Title of Invention	"ACYLAMINOPIPERIDINE-1-CARBOXAMIDINE COMPOUND OF FOUMULA 1"
Abstract	Acylaminopiperidine-l-carboxamidine compound of general formula (1), or a pharmaceutically acceptable salt thereof: wherein R1 is selected from H, lower alkyl, R4-CO, R4-O2CCH2, R5-OCO and R5-SO2; R2 is selected from lower alkyl, cycloalkyl optionally substituted with an alkyl or alkyloxy group, (C5-C12)cycloalkylalkyl optionally substituted with an alkyl or alkyloxy group, aralkyl optionally substituted with up to three groups chosen from F, CI, Br, I, OH, lower alkyl, O-(lower alkyl), O-benzyl, NH2, NO2, NH-acyl, CN and CF3, and aralkyloxymethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and 0-(lower alkyl); or R1 and R2 together are an o-xylylene group optionally substituted on the aromatic ring with a group selected from F, CI, Br, OH, lower alkyl and 0-(lower alkyl); R3 is selected from H, OH and O-lower alkyl; R4 is selected from H, lower alkyl and phenyl; and R5 is selected from lower alkyl, phenyl and benzyl. The compounds are useful as pharmaceutical compositions.

Title of Invention

"ACYLAMINOPIPERIDINE-1-CARBOXAMIDINE COMPOUND OF FOUMULA 1"

Abstract

Acylaminopiperidine-l-carboxamidine compound of general formula (1), or a pharmaceutically acceptable salt thereof: wherein R1 is selected from H, lower alkyl, R4-CO, R4-O2CCH2, R5-OCO and R5-SO2; R2 is selected from lower alkyl, cycloalkyl optionally substituted with an alkyl or alkyloxy group, (C5-C12)cycloalkylalkyl optionally substituted with an alkyl or alkyloxy group, aralkyl optionally substituted with up to three groups chosen from F, CI, Br, I, OH, lower alkyl, O-(lower alkyl), O-benzyl, NH2, NO2, NH-acyl, CN and CF3, and aralkyloxymethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and 0-(lower alkyl); or R1 and R2 together are an o-xylylene group optionally substituted on the aromatic ring with a group selected from F, CI, Br, OH, lower alkyl and 0-(lower alkyl); R3 is selected from H, OH and O-lower alkyl; R4 is selected from H, lower alkyl and phenyl; and R5 is selected from lower alkyl, phenyl and benzyl. The compounds are useful as pharmaceutical compositions.

