Cell adhesion is a process by which cells associate with each other, migrate towards a specific target or localise within the extra-cellular matrix. Many of the cell-cell and cell-extracellular matrix interactions are mediated by protein ligands (e. g. fibronectin, vitronectin and VCAM-1) and their integrin receptors [e. g. VLA-4 (a4ß1)]. Recent studies have shown these interactions to play an important part in many physiological (e. g. embryonic development and wound healing) and pathological conditions (e. g. tumour-cell invasion and metastasis, inflammation, atherosclerosis and autoimmune disease).

A wide variety of proteins serve as ligands for integrin receptors. In general, the proteins recognised by integrins fall into one of three classes: extracellular matrix proteins, plasma proteins and cell surface proteins. Extracellular matrix proteins such as collagen fibronectin, fibrinogen, laminin, thrombospondin and vitronectin bind to a number of integrins. Many of the adhesive proteins also circulate in plasma and bind to activated blood cells. Additional components in plasma that are ligands for integrins include fibrinogen and factor X. Cell bound complement C3bi and several transmembrane proteins, such as Ig-like cell adhesion molecule (ICAM-1,2,3) and vascular cell adhesion molecule (VCAM-1), which are members of the Ig superfamily, also serve as cell-surface ligands for some integrins.

Integrins are heterodimeric cell surface receptors consisting of two subunits called a and ß.

There are at least twelve different a-subunits (al-a6, a-L, a-M, a-X, a-IIb, a-V and a-E) and at least nine different ß (1-9) subunits. The integrin family can be subdivided into classes based on the ß subunits, which can be associated with one or more a-subunits. The most widely distributed integrins belong to the 1 class, also known as the very late antigens (VLA). The second class of integrins are Ieukocyte specific receptors and consist of one of three a-subunits (a-L, a-M or a-X) complexe with the ß2 protein. The cytoadhesins a-IIbp3 and a-V (33, constitute the third class of integrins.

The present invention principally relates to agents which modulate the interaction of the ligand VCAM-1 with its integrin receptor a4 (31 (VLA-4), which is expressed on numerous hematopoietic cells and established cell lines, including hematopoietic precursors, peripheral and cytotoxic T lymphocytes, B lymphocytes, monocytes, thymocytes and eosinophils.

The integrin a4pl mediates both cell-cell and cell-matrix interactions. Cells expressing o4pl bind to the carboxy-terminal cell binding domain of the extracellular matrix protein fibronectin, to the cytokine-inducible endothelial cell surface protein VCAM-1, and to each other to promote homotypic aggregation. The expression of VCAM-1 by endothelial cells is upregulated by proinflammatory cytokines such as INF-y, TNF-a and LI-lß.

Regulation of o4pl mediated cell adhesion is important in numerous physiological processes, including T-cell proliferation, B-cell localisation to germinal centres, and adhesion of activated T-cells and eosinophils to endothelial cells. Evidence for the involvement of VLA-4/VCAM-1 interaction in various disease processes such as melanoma cell division in metastasis, T-cell infiltration of synovial membranes in rheumatoid arthritis, autoimmune diabetes, collitis and leukocyte penetration of the blood-brain barrier in experimental autoimmune encephalomyelitis, atherosclerosis, peripheral vascular disease, cardiovascular disease and multiple sclerosis, has been accumulated by investigating the role of the peptide CS-1 (the variable region of fibronectin to which o4 [3l binds via the sequence Leu-Asp-Val) and antibodies specific for VLA-4 or VCAM-1 in various in vitro and in vivo experimental models of inflammation. For example, in a Streptococcal cell wall-induced experimental model of arthritis in rats, intravenous administration of CS-1 at the initiation of arthritis suppresses both acute and chronic inflammation (S. M. Wahl et al., J. Clin. Invest., 1994,94, pages 655-662). In the oxazalone- sensitised model of inflammation (contact hypersensitivity response) in mice, intravenous administration of anti-a4 specific monoclonal antibodies significantly inhibited (50-60% reduction in the ear swelling response) the efferent response (P. L. Chisholm et al. J. Immunol., 1993,23, pages 682-688).

We have now found a novel group of substituted (3-alanines which have valable pharmaceutical properties, in particular the ability to regulate the interaction of VCAM-1 and fibronectin with the integrin VLA-4 (a4pl).

Thus, in one aspect, the present invention is directed to compounds of general formula (I):- wherein:- Rl is hydrogen, halogen, lower alkyl or lower alkoxy; X1, X2 and X6 independently represent N or CR2; and one of X3, X4 and X5 represents CR3 and the others independently represents N or CR2 [where R2 is hydrogen, halogen, lower alkyl or lower alkoxy; and R3 represents a group -L1-(CH2)(CH2) n-C (=O)-N (R4)-CH2-CH2-Y in which: R4 is aryl or heteroaryl, or R4 is alkyl, alkenyl, alkynyl each optionally substituted by one or more groups chosen from halo, oxo, R5,-C (=O)-R7,-NH-C (=O)-R7or-C (=O) NYlY2, or R4 is cycloalkenyl, cycloalkyl or heterocycloalkyl each optionally substituted by one or more groups chosen from oxo, R6 or-L2-R6 {where R5 is an acidic functional group (or corresponding protected derivative), aryl, cycloalkyl, cycloalkenyl, heteroaryl, heterocycloalkyl,-ZR7 or -NYlY2; R6 is an acidic functional group (or corresponding protected derivative), aryl, heteroaryl, heterocycloalkyl,-ZH,-Z1R7 or-NYlY2; R7 is alkyl, aryl, arylalkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroarylalkyl, heterocycloalkyl or heterocycloalkylalkyl; L2 is alkylene; yl and y2 are independently hydrogen, acyl, alkyl [optionally substituted by hydroxy, heterocycloalkyl, or one or more carboxy or-C (=O)-NHR8 groups (where R8 is hydrogen or lower alkyl)], alkylsulphonyl, aryl, arylalkyloxycarbonyl, arylsulphonyl, arylalkyl, heteroaryl, heteroarylalkyl, heterocycloalkyl or heterocycloalkylalkyl; or the group-NYlY2 may form a 5-7 membered cyclic amine which (i) may be optionally substituted with one or more substituents selected from carboxamido, carboxy, hydroxy, oxo, hydroxyalkyl, HOCH2CH2-(OCH2CH2) m-(OCH2CH2) m- (where m is zero, or an integer one or two), or alkyl optionally substituted by carboxy or carboxamido (ii) may also contain a further heteroatom selected from O, N, S or SO2 and (iii) may also be fused to addition aromatic, heteroaromatic,

