GB2315750A - Metalloproteinase inhibitors - Google Patents

Abstract

Compounds of formula (I) wherein X is a -CO 2 H or -CONHOH group; R 1 is methyl, ethyl, allyl, thienylsulphanylmethyl, thienylsulphinylmethyl, or thienylsulphonylmethyl; R 2 is iso-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, propylsulphanyl, cyclohexylpropyl, phenylpropyl, 4-chlorophenylpropyl, 4-methylphenylpropyl, 4-methoxyphenylpropyl, phenylbutyl, or propyloxymethyl;. R 3 is a group -C(C 1 -C 6 alkyl) 2 R 11 wherein R 11 is -OH, -SH, -O(C 1 -C 6 )alkyl, -S(C 1 -C 6 )alkyl, -SO(C 1 -C 6 )alkyl, - SO 2 (C 1 -C 6 ) alkyl, cyclohexylmethylsulphanyl, -OPh, -OCH 2 Ph, -SPh, - SOPh, -SO 2 Ph, -SCH 2 Ph, -SOCH 2 Ph, or -SO 2 CH 2 Ph in which any of the foregoing Ph (phenyl) groups may be substituted; R 4 is (C 1 -C 6 )alkyl, (C 1 -C 4 )perfluoroalkyl or a group D-(C 1 -C 6 )alkyl- wherein D represents hydroxy, (C 1 -C 6 )alkoxy, (C 1 -C 6 )alkylsulphanyl, acylamino, optionally substituted phenyl or heteroaryl; R 5 is hydrogen; and salts, hydrates or solvates thereof have matrix metalloproteinase inhibiting activity.

Description

Metalloproteinase Inhibitors This patent application is a divisional of our copending application no. GB 9611282.6.

The present invention relates to therapeutically active hydroxamic acid and carboxylic acid derivatives, to processes for their preparation, to pharmaceutical compositions containing them, and to the use of such compounds in medicine. In particular, the compounds are inhibitors of metalloproteinases involved in tissue degradation, and in addition are inhibitors of the release of tumour necrosis factor from cells.

Background to the Invention Compounds which have the property of inhibiting the action of metalloproteinases involved in connective tissue breakdown such as collagenase, stromelysin and gelatinase (known as "matrix metalloproteinases", and herein referred to as MMPs) are thought to be potentially useful for the treatment or prophylaxis of conditions involving such tissue breakdown, for example rheumatoid arthritis, osteoarthritis, osteopenias such as osteoporosis, periodontitis, gingivitis, corneal epidermal or gastric ulceration, and tumour metastasis, invasion and growth. MMP inhibitors are also of potential value in the treatment of neuroinflammatory disorders, including those involving myelin degradation, for example multiple sclerosis, as well as in the management of angiogenesis dependent diseases, which include arthritic conditions and solid tumour growth as well as psoriasis, proliferative retinopathies, neovascular glaucoma, ocular tumours, angiofibromas and hemangiomas.

However, the reiative contributions of individual MMPs in any of the above disease states is not yet fully understood.

Metalloproteinases are characterised by the presence in the structure of a zinc(ll) ionic site.

It is now known that there exists a range of metalloproteinase enzymes that includes fibroblast collagenase (Type 1), PMN-collagenase, 72 kDa-gelatinase, 92 kDa-gelatinase, stromelysin, stromelysin-2 and PUMP-1 (L.M. Matrisian, Trends in Genetics, 1990, 6, 121125). Many known MMP inhibitors are peptide derivatives, based on naturally occurring amino acids, and are analogues of the cleavage site in the collagen molecule. A recent paper by Chapman et al (J. Med. Chem. 1993, 36, 4293-4301) reports some general structure/activity findings in a series of N-carboxyalkyl peptides. Other known MMP inhibitors are less peptidic in structure, and may more properly be viewed as pseudopeptides or peptide mimetics. Such compounds usually have a functional group capable of binding to the zinc (II) site in the MMP, and known classes include those in which the zinc binding group is a hydroxamic acid, carboxylic acid, sulphydryl, and oxygenated phosphorus (eg phosphinic acid and phosphonamidate including aminophoshonic acid) groups.

Two known classes of pseudopeptide or peptide mimetic MMP inhibitors have a hydroxamic acid group and a carboxylic group respectively as their zinc binding groups. With a few exceptions, such known MMPs may be represented by the structural formula (I)

in which X is the zinc binding hydroxamic acid (-CONHOH) or carboxylic acid (-COOH) group and the groups R1 to R5 are variable in accordance with the specific prior art disclosures of such compounds. Examples of patent publications disclosing such structures are given below.

In such compounds, it is generally understood in the art that variation of the zinc binding group and the substituents R1, R2 and R3 can have an appreciable effect on the relative inhibition of lhe metalloproteinase enzymes. The group X is thought to interact with metalloproteinase enzymes by binding to a zinc(ll) ion in the active site. Generally the hydroxamic acid group is preferred over the carboxylic acid group in terms of inhibitory activity against the various metalloproteinase enzymes. However, the carboxylic acid group in combination with other substituents can provide selective inhibition of gelatinase (EP489,577-A). The R1, R2 and R3 groups are believed to occupy respectively the P1, P1' and P2' amino acid side chain binding sites for the natural enzyme substrate. There is evidence that a larger R1 substituent can enhance activity against stromelysin, and that a (C1-C6)alkyl group (such as iso-butyl) at R2 may be preferred for activity against collagenase whilst a phenylalkyl group (such as phenylpropyl) at R2 may provide selectivity for gelatinase over the other metalloproteinases.

Pseudopeptide or peptide mimetic MMP inhibitors of formula (I) with potent in vitro activities are known, but are generally poorly absorbed following oral administration. Although it is known that a number of factors can influence oral absorption (such as aqueous solubility, pKa, log P and molecular weight), the design of pseudopeptide enzyme inhibitors with high oral absorption is far from straightforward. Finding a combination of R1, R2, R3, R4 or Rs substituents that permits a good balance of intrinsic level of activity, water solubility, oral absorbtion, and pharmacokinetic properties is a continuing problem in the art, since those properties can vary in an unpredictable way as the substituents R, - R5 are varied.

Identifying hydroxamic and carboxylic acid-based MMP inhibitors having such properties remains a much sought after goal in the art.

Tumour necrosis factor (herein referred to as "TNF") is a cytokine which is produced initially as a cell-associated 28kD precursor. It is released as an active, 17kD form, which can mediate a large number of deleterious effects in vivo. When administered to animals or humans it causes inflammation, fever, cardiovascular effects, haemorrhage, coagulation and acute phase responses, similar to those seen during acute infections and shock states.

Chronic administration can also cause cachexia and anorexia. Accumulation of excessive TNF can be lethal.

There is considerable evidence from animal model studies that blocking the effects of TNF with specific antibodies can be beneficial in acute infections, shock states, graft versus host reactions and autoimmune disease. TNF is also an autocrine growth factor for some myelomas and lymphomas and can act to inhibit normal haematopoiesis in patients with these tumours.

Compounds which inhibit the production or action of TNF are therefore thought to be potentially useful for the treatment or prophylaxis of many inflammatory, infectious, immunological or malignant diseases. These include, but are not restricted to, septic shock, haemodynamic shock and sepsis syndrome, post ischaemic reperfusion injury, malaria, Crohn's disease, mycobacterial infection, meningitis, psoriasis, congestive heart failure, fibrotic disease, cachexia, graft rejection, cancer, autoimmune disease, rheumatoid arthritis, multiple sclerosis, radiation damage, toxicity following administration of immunosuppressive monoclonal antibodies such as OKT3 or CAMPATH-1 and hyperoxic alveolar injury.

Since excessive TNF production has been noted in several diseases or conditions also characterised by MMP-mediated tissue degradation, compounds which inhibit both MMPs and TNF production may have particular advantages in the treatment or prophylaxis of diseases or conditions in which both mechanisms are involved.