Full Text	INHIBITORS The'present invention relates to a series of novel compounds that are selective inhibitors of the enzyme plasma kallikrein, to pharmaceutical compositions comprising these inhibitors, and the use of such compositions in the treatment of human diseases. BACKGROUND The enzyme plasma kallikrein, also known by the classification EC.3.4.21.34, is a member of a family of trypsin-like serine protease that also includes tissue kallikrein, thrombin, trypsin and plasmin. It is found in plasma as an inactive zymogen that is activated by Factor XI la. The enzyme has a broad spectrum of activity. Plasma kallikrein liberates the vasoactive peptide bradykinin from high molecular weight kininogen by cleavage of Lys-Arg and Arg-Ser bonds. The same peptide can also be liberated from low molecular weight kininogen in the presence of neutrophil elastase. It is also capable of activating prourokinase and plasminogen, and is also thought to participate in the conversion of prorenin to renin. Plasma kallikrein is an essential component of the intrinsic blood coagulation cascade although its role does not involve the release of bradykinin or enzymatic cleavage. High molecular weight kininogen, the preferred substrate for plasma kallikrein, is essential for the activation in this cascade (K. D. Bhoola et a/., Pharm. Rev., 1992,44,1-80). The physiological effects of plasma kallikrein are likely to result from the proteolytic cleavage of kininogens to liberate kinins or of other substrates, e.g. precursors of growth factors. Kinins such as bradykinin are potent mediators of inflammation. In addition they influence cellular functions such as blood pressure, local blood flow, glucose transport and cell proliferation. These cellular actions which are modified by release of secondary messengers such as platelet activating factor, leukotrienes, prostaglandins, Substance P, acetylcholine and noradrenaline. Several groups have disclosed synthetic inhibitors of plasma kallikrein. These include arginine ketomethylene derivatives (WO 92/04371 and D. M. Evans et al„ Immunopharmacology, 1996, 32, 115-116), noragmatine and agmatine derivatives (WO 95/07291, WO 94/29335), benzamidine derivatives (J. StOrzbecher et al., Brazilian J. Med. Biol. Res. 1994, 27, 1929-1934), boronic acid derivatives (US 5,187,157) and aminomethylcyclohexanoyl derivatives (N. Teno et a/., Chem. Pharm. Bull., 1993, 41, 1079-1090). The aminomethylcyclohexanoyl derivatives have been shown to be active in models of collagen-induced arthritis in mice (Y. Fujimora et a/., Agents Actions, 1993, 39, 42-48) and endotoxin-induced disseminated intravascular coagulation (OIC) in rats (S. Okamoto et al., Agents Actions (Supplement), 1992, 38(Part 1), 198-205). The boronic acid derivatives are active in models of inflammatory bowel disease (A. Stadnicki et a/., Digestive Diseases and Sciences, 1996,41, 912-920 and FASEB, 1998,12,325-333). Selectivity with respect to the other members of the trypsin-like serine protease family is an important issue. Inhibitors of tissue kallikrein displaying poor plasma kalllkrein activity have previously been reported (M. Szelke et a/., Brazilian J. Med. Biol. Res. 1994, 27, 1935 and D. M. Evans ef a/., Immunopharmacology, 1996, 32,117), but there remains a need for compounds that selectively inhibit plasma kallikrein and not tissue kallikrein. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a series of acylaminopiperidine-1-carboxamidines that are inhibitors of plasma kallikrein. These compounds demonstrate good selectivity for plasma kallikrein, and are potentially useful in the treatment of inflammatory bowel disease, arthritis, inflammation, septic shock, hypotension, cancer, adutt respiratory distress syndrome, disseminated intravascular coagulation, cardiopulmonary bypass surgery and bleeding from post-operative surgery. The invention further relates to pharmaceutical compositions of the inhibitors, to the use of the compositions as therapeutic agents, and to methods of treatment using the compositions. DETAILED DESCRIPTION OF THE INVENTION In a first aspect, the present invention comprises a series of novel 4-(dipeptidylamino)-piperidine-1-carboxamidines according to general formula 1. (Formula Removed) In general formula 1, R1 represents a group selected from a hydrogen atom (H), a lower alkyl group, a group according to R4-CO, a group according to R4-02CCH2, a group according to R5-OCO, and a group according to R5-S02. R2 represents a group selected from a lower alkyl group, a cycloalkyl or (C5-C12)cycloalkylalkyl group, either of which may optionally be substituted with an alkyl or alkoxy group, an aralkyl group which may optionally be substituted with up to three groups chosen from F, CI, Br, I, OH, lower alkyl, O-(lower alkyl), O-benzyl, NH2l N02, NH-acyl, CN and CF3l and an aralkyloxymethyl group which may optionally be substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl). Alternatively, R1 and R2 together may constitute an oriho-xylylene group (o-C6H4(CH2)2). The aromatic ring of this xylylene group may optionally be substituted with a group selected from F, CI, Br, OH, lower alkyl and O-(lower alkyf). R3 represents a group selected from H, OH and O-(lower alkyl). R4 represents a group selected from H, lower alkyl and phenyl. R5 represents a group selected from lower alkyl, phenyl and benzyl. In the context of the present disclosure, the terms "alkyl group" and "lower alkyl group" are used interchangeably to denote linear and branched saturated hydrocarbon groups with between 1 and 8 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, neopentyl and isooctyl groups. The term "cycloalkyl group" Is used to denote monocyclic or polycyclic saturated hydrocarbon groups with between 3 and 12 carbon atoms, such as cyclopropyl, cyclohexyl, bicyclo[4.4.0]decyl (i.e. decahydronaphthyl) and adamantyl groups. The term "cycloakylalkyl group" is used to denote alkyl groups that bear a cycloalkyl group as a substituent, such as cyclohexylmethyl and 1-(cyclopentyl)ethyl groups. Where a limit is specified, as in (Ca-Cb)cycloa!kylalkyl, this denotes that the cycloalkyl moiety has between a and b carbon atoms. The term "alkoxy group" is used to denote O-(alkyl) groups. The term "acyl group" is used to denote formyl (H-CO) and alkyl-CO groups. The term "aralkyl group" is used to denote alkyl groups that bear an aryl group as a substituent, such as benzyl and 1-naphthylmethyl groups. The term "aryl group" includes phenyl, naphthyl, furyl, thienyl, pyrrolyl and pyridyl groups. The term "aralkyloxymethyl group" is used to denote aralkyl-OCH2 groups. The compounds of the present invention all have a guanidine functional group and so can form addition salts with acids. To the extent that such acids are pharmaceutically acceptable then these salts fall within the scope of the invention. Examples of suitable acids include acetic acid, trifluoroacetic acid, fumaric acid, malic acid, citric acid, benzoic acid, benzenesulphonic acid, hydrochloric acid, sulphuric acid and phosphoric acid. Certain compounds within the invention have an acidic functional group and so can form salts with alkaline and alkaline earth metals. Again, insofar as these are pharmaceutically acceptable they are included in the scope of the invention. Examples of such salts include the sodium, potassium and calcium salts. The compounds of the present invention all have at least two stereogenic centres (asymmetric carbon atoms) and so can exist as optical isomers, such as enantiomers, diastereomers and epimers. All such isomers are included, in the scope of the present invention. Mixtures of such isomers, including (but not limited to) racemic mixtures are also included in the scope of the invention. In a preferred embodiment, the present invention comprises compounds according to general formula 1 in which R1 is selected from H, lower alkyl and R4-02CCH2. In another preferred embodiment, the present invention comprises compounds according to general formula 1 in which R2 is selected from (C6-C10)cycloalkyialkyl, benzyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl), phenethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl), and benzyloxyrnethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl). More preferably R2 is selected from cyclohexylmethyl, decahydronaphth-2-ylmethyl, benzyl, 4-fluorobenzyl, 4-chlorobenzyl, 4-hydroxybenzyl, 4-(lower alkyl)oxybenzyl, α-hydroxybenzyl, α-methoxybenzyl, phenethyl and benzyloxyrnethyl. In another preferred embodiment, the present invention comprises compounds according to general formula 1 in which the absolute stereochemistry is as depicted in general formula 1A. More preferably, the absolute stereochemistry is as depicted in general formula 1B. (Formula Removed) In another preferred embodiment, the present invention comprises a compound selected from: (2'S,2",R)-4-(2'-(2"-amino-3"-(4",-ethoxyphenyl)propanoylamino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine; (2'S,2"R)-4-(2,-(2"-carboxymethylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2,S,2"R)-4-(2'-(3"-(4",-ethoxyphenyl)-2"-(methyloxycarbonyimethylamino)-propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2,S,2"H)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1-carboxamidine; (2'S,2"R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2'S,2"R)-4-(2-(3"-cyclohexyl-2"-(methyloxycarbonylmethy!amino)propanoylamino)-3,-phenylprapanoylamino)piperidine-1-carboxamidine; (2'S,2'R)-4-{2,-(2,,-amino-3"-phenylpropanoylamino)-3'-phenyIpropanoylamino)piperidine-1-carboxamidine; (2,S,2"R)-4-{2-(2"-carboxymethylarnino-3',-phenylpropanoylamino)-3,-phenyl-propanoylamino)piperidine-1-carboxamidine; (2'S,2"R)-4-(2,-(2"-(methyloxycarbonyImethylamino)-3"-phenylpropanoylamino)-3,-phenylpropanoylamino)piperidine-1-carboxamidine; (2'S,2"R)-4-2,-(2'-amino-3'-decahydronaphth-2,'-ylpropanoylanriino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine; (2'S,2"R)-4-(2'-(2"-carboxymethyiamino-3',-decahydronaphth-2,,,-ylprapanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2,S,2"R)-4-(2'-(3"-decahydronaphth-2",-yl-2"-(methyloxycarbonylmethylamino)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2'S,2"R,3'R)-4-(2-(2"-amino-3"-cyclotiexylpropanoylamino)-3-hydroxy-3-phenyl-propanoylamino)piperidine-1-carboxamidine; (2'S,2"R,3'R)4--(2'-(2"-carboxymethylamino-3'-cyclohexylpropanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)p;peridine-1-carboxamidine; (2'S,2"R,3'R)4--(2'-(3',-cyclohexyl-2,,-(methyloxycarbonylmethylamino)propanoylamino)-3,-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine; (2'S,2"R,3'R)4--(2'-(2,,-amino-3"-(4,,,-ethoxyphenyl)propanoylamino)-3,-methoxy-3,-phenyl-propanoylamino)piperidine-1-carboxamidine; (2'S,2"R,3'R)4--(2'-(2',-carboxyImethylamino-3,,-(4"',-ethoxyphenyl)propanoylamino)-3,-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine; and (2'S,2"R,3'R)4--(2'-(3,,-(4",-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine. The compounds of the present invention may be prepared by the methods generally known in the art, and particularly those methods used in the field of peptide chemistry. A useful starting material Is 4-amino-1-benzylpiperidine (2). Protection of the primary amine with a tert-butyloxycarbonyl (Boc) group to give 3 and hydrogenolysis provides piperidine derivative 4. This can be treated with isothiourea derivative 5 to give the carboxamidinopiperidine derivative 6 in which the amine and guanidine functional groups are differentially protected. (Formula Removed) The carboxamidinopiperidine derivative 6 can then be selectively deprotected and coupled to an N-protected amino acid 7 to give intermediate 8. (Formula Removed) The elaboration of intermediate 8 to give the final product depends to some extent on