages plus 0~1 to 30 mg ACE
inhibitor/kg of mammalian weight per day in single or ~ivided dosages. The exact dose of any component or combination to be administered is determined by the attending clinician and is dependent on the potency of the compound administered, t~e age, weig~t, condition and response of the patient~
Generally, in treating humans having hypertension, congestive heart fail~re, edema or renal insufficiency, t~e compounds or combinations of this invention may be administered t~ patients in a dosage range as follows: for treatment with carboxyalkyl dipeptides alone, about 10 to about 500 mg per dose given 1 to 4 times a day, giving a total daily dose of about 10 to 2000 mg per day; for the combination of carboxyalkyl dipeptide and ANF, about 10 to about 500 mg carboxyalkyl dipeptide per dose given 1 to 4 times a day and about 0~001 to about 1 mg ANF qiven 1 to 6 times a day (total daily dosage range of 10 to 2000 mg day and .Ool to 6 WO9l/05796 PCT/US90/05~0 mg/day, respectively); and for the combination of a carboxyalkyl dipeptide and an ACE inhibitor, about 10 to about 500 mg carboxyalkyl dipeptide per dose given 1 to 4 times a day and about 5 to about 50 mg ACE inhibitor given 1 to 3 times a day (total daily dosage range of 10 to 2000 mg/day and 5 to 150 ~g/day, respectively). Where the components of a combination are administered separately, the number of doses of Qach component given per day may not necessarily be~the same, e.g. where one component may have a greater duration of activity, and will th~refore need to be administered less ~requently.
To produce an analgesic effect, compounds of this invention will be administered in a dosage range of ~rom about 1 to about 100 mg/kg. The doses are to be administered at intervals of from 3 to 8 hours. However, the quantity and frequency of dosage will depend upon such factors as the severity of ~he pain, the general physical condition of the patient, the age and weight of the patient, and other factors recogni2ed by the skilled clinician.
Typical oral formulations include tablets, capsules, syrups, elixirs and suspensions. Typical injectable formulations include solutions and suspensions.
The typical acceptable pharmaceutical carriers for use in the formulations described above are exemplified by: sugars such as lactose, sucrose, mannitol and sorbitol, starches such as cornstarch, tapioca starch and potato starch; cellulose and derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and methyl cellulose; calciu~ phosphates such as dicalcium phosphate and tricalcium phosphate; sodium sulfate;
calcium sufate; polyvinylpyrrolidone, polyvinyl alcohol;
stearic acid; alkaline earth metal stearates such as m~gnesium stearate and calcium stearate, stearic acid, WO91/0~9~ -31- 2 0 ~

vegetable oils such as peanut oil, cottonseed oil, sesame oil, olive oil and corn oil; non-ionic, cationic and anionic surfactants; ethylene gylcol polymers; beta-cyclodextrin; fatty alcohols and hydrolyzed cereal solids; as well as other nontoxic compatible fillers, binders, disintegrants, buffers, preservatives, anti~
oxidants, lubricants, flavoring agents, and ~he li~e commonly used in pharmaceutical formulations.
SincQ the present invention relates to treatmeht of hypertension with a combination o~ active ingrQdi~nts wherein said activ~ ingrQdiQnts may ba administerQd separately, thQ invantion also relates to combining separate pharmaceutical compositions in kit ~orm. That is, two kits are contampl~ted, each combining two separate units: a carboxyalkyl dipeptidQ
pharmaceutical composition and an ANF pharmaceutical composition in one kit and a carboxyalkyl dipeptide ~harmaceutical composition and an ACE inhibitor pharmaceutical composition in a second kit. The kit form is particularly advantageous when the separate components must be administered in different dosage forms te.g. oral and parenteral) or are administered at different dosage intervals.