Recently, WO 93/20047 disclosed a class of hydroxamic acid based MMP inhibitors which also are active in inhibiting TNF production.

As mentioned above, MMP inhibitors have been proposed with hydroxamic acid or carboxylic acid zinc binding groups. The following patent publications disclose hydroxamic acid-based MMP inhibitors: US 4599361 (Searle) EP-A-0236872 (Roche) EP-A-0274453 (Bellon) WO 90/05716 (British Bio-technology) WO 90/05719 (British Bio-technology) WO 91/02716 (British Bio-technology) EP-A-0489577 (Celltech) EP-A-0489579 (Celltech) EP-A-0497192 (Roche) WO 92/13831 (British Bio-technology) WO 9v2/17460 (SmithKline Beecham) WO 92/22523 (Research Corporation Technologies) WO 93/09090 (Yamanouchi) WO 93/09097 (Sankyo) WO 93/20047 (British Bio-technology) WO 93/24449 (Celltech) WO 93/24475 (Celltech) EP-A-0574758 (Roche) The following patent publications disclose carboxylic acid-based MMP inhibitors: EP-A-0489577 (Celltech) EP-A-0489579 (Celltech) WO 93/24449 (Celltech) WO 93/24475 (Celltech) Brief Description of the Invention Recent studies comparing the absorption of peptides with their N-methylated analogues suggest that hydrogen bonding potential is a determinant of in vivo absorption (M.S. Karls et al., Pharmaceutical Research, 1991, 8, 1477-1481). It is argued that peptides with lower hydrogen bonding potential are more readily absorbed because there is a lower cost in terms of desolvation energy on absorbtion into the intestinal mucosa. It was the hypothesis of the inventors of the present invention that appropriate modification of the groups R3, R4 and R5, in structures of formula (I) that are proximate to the amide bonds, could lead to metalloproteinase inhibitors with enhanced oral absorption. In particular, it was thought that the introduction of steric bulk proximate to the amide bonds could reduce their hydrogen bonding potential. It was a further hypothesis of the inventors that the introduction of heteroatoms (such as oxygen, sulphur or fluorine) in an appropriate position in R3 or R4 such that they form intermolecular hydrogen bonds with the N-H of one of the amide groups could reduce the desolvation energy for absorption.

International patent applications WO 94/25434 and WO 94/254435 claim compounds of general formula (I) above wherein R3 is a trisubstituted methyl group. The compounds of the present invention fall within the claims of those applications as published, but are not specifically disclosed therein. The compounds of the invention include those with appropriate aqueous solubility, pKa, log P and molecular weight for good oral absorption, which maintain good inhibitory potencies against the various metalloproteinase enzymes, and which have other desirable pharmacokinetic and physicochemical properties.

A further advantage of certain compounds of the present invention is that they inhibit the production of the pro-inflammatory cytokine TNF.

Detailed DescriDtion of the Invention The present invention provides A compound of formula (I)

wherein X is a -CO2H or -CONHOH group; R, is methyl, ethyl, allyl, thienylsulphanylmethyl, thienylsulphinylmethyl, or thienylsulphonylmethyl; R2 is iso-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, propylsulphanyl, cyclohexylpropyl, phenylpropyl, 4-chlorophenylpropyl, 4 methylphenylpropyl, 4-methoxyphenylpropyl, phenylbutyl, or propyloxymethyl; R3 is a group -C(C,-C6 alkyl)2R" wherein R1, is -OH, -SH, -O(C1-C6)alkyl, -S(C1-C6)alkyl, -SO(C1-C6)alkyl, - SO2(C,-C6) alkyl, cyclohexylmethylsulphanyl, -OPh, -OCH2Ph, -SPh, SOPh, -SO2Ph, -SCH2Ph, -SOCH2Ph, or -SO2CH2Ph in which any of the foregoing Ph (phenyl) groups may be substituted; R4 is (C,-C6)alkyl, (C1-C4)perfluoroalkyl or a group D-(C,-C6)alkyl- wherein D represents hydroxy, (C,-C6)alkoxy, (C,-C6)alkylsulphanyl, acylamino, optionally substituted phenyl or heteroaryl; R5 is hydrogen; or a salt, hydrate or solvate thereof.

As used herein the term "(C,-C6)alkyl" or "lower alkyl" means a straight or branched chain alkyl moiety having from 1 to 6 carbon atoms, including for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl and hexyl.

The "heteroaryl" means a 5-7 membered substituted or unsubstituted aromatic heterocycle containing one or more heteroatoms. Illustrative of such rings are thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, pyrazolyl, isoxazolyl, isothiazolyl, trizolyl, thiadiazolyl, oxadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl and triazinyl.

Unless otherwise specified in the context in which it occurs, the term "substituted" as applied to any moiety herein means substituted with up to four substituents, each of which independently may be C1-C6 alkoxy, hydroxy, thio, C,-C6 alkylthio, amino, halo (including fluoro, chloro, bromo and iodo), trifluoromethyl, nitro, -COOH, -CON H2 or -CONHRA wherein RA is a C1-C6 alkyl group or the residue of a natural alpha-amino acid.

Salts of the compounds of the invention include physiologically acceptable acid addition salts for example hydrochlorides, hydrobromides, sulphates, methane sulphonates, ptoluenesulphonates, phosphates, acetates, citrates, succinates, lactates, tartrates, fumarates and maleates. Salts may also be formed with bases, for example sodium, potassium, magnesium, and calcium salts.

There are several chiral centres in the compounds according to the invention because of the presence of asymmetric carbon atoms. The presence of several asymmetric carbon atoms gives rise to a number of diastereoisomers with R or S stereochemistry at each chiral centre. General formula (I), and (unless specified otherwise) all other formulae in this specification are to be understood to include all such stereoisomers and mixtures (for example racemic mixtures) thereof.

In the compounds of the invention, the preferred stereochemistry is in general as follows: C atom carrying the R, and X group - S, C atom carrying the R2 group C atom carrying the R3 group - S, but mixtures in which the above configurations predominate are also contemplated.

In the compounds of the invention, R3 may be 2-hydroxyprop-2-yl, 2-mercaptoprop2-yl, 2-methoxyprop-2-yl, 2-(2-methoxyethoxymethoxy)prop-2-yl, 2methylsulphanylprop-2-yl, 2-methylsulphinylprop-2-yl, 2-methylsulphonylprop-2-yl, 2-benzylsulphanylprop-2-yi, 2-benzylsulphinylprop-2-yl, 2-benzylsulphonylprop-2-yl, 2-(4-methoxybenzylsulph nyl)prop-2-yl, 2-(4-methoxybenzylsulphinyl)prop-2-yl, 2 (4-methoxybenzylsulphonyl)prop-2-yl, 2-cyclohexylmethylsulphanyl-prop-2-yl, cyclohexylmethylsulphinyl-prop-2-yl, or cyclohexylmethylsulphanyl-prop-2-yl.

In the compounds of the invention1 R4 may be methyl, ethyl1 propyl, n-butyl, t-butyl, hydroxyethyl, hyd roxypropyl, 2,2-d imethyl-3-hydroxypropyl , hydroxybutyl, methoxyethyl, ethoxyethyl, methoxypropyl, 2,2-dimethyl-3-methoxypropyl, 2,2-dimethyl-3ethoxypropyl, 2-ethylthioethyl, 2-acetoxyethyl, N-acetyl-aminoethyl, pyrrolidone)propyl, optionally substituted phenylethyl, phenylpropyl, phenylbutyl or phenylpentyl.