heterocycloalkyl or cycloalkyl rings to form a bicyclic or tricyclic ring system; Z is O or S; and z1 is O or S (O) m} i L1 represents a-R9-R1O-linkage, in which R9 is a straight or branched C1 6alkylene chain, a straight or branched C2 6alkenylene chain or a straight or branched C2 6alkynylene chain, and R1O is a direct bond, cycloalkylene, heterocycloalkylene, arylene, heteroaryldiyl,-C (=Z)-NRil-, -NR11-,-C(=O)-,-C(=NOR11)-,-NR11-C(=Z)-NR11-,-SO2-NR11-,-NR1 1-C(=Z)-,-Z1-, -NRll-SO2-,-O-C (=O)-,-C (=O)-O-,-NRll-C (=O)-O- or-O-C (=O)-NRll- (where Rll is a hydrogen atom or R4); but excluding compounds where an oxygen, nitrogen or sulphur atom is attached directly to a carbon carbon multiple bond; Y is carboxy (or an acid bioisostere) or-C (=O)-NYlY2; and n is an integer from 1 to 6; and their prodrugs, and pharmaceutically acceptable salts and solvates (e. g. hydrates) of such compounds and their prodrugs.

In the present specification, the term"compounds of the invention", and equivalent expressions, are meant to embrace compounds of general formula (I) as hereinbefore described, which expression includes the prodrugs, the pharmaceutically acceptable salts, and the solvates, e. g. hydrates, where the context so permits. Similarly, reference to intermediates, whether or not they themselves are claimed, is meant to embrace their salts, and solvates, where the context so permits. For the sake of clarity, particular instances when the context so permits are sometimes indicated in the text, but these instances are purely illustrative and it is not intended to exclude other instances when the context so permits.

As used above, and throughout the description of the invention, the following terms, unless otherwise indicated, shall be understood to have the following meanings:- "Patient"includes both human and other mammals.

"Acid bioisostere"means a group which has chemical and physical similarities producing broadly similar biological properties to a carboxy group (see Lipinski, Annual Reports in Medicinal Chemistry, 1986,21, p283"Bioisosterism In Drug Design" ; Yun, Hwahak Sekye, 1993,33, p576-579"Application Of Bioisosterism To New Drug Design" ; Zhao, Huaxue Tongbao,

1995, p34-38"Bioisosteric Replacement And Development Of Lead Compounds In Drug Design" ; Graham, Theochem, 1995,343, plO5-109"Theoretical Studies Applied To Drug Design: ab initio Electronic Distributions In Bioisosteres"). Examples of suitable acid bioisosteres include:-C (=O)-NHOH,-C (=O)-CH20H,-C (=O)-CH2SH,-C (=O)-NH-CN, sulpho, phosphono, alkylsulphonylcarbamoyl, tetrazolyl, arylsulphonylcarbamoyl, heteroarylsulphonylcarbamoyl, N-methoxycarbamoyl, 3-hydroxy-3-cyclobutene-1,2-dione, 4-oxadiazolidinyl or heterocyclic phenols such as 3-hydroxyisoxazolyl and 3-hydoxy-1-methylpyrazolyl.

"Acidic functional group"means a group with an acidic hydrogen within it. The"corresponding protected derivatives"are those where the acidic hydrogen atom has been replaced with a suitable protecting group. For suitable protecting groups see T. W. Greene and P. G. M. Wuts in "Protective Groups in Organic Chemistry"John Wiley and Sons, 1991. Exemplary acidic functional groups include carboxyl (and acid bioisosteres), hydroxy, mercapto and imidazole.

Exemplary protected derivatives include esters of carboxy groups, ethers of hydroxy groups, thioethers of mercapto groups and N-arylalkyl (e. g. N-benzyl) derivatives of imidazoles.

"Acyl"means an H-CO-or alkyl-CO-group in which the alkyl group is as described herein.

"Acylamino"is an acyl-NH-group wherein acyl is as defined herein.

"Alkenyl"means an aliphatic hydrocarbon group containing a carbon-carbon double bond and which may be straight or branched having about 2 to about 15 carbon atoms in the chain.

Preferred alkenyl groups have 2 to about 12 carbon atoms in the chain; and more preferably about 2 to about 4 carbon atoms in the chain. "Branched", as used herein and throughout the text, means that one or more lower alkyl groups such as methyl, ethyl or propyl are attached to a linear chain; here a linear alkenyl chain."Lower alkenyl"means about 2 to about 4 carbon atoms in the chain which may be straight or branched. Exemplary alkenyl groups include ethenyl, propenyl, n-butenyl, i-butenyl, 3-methylbut-2-enyl, n-pentenyl, heptenyl, octenyl, cyclohexylbutenyl and decenyl.

"Alkenylene"means an aliphatic bivalent radical derived from a straight or branched alkenyl group, in which the alkenyl group is as described herein. Exemplary alkenylene radicals include C2 4alkenylene radicals such as vinylene and propylene.