2~R)-TRIFLUORONETHANESULFONYLOXY-4 PHENYLBUTYRIC ACID BENZYL ESTER

Step A: 2(R~-AcetoxY-4-Phenylbutyric Acid: Add sodium nitrite (15.5 g) portionwise to 2(R)-amino-4-phanylbutyric acid (lO.Og) in glacial acetic acid (560 ml) over 2 hours. Stir the reaction mixture for l hour and concentrate in vacuo. Partition the residue between water and diethyl ether. Dry (MgSO4) and concentrate WO91/05796 ~ 3~ -32- PCT/US90/05~0 the ether in vacuo to obtain an amber oil, [~26D=+12.1(MeOH).

SteP B: 2(R)-HvdroxY-4-Phenylbutyric Acid: At 0C, treat the product of step A (11.4 g) in methanol (100 ml) with 2N NaOH (52 ml), warm the resultinq mixture to room termperature, and stir for 20 hours. Concentrate the reaction mixture in vacuo and partition with water and ethyl acetatQ. Acidify the aquQous solution with concentratQd hydrochloric acid and extract with ethyl acetatQ~ Dry (MgS04) and concQntrate thQ ethyl acetate solution in ~acuo to obtain a light tan solid, ~.p. 104-105C, t~]26Dc-6.7(MeOH).

Ste~ C: ~ butyric Acid Benzyl Ester:
Treat the product of step B (9.71 g) in dimethylformamide (85 ml) with cesium carbonate ~18.1 g) and benzyl chloride (6.5 ml) at room temperature for 18 hours.
Concentrate the reaction mixture in vacuo and parti~ion between ethyl acetate and water. Dry (MgSO4) and concentrate the ethyl acetate solution in vacuo to obtain a yellow oil. Chromatograph this oil on silica gel (2000 ml) using dichloromethane as eluant. Concentrate the fractions containing t~e desired compound to obtain a pale yellow oil, ~]26D=+0.4 tMeOH).

Step D: 2(R)-Trifluoromethanesulfonyloxy-4-Phenylbutyric Acid Benzyl Ester: At -22C, add trifluoromethanesulfonic anhydride (2.71 ml) to a solution of pyridine (1~35 ml) in dichloromethane ~30 ml) (dried over Molecular sieves 4 A). After 15 minutes, add the product of step C (4.35 g) in dichloromethane (30 ml) and stir ~or 15 minutes. Quench the reaction mixture with lN HCl and extract the mixture with dichlorQmethane. Extract the dichloromet~ane solution WO9l/0~796 33 2Q~ Pcr/l S9n 0~640 with saturated NaHCO3 solution. Dry (MgSO4) and concentrate the dichloromethane solution in vacuo to obtain a liqht amber oil.

PREPARATION ~

l-AMINOCYCLOPENTANE-l-CARBOXYLIC ACID t-BUTYL ESTER

StQp A: l-tN-Ben~vloxyearbonylsmino)CyelopQntane-l-Carboxylic Aeid t-Butyl Ester: Suspend l-(N-bQnzyloxycar~onylamino~eyclopentane-l-carboxylie aeid (2.0 g~ in diehlorom~t~an~ (25 ml) in a pressure bottle and eool to 0-5~C~ Add eoncentraeQd H2SO4 t0.4 ml~ and eool to -20C. Condense isobutylene tl ml~, sQal the pressure bottle (20 lb~ and stir the reaction mixture at room temperature for 7 days. Pour the reaetion miXtUrQ
into dilute NaOH solution and stir for 10 min. Wash the dichloromethane solution with dilute NaOH and then water. Coneentrate the dried (MgSO4) ethyl acet~te in vacuo to obtain an oil.

Step B: l-Aminocyclopentane-l-CarboxYlie Aeid t-ButYl Ester: Hydrogenate the product of step A (1.8 g) in methanol (30 ml) containing 10S Pd/C (0.30 g) at 50 psi for 6.5 hours. Filter and concentrate the filtrate ~n vaeuo to obtain an oil.