Specific compounds of the invention include: 3R-[2-Benzylsul phanyl-2-methyl-1 S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Cyclohexylmethylsulphanyl-2-methyl-1 S-(methylcarbamoyl) propylcarbamoyl]-5-1nethyl-2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Methylsulphinyl-2-methyl-1 S-(methylcarbamoyl )-p ropylca rba moyl]-5-methyl- 2S-propen-2-yl-hexanohyd roxamic acid, 3 R-[2-Methylsulphonyl-2-methyl-1 S-(methylcarbamoyl )-propylcarbamoyl]-5-methyl- 2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Mercapto-2-methyl-l S-(methylcarbamoyl )-propylcarbamoyl]-5-methyl-2Spropen-2-yl-hexanohydroxamic acid, 3R-[2-Methylth io-2-methyl-1 S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl-2S propen-2-yl-hexanohydroxamic acid, and salts, solvates or hydrates thereof.

Compounds according to the present invention in which X is a hydroxamic acid group CONHOH may be prepared from corresponding compounds of the invention in which X is a carboxylic acid group -COOH or from the corresponding protected hydroxamic acid derivatives. That process, which forms another aspect of the invention, comprises: (a) causing an acid of general formula (II)

or an activated derivative thereof to react with hydroxylamine, O-protected hydroxylamine, or an N,O-diprotected hydroxylamine, or a salt thereof, R1, R2, R3, R4, and Rs being as defined in general formula (I) except that any substituents in R1, R2, R3, R4, and Ras which are potentially reactive with hydroxylamin e, O-protected hydroxylamine, the N,O-diprotected hydroxylam ine or their salts may themselves be protected from such reaction, then removing any protecting groups from the resultant hydroxamic acid moiety and from any protected substituents in R" R2, R3, R4, and Rs; or (b) deprotecting a diprotected hydroxamic acid derivative of formula (llb)

in which R1, R2, R3, R4, and R5 are as defined in general formula (I), R,4 is an amino protecting group and R,s is a hydroxyl protecting group.

For method (a) conversion of (II) to an activated intermediate such as the pentafluorophenyl, hydroxysuccinyl, or hydroxybenzotriazolyl ester may be effected by reaction with the appropriate alcohol in the presence of a dehydrating agent such as dicyclohexyl dicarbodiimide (DCC), N,N-dimethylaminopropyl-N'-ethyl carbodiimide (EDC), or 2-ethoxy-1 -ethoxycarbonyl-1 ,2-dihydroquinoline (EEDQ).

Protecting groups as referred to above are well known per se, for example from the techniques of peptide chemistry. Amino groups are often protectable by benzyloxycarbonyl, t-butoxycarbonyl or acetyl groups, or in the form of a phthalimido group. Hydroxy groups are often protectable as readily cleavable ethers such as the tbutyl or benzyl ether1 or as readily cleavable esters such as the acetate. Carboxy groups are often protectable as readily cleavable esters, such as the t-butyl or benzyl ester.

Examples of O-protected hydroxylamines for use in method (a) above include 0 benzylhydroxylamine, 04-methoxybenzylhydroxylamine, O-trimethylsilylhydroxylamine, and O-tert-butoxycarbonylhydroxylamine.

Examples of O,N-diprotected hydroxylamines for use in method (a) above include N,O bis(benzyl)hydroxylanline, N ,O-bis(4-methoxybenzyl)hydroxylamine, N-tertbutoxycarbonyl-O-tert-butyldimethylsilylhyd roxylamine, N-tert-butoxycarbonyl-Otetrahydropyranylhydroxylamine, and N, O -bis(tert-butoxycarbonyl)hydroxylamine.

For method (b) suitable protecting groups R,4 and R,s are benzyl and substituted benzyl (eg 4-methoxybenzyl). Such protecting groups may be removed by hydrogenolysis, while the 4-methoxybenzyl group may also be removed by acid hydrolysis.

In method (a) in the special case where R, in compound (I) is hydroxy, a particularly useful technique may be reaction of hydroxylamine with a dioxalone of formula (ill):

wherein the groups R,2 and R13 are derived from a dioxalone forming reagent, and may be, for example, hydrogen, alkyl, phenyl or substituted phenyl. The dioxalone ring is opened on reaction with hydroxylamine to give the required hydroxamic acid derivative of formula (I).

Compounds according to the present invention in which X is a carboxylic acid group COOH may be prepared by a process comprising: coupling an acid of formula (III) or an activated derivative thereof with an amine of formula (IV)

wherein R, R2, R3, R4, and Rs are as defined in general formula (I) except that any substituents in R" R2, R3, R4, and R5 which are potentially reactive in the coupling reaction may themselves be protected from such reaction, and R" represents a hydroxy protecting group, and subsequently removing the protecting group R" and any protecting groups from R, R2, R3, R4, and R5.

Compounds of formula (llb) may be prepared by a process comprising: causing an acid of formula (Illa) or an activated derivative thereof to react with an amine of formula (IV)

wherein R" R2, R3, R4, and R5 are as defined in general formula (I) except that any substituents in R" R2, R3, R4, and R5 which are potentially reactive in the coupling reaction may themselves be protected from such reaction, R,4 is an amino protecting group and R,s is a hydroxyl protecting group as referred to in connection with formula (llb) above, and subsequently removing any protecting groups from R" R2, R3, R4, and R5.

Active derivatives of acids (III) and (Illa) include activated esters such as the pentafluorophenyl ester, acid anhydrides and acid halides, eg chlorides. Suitable hydroxy protecting groups R" may be selected from those known in the art.

Amine intermediates of formula (IV) are either known compounds or may be prepared from known amino acid starting materials using standard methods and by analogy with the specificpreparative examples herein.

In the special case where R, in compound (III) or (Illa) is hydroxy, it too may be protected during the coupling of compounds (III) or (Illa) and (IV). In the case where R, is hydroxy in compound (III) a particularly useful technique may be simultaneous protection of the two hydroxy groups as a dioxalone of formula (V):

wherein the groups R,2 and R,3 are derived from a dioxalone forming reagent, and may be, for example, hydrogen, alkyl, phenyl or substituted phenyl.

As mentioned above, compounds of formula (I) are useful in human or veterinary medicine since they are active as inhibitors of MMPs, and a further advantage lies in their ability to inhibit the release of tumour necrosis factor (TNF) from cells.

Diseases or conditions mediated by MMPs include those involving tissue breakdown such as bone resorption, inflammatory and neuroinflammatory diseases, dermatological conditions, solid tumour growth and tumour invasion by secondary metastases, and angiogenesis dependent diseases, in particular rheumatoid arthritis, osteoarthritis, periodontitis, gingivitis, corneal ulceration, solid tumour growth and tumour invasion by secondary rqetastases, neovascular glaucoma, multiple sclerosis, and psoriasis.

Diseases or conditions mediated by TNF include inflammation, fever, cardiovascular effects, haemorrhage, coagulation and acute phase response, cachexia and anorexia, acute infections, shock states, graft versus host reactions and autoimmune disease.

In a further aspect of the invention there is provided a pharmaceutical or veterinary composition comprising a compound of formula (I) together with a pharmaceutically or veterinarily acceptable excipient or carrier. Included within this aspect of the invention is a pharmaceutical or veterinary composition comprising a compound of formula (I) together with a pharmaceutically or veterinarily acceptable excipient or carrier, characterised in that the composition is adapted for oral administration.

One or more compounds of general formula (I) may be present in the composition together with one or more excipient or carrier.

The compounds with which the invention is concerned may be prepared for administration by any route consistent with their pharmacokinetic properties. The orally administrable compositions may be in the form of tablets, capsules, powders, granules, lozenges, liquid or gel preparations, such as oral, topical, or sterile parenteral solutions or suspensions. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinyl-pyrrolidone; fillers for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricant, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants for example potato starch, or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, glucose syrup, gelatin hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservativeSs, for example methyl or propyl p-hydroxybenzoate or sorbic acid, and if desired conventional flavouring or colouring agents.