"Alkoxy"means an alkyl-O-group in which the alkyl group is as described herein. Exemplary alkoxy groups include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy and heptoxy.

"Alkoxycarbonyl"means an alkyl-O-CO-group in which the alkyl group is as described herein.

Exemplary alkoxycarbonyl groups include methoxy-and ethoxycarbonyl.

"Alkyl"means, unless otherwise specified, an aliphatic hydrocarbon group which may be straight or branched having about 1 to about 15 carbon atoms in the chain optionally substituted by one or more halogen atoms. Particular alkyl groups have from 1 to about 6 carbon atoms."Lower alkyl"as a group or part of a lower alkoxy group means unless otherwise specified, an aliphatic hydrocarbon group which may be straight or branched having about 1 to about 4 carbon atoms in the chain. Exemplary alkyl groups include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, 3-pentyl, heptyl, octyl, nonyl, decyl and dodecyl.

"Alkylene"means an aliphatic bivalent radical derived from a straight or branched alkyl group, in which the alkyl group is as described herein. Exemplary alkylene radicals include C1 4alkylene radicals such as methylene, ethylene and trimethylene.

"Alkylsulphinyl"means an alkyl-SO-group in which the alkyl group is as previously described.

Preferred alkylsulphinyl groups are those in which the alkyl group is CI-4alkyl.

"Alkylsulphonyl"means an alkyl-SO2-group in which the alkyl group is as previously described. Preferred alkylsulphonyl groups are those in which the alkyl group is Cl-4alkyl.

"Alkylsulphonylearbamoyl"means an alkyl-SO2-NH-C (=O)- group in which the alkyl group is as previously described. Preferred alkylsulphonylcarbamoyl groups are those in which the alkyl group is C1 4alkyl.

"Alkylthio"means an alkyl-S-group in which the alkyl group is as previously described.

Exemplary alkylthio groups include methylthio, ethylthio, isopropylthio and heptylthio.

"Alkynyl"means an aliphatic hydrocarbon group containing a carbon-carbon triple bond and which may be straight or branched having about 2 to about 15 carbon atoms in the chain.

Preferred alkynyl groups have 2 to about 12 carbon atoms in the chain; and more preferably about 2 to about 4 carbon atoms in the chain. Exemplary alkynyl groups include ethynyl, propynyl, n-butynyl, i-butynyl, 3-methylbut-2-ynyl, and n-pentynyl.

"Alkynylene"means an aliphatic bivalent radical derived from a straight or branched alkynyl group, in which the alkynyl group is as described herein. Exemplary alkynylene radicals include C2 4alkynylene radieals such as ethynylene and propynylene.

"Aroyl"means an aryl-CO-group in which the aryl group is as described herein. Exemplary aroyl groups include benzoyl and 1-and 2-naphthoyl.

"Aroylamino"is an aroyl-NH-group wherein aroyl is as previously defined.

"Aryl"as a group or part of a group denotes: (i) an optionally substituted monocyclic or multicyclic aromatic carbocyclic moiety of about 6 to about 14 carbon atoms or (ii) an optionally substituted partially saturated multicyclic aromatic carbocyclic moiety in which an aryl and a cycloalkyl or cycloalkenyl group are fused together to form a cyclic structure such as a tetrahydronaphthyl, indenyl or indanyl ring. When R4 contains an optionally substituted aryl group, this may particularly represent optionally substituted phenyl with one or more aryl group substituents which may be the same or different, where"aryl group substituent"includes, for example, acyl, acylamino, alkoxy, alkoxycarbonyl, alkylsulphinyl, alkylsulphonyl, alkylthio, aroyl, aroylamino, aryl, arylalkyloxy, arylalkyloxycarbonyl, arylalkylthio, aryloxy, aryloxycarbonyl, arylsulphinyl, arylsulphonyl, arylthio, carboxy, cyano, halo, heteroaroyl, heteroaryl, heteroarylalkyloxy, heteroarylamino, heteroaryloxy, hydroxy, nitro, trifluoromethyl, Y3Y4N-, y3y4NCO-, Y3Y4NSO2-(where Y3 and Y4 are independently hydrogen, alkyl, aryl, and arylalkyl), Y3Y4N-L3-Z2- (where L3 is C2 6alkylene and Z2 is O, NR8 or S (O) m) alkylC (=O)-Y3N-, alkylSO2-Y3N-or alkyl optionally substituted with aryl, heteroaryl, hydroxy, or Y3Y4N-.

"Arylalkyl"means an aryl-alkyl-group in which the aryl and alkyl moieties are as previously described. Preferred arylalkyl groups contain a Cl-4alkyl moiety. Exemplary arylalkyl groups include benzyl, 2-phenethyl and naphthlenemethyl.

"Arylalkyloxy"means an arylalkyl-O-group in which the arylalkyl groups is as previously described. Exemplary arylalkyloxy groups include benzyloxy and 1-or 2-naphthalenemethoxy.

"Arylalkyloxycarbonyl"means an arylalkyl-O-CO-group in which the arylalkyl groups is as previously described. An exemplary arylalkyloxycarbonyl group is benzyloxycarbonyl.

"Arylalkylthio"means an arylalkyl-S-group in which the arylalkyl group is as previously described. An exemplary arylalkylthio group is benzylthio.

"Arylene"means an optionally substituted bivalent radical derived from an aryl group as defined above. Exemplary arylene groups include optionally substituted phenylene, naphthylene and indanylene. Suitable substituents include one or more"aryl group substituents"as defined above, particularly halogen, methyl or methoxy.

"Aryloxy"means an aryl-O-group in which the aryl group is as previously described.