1- r r 1 (S2 -BENZYLOXYCARBONYL-3-PHENYLPROPYL]-AMINO~CYCLOPENTANE CARBOXYLIC ACID HYDROCHLORIDE

Step A: l-tl(S)-BenzYloxycarbonyl-3-phenylPropyl]-aminocyelopentane Carboxylic Aeid t-ButYl Ester: At 0-5C, add a solution of the produet of Preparation 2 (2.6 WO91/05796 ~9 34 PCT/US90/0;~0 g) and Proton Sponge~ (1,8-bis(dimethylamino)naphthalelle) (2.0 g.) in dichloromethane (40 ml) (dried over Molecular sieves 4A) dropwise to a solution of the product of Preparation 1 (5.6 g) in dichloromethane (30 ml) and stir the resulting mixture at room temperature ~or 18 hours.
Filter and concentrate the reaction mixture in vacuo.
Triturate the residue with diethyl ether ~500 ml) and filter. Extract the diethyl ether solution (500 ml) with 200 ml portions of 5~ o~ KHSO4, H20, 5% NH4QH, H20, 5 XHSO4, H2O, 5% NaHCO3 and H2O. Dry (MgSO~) and concQntrate the diathyl eth~r solution to obtain a y~llow oil. Chromatograph this oil on a column of silica gel (800 ml) using dichloromethane as eluant. Concentrate thQ desired fractions to obtain a pale yQllow oil, t~26D-~2.6O (MeOH), Step B: l-rl(S)-Benzyloxycarboxvl-3-PhenylpropYl~
aminoc w lopentane Carboxylic Acid HYdrochloride: Treat the product of step A (3.7 g) in d~chloromethane (40 ml) with trifluoroacetic acid (25 ml), and stir the resulting mixture at room temperatuxe for 19 hours. Concentrate the reaction mixture in vacuo, add dichloromethane (20 ml), and concentrate in vacuo. Add excess HCl in dichloromethane to the residue and concentrate in vacuo. Triturate the residue with diethyl ether and filter to obtain the title compound as a white crystalline solid, m.p. 155-6C, t~]26D-+1.2 (MeOH).

N-tl-ttl(S)-BENZYLOXYCARBONYL-3-PHENYLPROPYL~AMINOl-YCLOPENTYLCARBONYLl-(S)-ISOSERINE BENZYL ESTER

At 0-5C, add triethylamine (1.7 ml) to the product of Preparation 3 ~1.45 g), 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide hydrochloride (EDC) ~0.8 g), WO91/OS796 -35- 2 ~ ~ 9 3 ~
l-hydroxybenzotriazole (HOBT) (0.4g) and tS)-isoserine benzyl ester hydrochloride (0.9 g) in DMF (7 ml) and warm the resulting mixture to room temperature and st~r for 72 hours~ Concentrate the resulting mixture in vacuo, and partition between ethyl acetate and water (twice), lN
NaH~03, dilute HCl, then brine. Dry (MgS04) snd concentrate the et~yl acetate solution to obtain an oil. Chromatograph this oil on a column of silica gal (300 ml, ~Baker~ 40 ~) using ethyl acetate: hexan~ 1:4 ~4L); 2:7 (1.5 ~); 1:3 and then ethyl acetate~
ConcentratQ the ~ractions containing the titlQ compound ~o obtain a colorless oil, t~26D~ 8^~

N- r 1- t r 1 t s ) -CARBOXY-3-PH~NYLPROPYL]AMINO~-CYCLOPENTYLCARBONYL~-(S)-ISOSERINE
Hydrogenate N-~ l(S)-benzyloxycarbonyl-3-phenylpropyl~amino~cyclopentyl-l-carbonyl](S)-isoserine (0~37 g~ in glacial acetic acid (20 ml~ in the presence of 5~ Pd/C (0~22 g~. After 5 hours, filter the mixture and concentrate in vacuo to obtain a residue. Dissolve the residue in dichloromethane/methanol, filter and evaporate to obtain a residue~ Triturate the resultant residue with diethyl ether and filter to obtain the title compound as a white solid, m.p~ 130-135C~ [~26D=+26.3 (MeOH~