The dosage unit involved in oral administration may contain from about 1 to 250mg, preferably from about 25 to 250mg of a compound of the invention. A suitable daily dose for a mammal may vary widely depending on the condition of the patient.

However, a dose of a compound of general formula I of about 0.1 to 300mg/kg body weight1 particularly from about 1 to 100mg/kg body weight may be appropriate.

For topical application to the skin, the drug may be made up into a cream, lotion or ointment. Cream or ointment formulations which may be used for the drug are conventional formulations well known in the art1 for example as described in standard textbooks of pharmaceutics such as the British Pharmacopoeia.

For topical application to the eye, the drug may be made up into a solution or suspension in a suitable sterile aqueous or non aqueous vehicle. Additives, for instance buffers such as sodium metabisulphite or disodium edeate; preservatives including bactericidal and fungicidal agents such as phenyl mercuric acetate or nitrate, benzalkonium chloride or chlorhexidine, and thickening agents such as hypromellose may also be included.

The dosage for topical administration will of course depend on the size of the area being treated. For the eyes, each dose may typically be in the range from 10 to 100mg of the drug.

The active ingredient may also be administered parenterally in a sterile medium.

Depending on the vehicle and concentration used, the drug can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as a local anaesthetic, preservative and buffering agents can be dissolved in the vehicle.

For use in the treatment of rheumatoid arthritis, the drug can be administered by the oral route or by injection intra-articularly into the affected joint. The daily dosage for a 70kg mammal may be in the range 1 Omgs to Igram.

The examples whicH follow illustrate embodiments of the invention but are not intended to limit the scope in any way. The amino acids used in the examples were commercially available or were prepared by procedures known to one skilled in the art.

The following abbreviations have been used throughout: DCHA Dicyclohexylamine DIPE Diisopropyl ether DMF N,N-Dimethylformamide HOBt 1 -Hydroxybenzotriazole LDA Lithium diisopropylamide mCPBA m-Chloroperbenzoic acid NMM N-Methylmorpholine THF Tetrahydrofuran TFA Trifluoroacetic acid TLC Thin layer chromatography EDC N-Ethyl-N'-(3-dimethylaminopropyl)carbodiimide hydrochloride 'H and 13C NMR spectra were recorded using a Bruker AC 250E spectrometer at 250.1 and 62.9 MHz, respectively. Elemental microanalyses were performed by CHN Analysis Ltd. (Alpha House, Countesthorpe Road, South Wigston, Leicester LE8 2PJ, UK) or Medac Ltd. (Department of Chemistry, Brunel University, Uxbridge, Middlesex UB8 3PH).

EXAMPLE 1 3R-[1 S-Methylcarbamoyl-2-benzylsulphanyl-2-methyl-propylcarbamoyl]-5-methyl- hexanohydroxamic acid

STEP A: N-(4-Methylpentanoyl)-4S-phenylmethyl-oxazolidin-2-one A dry 500 ml flask equipped with a magnetic stirrer was charged with 4S-phenylmethyloxazolidin-2-one (17.72 g, 100 mmol), this was capped with a rubber septum and flushed with nitrogen. Anhydrous THF (300 ml) was added via a cannula and the resulting solution was cooled to -78"C in an acetone/dry-ice bath. A solution of 1.47 M n-butyllithium in hexane (68.4 ml, 101 mmol) was transferred via cannula to a dry, septum-stoppered 100 ml dropping funnel. This was added dropwise to the THF solution over 10 minutes.

4-Methylvaieric acid chloride (14.80 g, 110 mmol) was added in one portion by syringe after completion of the addition of n-butyllithium. The resulting solution was stirred at 780C for 30 minutes and then allowed to warm to ambient temperature over 30 minutes.

Excess acid chloride was quenched by the addition of aq. ammonium chloride (60 ml) and the bulk of the solvent was removed under reduced pressure. The resulting slurry was extracted with dichloromethane (2 x 80 ml). The combined organic extracts were washed with 1M sodium hydroxide (75 ml), brine (75 ml), dried (anhydrous sodium sulphate) and filtered. The solvent was removed to yield a yellow oil (29.20 g, including residual solvent) which was used directly in Step B. 'H-NMR; 6 (CDCl3), 7.34 - 7.19 (5H, m), 4.73-4.63(1 H, m), 4.25 - 4.16 (2H, m), 3.30 (1 H, dd, J = 3.3 Hz), 3.05 - 2.85 (2H, m), 2.78 (1H, dd, J = 9.5 Hz), 1.76 - 1.53 (3H, m) and 0.97 (6H, d, J = 6.2Hz).

STEP B: N-(4-(tert-Butyl)-2R-isobutyl-butan-1 ,4-dioyl)4S-phenylmethyl-oxazolidin-2-one N-(4-Methylpentanoyl)-4S-phenylmethyl-oxazolidin-2-one (20 g, 72.6 mmol) was placed in a dry 1 litre 3-necked flask to which was added dry THF (400 ml). The mixture was kept under a stream of argon and cooled to -780C (dry ice/acetone). Sodium bis(trimethyl)silylamide (1M solution in THF, 72.6 ml, 72.6 mmol) was added dropwise through a dropping funnel. After stirring for 20 minutes, tert-butyl bromoacetate (21.02 g, 15.8 ml, 109 mmol) was added dropwise over 1 minute, to give an orange solution.

The mixture was kept at -780C and allowed to warm to -500C over 2 hours (after which time it turned pink). The reaction was then quenched by adding acetic acid (10.90 g, 10.4 ml, 182 mmol) in ether (50 ml) at -50tC, whereupon the solution became colourless. The solvent was removed under reduced pressure and the resulting slurry was partitioned between ethyl acetate and brine. The ethyl acetate layer was washed once with brine and the original brine layer was back-extracted with ethyl acetate. The combined organic layers were dried and the solvent removed, giving a yellow oil which crystallised on cooling overnight to yield the title compound as a crystalline solid (21.36 g, 76%). 'H-NMR; F (CDCl3). 7.38 - 7.24 (5H, m), 4.67 (1H, m), 4.27 (1H, m), 4.18 4.16 (2H, m), 3.36 (1H, dd, J = 3.3 Hz), 2.72 (1H, dd, J = 2.3 Hz), 2.49 (1H, dd, J = 4.6 Hz), 1.72 - 1.24 (3H, m), 1.44 (9H, s) and 0.91 - 0.96 (6H, dd, J = 4.5 Hz). ja1250 = + 66.9" (c=1, MeOH).

STEP C: 2R-lsobutyl-butan-1,4-dioic acid4-tert-butyl ester N-(4-(teff-Butyl)-2R-isobutyl-butan-1,4-dioyl)-4S-phenylmethyl-oxazolidin-2-one (15.30 g, 39 mmol) was placed in a 1 litre flask with a stirrer bar and to it was added a mixture of THF (600 ml) and water (150 ml). The solution was stirred and cooled to 00C (ice/acetone bath) then 60% aq. hydrogen peroxide (4.5 ml, 157 mmol) was added via syringe over 5 minutes, followed by lithium hydroxide (2.65 g, 63 mmol) in 100 ml water.