the nature of R1. When R1 is R5-OCO then the synthesis may conveniently proceed via intermediate 9. (Formula Removed) When R1 is H, R4-CO, R4-02CCH2 or R5-S02 then the synthesis may conveniently proceed via intermediates 10 and 11. (Formula Removed) Deprotection of the guanidine functional group gives compounds according to general formula 1 in which R1 is H. Derivatisation of the primary amine prior to deprotection of the guanidine gives access to other embodiments of R1. (Formula Removed) Intermediates 12, 13 and 14 may then be deprotected to give the corresponding compounds according to general formula 1. When R1 is alkyl, or when R1 and R2 together form a xylylene group, the synthesis may conveniently proceed via intermediate 15. (Formula Removed) Two deprotection steps then give the corresponding compounds according to general formula 1. The compounds of the present invention are potent and selective inhibitors of plasma kallikrein. They are therefore useful in the treatment of disease conditions for which over activity of plasma kallikrein is a causative factor. Generally, for use in such treatment the compounds will be formulated for administration to the patient The pharmaceutical formulation may be a solid or liquid, such as a tablet, capsule, solution or suspension. Methods of preparing such formulations are well known in the pharmaceutical art. The compositions will be administered to the patient under the supervision of the attending physician. EXAMPLES The following abbreviations have been used: AcOH acetic acid Boc-DCha-OH N-(tert-buryioxycarbonyl)-3-cyclohexyl-D-alanine Boc-DTyr(Et)-OH N-(tert-butyloxycarbonyl)-O-ethyl-D-tyrosine Boc-Phe-ONSu N-(tert-butyloxycarbonyl)-phenylalanine succinimidyl ester DMF dimethylformamide H-thPse-OH threo-3-phenylserine mplc medium pressure liquid chromatography TFA trifluoroacetic acid "Celite" is a registered trademark of Celite Corp. "Vydac" is a registered trademark of W.R. Grace & Co. EXAMPLE 1 (2'S,2"R)-4-(2'-(2"-Amino-3"-(4''-ethoxyphenyl)propanoylamino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine trifluoroacetate (Formula Removed) 1 A. 1 -Benzyl-4-(tert-butyloxycarbonylamino)piperidine 4-Amino-1-benzylpiperidine (3.2g, 16.8mmol) was dissolved in CH2CI2 (100ml). Di-tert- butyl dicarbonate (3.7g, 17.0mmol) and N,N-diisopropylethylamine (1.9g, 19mmol) were added. The mixture was stirred for 18h at room temperature then the solvent was removed in vacuo and the residue was taken up in ethyl acetate (150ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHCOj (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a yellow oi! which was purified by flash chromatography on silica gel (eluant 70% chloroform, 30% cyclohexane) to give a yellow solid identified as 1-benzyl-4-(tert-buryloxycarbonylamino)piperidine (4.9g, 18.9 mmol, 100%). 1B. 4-(tert-Butyloxycarbonylamino)piperidine 1-Benzyl-4-(tert-butyloxycarbonylamino)piperidine (4.9g, 18.9mmol) was dissolved in ethanol (100ml). This solution was hydrogenated over 10% palladium on charcoal at 60 psi. After 18h at room temperature the mixture was filtered through Celrte and the residue washed with ethanol (100ml). The combined filtrates were evaporated in vacuo to give a white solid identified as 4-(tert-butyloxycarbonylarnino)piperidine (2.3g, 7.1 mmol, 51%). 1C. N,N-Di(benzyloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1 -carboxamidine 4-(tert-Butyloxycarbonylamino)piperidine (1.5g, 7.5mmoI) was dissolved in ethanol (100ml). N,N-Bis(ben2yloxycarbonyl)-S-methylisothiourea (3.1g, 8.7mmol) and mercuric oxide (1.9g, 8.8mmol) were added. The mixture was stirred at 40°C for 4h then the solid was filtered off and washed with ethanol (50 ml). The combined filtrates were evaporated in vacuo to give a colourless oil which was purified by flash chromatography on silica gel (eluant. 90% pet ether 60-80,10% ethyl acetate) to give a colourless oil identified as N,N-dl(ben2yloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1-carboxamidine (3.3g, 6.6mmol, 87%). 1D. (2,S)-N,N-Di(benzyloxycarbonyl)-4-{2'-(tert-butyloxycarbonylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidine N,N-Di(benzyloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1-carboxamidine (3.1 g,6.1 mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue was dissolved in CH2CI2 (60ml). This solution was cooled to 0°C, Boc-Phe-ONSu (2.2g, 6.1 mmol) was added and the pH adjusted to 9 with N-methylmorpholine. The mixture was stirred at room temperature for 4 h, the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water(2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 70% chloroform, 30% cyclohexane) to give a white solid identified as (2,S)-N,N-di(ben2yloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine (3.56g,5.4 mmol, 89%). 1E. (2'S,2"R)-N,N-Di(benzyloxycarbonyl)-4-{2,-(2"-(tert-butyloxycarbonylamino)-3"-(4"-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2'S)-N,N'-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylpropanoyl-' amino)piperidine-1-carboxamidine (2.5g, 3.85mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (1.2g, 3.84mmol) was added followed by 1-hydroxybenzotriazole hydrate (680mg, 5.0mmol) and water-soluble carbodiimide (1.0g, 5.0mmol). After 15min the pH adjusted to 8 with N-methylmorpholine The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in chloroform (200ml). This solution was washed with 0.3M KHSO4 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 85% chloroform, 15% hexane) to give a white solid identified as (2'S.2"R)-N,N-di(benzyloxycarbonyl)-4-(2,-(2",-(tert-butyloxycarbonylamino)-3"-(4'"-ethoxyphenyl)-propanoylamino)-3-phenylpropanoylamino)piperidine-1-carboxamidine (2.47g, 3.2mmol, 65%). 1F.(2'S,2"R)-4-{2,-(2"-Amino-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidinetrifluoroacetate (2,S,2"R)-N,N'-Di(benzyloxyrarbonyl)-4-(2'-(2"-(tert-butyloxycrbonylamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2.1g, 2.7mmol) was dissolved in 4M HCI/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as H-DTyr(Et)-Phe-4-amino-1-amidinopiperidine trifluoroacetate (1.12g). [M+H]+ = 480.6 EXAMPLE 2 (2'S,2"R)-4-(2-(3"-Cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoylamino)-3'-pheny!propanoylamino)piperidine-1-carboxamidine trifluoroacetate 2A. (2'S,2"R)-N,N-Di(benzyloxycarbonyl)-4-(2'-{2'-(tert-butyloxycarbonylamino)-3",-cyclohexyIpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2'S)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylprapanoy amino)piperidine-1-carboxamidine (from Example 1D, 1.9g, 2.99mmoI) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DCha-OH (900mg, 3.3mmol) was added followed by 1-hydroxybenzotriazole hydrate (820mg, 6.1mmol) and water-soluble carbodiimide (730mg, 3.6mmol). After 15min the pH was adjusted to 8 with N-methylmorpholine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in chloroform (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 90% chloroform, 10% hexane) to give a white solid identified as (2'S,2"R)-N,N-di(benzyloxycaroonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-cyclohexyl- propanoylamino)-3'-phenylpropanoylaminojpiperidine-l-carboxamidine (1.73g, 2.14 mmol, 72%). 2B. (2,S,2"R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(3"-cyclohexyl-2"-{methyioxy- carbonylmethylamino)propanoyIamino)-3'-phenylpropanoylamino)piperidine-1- carboxamidine (2'S,2'R)-N,N'-Di(benzyloxycarbonyI)-4-(2-(2-(tert-fautyloxycarfaonylamino)-3"cycIohexyl-propanoylamino)-3'-phenylpropanoylamino)pipericline-1-carboxamidine (1 73g, 2.14mmol) was dissolved in 4M HCl/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in acetonitrile (100ml). Methyl bromoacetate (400mg, 2.6mmol) and N,N-diisopropylethylamine (440mg, 4.4mmol) were added. The reaction mixture was stirred at 60°C for 5h after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a yellow oil which was purified by flash chromatography on silica gel (eluant: 90% chloroform, 10% hexane) to give a white solid identified as (2'S,2"R)-N,N,-di(ben2y!oxycarbonyl)-4-(2,-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoylamino)-3'-phenyipropanoylamino)piperidine-1-carboxamidine (1.65g, 2.11 mmol, 98%). 2C. (2'S,2"R)-4-{2,-(3"-Cyclohexyl-2",-{methyloxycarbonylmeaiylamino)propanoyI-arnino)-3'-phenylpropanoy!amino)plperidine-1 -carboxamidine trifluoroacetate methylaminoJpnapanoyiamino)-3'-phenylpixipanoylaminoJpiperKline-l-carboxamidine (1.62g, 2.11 mmol) was dissolved in AcOH/water (95:5, 50mi). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on VydacC18 (15-25u) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2'-(3"-cyclohexyl-2-metthoxycarbonylmethylamino)propanoylamlno)-3'-phenylpropanoyl-amino)piperidine-1-carboxamidine trifluoroacetate (570mg). [M+H]+ = 515 EXAMPLE 3 (2'S,2"R)-4-(2'-(2"-{Carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenyl- propanoylamino)piperidine-1-carboxarnidinetrifluoroacetate (Formula Removed) 3A.(2'S,2"R)-N,N-Di(benzyIoxycarbonyl)-4-(2'-(2"-(carboxymethyIamino)-3"-cycIohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2'S,2"R)-N,N-Di(benzyloxyrarbonyl)-4-(2H3"cyclohexyl-2"-(methytoxycarbonyl-methylamino)propanoylamino)-3'-phenyipropanoylamino)piperidine-1-carboxamidine(from Example 2B, 1.6g, 2.1mmol) was dissolved in tetrahydrofuran (50ml). 1M Lithium hydroxide (3ml, 3mmol) was added. After 18h the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (150ml). This solution was washed with 1M citric acid (1 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid identified as (2'S,2"R)-N,N-di(benzyloxycarbonyl)-4-(2,-(2"-(carboxymethylamino)-3"-cyclohexylpropanoylamino)-3-phenylpropanoylamino)piperidine-1-carboxamidine (1.62g, 2.11mmol, 100%). 3B. (2'S,2"R)-4-(2'-(2"-(Carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidinetrifluoroacetate (2'S,2"R)-N,N-Di(benzyloxycaitonyl)-4-(2'-(2"(carboxymethylamino)-3"-cyclohexyl-propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.62g, 2.11mmol) was dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2'-(2"-(carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (570mg). [M+H]+ = 501 EXAMPLE 4 {2,S,2"R)-4-(2-(2"-Benzoylamino-3,-(4'"-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidinetrifiuoroacetate (Formula Removed) 4A. (2'S,2"R)-4-{2,-(2"-Benzoylamino-3"-(4"',-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)-N,N-di(benzyIoxycarbonyl)piperidine-1-carboxamidine (2'S,2"R)-N,N'-Di(benzyloxycycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-(4"'- ethoxyphenyl)propanoylamino)-3,-phenylpropanoylarnino)piperidine-1-carboxamidine(from Example 1F, 100mg, 0.12mmol) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2 Cl2 (20ml). This solution was cooled to 0°C and benzoyl chloride (19.7mg, 0.141mmol) and triethylamine (36mg, 0.36mmol) were added. The mixture was stirred at room temperature for 18 h, the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (70ml). This solution was washed with 0.3M KHS04 (2 x 20ml), sat. NaHC03 (2 x 20ml), water (2 x 20ml) and brine (1 x 20ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 85% chloroform, 15% cyclohexane) to give a white solid identified as (2'S,2"R)-4-(2'-(2"-benzoylamino-3"-(4'"-ethoxyphenyl)propanoylamino)-3,-phenylpropanoylamino)-N,N-di(benzyloxycarbonyl)piperidine-1-carboxamidine (65mg, 0.072 mmol, 60%). 