Exemplary aryloxy groups include optionally substituted phenoxy and naphthoxy.

"Aryloxycarbonyl"means an aryl-O-CO-group in which the aryl group is as previously described. Exemplary aryloxycarbonyl groups include phenoxycarbonyl and naphthoxycarbonyl.

"Arylsulphinyl"means an aryl-SO-group in which the aryl group is as previously described.

"Arylsulphonyl"means an aryl-S02-group in which the aryl group is as previously described.

"Arylsulphonylcarbamoyl"means an aryl-SO2-NH-C (=O)- group in which the aryl group is as previously described.

"Arylthio"means an aryl-S-group in which the aryl group is as previously described.

Exemplary arylthio groups include phenylthio and naphthylthio.

"Azaheteroaryl"means an aromatic carbocyclic moiety of about 5 to about 10 ring members in which one of the ring members is nitrogen and the other ring members are chosen from carbon,

oxygen, sulphur, or nitrogen. Examples of azaheteroaryl groups include pyridyl, pyrimidinyl, quinolinyl, isoquinolinyl, quinazolinyl, imidazolyl, and benzimidazolyl.

"Cycloalkenyl"means a non-aromatic monocyclic or multicyclic ring system containing at least one carbon-carbon double bond and having about 3 to about 10 carbon atoms. Exemplary monocyclic cycloalkenyl rings include C3 gcycloalkenyl rings such as cyclopentenyl, cyclohexenyl or cycloheptenyl.

"Cycloalkyl"means a saturated monocyclic or bicyclic ring system of about 3 to about 10 carbon atoms optionally substituted by oxo. Exemplary monocyclic cycloalkyl rings include C3 gcycloalkyl such as cyclopropyl, cyclopentyl, cyclohexyl and cycloheptyl.

"Cycloalkylalkyl"means a cycloalkyl-alkyl-group in which the cycloalkyl and alkyl moieties are as previously described. Exemplary monocyclic cycloalkylalkyl groups include C3 gcycloalkylCl 4alkyl groups such as cyclopropylmethyl, cyclopentylmethyl, cyclohexylmethyl and cycloheptylmethyl.

"Cycloalkylene"means a divalent radical derived from a cycloalkyl group as defined above.

Exemplary cycloalkylene radicals include C3 gcycloalkylene radicals such as cyclopentylene and cyclohexylene.

"Halo"or"halogen"means fluoro, chloro, bromo, or iodo. Preferred are fluoro or chloro.

"Heteroaroyl"means a heteroaryl-CO-group in which the heteroaryl group is as described herein. Exemplary groups include pyridylcarbonyl.

"Heteroaryl"as a group or part of a group denotes: (i) an optionally substituted aromatic monocyclic or multicyclic organic moiety of about 5 to about 10 ring members in which one or more of the ring members is/are element (s) other than carbon, for example nitrogen, oxygen or sulphur (examples of such groups include benzimidazolyl, benzthiazolyl, furyl, imidazolyl, indolyl, indolizinyl, isoxazolyl, isoquinolinyl, isothiazolyl, oxadiazolyl, pyrazinyl, pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl and triazolvl groups, optionally substituted by one or more aryl group substituents as defined above); (ii) an optionally substituted partially saturated multicyclic heterocarbocycHc

moiety in which a heteroaryl and a cycloalkyl or cycloalkenyl group are fused together to form a cyclic structure (examples of such groups include pyrindanyl groups). Optional substituents include one or more"aryl group substituents"as defined above. When L1 or R4 contains an optionally substituted heteroaryl group this may particularly represent an optionally substituted "azaheteroaryl"group.

"Heteroarylalkyl"means a heteroaryl-alkyl-group in which the heteroaryl and alkyl moieties are as previously described. Preferred heteroarylalkyl groups contain a CI-4alkyl moiety such as optionally substituted pyridylC1 4alkyl (e. g. optionally substituted pyridylmethyl).

"Heteroarylalkyloxy"means an heteroarylalkyl-O-group in which the heteroarylalkyl group is as previously described. Preferred heteroarylalkyloxy groups include heteroarylC1 4alkyloxy such as optionally substituted pyridylC1 4alkyloxy (e. g. optionally substituted pyridylmethoxy).

"Heteroarylamino"means a heteroaryl-NH-group in which the heteroaryl moiety are as previously described.

"Heteroaryldiyl"means a bivalent radical derived from a heteroaryl group as defined above.

"Heteroaryloxy"means an heteroaryl-O-group in which the heteroaryl group is as previously described. Exemplary heteroaryloxy groups include optionally substituted pyridyloxy.

"Heteroarylsulphonylcarbamoyl"means a heteroaryl-SO2-NH-C (=O)- group in which the heteroaryl group is as previously described.

"Heterocycloalkyl"means: (i) a cycloalkyl group of about 3 to 7 ring members in which one or more of the ring carbon atoms is replace by O, S or NY5 (where Y5 is hydrogen, alkyl, arylalkyl, and aryl); (ii) a partially saturated bicyclic system in which an aryl or heteroaryl ring is fused to a heterocycloalkyl ring as defined in (i) above. Examples of (ii) include 1,4-benzodioxanyl, 1,3-benzodioxolyl, chromanyl, dihydrobenzofuranyl, indolinyl and dihydropyrrolopyridinyl groups).

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

"Heterocycloalkylene"means a bivalent radical derived from a heterocycloalkyl group as defined above.

"Hydroxyalkyl"means a HO-alkyl-group in which alkyl is as previously defined. Preferred hydroxyalkyl groups contain CI-4alkyl for example hydroxymethyl and 2-hydroxyethyl.

"Y3Y4N-"means a substituted or unsubstituted amino group, wherein Y3 and Y4 are as previously described. Exemplary groups include amino (H2N-), methylamino, ethylmethylamino, dimethylamino and diethylamino.