The reaction mixture was stirred for 1h at 0 "C. TLC analysis (10% methanol in dichloromethane) showed complete reaction (product gave a yellow spot on TLC on staining with bromocresol green and heating). The reaction mixture was quenched with sodium nitrite (10.88 91157 mmol), the final pH was 12-13. THF was removed in-vacuo and the aqueous layer was extracted with dichloromethane (3 x 200 ml) to recover the chiral auxiliary. The organic extracts were dried (anhydrous magnesium sulphate), filtered and the solvent removed in-vacuo and the resulting solid chiral auxiliary (7.05 g, 39 mmol, 100%) recrystallised from ethyl acetate-hexane (2:1). [x]25D = - 13.0" (c=1, MeOH) The aqueous layer was cooled in an ice bath and acidified to pH 5-6 with 2M hydrochloric acid. The resulting cloudy solution was extracted with ethyl acetate (4 x 200 ml), readjusting the pH to 5-6 in between extractions. The combined organic extracts were dried over magnesium sulphate, filtered and the solvent was removed to yield the title compound as a pale yellow oil (8.21 g, 91%). tH-NMR; 6 (CDCl3), 2.85 (1H, m), 2.59 (1H, dd, J = 16, 9 Hz), 2.38 (1H, dd, J = 16, 5 Hz), 1.64 (1H, m), 1.43 (9H, s), 1.28 (1H, m) and 0.93 (6H, dd, J = 7,8 Hz). [a]25D = + 10.4" (c=1, MeOH).

STEP D: 3R-[2-Benzyisulphanyl-1 S-(methylcarbamoyl)-2-methyl-propylcarbamoyl]-5-methyl- hexanoic acid tert-butyl ester 2R-lsobutyl-butan-l ,4-dioic acid-4-tert-butyl ester (8.83 g, 38.4 mmol) was dissolved in DMF (300 ml) and the solution was cooled in an ice bath. HOBt (6.22 g, 46.0 mmol), EDC (8.82 g, 46.0 mmol) and S-benzyl-L-penicillamide-N-methylamide (19.419, 76.7 mmol) were added and the reaction mixture was stirred overnight at room temperature with stirring. TLC analysis indicated that all of the carboxylic acid precursor had been consumed. The solvent was removed and the residue was taken up in ethyl acetate and washed successively with water, sat. sodium hydrogen carbonate, 1 M hydrochloric acid and brine. The organic phase was dried (anhydrous magnesium sulphate), filtered and evaporated to leave the product as a yellow foam (18.14 g, 98%). 'H-NMR; 6 ((CD3)2SO), 7.99 (1H, m), 7.83 (1H, m), 7.21 - 7.01 (5H, br m), 4.48 (1H, d, J = 9.7 Hz), 3.68 (2H, s), 2.76 (1H, m), 2.45 (3H, d, J = 4.4 Hz), 2.30 (1H, m), 2.05 (1H, dd, J = 6.9, 16.0 Hz), 1.40 - 1.20 (3H, br m), 1.21 (12H, s), 1.12 (3H, s), 0.72 (3H, d, J = 6.2 Hz) and 0.66 (3H, d, J = 6.1 Hz).

STEP E: 3R-[2-Benzylsulphanyl-1 S-(methylcarbamoyl)-2-methyl-propylcarbamoyl]-5-methyl- hexanoic acid 3R-[2-Benzylsulphanyl-1 S-(methylcarbamoyl)-2-methyl-propylcarbamoylj-5-methyl- hexanoic acid tert-butyl ester (5.575, 11.6 mmol) was dissolved in dichloromethane (50 ml) and TFA (50 ml) and the solution was stored overnight at 4"C. The solvents were removed in vacuo, the residue was dissolved in ethyl acetate and washed twice with water to remove residual TFA. The organic phase was dried (anhydrous magnesium sulphate), filtered and evaporated to leave a white foam (4.98 g, including residual solvent). 'H-NMR; 6 (CDCl3), 7.49 (1H, d, J = 9.0 Hz), 7.37 - 7.17 (5H, br m), 6.44 (1H, m), 4.67 (1H, d, J = 9.0 Hz), 3.81 (2H, m), 2.87 (1H, m), 2.75 (3H, d, J = 4.7 Hz), 2.68 (1 H, m), 2.45 (1 H, dd, J = 4.1, 16.9 Hz), 1.67 - 1.43 (2H, br m), 1.40 (3H, s), 1.35 - 1.23 (4H, s and m), 0.89 (3H, d, J = 6.5 Hz) and 0.86 (3H, d, J = 6.3 Hz).

STEP F: 3R-[2-Benzylsulphanyl-1 S-(methylcarbamoyl)-2-methyl-propylcarbamoyl]-5-methyl- hexanohydroxamic acid 3R-[2-Benzylsu lphanyl-1 S-(methylcarbamoyl )-2-methyl-propylcarbamoyl]-5-methyl- hexanoic acid (4.98 9, 11.6 mmol) was dissolved in DMF (75 ml) and the solutin was cooled in an ice bath. HOBt (1.88 g, 17.4 mmol) and EDC (2.67 g, 13.9 mmol) were added and the mixture was stirred at 0 C for 1 h then at room temperature for 2h. The solution was cooled back to 0 C during the addition of hydroxylamine hydrochloride (1.21 g, 17.4 mmol), then stirred overnight at room temperature. The solvent was removed under reduced pressure to leave an oil which was triturated with diethyl ether (120 ml) / water (120 ml) and left to stand in an ice bath for 1.5 h. The resulting precipitate was collected by filtration and washed with cold diethyl ether. The desired product (1.12 g, 24%) was obtained as a white solid following column chromatography (acid-washed silica gel, 5% methanol in dichloromethane). m.p. 69 - 70"C. 'H-NMR; 5 (CD3OD), 7.96 (1H, m), 7.15 (5H, m), 4.52 (1H, m), 3.72 (2H, s), 2.83 (1H, m), 2.65 (3H, s), 2.28 (1H, m), 2.08 (1H, m), 1.34 (3H, s), 1.27 (3H, s), 1.20 (1H, m), 0.81 (3H, d, J = 6.5 Hz) and 0.77 (3H, d, J = 6.4 Hz). 13C-NMR; 6 (CDaOD), 177.0, 172.2, 170.6, 139.2, 130.3, 129.4, 60.0, 42.0, 37.2, 34.1, 27.1, 26.5, 26.2, 25.8, 23.5 and 22.5. IR (KBr disc); Vma", 3288, 2958, 1644, 1533, 1464 and 1368cm-1. Found: C 58.90, H 7.85, N 9.64%; C21H33N3O4S .0.3 H2O requires C 58.80, H 7.89, N 9.80%.

EXAMPLE 3 3R-[2-Benzylsulphanyl-1S-(methylcarbamoyl)-2-methyl-propylcarbamoyl]-6-phenyl- hexanohydroxamic acid

White crystalline solid. m.p. 165 - 1670C. 1H-NMR; 6 ((CD3)2SO), 8.56 (1H, s), 8.027.93 (1H, m), 7.88 (1H, d, J = 9.5 Hz), 7.21-6.95 (10H, m), 4.48 (1H, d, J = 9.6 Hz), 3.65 (2H, s), 2.48 - 2.23 (2H, m), 2.43 (3H, d, J = 4.5 Hz), 2.07 (1H, dd, J = 5.9, 14.5 Hz), 1.93 (1H, dd, J = 8.3, 14.4 Hz), 1.42-1.17 (4H, m), 1.22 (3H, s) and 1.14 (3H, s). 13C NMR; 6 ((CD3)2SO), 173.9,169.6,167.5, 142.2, 137.9, 129.2, 128.3, 128.2, 126.7, 125.6, 57.7, 48.5, 41.2, 35.4, 35.2, 32.3, 31.4, 28.6, 25.8, 25.4 and 25.1. IR (KBrdisc); vmaXX 3215, 2931, 1647 and 1518cm1.