4A. (2'S,2"R)-4-{2,-(2"-Benzoylamino-3"-(4"',-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine trifluoroacetate (2,S,2"R)-4-(2,-(2"-Benzoylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenyl- propanoylamino)-,N-di(benzyloxycarbonyl)piperidine-1-carboxamidine (65mg, 0.072mmol) was dissolved in AcOH/water (95:5, 25ml). This solution was hydrogenated over 10% palladium on charcoal. After 1 hour at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 20ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on VydacC18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2,-(2"-ben2oylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (44mg). [M+H]+ = 585 EXAMPLE 5 (2,S,2"R,3'R)-4-(2'-(2"-Amino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1 -carboxamidine trifluoroacetate (Formula Removed) 5A. (2S,3R)-2-(tert-Butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoic acid H-thPse-OH (J. Biol. Chem., 1953, 204, 323) (1.4g, 7.73mmo!) was dissolved in dioxan (75ml). Sodium hydroxide 820mg, 20.5mmol) in water (75ml) was added followed by di-tert-butyl dicarbonate (2.1g, 9.6mmol). The mixture was stirred for 18h at room temperature then the dioxan was removed in vacuo and the residue was washed with diethyl ether (1 x 100ml), acidified to pH 4 with 1M HCI and extracted with CHCI3 (3 x 100ml). The combined extracts were washed with water (1 x 50ml) and brine (1 x 50ml), dried (Na2SO4) and evaporated in vacuo to give a white solid identified as (2S,3R)-2-(tert-butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoicacid (1.6g, 5.7 mmol, 74%). 5B{2,S,3'R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylpropanoy!arnino)piperidine-1-carboxarnidine N,N-Di(benzyloxycarbonyl)-4-tert-butyloxycarbonylamino)piperidine-1-carboxamidine (from Example 1C, 2.3g, 4.5mmol) was dissolved in 4M HCl/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and (2S,3R)-2-(tert-butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoic acid (1.6g, 5.6mmol) was added followed by 1-hydroxybenzotriazole hydrate (1.1g, 8.1mmol) and water-soluble carbodiimide (1.4g, 75.0mmol). After 15 min the pH adjusted to 8 with N-methylmorpholine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na^Qi) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 50% ethyl acetate, 50% pet. ether) to give a white solid identified as (2,S,3'/?)-A/,Ar-di(benzyloxycarbonyl)-4-(2'-(tert-butyioxycarbonylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.1g, 1.6 mmol, 36%). 5C.(2'S,2"R,3'R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert:-butyloxycarbonylamino)-3"-{4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine phenylpropanoylamino)piperidine-1-carboxamidine (1.1g, 1.6mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (620mg, 2.0mmol) was added followed by 1-hydroxybenzotriazole hydrate (270mg, 2.0mmol) and water-soluble carbodiimide (420mg, 2.1 mmol). After 15min the pH was adjusted to 8 with N-methylmorpholine The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved In ethyl acetate (200ml). This solution was washed with 0.3M KHSO4 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 60% ethyl acetate, 40% pet. ether) to give a white solid identified as (2'S,2"R,3'R)-N,N-di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.2g, 1.3 mmol, 80%). 5D.(2,S,2"R,3'R)-4-{2,.{2"-Amino-3"-(4",-ethoxyphenyl)propanoylammo)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine triftuoroacetate (2'S,2",R,3'R)-N,N-Di(benzyloxycarlwnyl)-4-(2'-(2"-tert-butyloxycaltonyiamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidipe (1.2g, 1.3mmol) was dissolved in 4M HCI/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Cel'rte and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25n) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R,3R)-4-(2,-(2"-amino-3"-(4,"-ethoxyphenyl)-propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (540mg). [M+H]+ = 497.0 EXAMPLE 6 (2'S,2"R,3'R)-4-(2'-(2"-Amino-3"-(4"-ethoxyphenyl)propanoylamino)-3'-methoxy-3,-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (Formula Removed) 6A.(2'SR,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenyIpropanoylarnino)piperidine-1-carboxamidine (2'SR,3'RS)-N,N-Di(benzyloxyrarbonyl)-4-2-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine was prepared by the same method as described in Example 5 but starting with racemic H-thPse-OH. 6B. (2,SR,3RS)-N,N'-Dr(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2'SR,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylprapanoylamino)piperidine-1-carboxamidine (180mg, 0.27mmol), was dissolved in CH2C!2 (30ml). lodomethane (190mg, 1.3mmol) and silver oxide (132mg, 0.8mmol) were added. After 18h at 60°C the mixture was filtered and the filtrate was evaporated in vacuo to give a brown oil which was purified by flash chromatography on silica gel (eluant: 50% ethyl acetate, 50% pet. ether) to give a white solid identified as (2'SR,3'RS)-/\/,A/'-di(benzyloxycarbonyI)-4-(2'-(tert-butyloxycarbonylamino)-3'-methoxy-3'-phenyipropanoyl-amino)piperidine-1-carboxamidine (112mg, 0.16mmol, 61%). 6C.{2,SR,2"R,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-{4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3,-pheny)propanoy)amino)piperidine-1-carboxamJdine (2'SR,3'RS)-N,N'-Di(benzyloxycarbonyl)-4-(2,-(tert-butyloxycarbonylamino)-3,-methoxy-3-phenylpropanoylamino)piperidine-1-carboxamidine (112mg, 0.16mmol) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2Cl2 (30ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (50mg, 0.16mmol) was added followed by PyBrop (76mg, 0.16mmol). The pH adjusted to 9 with N,N-diisopropylethylamine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (70ml). This solution was washed with 0.3M KHSO4 (1 x 20ml), sat. NaHC03 (1 x 20ml), water (1 x 20ml) and brine (1 x 20ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 65% chloroform, 15% hexane) to give a white solid identified as (2'SR,2"R,3'RS)-N,N'-di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-(4"'- ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (108mg, 0.12 mmol, 75%). 6D. (2'S,2"R,3'R)-4-{2'-(2"-Amino.3'-(4'"-ethoxyphenyl)propanoylamino)-3,-methoxy-3'-phenylpropanoylamino)piperidlne-1-carboxamidinetrifluoroacetate {2,SR,2"R,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-{4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino_piperidine-1-carboxamidine (108mg, 0.12mmo[) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in AcOH/water (95:5, 20ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R,3'R)-4-(2,-(2"-amino-3',-(4",-ethoxyphenyl)-propanoylamino)-3'-methoxy-3'-phenylpropanoylaminoJpiperidine-1-carboxamidine trifluoroacetate (18mg). [M+H]+ = 511.3 The following compounds were prepared using analogous methods. Examples 7-17 (Table with Figure Removed) Examples 18-52 (Table with Figure Removed) Examples 53 - 54 (Table with Figure Removed) Examples 55 - 58 (Table with Figure Removed) Example 59 Determination of the inhibition constant K1 for plasma kallikrein Inhibition of plasma kailikrein activity in vitro was determined using standard published methods (see e.g. Johansen et al., Int. J. Tiss. Reac. 1986, 8,185; Short et al. Biochem. Pharmacol., 1992, 43, 1209; Storzebecher et a/., Biol. Chem. Hoppe-Seyler, 1992, 373, 1025). Human plasma kailikrein (Callbiochem) was incubated at 37°C with three different concentrations of the chromogenic substrate S-2302 (Chromogenix AB) and various concentrations of the test compound. Residual enzyme activity (initial rate of reaction) was determined by measuring the change in optical absorbance at 405nm and the inhibitory constant K1 for the test compound as determined from a Dixon plot (Dixon, Biochem. J., 1953,55,170). Typical results are presented in the Table. (Table with Figure Removed) Example 60 Determination of enzyme selectivity Selected compounds were further screened for inhibitory activity against other trypsin-like proteases following the method of Example 59 and using the appropriate enzyme and chromogenic substrate (Chromogenix AB). Representative results are presented in the Table. The selectivity is given by: Selectivity = (Kf for test enzyme) / (Ki for plasma kallikrein) (Table with Figure Removed) We Claim: 1. An acylaminopiperidine-1 -carboxamidine of formula 1, or a pharmaceutically acceptable salt thereof, (Formula Removed) wherein R4s selected from H, lower alkyl, R4-CO, R4-O2CCH2, R5-OCO and R5-SO2; R2 is selected from lower alkyl, cycloalkyl optionally substituted with an alkyl or alkyloxy group, (C5-C12) cycloalkylalkyl optionally substituted with an alkyl or alkyloxy group, aralkyl optionally substituted with up to three groups chosen from F, Cl, Br, I, OH, lower alkyl, O-(lower alkyl), O-benzyl, NH2, NO2, NH-acyl, CN and CF3, and aralkyloxymethyl optionally substituted with up to three groups chosen from F, Cl, Br, OH, lower alkyl and O-(lower alkyl); or R1and R2 together are an o-xylylene group optionally substituted on the aromatic ring with a group selected from F, Cl, Br, OH, lower alkyl and 0-(lower alkyl); R3 is selected from H, OH and O-lower alkyl; R4 is selected from H, lower alkyl and phenyl; and R5 is selected from lower alkyl, phenyl and benzyl. 2. The acylaminopiperidine-1-carboxamidine compound as claimed in claim 1 wherein R1 is selected from H, lower alkyl, and R4-O2CCH2. 3. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 and 2 wherein R2 is selected from (C6-C10) cycloalkylmethyl, benzyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl), phenethyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl) and benzyloxymethyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl). 4. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 3 wherein R2 is selected from cyclohexylmethyl, decahydronaphth-2-ylmethyl, benzyl, 4- fluorobenzyl, 4-chlorobenzyl, 4-hydroxybenzyl, 4-(lower alkyl) oxybenzyl, a-hydroxybenzyl, a- methoxybenzyl, phenethyl and benzyloxymethyl. 5. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 4 wherein the absolute stereochemistry is as depicted in general formula 1A. (Formula Removed) 6. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 5 wherein the absolute stereochemistry is as depicted in general formula 1B. (Formula Removed) 7. The acylaminopiperidine-1-carboxamidine compound according to any of Claims 1 to 6 selected from (2'S, 2"R)-4-(2'-(2"-amino-3"-(4'"-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-(4'"-ethoxyphenyl)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(3"-(4''-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine; (2'S, 2"R)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(2"-amino-3"-phenylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-phenylpropanoylamino)-3'-phenyl-propanoylamino)piperidine-1 -carboxamidine; (2'S, 2'R)-4-(2'-(2"-(methyloxycarbonylmethylamino)-3'-phenylpropanoyl-amino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine; (2'S, 2"R)-4-(2'-(2"-amino-3"-decahydronaphth-2'"-yl-propanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-decahydronaphth-2'"-yl-propanoylamino)-3 '-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S,2"R)-4-(2'-(3"-decahydronaphth-2'"-yl-2"-(methyloxycarbonylmethyl-amino)propanoylamino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine; (2'S, 2"R, 3'R)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R, 3'R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-hydroxy-3 '-phenylpropanoylamino)piperidine-1 -carboxamidine; (2'S, 2"R,3'R)-4-(2'-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine; (2'S, 2"R, 3'R)-4-(2'-(2"-amino-3"-(4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine; (2'S, 2"R, 3'R)-4-(2'-(2"-carboxymethylamino-3"-(4"'-ethoxyphenyl)propanoyl-amino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine; and (2'S, 2"R, 3'R)-4-(2'-(3"-(4'"-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine or a pharmaceutically acceptable salt thereof. 8. A pharmaceutical composition comprising a acylaminopiperidine-1 -carboxamidine compound as claimed in claims 1 to 7 or a pharmaceutical acceptable salt thereof. 9. The acylaminopiperidine-1 -carboxamidine compound as claimed in claims 1-7 as and when used in the manufacture of a medicament for the treatment of a disease condition in human or animal for which over activity of plasma Kallikrein is the causative factor.