"Yy3y4NCO-"means a substituted or unsubstituted carbamoyl group, wherein Y3 and Y4 are as previously described. Exemplary groups are carbamoyl (H2NCO-) and dimethylcarbamoyl (Me2NCO-).

"Yy3y4NS02-"means a substituted or unsubstituted sulphamoyl group, wherein Y3 and Y4 are as previously described. Exemplary groups are sulphamoyl (H2NS02-) and dimethylsulphamoyl (Me2NSO2-).

"Prodrug"means a compound which is convertible in vivo by metabolic means (e. g. by hydrolysis) to a compound of formula (I), including N-oxides thereof. For example an ester of a compound of formula (I) containing a hydroxy group may be convertible by hydrolysis in vivo to the parent molecule. Alternatively an ester of a compound of formula (I) containing a carboxy group may be convertible by hydrolysis in vivo to the parent molecule.

Suitable esters of compounds of formula (I) containing a hydroxy group, are for example acetates, citrates, lactates, tartrates, malonates, oxalates, salicylates, propionates, succinates, fumarates, maleates, methylene-bis-ß-hydroxynaphthoates, gentisates, isethionates, di-p-toluoyltartrates, methanesulphonates, ethanesulphonates, benzenesulphonates, p-toluenesulphonates, cyclohexylsulphamates and quinates.

An especially useful class of esters of compounds of formula (I) containing a hydroxy group, may be formed from acid moieties selected from those described by Bundgaard et. al., J. Med. Chem., 1989,32, page 2503-2507, and include substituted (aminomethyl)-benzoates, for example dialkylamino-methylbenzoates in which the two alkyl groups may be joined together and/or interrupted by an oxygen atom or by an optionally substituted nitrogen atom, e. g. an alkylated nitrogen atom, more especially (morpholino-methyl) benzoates, e. g. 3-or 4- (morpholinomethyl)-benzoates, and (4-alkylpiperazin-1-yl) benzoates, e. g. 3-or 4- (4-alkylpiperazin-1-yl) benzoates.

Where the compound of the invention contains a carboxy group, or a sufficiently acidic bioisostere, base addition salts may be formed and are simply a more convenient form for use; and in practice, use of the salt form inherently amounts to use of the free acid form. The bases which can be used to prepare the base addition salts include preferably those which produce, when combined with the free acid, pharmaceutically acceptable salts, that is, salts whose cations are non-toxic to the patient in pharmaceutical doses of the salts, so that the beneficial inhibitory effects inherent in the free base are not vitiated by side effects ascribable to the cations.

Pharmaceutically acceptable salts, including those derived from alkali and alkaline earth metal salts, within the scope of the invention include those derived from the following bases: sodium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminium hydroxide, lithium hydroxide, magnesium hydroxide, zinc hydroxide, ammonia, ethylenediamine, N-methyl- glucamine, lysine, arginine, ornithine, choline, N, N'-dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, diethylamine, piperazine, tris (hydroxymethyl) aminomethane, tetramethylammonium hydroxide, and the like.

Some of the compounds of the present invention are basic, and such compounds are useful in the form of the free base or in the form of a pharmaceutically acceptable acid addition salt thereof.

Acid addition salts are a more convenient form for use; and in practice, use of the salt form inherently amounts to use of the free base form. The acids which can be used to prepare the acid addition salts include preferably those which produce, when combined with the free base, pharmaceutically acceptable salts, that is, salts whose anions are non-toxic to the patient in pharmaceutical doses of the salts, so that the beneficial inhibitory effects inherent in the free base are not vitiated by side effects ascribable to the anions. Although pharmaceutically acceptable salts of said basic compounds are preferred, all acid addition salts are useful as sources of the free base form even if the particular salt, per se, is desired only as an intermediate

product as, for example, when the salt is formed only for purposes of purification, and identification, or when it is used as intermediate in preparing a pharmaceutically acceptable salt by ion exchange procedures. Pharmaceutically acceptable salts within the scope of the invention include those derived from mineral acids and organic acids, and include hydrohalides, e. g. hydrochlorides and hydrobromides, sulphates, phosphates, nitrates, suiphamates, acetates, citrates, lactates, tartrates, malonates, oxalates, salicylates, propionates, succinates, fumarates, maleates, methylene-bis-b-hydroxynaphthoates, gentisates, isethionates, di-p-toluoyltartrates, methane-sulphonates, ethanesulphonates, benzenesulphonates, p-toluenesulphonates, cyclohexylsulphamates and quinates.

As well as being useful in themselves as active compounds, salts of compounds of the invention are useful for the purposes of purification of the compounds, for example by exploitation of the solubility differences between the salts and the parent compounds, side products and/or starting materials by techniques well known to those skilled in the art.

With reference to formula (I) above, the following are particular and preferred groupings: Rl may particularly represent hydrogen, especially when X1 represents C-R2 where R2 is lower alkyl or lower alkoxy.

X1 may particularly represent CR2, especially where R2 is C1 4alkyl (e. g. methyl) or Cl-4alkoxy (e. g. methoxy).

X2 may particularly represent CR2, especially where R2 is CI-4alkyl (e. g. methyl) or C1 4alkoxy (e. g. methoxy).

X3 may particularly represent CR2 and is preferably CH.

X6 may particularly represent CR2 and is preferably CH.

One of X4 and X5 may particularly represent CR3 and the other represents CR2, especially CH.