~ he following formulations exemplify some of the dosage forms of the compositions of this invention~
In each, the term ~active compound~ designates a compound of formula I, preferably N-[l-[l~S~-carboxy-3-phenylpropyl~amino]cyclopentylcarbonyl~-(S)-isoserine.
However, this compound may be replaced by equally effective amounts of other compounds of formula I.

wogltO5796 2~93~ -36- PCT/US90/oS~O
Pharmaceutical Dosage Form Examples Example A

Tablets No. In~redient mg~tablet mg/tablet 1 Active Compound 100 S00 2 Lactose USP 122 113 3 Corn 5tarch, Food Grade, 30 ~0 as a 10~ paste in Puri~ied Water Corn Starch, Food Grade 45 40 5 Magnesium Stearate 3 7 Total 300 700 Method of Manufacture Mix Item Nos. 1 and 2 in suitable mixer for 10-15 minutes~ Granulate the mixture wit~ Item No. 3. Mill the damp granules through a coarse screen ~e.g., l/4~, O.63 cm) if necessary. Dry the damp granules. Screen the dried granules if necessary and mix with Item No. 4 and mix for 10-15 minutes. Add Item No. 5 and mix for 1-3 minutes. Compress the mixture to appropriate size and weight on a suitable tablet machine.

E~ple 8 C~Y~les No. ~ dient mg/car~le mg/capEule 1. Active oo~x~rd 100 500 2~ L~X~Q USP 106 123 3. Corn S~x~, Food Grade40 70 4. M~F~si~m Stearate NF 4 7 ` lor~L 250 700 W091/05796 _3?2 a ~ 2 PCT/US90/0;640 Method of Manufacture Mix Item Nos. 1, 2 and 3 in a suitable blender for 10-15 minutes. Add Item No. 4 and mix for 1-3 minutes. Fill the mixture into suitable two-piece hard gelatin capsules on a suitable encapsulating machine.

Example C

Parenteral PrQParation InqrQdient mg/~ial mg/vial Acti~e ~ompound Steri 1Q Powder 100 S00 For reconstitution add sterile water for injection or bacteriostatic water for injection.

Claims (17)

We Claim:

1. A compound represented by the formula I

wherein R1 is H, alkyl, arylalkyl or aryl;
R2 is H, alkyl, alkenyl or alkynyl, wherein the alkyl portion is substituted with 0-3 substituents independently selected from the group consisting of hydroxy, alkoxy, alkoxyalkoxy, alkylthio, aryl, alkoxyalkylthio, arylalkoxy and arylalkylthio;

R3 and R4 are independently alkyl or arylalkyl; or R3 and R4 together with the carbon to which they are attached form a 5-, 6- or 7-membered ring wherein said ring comprises 0 to 1 heteroatoms selected from the group consisting of sulfur and oxygen, wherein said ring is unsubtituted or is substituted on a carbon atom ring member by an alkyl or aryl group, or wherein said ring is substituted by a fused benzene ring;

R5 is H, alkyl, alkoxyalkyl, alkylthioalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, arylalkoxyalkyl or arylalkylthioalkyl;

R6 is H, hydroxy, alkoxy, alkyl, alkoxyalkyl, alkylthioalkyl, arylalkoxyalkyl, arylalkylthioalkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl;

R7 is hydroxy, alkoxy, aryloxy, arylalkoxy, amino, alkylamino or dialkylamino;
m is 0 or 1;
n is 0, 1, 2 or 3;
or a pharmaceutically acceptable salt thereof.

2. A compound of claim 1 wherein R2 is arylalkyl.

3. A compound of claim 2 wherein R3 and R4 together with the carbon to which they are attached form a carbocyclic 5-, 6- or 7-membered ring.