Full Text

INHIBITORS
The'present invention relates to a series of novel compounds that are selective inhibitors of the enzyme plasma kallikrein, to pharmaceutical compositions comprising these inhibitors, and the use of such compositions in the treatment of human diseases.
BACKGROUND
The enzyme plasma kallikrein, also known by the classification EC.3.4.21.34, is a member of a family of trypsin-like serine protease that also includes tissue kallikrein, thrombin, trypsin and plasmin. It is found in plasma as an inactive zymogen that is activated by Factor XI la. The enzyme has a broad spectrum of activity. Plasma kallikrein liberates the vasoactive peptide bradykinin from high molecular weight kininogen by cleavage of Lys-Arg and Arg-Ser bonds. The same peptide can also be liberated from low molecular weight kininogen in the presence of neutrophil elastase. It is also capable of activating prourokinase and plasminogen, and is also thought to participate in the conversion of prorenin to renin. Plasma kallikrein is an essential component of the intrinsic blood coagulation cascade although its role does not involve the release of bradykinin or enzymatic cleavage. High molecular weight kininogen, the preferred substrate for plasma kallikrein, is essential for the activation in this cascade (K. D. Bhoola et a/., Pharm. Rev., 1992,44,1-80).
The physiological effects of plasma kallikrein are likely to result from the proteolytic cleavage of kininogens to liberate kinins or of other substrates, e.g. precursors of growth factors. Kinins such as bradykinin are potent mediators of inflammation. In addition they influence cellular functions such as blood pressure, local blood flow, glucose transport and cell proliferation. These cellular actions which are modified by release of secondary messengers such as platelet activating factor, leukotrienes, prostaglandins, Substance P, acetylcholine and noradrenaline.
Several groups have disclosed synthetic inhibitors of plasma kallikrein. These include arginine ketomethylene derivatives (WO 92/04371 and D. M. Evans et al„ Immunopharmacology, 1996, 32, 115-116), noragmatine and agmatine derivatives (WO 95/07291, WO 94/29335), benzamidine derivatives (J. StOrzbecher et al., Brazilian J. Med. Biol. Res. 1994, 27, 1929-1934), boronic acid derivatives (US 5,187,157) and
aminomethylcyclohexanoyl derivatives (N. Teno et a/., Chem. Pharm. Bull., 1993, 41, 1079-1090). The aminomethylcyclohexanoyl derivatives have been shown to be active in models of collagen-induced arthritis in mice (Y. Fujimora et a/., Agents Actions, 1993, 39, 42-48) and endotoxin-induced disseminated intravascular coagulation (OIC) in rats (S. Okamoto et al., Agents Actions (Supplement), 1992, 38(Part 1), 198-205). The boronic acid derivatives are active in models of inflammatory bowel disease (A. Stadnicki et a/., Digestive Diseases and Sciences, 1996,41, 912-920 and FASEB, 1998,12,325-333).
Selectivity with respect to the other members of the trypsin-like serine protease family is an important issue. Inhibitors of tissue kallikrein displaying poor plasma kalllkrein activity have previously been reported (M. Szelke et a/., Brazilian J. Med. Biol. Res. 1994, 27, 1935 and D. M. Evans ef a/., Immunopharmacology, 1996, 32,117), but there remains a need for compounds that selectively inhibit plasma kallikrein and not tissue kallikrein.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a series of acylaminopiperidine-1-carboxamidines that are inhibitors of plasma kallikrein. These compounds demonstrate good selectivity for plasma kallikrein, and are potentially useful in the treatment of inflammatory bowel disease, arthritis, inflammation, septic shock, hypotension, cancer, adutt respiratory distress syndrome, disseminated intravascular coagulation, cardiopulmonary bypass surgery and bleeding from post-operative surgery. The invention further relates to pharmaceutical compositions of the inhibitors, to the use of the compositions as therapeutic agents, and to methods of treatment using the compositions.
DETAILED DESCRIPTION OF THE INVENTION
In a first aspect, the present invention comprises a series of novel 4-(dipeptidylamino)-piperidine-1-carboxamidines according to general formula 1.
(Formula Removed)
In general formula 1, R1 represents a group selected from a hydrogen atom (H), a lower alkyl group, a group according to R4-CO, a group according to R4-02CCH2, a group according to R5-OCO, and a group according to R5-S02. R2 represents a group selected from a lower alkyl group, a cycloalkyl or (C5-C12)cycloalkylalkyl group, either of which may optionally be substituted with an alkyl or alkoxy group, an aralkyl group which may optionally be substituted with up to three groups chosen from F, CI, Br, I, OH, lower alkyl,
O-(lower alkyl), O-benzyl, NH2l N02, NH-acyl, CN and CF3l and an aralkyloxymethyl group which may optionally be substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl). Alternatively, R1 and R2 together may constitute an oriho-xylylene group (o-C6H4(CH2)2). The aromatic ring of this xylylene group may optionally be substituted with a group selected from F, CI, Br, OH, lower alkyl and O-(lower alkyf).
R3 represents a group selected from H, OH and O-(lower alkyl).
R4 represents a group selected from H, lower alkyl and phenyl.
R5 represents a group selected from lower alkyl, phenyl and benzyl.
In the context of the present disclosure, the terms "alkyl group" and "lower alkyl group" are used interchangeably to denote linear and branched saturated hydrocarbon groups with between 1 and 8 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, neopentyl and isooctyl groups.
The term "cycloalkyl group" Is used to denote monocyclic or polycyclic saturated hydrocarbon groups with between 3 and 12 carbon atoms, such as cyclopropyl, cyclohexyl, bicyclo[4.4.0]decyl (i.e. decahydronaphthyl) and adamantyl groups.
The term "cycloakylalkyl group" is used to denote alkyl groups that bear a cycloalkyl group as a substituent, such as cyclohexylmethyl and 1-(cyclopentyl)ethyl groups. Where a limit is specified, as in (Ca-Cb)cycloa!kylalkyl, this denotes that the cycloalkyl moiety has between a and b carbon atoms.
The term "alkoxy group" is used to denote O-(alkyl) groups.
The term "acyl group" is used to denote formyl (H-CO) and alkyl-CO groups.
The term "aralkyl group" is used to denote alkyl groups that bear an aryl group as a substituent, such as benzyl and 1-naphthylmethyl groups. The term "aryl group" includes phenyl, naphthyl, furyl, thienyl, pyrrolyl and pyridyl groups.
The term "aralkyloxymethyl group" is used to denote aralkyl-OCH2 groups.
The compounds of the present invention all have a guanidine functional group and so can form addition salts with acids. To the extent that such acids are pharmaceutically acceptable then these salts fall within the scope of the invention. Examples of suitable acids include acetic acid, trifluoroacetic acid, fumaric acid, malic acid, citric acid, benzoic acid, benzenesulphonic acid, hydrochloric acid, sulphuric acid and phosphoric acid. Certain compounds within the invention have an acidic functional group and so can form salts with alkaline and alkaline earth metals. Again, insofar as these are pharmaceutically acceptable they are included in the scope of the invention. Examples of such salts include the sodium, potassium and calcium salts.
The compounds of the present invention all have at least two stereogenic centres (asymmetric carbon atoms) and so can exist as optical isomers, such as enantiomers, diastereomers and epimers. All such isomers are included, in the scope of the present invention. Mixtures of such isomers, including (but not limited to) racemic mixtures are also included in the scope of the invention.
In a preferred embodiment, the present invention comprises compounds according to general formula 1 in which R1 is selected from H, lower alkyl and R4-02CCH2.
In another preferred embodiment, the present invention comprises compounds according to general formula 1 in which R2 is selected from (C6-C10)cycloalkyialkyl, benzyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl), phenethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl), and benzyloxyrnethyl optionally substituted with up to three groups chosen from F, CI, Br, OH, lower alkyl and O-(lower alkyl). More preferably R2 is selected from cyclohexylmethyl, decahydronaphth-2-ylmethyl, benzyl, 4-fluorobenzyl, 4-chlorobenzyl, 4-hydroxybenzyl, 4-(lower alkyl)oxybenzyl, α-hydroxybenzyl, α-methoxybenzyl, phenethyl and benzyloxyrnethyl.
In another preferred embodiment, the present invention comprises compounds according to general formula 1 in which the absolute stereochemistry is as depicted in general formula 1A. More preferably, the absolute stereochemistry is as depicted in general formula 1B.
(Formula Removed)
In another preferred embodiment, the present invention comprises a compound selected from:
(2'S,2",R)-4-(2'-(2"-amino-3"-(4",-ethoxyphenyl)propanoylamino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine;
(2'S,2"R)-4-(2,-(2"-carboxymethylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2,S,2"R)-4-(2'-(3"-(4",-ethoxyphenyl)-2"-(methyloxycarbonyimethylamino)-propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2,S,2"H)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1-carboxamidine;
(2'S,2"R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2'S,2"R)-4-(2-(3"-cyclohexyl-2"-(methyloxycarbonylmethy!amino)propanoylamino)-3,-phenylprapanoylamino)piperidine-1-carboxamidine;
(2'S,2'R)-4-{2,-(2,,-amino-3"-phenylpropanoylamino)-3'-phenyIpropanoylamino)piperidine-1-carboxamidine;
(2,S,2"R)-4-{2-(2"-carboxymethylarnino-3',-phenylpropanoylamino)-3,-phenyl-propanoylamino)piperidine-1-carboxamidine;
(2'S,2"R)-4-(2,-(2"-(methyloxycarbonyImethylamino)-3"-phenylpropanoylamino)-3,-phenylpropanoylamino)piperidine-1-carboxamidine;
(2'S,2"R)-4-2,-(2'-amino-3'-decahydronaphth-2,'-ylpropanoylanriino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine;
(2'S,2"R)-4-(2'-(2"-carboxymethyiamino-3',-decahydronaphth-2,,,-ylprapanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2,S,2"R)-4-(2'-(3"-decahydronaphth-2",-yl-2"-(methyloxycarbonylmethylamino)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2'S,2"R,3'R)-4-(2-(2"-amino-3"-cyclotiexylpropanoylamino)-3-hydroxy-3-phenyl-propanoylamino)piperidine-1-carboxamidine;
(2'S,2"R,3'R)4--(2'-(2"-carboxymethylamino-3'-cyclohexylpropanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)p;peridine-1-carboxamidine;
(2'S,2"R,3'R)4--(2'-(3',-cyclohexyl-2,,-(methyloxycarbonylmethylamino)propanoylamino)-3,-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine;
(2'S,2"R,3'R)4--(2'-(2,,-amino-3"-(4,,,-ethoxyphenyl)propanoylamino)-3,-methoxy-3,-phenyl-propanoylamino)piperidine-1-carboxamidine;
(2'S,2"R,3'R)4--(2'-(2',-carboxyImethylamino-3,,-(4"',-ethoxyphenyl)propanoylamino)-3,-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine; and
(2'S,2"R,3'R)4--(2'-(3,,-(4",-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine.
The compounds of the present invention may be prepared by the methods generally known in the art, and particularly those methods used in the field of peptide chemistry. A useful starting material Is 4-amino-1-benzylpiperidine (2). Protection of the primary amine with a tert-butyloxycarbonyl (Boc) group to give 3 and hydrogenolysis provides piperidine derivative 4. This can be treated with isothiourea derivative 5 to give the carboxamidinopiperidine derivative 6 in which the amine and guanidine functional groups are differentially protected.
(Formula Removed)
The carboxamidinopiperidine derivative 6 can then be selectively deprotected and coupled to an N-protected amino acid 7 to give intermediate 8.
(Formula Removed)
The elaboration of intermediate 8 to give the final product depends to some extent on the nature of R1. When R1 is R5-OCO then the synthesis may conveniently proceed via intermediate 9.
(Formula Removed)
When R1 is H, R4-CO, R4-02CCH2 or R5-S02 then the synthesis may conveniently proceed
via intermediates 10 and 11.
(Formula Removed)
Deprotection of the guanidine functional group gives compounds according to general formula 1 in which R1 is H. Derivatisation of the primary amine prior to deprotection of the guanidine gives access to other embodiments of R1.
(Formula Removed)
Intermediates 12, 13 and 14 may then be deprotected to give the corresponding compounds according to general formula 1.
When R1 is alkyl, or when R1 and R2 together form a xylylene group, the synthesis may
conveniently proceed via intermediate 15.
(Formula Removed)
Two deprotection steps then give the corresponding compounds according to general formula 1.
The compounds of the present invention are potent and selective inhibitors of plasma kallikrein. They are therefore useful in the treatment of disease conditions for which over activity of plasma kallikrein is a causative factor. Generally, for use in such treatment the compounds will be formulated for administration to the patient The pharmaceutical
formulation may be a solid or liquid, such as a tablet, capsule, solution or suspension. Methods of preparing such formulations are well known in the pharmaceutical art.
The compositions will be administered to the patient under the supervision of the attending physician.
EXAMPLES
The following abbreviations have been used:
AcOH acetic acid
Boc-DCha-OH N-(tert-buryioxycarbonyl)-3-cyclohexyl-D-alanine
Boc-DTyr(Et)-OH N-(tert-butyloxycarbonyl)-O-ethyl-D-tyrosine
Boc-Phe-ONSu N-(tert-butyloxycarbonyl)-phenylalanine succinimidyl ester
DMF dimethylformamide
H-thPse-OH threo-3-phenylserine
mplc medium pressure liquid chromatography
TFA trifluoroacetic acid
"Celite" is a registered trademark of Celite Corp. "Vydac" is a registered trademark of W.R. Grace & Co.
EXAMPLE 1
(2'S,2"R)-4-(2'-(2"-Amino-3"-(4''-ethoxyphenyl)propanoylamino)-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine trifluoroacetate
(Formula Removed)
1 A. 1 -Benzyl-4-(tert-butyloxycarbonylamino)piperidine
4-Amino-1-benzylpiperidine (3.2g, 16.8mmol) was dissolved in CH2CI2 (100ml). Di-tert-
butyl dicarbonate (3.7g, 17.0mmol) and N,N-diisopropylethylamine (1.9g, 19mmol) were
added. The mixture was stirred for 18h at room temperature then the solvent was removed in vacuo and the residue was taken up in ethyl acetate (150ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHCOj (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a yellow oi! which was purified by flash chromatography on silica gel (eluant 70% chloroform, 30% cyclohexane) to give a yellow solid identified as 1-benzyl-4-(tert-buryloxycarbonylamino)piperidine (4.9g, 18.9 mmol, 100%).
1B. 4-(tert-Butyloxycarbonylamino)piperidine
1-Benzyl-4-(tert-butyloxycarbonylamino)piperidine (4.9g, 18.9mmol) was dissolved in ethanol (100ml). This solution was hydrogenated over 10% palladium on charcoal at 60 psi. After 18h at room temperature the mixture was filtered through Celrte and the residue washed with ethanol (100ml). The combined filtrates were evaporated in vacuo to give a white solid identified as 4-(tert-butyloxycarbonylarnino)piperidine (2.3g, 7.1 mmol, 51%).
1C. N,N-Di(benzyloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1 -carboxamidine
4-(tert-Butyloxycarbonylamino)piperidine (1.5g, 7.5mmoI) was dissolved in ethanol (100ml). N,N-Bis(ben2yloxycarbonyl)-S-methylisothiourea (3.1g, 8.7mmol) and mercuric oxide (1.9g, 8.8mmol) were added. The mixture was stirred at 40°C for 4h then the solid was filtered off and washed with ethanol (50 ml). The combined filtrates were evaporated in vacuo to give a colourless oil which was purified by flash chromatography on silica gel (eluant. 90% pet ether 60-80,10% ethyl acetate) to give a colourless oil identified as N,N-dl(ben2yloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1-carboxamidine (3.3g, 6.6mmol, 87%).
1D. (2,S)-N,N-Di(benzyloxycarbonyl)-4-{2'-(tert-butyloxycarbonylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidine
N,N-Di(benzyloxycarbonyl)-4-(tert-butyloxycarbonylamino)piperidine-1-carboxamidine (3.1 g,6.1 mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue was dissolved in CH2CI2 (60ml). This solution was cooled to 0°C, Boc-Phe-ONSu (2.2g, 6.1 mmol) was added and the pH adjusted to 9 with N-methylmorpholine. The mixture was stirred at room temperature for 4 h, the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water(2 x