EXAMPLE 20 3R-[2-Methyllthio-2-methyl-1 S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2S-propen- 2-yl-hexanohydroxamic acid

STEP A: 3R,S-AIIyl-2R-isobutyl-butan-1 ,4-dioic acidA-tert-butyl ester (1 :9, RS:RR) To a stirred solution of 2R-isobutyl-butan-1 ,4-dioic acid-4-tert-butyl ester (5 9, 21.7 mmol) in dry THF (100 ml), under an argon atmosphere, at -78"C, was added 1.5M LDA (31.8 ml, 47.7 mmol) dropwise via cannula. After stirring the solution at -780C for 1 hour, allyl bromide (2.44 ml, 28.2 mmol) was added dropwise via syringe. The resulting solution was allowed to warm to room temperature over a 2 hour period. Methanol (10 ml) was added and the solution stirred at room temperature. After 30 minutes the reaction mixture was concentrated under reduced pressure. The residue was taken up in dichloromethane (100 ml) and washed with 1M hydrochloric acid (100 ml) and brine (100 ml). The dichloromethane layer was dried over anhydrous magnesium sulphate filtered and solvent removed under reduced pressure to give the title compound as a golden oil (5.6 g, 97%) (1:9, RS:RR) 1H-NMR; 6 (CDCl3, major diastereoisomer), 5.78 5.63 (1 H, m), 5.01 - 5.11 (2H, m), 2.57 - 2.72 (2H, m), 2.37 (2H, m), 1.52 - 1.67 (2H, m), 1.42 (9H, s), 1.37 (1 H, m) and 0.90 (6H, d, J = 6.3 Hz). '3C-NMR; 6 (CDCl3, major diastereoisomer) 181.1,172.9, 134.6, 117.3, 81.2, 47.8, 44.3, 38.4, 27.9, 25.9, 23.5, and 21.5.

STEP B: 3S-Allyl-2R-isobutyl-butan-1 ,4-dioic acid-4-terf-butyl ester (dicyclohexylamine salt) (i) To a stirred solution of 3R,S-allyl-2R-isobutyl-butan-l ,4-dioic acidA-tert-butyl ester (1:9, RS:RR) (5.11 g, 18.9 mmol) in dry THF (100 ml) under argon at -78"C was added 1.5M LDA (27.7 ml, 41.6 mmol) via cannula. The reaction mixture was warmed to room temperature over a 2 hour period then cooled back to -78"C and methanol (8 ml) was added via syringe. The reaction was then allowed to warm to room temperature for a further 2 hours. The solvent was removed under reduced pressure.

The residue was taken up in dichloromethane (150 ml) and washed with 1M hydrochloric acid (150 ml) and brine (150 ml). The dichloromethane layer was dried over anhydrous magnesium sulphate, filtered and the solvent removed under reduced pressure to yield the title compound (3:2, RS:RR), as a brown oil (4.7 g, 92%).

(ii) Utilising the epimerisation procedure described in Step B(i), but employing a reaction temperature of -78"C after addition of LDA in lieu of allowing the reaction mixture to warm to room temperature yielded the title compound, as the major diastereomer as a brown oil (4.6 g, 98%) (3:1, RS:RR). 1H-NMR; 6 (CDCl3, major diastereoisomer), 11.60 (1 H, br s), 5.75 - 5.61(1 H, br m), 5.06 - 4.96 (2H, br m), 2.70 2.52 (2H, br m), 2.36 - 2.19 (2H, br m), 1.65 - 1.44 (2H, br m), 1.40 (9H, s), 1.13 (1H, m) and 0.86 (6H, dd, J = 4.4, 2.1 Hz). 13C-NMR; 6 (CDCI3, major diastereoisomer) 180.7, 172.2, 134.6, 117.1, 81.0, 48.6, 45.7, 38.9, 34.8, 33.4, 27.9, 26.2 and 21.2.

(iii) The above reaction was repeated and the combined products (36.85 g, 136 mmol) were dissolved in hexane and the solution allowed to stand overnight before filtering through glass microfibre filter papers (Whatman GFF) to remove a small amount of a coloured solid. Dicyclohexylamine (27 ml, 136 mmol) was added to the filtrate: crystallisation commenced after approximately 30 minutes. The mixture was chilled in a refridgerator overnight and the product was collected by filtration, washed with cold hexane and dried under vacuum. Yield: 14.19 9 (23%). 'H- NMR 6 (CDCl3), 6.89 - 6.58 (2H, m), 5.76 (1 H, m), 5.08-4.91 (2H, m), 2.99-2.82 (2H, m), 2.53 - 2.26 (4H, m), 2.09 - 1.93 (4H, m), 1.86 - 1.56 (8H, m), 1.54 - 0.99 (11 H, m), 1.42 (9H, s), 0.92 (3H, d, J = 6.5 Hz), 0.87 (3H, d, J = 6.5 Hz). 13C-NMR; 5 (CDCl3 single diastereoisomer), 179.0, 173.9,135.9,115.7,79.7, 52.1,50.8,49.7, 41.2,35.9,29.2,29.1, 27.9, 26.5, 25.1, 24.6, 24.0 and 21.5.

STEP C: 3R- [2-Methyllthio-2-methyl- 1 S-(methylcarbamoyl )propylcarbamoyl]-5-methyl-2S- propen-2-yl-hexanoic acid tert-butyl ester To a cooled 0"C solution of S-methyl-L-penicillamine-N-methylamide (1.60 9, 9.1 mmol) and 3S-allyl-2R-isobutyl-butan-I ,4-dioic acid-4-tert-butyl ester DCHA salt (4.5 9, 10.0 mmol ) in ethyl acetate (130 ml) was added HOBt (1.47 g, 10.9 mmol) and EDC (2.09 g, 10.9 mmol). The mixture was heated at reflux for 4 hours then stirred overnight at room temperature. The solid precipitate was removed by filtration and the filtrate was washed with 1 M hydrochloric acid, 0.5 M sodium carbonate and brine, dried over anhydrous magnesium sulphate, filtered and the solvent removed under reduced pressure. The residue was purified by column chromatography (silica gel, 5% methanol in dichloromethane) to afford a yellow foam (3.0 9, 77%) which was used without further purification.t'H-NMR; 5 (CDCI3), 6.77 (1H, m), 6.67 (1H, d, J = 8.4 Hz), 5.70 (1H, m), 5.00 (2H, ddd, J = 16.8, 7.6, 1.7 Hz), 4.53 (1 H, d, J = 8.4 Hz), 2.79 (3H, d, J = 4.8 Hz), 2.52 (2H, m), 2.26 (2H, m), 2.08 (3H, s), 1.65 (1H, m), 1.46 (1H, m), 1.43 (9H, s), 1.38 (3H, s), 1.29 (3H, s), 1.12(1 H, m), 0.88 (3H, d, J = 6.4 Hz) and 0.85 (3H, d, J = 6.4 Hz) STEP D: 3R-[2-Methyllthio-2-methyl- 1 S-(methylcarbamoyl )propylcarbamoyl]-5-methyl-2S-propen- 2-yl-hexanoic acid 3R-[2-Methyllthio-2-methyi-1 S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2S-propen2-yl-hexanoic acid tert-butyl ester (3.0 g, 7.0 mmol) was dissolved in dichloromethane (80 ml) and TFA (80 ml) and the solution was stored at 0OC overnight. The solvents were removed under reduced pressure and the residue was azeotroped with toluene to leave a yellow foam (3.07 g, contained residual TFA) which was used without further purification.

STEP E: 3R-[2-Methyllthio-2-methyl-1 S-(methylcarbamoyi)propylcarbamoyl]-5-methyl-2S-propen- 2-yl-hexanohydroxamic acid.