Within R3 the moiety L1 may particularly represent a-R9-R1O-linkage where R9 represents a straight or branched C1 6alkylene chain, especially a straight C1 4alkylene chain such as methylene or ethylene, and RIO represents-C (=Z)-NR1l-, preferably-C (=O)-NR11- especially where R1l is:- (i) hydrogen; (ii) C1-6alkyl (e. g. C1-4alkyl groups such as ethyl, propyl or especially methyl); (iii) C1 6alkyl (especially C1 3alkyl) substituted by R5, where R5 is aryl (e. g. phenyl); (iv) C1 6alkyl (especially C1 3alkyl) substituted by R5, where R5 is heteroaryl (exemplary heteroaryl groups include indolyl, imidazolyl, pyridyl and furyl); (v) C1-6alkyl (especially C1-3alkyl) substituted by R5, where R5 is cycloalkyl (e. g. C3 gcycloalkyl such as cyclopentyl and cyclohexyl); (vi) C1-6alkyl (especially C1-3alkyl) substituted by R5, where R5 is carboxy (or an acid bioisostere); or (vii) C1 6alkyl (e. g. Chalky ! such as ethyl or propyl) substituted by R5, where R5 is-NYlY2 (exemplary-NYlY2 groups include acylamino, aryl (alkyl) amino, N-pyrrolidinyl and 2-oxo-N-pyrrolidinyl).

Within R3 the moiety R4 may particularly represent straight or branched C1-10alkyl (e. g. methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, 1,5-dimethylhexyl, n-nonyl or n-decyl).

Within R3 the moiety R4 may also particularly represent straight or branched C1 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is aryl. Exemplary aryl groups include phenyl optionally substituted by one or more"aryl group substituents", for example alkoxyphenyl, dialkoxyphenyl, arylalkyloxy (alkoxy) phenyl, halophenyl, dialkylaminophenyl, trifluoromethylphenyl and methanesulphonylphenyl. R4 is preferably straight or branched C1-3alkyl substituted by diC1-3alkoxyphenyl and is particularly 3,4-diC1-3alkoxybenzyl.

Within R3 the moiety R4 may also particularly represent straight or branched C1-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is heteroaryl.

Exemplary heteroaryl groups include indolyl, imidazolyl, pyridyl and furyl. R4 is preferably straight or branched C1-3alkyl substituted by azaheteroaryl and is particularly 3-(imidazol-1- yl)-C1 3alkyl).

Within R3 the moiety R4 may also particularly represent straight or branched C1-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is C3 gcycloalkyl. R4 is preferably straight or branched C1 3alkyl substituted by CS 6cycloalkyl.

Within R3 the moiety R4 may also particularly represent straight or branched Chalky ! (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is C1 6alkoxy, especially C1-4alkoxy such as methoxy.

Within R3 the moiety R4 may also particularly represent straight or branched Chalky ! (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is halo.

Within R3 the moiety R4 may also particularly represent straight or branched Chalky ! (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is an acidic functional group. R4 is preferably straight or branched C1-3alkyl substituted by carboxy.

Within R3 the moiety R4 may also particularly represent straight or branched C1-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is heterocycloalkyl.

Exemplary heterocycloalkyl groups include benzodioxolyl and benzodioxanyl. R4 is preferably straight or branched C1-3alkyl substituted by benzodioxolyl and benzodioxanyl.

Within R3 the moiety R4 may also particularly represent straight or branched C1-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by-NYlY2. Exemplary-NYlY2 groups include acylamino, aryl (alkylamino) and-NYlY2 groups derived from 5-7 membered cyclic

amines such as morpholine, piperidine, pyrrolidine and 2-oxo-pyrrolidine. R4 is preferably straight or branched C2-3alkyl substituted by an N-linked 5-7 membered cyclic amine, especially 3-3alkyl.

Within R3 the moiety R4 may also particularly represent C1_4alkenyl (e. g. allyl).

Within R3 the moiety n may particularly represent the integer 1 to 3, especially 1.

Within R3 the moiety Y may particularly represent carboxy or an acid bioisostere, especially carboxy.

It is to be understood that this invention covers all appropriate combinations of the particular and preferred groupings referred to herein.

A particular group of compounds of the invention are compounds of formula (Ia):- in which R4, R9, RII and Y are as hereinbefore defined, XI and X2 each independently represent CR2 (wherein each R2 group is as hereinbefore defined), and -R9-CON (R1l)-CH2-CoN (R4)-CH2-CH2-Y is attached at the ring 3 or 4 position, and their prodrugs and pharmaceutically acceptable salts, and solvates (e. g. hydrates) of compounds of formula (Ia) and their prodrugs.

Compounds of formula (Ia) in which R4 represents straight or branched C1-10alkyl (e. g. methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, n-pentyl, i-pentyl, n-hexyl, n-heptyl, n-octyl, 1,5-dimethylhexyl, n-nonyl, or n-decyl) are preferred.

Compounds of formula (Ia) in which R4 represents straight or branched CI-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is aryl are also preferred.

Exemplary aryl groups include phenyl optionally substituted by one or more"aryl group substituents", for example alkoxyphenyl, dialkoxyphenyl, arylalkyloxy (akoxy) phenyl, halophenyl, dialkylaminophenyl, trifluoromethyl and methanesulphonylphenyl. Compounds of formula (Ia) in which R4 represents straight or branched C1-3alkyl substituted by diCl.3alkoxyphenyl, particularly 3,4-diC1-3alkoxybenzyl (e. g. 3,4-dimethoxybenzyl 3,4-diethoxybenzyl and 3-ethoxy-4-methoxybenzyl), are especially preferred.

Compounds of formula (Ia) in which R4 represents straight or branched Chalky ! (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is heteroaryl are also preferred.

Exemplary heteroaryl groups include indolyl, imidazolyl, pyridyl and furyl. Compounds of formula (Ia) in which R4 represents straight or branched C1 3alkyl substituted by azaheteroaryl, particularly 3- (imidazol-1-yl)-C1 3alkyl (e. g. 3- (imidazol-1-yl)-propyl), are especially preferred.