30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 70% chloroform, 30% cyclohexane) to give a white solid identified as (2,S)-N,N-di(ben2yloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine (3.56g,5.4 mmol, 89%).
1E. (2'S,2"R)-N,N-Di(benzyloxycarbonyl)-4-{2,-(2"-(tert-butyloxycarbonylamino)-3"-(4"-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine
(2'S)-N,N'-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylpropanoyl-' amino)piperidine-1-carboxamidine (2.5g, 3.85mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (1.2g, 3.84mmol) was added followed by 1-hydroxybenzotriazole hydrate (680mg, 5.0mmol) and water-soluble carbodiimide (1.0g, 5.0mmol). After 15min the pH adjusted to 8 with N-methylmorpholine The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in chloroform (200ml). This solution was washed with 0.3M KHSO4 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 85% chloroform, 15% hexane) to give a white solid identified as (2'S.2"R)-N,N-di(benzyloxycarbonyl)-4-(2,-(2",-(tert-butyloxycarbonylamino)-3"-(4'"-ethoxyphenyl)-propanoylamino)-3-phenylpropanoylamino)piperidine-1-carboxamidine (2.47g, 3.2mmol, 65%).
1F.(2'S,2"R)-4-{2,-(2"-Amino-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidinetrifluoroacetate
(2,S,2"R)-N,N'-Di(benzyloxyrarbonyl)-4-(2'-(2"-(tert-butyloxycrbonylamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (2.1g, 2.7mmol) was dissolved in 4M HCI/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the
residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as H-DTyr(Et)-Phe-4-amino-1-amidinopiperidine trifluoroacetate (1.12g).
[M+H]+ = 480.6
EXAMPLE 2
(2'S,2"R)-4-(2-(3"-Cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoylamino)-3'-pheny!propanoylamino)piperidine-1-carboxamidine trifluoroacetate
2A. (2'S,2"R)-N,N-Di(benzyloxycarbonyl)-4-(2'-{2'-(tert-butyloxycarbonylamino)-3",-cyclohexyIpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine
(2'S)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-phenylprapanoy amino)piperidine-1-carboxamidine (from Example 1D, 1.9g, 2.99mmoI) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DCha-OH (900mg, 3.3mmol) was added followed by 1-hydroxybenzotriazole hydrate (820mg, 6.1mmol) and water-soluble carbodiimide (730mg, 3.6mmol). After 15min the pH was adjusted to 8 with N-methylmorpholine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in chloroform (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 90% chloroform, 10% hexane) to give a white solid identified as (2'S,2"R)-N,N-di(benzyloxycaroonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-cyclohexyl-
propanoylamino)-3'-phenylpropanoylaminojpiperidine-l-carboxamidine (1.73g, 2.14 mmol, 72%).
2B. (2,S,2"R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(3"-cyclohexyl-2"-{methyioxy-
carbonylmethylamino)propanoyIamino)-3'-phenylpropanoylamino)piperidine-1-
carboxamidine
(2'S,2'R)-N,N'-Di(benzyloxycarbonyI)-4-(2-(2-(tert-fautyloxycarfaonylamino)-3"cycIohexyl-propanoylamino)-3'-phenylpropanoylamino)pipericline-1-carboxamidine (1 73g, 2.14mmol) was dissolved in 4M HCl/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in acetonitrile (100ml). Methyl bromoacetate (400mg, 2.6mmol) and N,N-diisopropylethylamine (440mg, 4.4mmol) were added. The reaction mixture was stirred at 60°C for 5h after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a yellow oil which was purified by flash chromatography on silica gel (eluant: 90% chloroform, 10% hexane) to give a white solid identified as (2'S,2"R)-N,N,-di(ben2y!oxycarbonyl)-4-(2,-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoylamino)-3'-phenyipropanoylamino)piperidine-1-carboxamidine (1.65g, 2.11 mmol, 98%).
2C. (2'S,2"R)-4-{2,-(3"-Cyclohexyl-2",-{methyloxycarbonylmeaiylamino)propanoyI-arnino)-3'-phenylpropanoy!amino)plperidine-1 -carboxamidine trifluoroacetate methylaminoJpnapanoyiamino)-3'-phenylpixipanoylaminoJpiperKline-l-carboxamidine (1.62g, 2.11 mmol) was dissolved in AcOH/water (95:5, 50mi). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on VydacC18 (15-25u) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2'-(3"-cyclohexyl-2-metthoxycarbonylmethylamino)propanoylamlno)-3'-phenylpropanoyl-amino)piperidine-1-carboxamidine trifluoroacetate (570mg).
[M+H]+ = 515
EXAMPLE 3
(2'S,2"R)-4-(2'-(2"-{Carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenyl-
propanoylamino)piperidine-1-carboxarnidinetrifluoroacetate
(Formula Removed)
3A.(2'S,2"R)-N,N-Di(benzyIoxycarbonyl)-4-(2'-(2"-(carboxymethyIamino)-3"-cycIohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine
(2'S,2"R)-N,N-Di(benzyloxyrarbonyl)-4-(2H3"cyclohexyl-2"-(methytoxycarbonyl-methylamino)propanoylamino)-3'-phenyipropanoylamino)piperidine-1-carboxamidine(from Example 2B, 1.6g, 2.1mmol) was dissolved in tetrahydrofuran (50ml). 1M Lithium hydroxide (3ml, 3mmol) was added. After 18h the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (150ml). This solution was washed with 1M citric acid (1 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2S04) and evaporated in vacuo to give a white solid identified as (2'S,2"R)-N,N-di(benzyloxycarbonyl)-4-(2,-(2"-(carboxymethylamino)-3"-cyclohexylpropanoylamino)-3-phenylpropanoylamino)piperidine-1-carboxamidine (1.62g, 2.11mmol, 100%).
3B. (2'S,2"R)-4-(2'-(2"-(Carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidinetrifluoroacetate (2'S,2"R)-N,N-Di(benzyloxycaitonyl)-4-(2'-(2"(carboxymethylamino)-3"-cyclohexyl-propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.62g, 2.11mmol) was dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2'-(2"-(carboxymethylamino)-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (570mg).
[M+H]+ = 501
EXAMPLE 4
{2,S,2"R)-4-(2-(2"-Benzoylamino-3,-(4'"-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1-carboxamidinetrifiuoroacetate
(Formula Removed)
4A. (2'S,2"R)-4-{2,-(2"-Benzoylamino-3"-(4"',-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)-N,N-di(benzyIoxycarbonyl)piperidine-1-carboxamidine
(2'S,2"R)-N,N'-Di(benzyloxycycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-(4"'-
ethoxyphenyl)propanoylamino)-3,-phenylpropanoylarnino)piperidine-1-carboxamidine(from Example 1F, 100mg, 0.12mmol) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2 Cl2 (20ml). This solution was cooled to 0°C and benzoyl chloride (19.7mg, 0.141mmol) and triethylamine (36mg, 0.36mmol) were added. The mixture was stirred at room temperature for 18 h, the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (70ml). This solution was washed with 0.3M KHS04 (2 x 20ml), sat. NaHC03 (2 x 20ml), water (2 x 20ml) and brine (1 x 20ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 85% chloroform, 15% cyclohexane) to give a white solid identified as (2'S,2"R)-4-(2'-(2"-benzoylamino-3"-(4'"-ethoxyphenyl)propanoylamino)-3,-phenylpropanoylamino)-N,N-di(benzyloxycarbonyl)piperidine-1-carboxamidine (65mg, 0.072 mmol, 60%).
4A. (2'S,2"R)-4-{2,-(2"-Benzoylamino-3"-(4"',-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine trifluoroacetate
(2,S,2"R)-4-(2,-(2"-Benzoylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenyl-
propanoylamino)-,N-di(benzyloxycarbonyl)piperidine-1-carboxamidine (65mg,
0.072mmol) was dissolved in AcOH/water (95:5, 25ml). This solution was hydrogenated over 10% palladium on charcoal. After 1 hour at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 20ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on VydacC18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R)-4-(2,-(2"-ben2oylamino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (44mg).
[M+H]+ = 585
EXAMPLE 5
(2,S,2"R,3'R)-4-(2'-(2"-Amino-3"-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1 -carboxamidine trifluoroacetate
(Formula Removed)
5A. (2S,3R)-2-(tert-Butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoic acid H-thPse-OH (J. Biol. Chem., 1953, 204, 323) (1.4g, 7.73mmo!) was dissolved in dioxan (75ml). Sodium hydroxide 820mg, 20.5mmol) in water (75ml) was added followed by di-tert-butyl dicarbonate (2.1g, 9.6mmol). The mixture was stirred for 18h at room temperature then the dioxan was removed in vacuo and the residue was washed with diethyl ether (1 x 100ml), acidified to pH 4 with 1M HCI and extracted with CHCI3 (3 x 100ml). The combined extracts were washed with water (1 x 50ml) and brine (1 x 50ml), dried (Na2SO4) and evaporated in vacuo to give a white solid identified as (2S,3R)-2-(tert-butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoicacid (1.6g, 5.7 mmol, 74%).
5B{2,S,3'R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylpropanoy!arnino)piperidine-1-carboxarnidine
N,N-Di(benzyloxycarbonyl)-4-tert-butyloxycarbonylamino)piperidine-1-carboxamidine (from Example 1C, 2.3g, 4.5mmol) was dissolved in 4M HCl/dioxan (70ml). After 30min at
room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and (2S,3R)-2-(tert-butyloxycarbonylamino)-3-hydroxy-3-phenylpropanoic acid (1.6g, 5.6mmol) was added followed by 1-hydroxybenzotriazole hydrate (1.1g, 8.1mmol) and water-soluble carbodiimide (1.4g, 75.0mmol). After 15 min the pH adjusted to 8 with N-methylmorpholine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (200ml). This solution was washed with 0.3M KHS04 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na^Qi) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 50% ethyl acetate, 50% pet. ether) to give a white solid identified as (2,S,3'/?)-A/,Ar-di(benzyloxycarbonyl)-4-(2'-(tert-butyioxycarbonylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.1g, 1.6 mmol, 36%).
5C.(2'S,2"R,3'R)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert:-butyloxycarbonylamino)-3"-{4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3,-phenylpropanoyl-amino)piperidine-1-carboxamidine
phenylpropanoylamino)piperidine-1-carboxamidine (1.1g, 1.6mmol) was dissolved in 4M HCI/dioxan (70ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2CI2/DMF (9:1, 50ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (620mg, 2.0mmol) was added followed by 1-hydroxybenzotriazole hydrate (270mg, 2.0mmol) and water-soluble carbodiimide (420mg, 2.1 mmol). After 15min the pH was adjusted to 8 with N-methylmorpholine The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved In ethyl acetate (200ml). This solution was washed with 0.3M KHSO4 (2 x 30ml), sat. NaHC03 (2 x 30ml), water (2 x 30ml) and brine (1 x 30ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 60% ethyl acetate, 40% pet. ether) to give a white solid identified as (2'S,2"R,3'R)-N,N-di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (1.2g, 1.3 mmol, 80%).
5D.(2,S,2"R,3'R)-4-{2,.{2"-Amino-3"-(4",-ethoxyphenyl)propanoylammo)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine triftuoroacetate
(2'S,2",R,3'R)-N,N-Di(benzyloxycarlwnyl)-4-(2'-(2"-tert-butyloxycaltonyiamino)-3",-(4"'-ethoxyphenyl)propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidipe (1.2g, 1.3mmol) was dissolved in 4M HCI/dioxan (50ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in AcOH/water (95:5, 50ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Cel'rte and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25n) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R,3R)-4-(2,-(2"-amino-3"-(4,"-ethoxyphenyl)-propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate (540mg).
[M+H]+ = 497.0
EXAMPLE 6
(2'S,2"R,3'R)-4-(2'-(2"-Amino-3"-(4"-ethoxyphenyl)propanoylamino)-3'-methoxy-3,-phenylpropanoylamino)piperidine-1-carboxamidine trifluoroacetate
(Formula Removed)
6A.(2'SR,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenyIpropanoylarnino)piperidine-1-carboxamidine
(2'SR,3'RS)-N,N-Di(benzyloxyrarbonyl)-4-2-(tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine was prepared by the same method as described in Example 5 but starting with racemic H-thPse-OH.
6B. (2,SR,3RS)-N,N'-Dr(benzyloxycarbonyl)-4-(2'-(tert-butyloxycarbonylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine
(2'SR,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-tert-butyloxycarbonylamino)-3'-hydroxy-3'-phenylprapanoylamino)piperidine-1-carboxamidine (180mg, 0.27mmol), was dissolved in CH2C!2 (30ml). lodomethane (190mg, 1.3mmol) and silver oxide (132mg, 0.8mmol) were added. After 18h at 60°C the mixture was filtered and the filtrate was evaporated in vacuo to give a brown oil which was purified by flash chromatography on silica gel (eluant: 50% ethyl acetate, 50% pet. ether) to give a white solid identified as (2'SR,3'RS)-/\/,A/'-di(benzyloxycarbonyI)-4-(2'-(tert-butyloxycarbonylamino)-3'-methoxy-3'-phenyipropanoyl-amino)piperidine-1-carboxamidine (112mg, 0.16mmol, 61%).
6C.{2,SR,2"R,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-{4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3,-pheny)propanoy)amino)piperidine-1-carboxamJdine
(2'SR,3'RS)-N,N'-Di(benzyloxycarbonyl)-4-(2,-(tert-butyloxycarbonylamino)-3,-methoxy-3-phenylpropanoylamino)piperidine-1-carboxamidine (112mg, 0.16mmol) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in CH2Cl2 (30ml). This solution was cooled to 0°C and Boc-DTyr(Et)-OH (50mg, 0.16mmol) was added followed by PyBrop (76mg, 0.16mmol). The pH adjusted to 9 with N,N-diisopropylethylamine. The mixture was stirred at room temperature for 18 h, after which time the solvent was evaporated in vacuo and the residue dissolved in ethyl acetate (70ml). This solution was washed with 0.3M KHSO4 (1 x 20ml), sat. NaHC03 (1 x 20ml), water (1 x 20ml) and brine (1 x 20ml), dried (Na2SO4) and evaporated in vacuo to give a white solid which was purified by flash chromatography on silica gel (eluant: 65% chloroform, 15% hexane) to give a white solid identified as (2'SR,2"R,3'RS)-N,N'-di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-(4"'-
ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-1-carboxamidine (108mg, 0.12 mmol, 75%).
6D. (2'S,2"R,3'R)-4-{2'-(2"-Amino.3'-(4'"-ethoxyphenyl)propanoylamino)-3,-methoxy-3'-phenylpropanoylamino)piperidlne-1-carboxamidinetrifluoroacetate
{2,SR,2"R,3'RS)-N,N-Di(benzyloxycarbonyl)-4-(2'-(2"-(tert-butyloxycarbonylamino)-3"-{4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino_piperidine-1-carboxamidine (108mg, 0.12mmo[) was dissolved in 4M HCI/dioxan (20ml). After 30min at room temperature the solvent was evaporated in vacuo and the residue dissolved in
AcOH/water (95:5, 20ml). This solution was hydrogenated over 10% palladium on charcoal. After 2h at room temperature the mixture was filtered through Celite and the residue washed with AcOH/water (9:1, 30ml). The combined filtrates were evaporated in vacuo and the residue purified by mplc on Vydac C18 (15-25µ) using MeCN/H20/TFA to give a white solid identified as (2'S,2"R,3'R)-4-(2,-(2"-amino-3',-(4",-ethoxyphenyl)-propanoylamino)-3'-methoxy-3'-phenylpropanoylaminoJpiperidine-1-carboxamidine trifluoroacetate (18mg).
[M+H]+ = 511.3
The following compounds were prepared using analogous methods. Examples 7-17
(Table with Figure Removed)
Examples 18-52
(Table with Figure Removed)
Examples 53 - 54
(Table with Figure Removed)
Examples 55 - 58
(Table with Figure Removed)
Example 59
Determination of the inhibition constant K1 for plasma kallikrein
Inhibition of plasma kailikrein activity in vitro was determined using standard published methods (see e.g. Johansen et al., Int. J. Tiss. Reac. 1986, 8,185; Short et al. Biochem. Pharmacol., 1992, 43, 1209; Storzebecher et a/., Biol. Chem. Hoppe-Seyler, 1992, 373, 1025). Human plasma kailikrein (Callbiochem) was incubated at 37°C with three different concentrations of the chromogenic substrate S-2302 (Chromogenix AB) and various concentrations of the test compound. Residual enzyme activity (initial rate of reaction) was determined by measuring the change in optical absorbance at 405nm and the inhibitory constant K1 for the test compound as determined from a Dixon plot (Dixon, Biochem. J., 1953,55,170). Typical results are presented in the Table.
(Table with Figure Removed)
Example 60
Determination of enzyme selectivity
Selected compounds were further screened for inhibitory activity against other trypsin-like proteases following the method of Example 59 and using the appropriate enzyme and chromogenic substrate (Chromogenix AB). Representative results are presented in the Table. The selectivity is given by:
Selectivity = (Kf for test enzyme) / (Ki for plasma kallikrein)
(Table with Figure Removed)