4. A compound of claim 2 wherein R5 is hydrogen, R6 is hydroxy, m is 1 and n is zero.

5. A compound of claim 1, 3 or 4 wherein R1 is hydrogen or benzyl and R7 is hydroxy or benzyloxy.

6. A compound of claim 1 which is:

N-[1-[[1(S)-benzyloxycarbonyl-3-phenylpropyl]amino]cyclopentylcarbonyl]-(S)-isoserine benzyl ester; or N-[1-[[1(S)-carboxyl-3-phenylpropyl]amino]-cyclopentylcarbonyl]-(S)-isoserine.

7. A method for treating hypertension, congestive heart failure, edema or renal insufficiency in mammals comprising admnistering to a mammal in need of such treatment an effective amount of a compound of claim 1 alone or in combination with an atrial natriuretic peptide or an angiotensin converting enzyme inhibitor.

8. A pharmaceutical composition for treating hypertension, congestive heart failure, edema or renal insufficiency comprising an effective amount of a compound of claim 1, alone or in combination with an atrial natriuretic peptide or an angiotensin converting enzyme inhibitor in a pharmaceutically acceptable carrier.

9. A composition of claim 8 wherein the atrial natriuretic peptide is chosen from .alpha. human AP 21, .alpha. human AP 28, .alpha. human AP 23, .alpha. human AP 24, .alpha. human AP 25, .alpha.
human 26, .alpha. human AP 33, and the corresponding atrial peptides wherein the methionine at position 12 is replaced by isoleucine.

10. A composition of claim 8 wherein the angiotensin converting enzyme inhibitor is selected from:
spirapril, enalapril, ramipril, perindopril, indolapril, lysinopril, quinapril, pentopril, cilazapril, captopril, zofenopril, pivalopril and fosinopril.

11. A kit comprising in separate containers in a single package pharmaceutical compositions for use in combination to treat hypertension or congestive heart failure in mammals which comprises in one container a pharmaceutical composition comprising a carboxylalkyl dipeptide and in a second container a pharmaceutical composition comprising an atrial natriuretic peptide.

12. A kit comprising in separate containers in a single package pharmaceutical compositions for use in combination to treat hypertension or congestive heart failure in mammals which comprises in one container a pharmaceutical composition comprising a carboxyalkyl dipeptide and in a second container a pharmaceutical composition comprising an angiotensin converting enzyme inhibitor.

13. A method for inhibiting the action of endopeptidases in a mammal thereby to elicit an analgesic effect comprising administering to a mammal in need of such treatment an analgesic-effective amount of a compound of claim 1.

14. An analgesic pharmaceutical composition comprising an analgesic-effective amount of a compound of claim 1 in a pharmaceutically acceptable carrier.

15. A method for preparing a pharmaceutical composition comprising admixing a compound of claim 1 with a pharmaceutically acceptable carrier.

16. The use of a compound of claim 1 for the manufacture of a medicament for treating hypertension, congestive heart failure, edema, renal insufficiency or pain conditions.

17. A process for the preparation of a compound of formula I as defined in claim 1, wherein the compound is prepared by an appropriate process selected from the following processes A, B and C, wherein R1, R2, R3, R4, R5, R6, R7, m and n are as defined in claim 1, including suitable protection:

Process A: condensation of a ketoester of formula II
with a dipeptide of formula III:
I
II III

Process B: alkylation of a dipeptide of formula III with a compound of formula IV wherein X is chloro, bromo, iodo, alkylsulfonyloxy, haloalkylsufonyloxy or arylsulfonyloxy:
I
IV

Process C: condensation of an aminoacid of formula V or a reactive derivative thereof with an amino acid of formula VI:
I

V VI

wherein Processes A, B and C are followed by isolation of the preferred isomer, if desired, and removal of the protecting groups, if necessary, to yield the desired product, and if desired, preparation of a salt thereof.