Compounds of formula (Ia) in which R4 represents straight or branched Cl. 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is C3 gcycloalkyl are also preferred. Compounds of formula (Ia) in which R4 represents straight or branched Chalky ! substituted by CS 6cycloalkyl groups are especially preferred.

Compounds of formula (Ia) in which R4 represents straight or branched C1-6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is C1 6alkoxy, especially C1 4alkoxy (e. g. methoxy), are also preferred.

Compounds of formula (Ia) in which R4 represents straight or branched Cl 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is halo are also preferred.

Compounds of formula (Ia) in which R4 represents straight or branched C1 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is an acidic functional group are also preferred. Compounds of formula (Ia) in which R4 is straight or branched C1-3alkyl substituted by carboxy are especially preferred.

Compounds of formula (Ia) in which R4 represents straight or branched C1 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by R5, where R5 is heterocycloalkyl are also preferred. Compounds of formula (Ia) in which R4 represents straight or branched C1-3alkyl substituted by benzodioxolyl and benzodioxanyl are especially preferred.

Compounds of formula (Ia) in which R4 represents straight or branched C1 6alkyl (e. g. methyl, ethyl, n-propyl, i-propyl or n-butyl) substituted by-NYlY2 are also preferred. Exemplary -NYlY2 groups include acylamino, aryl (alkylamino) and-NYlY2 groups derived from 5-7 membered cyclic amines such as morpholine, piperidine, pyrrolidine and 2-oxo-pyrrolidine.

Compounds of formula (Ia) in which R4 represents straight or branched C1-3alkyl substituted by an N-linked 5-7 membered cyclic amine, especially 3- (2-oxo-pyrrolidin-1-Yl)-CI-3alkyl (e. g.

3- (2-oxo-pyrrolidin-1-yl)-propyl), are particularly preferred.

Compounds of formula (Ia) in which R4 represents C1 4alkenyl (e. g. allyl) are also preferred.

Compounds of formula (Ia) in which R9 represents a straight or branched CI-6alkylene chain, especially a straight or branched C1 4alkylene chain, more especially methylene, are preferred.

Compounds of formula (Ia) in which R1l represents hydrogen are preferred.

Compounds of formula (Ia) in which R11 represents straight or branched Cl 4alkyl, particularly methyl, are also preferred.

Compounds of formula (Ia) in which R11 represents straight or branched Cl 3alkyl substituted by R5, where R5 is aryl (e. g. phenyl), are also preferred. Compounds of formula (Ia) in which R1l represents straight chain C1 3alkyl substituted by phenyl are especially preferred.

Compounds of formula (Ia) in which R1l represents straight or branched C1-3alkyl substituted by R5, where R5 is heteroaryl, are also preferred. Exemplary heteroaryl groups include indolyl, imidazolyl, pyridyl and furyl. Compounds of formula (Ia) in which R1l represents straight chain C1 3alkyl substituted by azaheteroaryl (e. g. imidazolyl or pyridyl) are especially preferred.

Compounds of formula (Ia) in which R1l represents straight or branched Ci. gaikyi substituted by R5, where R5 is cycloalkyl (e. g. C3 gcycloalkyl), are also preferred. Exemplary C3 gcycloalkyl groups include cyclopentyl and cyclohexyl. Compounds of formula (Ia) in which RII represents straight chain C1-3alkyl substituted by cyclohexyl are especially preferred.

Compounds of formula (Ia) in which Rll represents straight or branched C1-3alkyl substituted by carboxy are also preferred.

Compounds of formula (Ia) in which Rll represents straight or branched C2.3alkyl (e. g. ethyl and n-propyl) substituted by-NYlY2 are also preferred. Exemplary-NYlY2 groups include acylamino, aryi (alkyl) amino and-NYlY2 groups derived from 5-7 membered cyclic amines such as pyrrolidine and 2-oxo-pyrrolidine. Compounds of formula (Ia) in which R11 represents ethyl or propyl substituted by 3-(2-oxo-pyrrolidin-1-yl), especially 3-(2-oxo-pyrrolidin-1-yl)-propyl, are preferred.

Compounds of formula (Ia) in which XI represents CR2 where R2 is C1-4alkyl or C1-4alkoxy (e. g. methyl or methoxy), especially methyl, are preferred.

Compounds of formula (Ia) in which X2 represents CR2 where R2 is hydrogen or C1 4alkoxy, especially methoxy, are also preferred.

Compounds of formula (Ia) in which Y represents carboxy are preferred.

The group-R9-C (=O)-N (R1l)-CH2-C (=O)-NR4-CH2-CH2-Y may preferably be attached at the ring 4 position.

A preferred group of compounds of the invention are compounds of formula (Ia) in which :- R4 is substitutedbyaryl(especially3,4-dimethoxyphenylC1-3alkyl),C1 -6alkylC1-10alkyl,C1-6alkyl substituted by heteroaryl (especially 3- (imidazol-1-yl)-propyl), C1 6alkyl substituted by cycloalkyl (especially cyclopentyl-and cyclohexyl-C1 3alkyl), C1 6alkyl substituted by heterocycloalkyl (especially C1 3alkyl substituted by benzodioxolyl and benzodioxanyl), C1-6alkyl substituted by C1 6alkoxy, C1 6alkyl substituted by halo, C1-6alkyl substituted by -NYlY2, [especially (2-oxo-pyrrolidin-1-yl) propyl], or C1.4alkenyl (e. g. allyl); Rll represents hydrogen, C1-4alkyl (especially methyl), C1-3alkyl substituted by aryl (especially phenylCl.3alkyl), C1.3alkyl C1.3alkyl substituted by heteroaryl (especially imidazol-1-ylC1 3alkyl and pyridylCl.3alkyl), C1_3alkyl C1_3alkyl substituted by C3-8cycloalkyl (especially cyclohexylC1-3alkyl), C1-3alkyl substituted by carboxy (especially-(CH2) 3CO2H), or C2 3alkyl substituted by -NYlY2 [especially (2-oxo-pyrrolidin-1-yl) propyl]; R9 represents a straight or branched C1 4alkylene chain, (preferably methylene); X1 represents CR2 where R2 is Chalky ! (especially methyl); X2 represent CR2 where R2 is C1 4alkoxy (e. g. methoxy); Y represents carboxy; and the group-R9-C (=O)-N (R1l)-CH2-C (=O)-NR4-CH2-CH2-Y is attached at the ring 4 position; and their prodrugs, and pharmaceutically acceptable salts and solvates (e. g. hydrates) of such compounds and their prodrugs.