We Claim:
1. An acylaminopiperidine-1 -carboxamidine of formula 1, or a pharmaceutically acceptable
salt thereof,
(Formula Removed)
wherein
R4s selected from H, lower alkyl, R4-CO, R4-O2CCH2, R5-OCO and R5-SO2;
R2 is selected from lower alkyl, cycloalkyl optionally substituted with an alkyl or alkyloxy group, (C5-C12) cycloalkylalkyl optionally substituted with an alkyl or alkyloxy group, aralkyl optionally substituted with up to three groups chosen from F, Cl, Br, I, OH, lower alkyl, O-(lower alkyl), O-benzyl, NH2, NO2, NH-acyl, CN and CF3, and aralkyloxymethyl optionally substituted with up to three groups chosen from F, Cl, Br, OH, lower alkyl and O-(lower alkyl); or
R1and R2 together are an o-xylylene group optionally substituted on the aromatic ring with a group selected from F, Cl, Br, OH, lower alkyl and 0-(lower alkyl);
R3 is selected from H, OH and O-lower alkyl;
R4 is selected from H, lower alkyl and phenyl; and
R5 is selected from lower alkyl, phenyl and benzyl.
2. The acylaminopiperidine-1-carboxamidine compound as claimed in claim 1 wherein R1 is selected from H, lower alkyl, and R4-O2CCH2.
3. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 and 2 wherein R2 is selected from (C6-C10) cycloalkylmethyl, benzyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl), phenethyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl) and benzyloxymethyl optionally substituted with up to three groups chosen from F, C1, Br, OH, lower alkyl and O-(lower alkyl).
4. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 3 wherein R2 is selected from cyclohexylmethyl, decahydronaphth-2-ylmethyl, benzyl, 4-
fluorobenzyl, 4-chlorobenzyl, 4-hydroxybenzyl, 4-(lower alkyl) oxybenzyl, a-hydroxybenzyl, a- methoxybenzyl, phenethyl and benzyloxymethyl.
5. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 4 wherein
the absolute stereochemistry is as depicted in general formula 1A.
(Formula Removed)
6. The acylaminopiperidine-1-carboxamidine compound as claimed in claims 1 to 5 wherein
the absolute stereochemistry is as depicted in general formula 1B.
(Formula Removed)
7. The acylaminopiperidine-1-carboxamidine compound according to any of Claims 1 to 6
selected from
(2'S, 2"R)-4-(2'-(2"-amino-3"-(4'"-ethoxyphenyl)propanoylamino)-3'-phenyl-propanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-(4'"-ethoxyphenyl)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(3"-(4''-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine;
(2'S, 2"R)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)propanoyl-amino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(2"-amino-3"-phenylpropanoylamino)-3'-phenylpropanoyl-amino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-phenylpropanoylamino)-3'-phenyl-propanoylamino)piperidine-1 -carboxamidine;
(2'S, 2'R)-4-(2'-(2"-(methyloxycarbonylmethylamino)-3'-phenylpropanoyl-amino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine;
(2'S, 2"R)-4-(2'-(2"-amino-3"-decahydronaphth-2'"-yl-propanoylamino)-3'-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R)-4-(2'-(2"-carboxymethylamino-3"-decahydronaphth-2'"-yl-propanoylamino)-3 '-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S,2"R)-4-(2'-(3"-decahydronaphth-2'"-yl-2"-(methyloxycarbonylmethyl-amino)propanoylamino)-3'-phenylpropanoylamino)piperidine-l-carboxamidine;
(2'S, 2"R, 3'R)-4-(2'-(2"-amino-3"-cyclohexylpropanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R, 3'R)-4-(2'-(2"-carboxymethylamino-3"-cyclohexylpropanoylamino)-3'-hydroxy-3 '-phenylpropanoylamino)piperidine-1 -carboxamidine;
(2'S, 2"R,3'R)-4-(2'-(3"-cyclohexyl-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-hydroxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine;
(2'S, 2"R, 3'R)-4-(2'-(2"-amino-3"-(4'"-ethoxyphenyl)propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine;
(2'S, 2"R, 3'R)-4-(2'-(2"-carboxymethylamino-3"-(4"'-ethoxyphenyl)propanoyl-amino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine; and
(2'S, 2"R, 3'R)-4-(2'-(3"-(4'"-ethoxyphenyl)-2"-(methyloxycarbonylmethylamino)-propanoylamino)-3'-methoxy-3'-phenylpropanoylamino)piperidine-l-carboxamidine
or a pharmaceutically acceptable salt thereof.
8. A pharmaceutical composition comprising a acylaminopiperidine-1 -carboxamidine compound as claimed in claims 1 to 7 or a pharmaceutical acceptable salt thereof.
9. The acylaminopiperidine-1 -carboxamidine compound as claimed in claims 1-7 as and when used in the manufacture of a medicament for the treatment of a disease condition in human or animal for which over activity of plasma Kallikrein is the causative factor.