3R-[2-Methyllthio-2-methyl-l S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2S-propen2-yl-hexanoic acid was dissolved in DMF (40 ml) and cooled to 0"C before successive addition of HOBt (1.14 g, 8.4 mmol), NMM (450 pI) and EDC (1.61 g, 8.4 mmol). The reaction mixture was allowed to cool to room temperature and stirred for two hours, cooled to 0"C and treated with hydroxylamine hydrochloride (731 mg, 10.5 mmol) and NMM (1.16 ml, 10.5 mmol). The reaction mixture was stirred ovemight at room temperature. The solvent was removed under reduced pressure and the residue was triturated with water (40 ml) and diethyl ether (40 ml). The white solid which precipitated was collected by filtration, washed successively with diethyl ether and ethyl acetate and dried at 80"C under high vacuum. Yield: 1.49 g (53%). m.p. 227.50C. 'H-NMR; 6 ((CD3)2SO), 10.29 (1H, s), 8.61 (1H, s), 7.90 (2H, m), 5.43 (1H, m), 4.71 (2H, m), 4.37 (1 H, d, J = 9.4 Hz), 2.52 (1 H, m), 2.40 (3H, d, J = 4.5 Hz), 2.09 (3H, m), 1.85 (3H, s), 1.24 (2H, m), 1.15 (3H, s), 1.11 (3H, s), 0.79 (1H, m), 0.63 (3H, d, J = 6.4 Hz) and 0.58 (3H, d, J = 6.4 Hz). 13C-NMR; 5 ((CD3)2SO), 172.3, 168.2, 168.1, 134.9,114.6, 55.8, 44.9, 44.7, 44.6, 33.5, 24.2, 24.1, 22.9, 22.7, 20.4 and 9.5. Found: C 55.17, H 8.57, N 10.81%; C,8H33N304S . 0.2 H2O requires C 55.27, H 8.61, N 10.74%.

The following additional compounds were prepared as single diastereoisomers (unless otherwise stated) by methods of Example 20, starting from the appropriate amino acids: EXAMPLE 21 3R-[2-Cyclohexylmethylsulphanyl-2-methyl-1 S-(methylcarbamoyl)propyl- carbamoyl]-5 methyl-2S-propen-2-yl-hexanohydroxamic acid

White solid. m.p. 187 - 188.5"C. H-NMR; 6 (CD3OD), 5.58 (1H, m), 4.88 (2H, m), 4.40 (1H, s), 2.60 (3H, s), 2.57 (1H, m), 2.38 (2H, m), 2.23 (3H, m), 1.72 - 1.51 (4H, br m), 1.28 (3H, s), 1.26 (3H, s), 1.17 (4H, m), 1.11 - 0.86 (6H, br m), 0.76 (3H, d, J = 6.4 Hz) and 0.72 (3H, d, J = 6.5 Hz). C-NMR; 5 (CD3OD), 176.3, 172.4, 172.0, 136.4, 117.2, 59.7, 41.6, 39.3, 36.3, 36.1, 34.3, 34.2, 27.4, 27.2, 27.0, 26.9, 26.2, 26.0, 24.9, 24.3 and 21.9 Found: C 59.94, H 9.15, N 8.84%; C24H43N3O4S . 0.6 H2O requires C 59.99, H 9.27, N 8.75%.

EXAMPLE 22 3R-[2-Benzylsulphanyl-2-methyl-1S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl-2Spropen-2-yl-hexanohydroxamic acid

White solid. m.p. 212 - 213 C. H-NMR; 6 (CD3OD), 7.26 (5H, m), 5.56 (1H, m), 4.86 (2H, m), 4.75 (1H, s), 3.91 (1H, d, J = 10.8 Hz), 3.76 (1H, d, J = 10.9 Hz), 2.69 (3H, s), 2.65 (1H, m), 2.49 (1H, m), 2.23 (2H, m), 1.53 (2H, m), 1.44 (3H, s), 1.35 (3H, s), 1.12 (1H, m), 0.84 (3H, d, J = 6.5 Hz) and 0.80 (3H, d, J = 6.5 Hz). 13C-NMR; 6 (CD3)2SO), 173.6, 169.5, 137.9, 136.1, 129.0, 128.2, 126.5, 115.7, 58.0, 48.3, 46.4, 46.1, 34.7, 32.5, 26.3, 25.4, 25.3, 24.6, 23.7 and 21.8.

EXAMPLE 24 3R-[2-Mercapto-2-methyl-1 S-(methylcarbamoyl )-propylcarbamoyl]-5-methyl-2S-propen 2-yl-hexanohydroxamic acid

Off-white solid. m.p. 191 - 193"C. tH-NMR; 6 ((CD3)2SO), 10.31 (1H, s), 7.87 (1H, d, J = 8.9 Hz), 7.77 (1 H, d, J = 4.7 Hz), 5.46 (1 H, m), 4.72 (2H, m), 4.31 (1 H, d, J = 8.9 Hz), 2.61 (1H, s), 2.55 (1H, m), 2.40 (3H, d, J = 3.9 Hz), 2.17-1.95 (3H, br m), 1.21 (6H, 2s), 1.03 (2H, m), 0.85 (1H, m), 0.65 (3H, d, J = 6.2 Hz) and 0.59 (3H, d, J = 6.4 Hz). '3C NMR; 5 ((CD3)2SO), 172.4, 167.9, 167.3, 134.6, 114.8, 59.8, 44.8, 44.6, 33.6, 28.4, 28.1, 24.2, 22.7, 20.4 and 20.0. IR (KBr disc); vmax, 3282, 3077, 2957, 2932, 1629, 1546, 1467,11412, 1387, 1369 and 1258 cm-1. Found: C 53.94, H 8.25, N 10.65%; C17H31N3O4S .0.4 H2O requires: C 53.63, H 8.42, N 11.04%.

EXAMPLE 33 3R-[2-Methylsulphinyl-2-methyl-1S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2Spropen-2-yl-hexanohydroxamic acid

1:1 mixture of diastereomeric sulphoxides White solid. m.p. 202 - 204"C. 1H-NMR; 5 (CD,OD), 5.58 (1 H, m), 4.90 (2H, m), 4.68 (0.4H, s), 4.50 (0.6H, s), 2.64 (1.8H, s), 2.62 (1.2H, s), 2.60 (1 H, m), 2.54 (1.8H, s), 2.39 (1.2H, s), 2.15 (3H, m), 1.37 (1.8H, s), 1.23 (1.2H, s), 1.20 (1.2H, s), 1.18 (2H, m), 1.15 (1.8H, s), 0.99 (1H, m) and 0.75 (6H, m). 'H-NMR; 6 (CD3OD), 176.6, 176.5, 172.1, 170.8, 169.9, 136.1, 135.9, 117.5, 117.4, 61.6, 59.6, 56.8, 56.3, 55.9, 41.6, 41.5, 36.2, 36.1, 35.9, 32.3, 31.2, 27.1, 26.9, 26.2, 24.2, 21.8, 21.7, 17.8 and 15.4. IR (KBr disc); vmax, 3254, 3077, 2954, 1634, 1540cm1. Found: C 52.61, H 8.23, N 10.18%; C18H33N3OsS .0.4 H20 requires: C 52.64, H 8.29, N 10.23%.

EXAMPLE 34 3R-[2-M ethylsulphonyl-2-methyl-1 S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2S propen-2-yl-hexanohydroxamic acid

White solid. m.p. 219 - 221 C. H-NMR; # (CD3OD), 5.53 (1H, m) 4.93 (2H, m), 4.73 (1H, s), 2.90 (3H, s), 2.60 (3H, s), 2.53 (lH, m), 2.15 (3H, m), 1.46 (3H, s), 1.41 (1H, m), 1.37 (3H, s), 1.26 (1H, m), 1.15 (1H, m), 0.76 (3H, d, J = 6.4 Hz) and 0.71 (3H, d, J = 6.5 Hz). 13C-NMR; # (CD3OD), 176.6, 172.3, 170.3, 136.2, 117.3,64.4,55.9,47.9, 41.7, 36.4, 35.9, 26.9, 26.2, 24.3, 21.8, 20.4 and 17.7. IR (KBr disc); #max, 3270, 3080, 2954, 1662, 1633, 1558, 1540, 1470 cm-1. Found: C 50.81, H 7.97, N 9.89%; C,8H33N306S . 0.3 H2O requires: C 50.88, H 7.97, N 9.89%.