Documents:

2544-DELNP-2004-Abstract-(08-09-2011).pdf

2544-delnp-2004-abstract.pdf

2544-DELNP-2004-Assignment-(07-01-2009).pdf

2544-DELNP-2004-Assignment-(08-09-2011).pdf

2544-delnp-2004-assignment.pdf

2544-DELNP-2004-Claims-(05-05-2011).pdf

2544-DELNP-2004-Claims-(08-09-2011).pdf

2544-delnp-2004-claims.pdf

2544-DELNP-2004-Correspondence Others-(05-05-2011).pdf

2544-DELNP-2004-Correspondence Others-(08-09-2011).pdf

2544-DELNP-2004-Correspondence-Others-(08-12-2010).pdf

2544-delnp-2004-correspondence-others.pdf

2544-delnp-2004-description (complete).pdf

2544-DELNP-2004-Form-1-(08-09-2011).pdf

2544-delnp-2004-form-1.pdf

2544-delnp-2004-form-18.pdf

2544-DELNP-2004-Form-2-(08-09-2011).pdf

2544-delnp-2004-form-2.pdf

2544-DELNP-2004-Form-3-(08-12-2010).pdf

2544-delnp-2004-form-3.pdf

2544-delnp-2004-form-5.pdf

2544-delnp-2004-form-6.pdf

2544-DELNP-2004-GPA-(08-09-2011).pdf

2544-delnp-2004-gpa.pdf

2544-delnp-2004-pct-101.pdf

2544-delnp-2004-pct-210.pdf

2544-delnp-2004-pct-220.pdf

2544-delnp-2004-pct-409.pdf

2544-delnp-2004-pct-416.pdf

abstract.jpg

« Previous Patent

Next Patent »

Patent Number

249968

Indian Patent Application Number

2544/DELNP/2004

PG Journal Number

48/2011

Publication Date

02-Dec-2011

Grant Date

25-Nov-2011

Date of Filing

31-Aug-2004

Name of Patentee

KALVISTA PHARMACEUTICALS LIMITED

Applicant Address

1 VENTURE ROAD, SOUTHAMPTON SCIENCE PARK, CHILWORTH SO16 7NP, UNITED KINGDOM

Inventors:

#	Inventor's Name	Inventor's Address
1	EVANS DAVID MICHAEL	114 ADELAIDE ROAD, DT.DENYS, SOUTHAMPTON SO17 2HX, UK

PCT International Classification Number

C07K 5/06

PCT International Application Number

PCT/GB2003/00908

PCT International Filing date

2003-03-04

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0205527.5	2002-03-08	U.K.