EXAMPLE 35 3R-[2-Benzylsulphinyl-2-methyl-1S-methylcarbamoyl-propylcarbamoyl]-5-methyl-2S- propen-2-yl-hexanohydroxamic acid

1:1 mixture of diastereomeric sulphoxides White powder. m.p. 143 - 144 C. H-NMR; 5 (CD3OD), 7.22 (5H, m), 5.49 (1H, m), 4.78 (3H, br m), 3.56 (0.9H, d, J = 12.5 Hz), 3.19 (1.1H, d, d, J = 12.1 Hz), 2.65 (1.5H, s), 2.63 (1.5H, s), 2.62 (1H, m), 2.18 - 2.06 (3H, br m), 1.42 (2H, m), 1.39 (1.8H, s), 1.36 (1.2H, s), 1.32 (1.2H, s), 1.29 (1.8H, s), 1.08 (1H, m) and 0.74 (6H, m). '3C-NMR; 5 (CD3OD), 176.8, 176.4, 172.1, 170.7, 170.5, 169.9, 135.9, 133.0, 131.7,130.5, 129.4, 127.9, 118.6, 62.9, 56.9, 53.9, 52.7, 41.8, 41.5, 36.1, 27.2, 27.1, 26.2, 24.2, 21.8, 18.5, 17.6, 16.9 and 16.3. IR (KBr disc); VmaX 3277, 3077, 2956, 1645, 1526, 1466, 1412 ,1387 cm-1 Found: C 57.65, H 7.53, N 8.68%; C24H37N3O5S . 1.1 H2O requires C 57.72, H 7.91, N 8.68%.

EXAMPLE 36 3 R-[2-Benzylsu I phanyl-2-methyl-1S-(methylcarbamoyl)propylcarbamoyl]-2S-hydroxy-6- phenyl-hexanoic acid

A solution of N-[2R-(2,2-dimethyl-4-oxo-1,3-dioxalan-5S-yl)-5-phenylpentanoyl]-S- benzyl-L-penicillamine-N-methylamide (prepared by a method analogous to that described in Example 4) (1.00 9, 1.90 mmol) in THF (15 ml) was cooled to 0"C and I M hydrochloric acid (15 ml) was added. The mixture was stirred overnight at room temperature after which TLC analysis indicated that all of the starting material had been consumed. The solvents were removed under reduced pressure to leave a pale yellow foam which was redissolved in ethyl acetate. The solution washed with brine, dried over magnesium sulphate', filtered and evaporated under reduced pressure to afford the title compound as an pale yellow foam (620 mg, 67%; single diastereoisomer). m.p. 730C.

'H-NMR; F (CDCI3), 7.50 (1H, d, J = 8.7 Hz), 7.31 - 7.12 lH, m), 6.62 (1H, d, J = 4.8 Hz), 4.56 (1 H, d, J = 8.8 Hz), 4.30 (1 H, d, J = 2.7 Hz), 3.80 (2H, s), 2.87 - 2.82 (1 H, m), 2.71 (3H, d, J = 4.7 Hz), 2.63 - 2.57 (2H, m), 1.79 - 1.71 (4H, m), 1.41 (3H, s) and 1.30 (3H, s). 13C-NMR; 6 (CDCl3), 175.0, 174.1, 169.9, 141.5, 137.4, 129.0, 128.5, 128.2, 127.1, 125.8, 70.7, 59.1, 49.5, 48.2, 35.4, 33.2, 29.1, 28.9, 26.2, 26.0, 25.6 and 21.0.

Found: C 63.67, H 7.08, N 5.64 %; C26HN2O5S . 0.2 H2O requires C 63.70, H 7.07, N 5.71%.

Claims (7)

Claims:

1. A compound of formula (I)

wherein X is a -CO2H or -CONHOH group; R1 is methyl, ethyl, allyl, thienylsulphanylmethyl, thienylsulphinylmethyl, or thienylsulphonylmethyl; R2 is iso-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, propylsulphanyl, cyclohexylpropyl, phenylpropyl, 4-chlorophenylpropyl, 4 methylphenylpropyl, 4-methoxyphenyl propyl, phenylbutyl, or propyloxymethyl; .

R3 is a group -C(C1-C6 alkyl)2R11 wherein R1, is -OH, -SH, -O(C1-C6)alkyl, -S(C1-C6)alkyl, -SO(C1-C6)alkyl, - SO2(C,-C6) alkyl, cyclohexylmethylsulphanyl, -OPh, -OCH2Ph, -SPh, SOPh, -SO2Ph, -SCH2Ph, -SOCH2Ph, or -SO2CH2Ph in which any of the foregoing Ph (phenyl) groups may be substituted; R4 is (C1-C6)alkyl, (C1-C4)perfluoroalkyl or a group D-(C1-C6)alkyl- wherein D represents hydroxy, (C1-C6)alkoxy, (C1-C6)alkylsulphanyl, acylamino, optionally substituted phenyl or heteroaryl; R5 is hydrogen; or a salt, hydrate or solvate thereof.

2. A compound as claimed in claim 1 wherein the stereochemistry is as follows: C atom carrying the R, and X groups - S, C atom carrying the R2 group C atom carrying the R3 group - S.

3. A compound as claimed in claim 1 or claim 2 wherein R3 is 2-hydroxyprop-2yl, 2-mercaptoprop-2-yl, 2-methoxyprop-2-yl, 2-(2-methoxyethoxymethoxy)prop-2-yl, 2-methylsulphanylprop-2-yl, 2-methylsulphinylprop-2-yl, 2-methylsulphonylprop-2-yl, 2-benzylsulphanylprop-2-yl, 2-benzylsulphinylprop-2-yl, 2-benzylsulphonylprop-2-yl, 2-(4-methoxybenzylsulphanyl)prop-2-yi, 2-(4-methoxybenzylsulphinyl)prop-2-yl, 2 (4-methoxybenzylsulphonyl)prop-2-yl, 2-cyclohexylmethylsulphanyl-prop-2-yl, cyclohexylmethylsulphinyl-prop-2-yl, or cyclohexylmethylsulphanyl-prop-2-yI.

4. A compound as claimed in claim 3 wherein R4 is methyl, ethyl, propyl, nbutyl, t-butyl, hydroxyethyl, hyd roxypropyl, 2 ,2-d imethyl-3-hydroxypropyl, hydroxybutyl, methoxyethyl, ethoxyethyl, methoxypropyl, 2,2-dimethyl-3 methoxyp ropyl, 2,2-dimethyl-3-ethoxypropyl, 2-ethylthioethyl, 2-acetoxyethyl, Nacetyl-aminoethyl, 3-(2-pyrrolidone)propyl, optionally substituted phenylethyl, phenylpropyl, phenylbutyl or phenylpentyl.

5. A compound selected from the group consisting of 3R-[2-Benzylsulphanyl-2-methyl-1 S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Cyclohexylmethylsulphanyl-2-methyl-1 S-(methylcarbamoyl)propylcarbamoyl]-5-methyl-2S-propen-2-yl-hexanohyd roxamic acid, 3R-[2-Methylsulphinyl-2-methyl-1 S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Methylsulphonyl-2-methyl-1S-(methylcarbamoyl)-propylcarbamoyl]-5-methyl- 2S-propen-2-yl-hexanohydroxamic acid, 3R-[2-Mercapto-2-methyl-l S-(methylca rbamoyl )-propylcarbamoyl]-5-methyl-2S propen-2-yl-hexanohydroxamic acid, 3R-[2-Methylth io-2-methyl- 1 S-(methylcarbamoyl )-propylcarbamoyl]-5-methyl-2S- propen-2-yl-hexanohydroxamic acid, and salts, solvates or hydrates thereof.

6. A pharmaceutical composition as claimed in any of claims 1 to 5 together with a pharmaceutically acceptable carrier.

7. A composition as claimed in claim 6 which is adapted for oral administration.