Particular compounds of the invention are selected from the following: 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl)-N-methyl amino)-acetyl]-[3-(2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}-propionic acid, Compound A; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl)-N-methyl amino)-acetyl]-[3-(3-imidazol-1-yl)- prop-1-yl]-amino}-propionic acid, Compound B; 3-{(3,4-dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)p henyl]-acetyl}-N-methylamino)- acetyl]-amino}-propionic acid. Compound C;

3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-[3-(2-oxo-pyrrolidin-1-yl)- prop-1-yl]-amino}-propionic acid, Compound D; 3-[[2-(ethyl-m-tolyl-amino)-ethyl]-({2-[3-methoxy-4-(3-o-tol ylureido)phenyl]-acetylamino}- acetyl)-amino]-propionic acid, Compound E; <BR> <BR> 3- [ (2-acetylamino-ethyl)- (12- [3-methoxy-4- (3-o-tolylureido) phenyll-acetylamino)-acetyl)-aminol- propionic acid, Compound F; 3- [ (2-chloro-benzyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound G; 3- [ (3-methoxy-prop-1-yi)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound H; 3- [cyclohexylmethyl- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol-acetyl)-aminol- propionic acid, Compound I; 3-[(4-methoxy-benzyl)-({2-[3-methoxy-4-(3-o-tolylureido)phen yl]-acetylamino}-acetyl)-amino]- propionic acid, Compound J; 3- [isobutyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound K; 3- [ ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- (1-phenyl-ethyl)-amino]- propionic acid, Compound L; <BR> <BR> 3- { ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- [4- (5H-1,2,4- [1,2,3] thiadiazol- 4-yl)-benzyl]-amino}-propionic acid, Compound M; 3-[[1-(4-fluoro-phenyl)-ethyl]-({2-[3-methoxy-4-(3-o-tolylur eido)phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound N; 3-[(2-ethoxy-benzyl)-({2-[3-methoxy-4-(3-o-tolylureido)pheny l]-acetylamino}-acetyl)-amino]- propionic acid, Compound O; <BR> <BR> 3- [ ( {2- [3-methoxy-4- (3-o-tolylureido) phenyi]-acetylamino}-acetyl)- (2-pyridin-2-yl-ethyl)-amino]- propionic acid, Compound P; 3- [ [2- (3-bromo-4-methoxy-phenyl)-ethyl]- (12- [3-methoxy-4- (3-o-tolylureido) phenyll- acetylamino}-acetyl)-amino]-propionic acid, Compound Q; <BR> <BR> 3- [ (3-methoxy-benzyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound R; 3-[(2-methoxy-ethyl)-({2-[3-methoxy-4-(3-o-tolylureido)pheny l]-acetylamino}-acetyl)-amino]- propionic acid, Compound S; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(3-methyl-butyl)-amino]- propionic acid, Compound T;

3-{({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-[2-(4-phenoxy-phenyl)-ethyl]- amino}-propionic acid, Compound U; 3-[(2-benzo[1,3]dioxol-5-yl-ethyl)-({2-[3-methoxy-4-(3-o-tol ylureido)phenyl]-acetylamino}- acetyl)-amino]-propionic acid, Compound V; 3-[butyl-({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylami no}-acetyl)-amino]-propionicacid, Compound W; 3- [ [2- (3, 5-dimethoxy-phenyl)-ethyl]- (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol- acetyl)-amino]-propionic acid, Compound X; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(furan-2-y-methyl)-amino]- propionic acid, Compound Y; <BR> <BR> 3- [allyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound Z; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-pyridin-3-ylmethyl-amino]- propionic acid, Compound AA; <BR> <BR> 3- [ (3-chloro-prop-1-yl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound AB; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(3-phenyl-prop-1-yl)-amino]- propionic acid, Compound AC; <BR> <BR> 3- [ (2-methoxy-benzyl)- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino)-acetyl)-amino]- propionic acid, Compound AD; 3- [ ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- (2-morpholin-4-yl-ethyl)- amino]-propionic acid, Compound AE; <BR> <BR> 3- [ (4-methanesulfonyl-benzyl)- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino)-acetyl)- amino]-propionic acid, Compound AF; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-methyl-amino]-propionicacid, Compound AG; <BR> <BR> 3-1 (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino)-acetyl)- [2- (naphthalen-2-ylamino)- ethyl]-amino}-propionic acid, Compound AH; 3- [ [2- (2, 3-dimethoxy-phenyl)-ethyl]- ( {{2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}- acetyl)-amino]-propionic acid, Compound AI; 3-[(2-diethylamino-ethyl)-({2-[3-methoxy-4-(3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound AJ; <BR> <BR> 3- [ (1, 5-dimethyl-hexyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound AK :

3- [ (12- [3-methoxy-4- (3-o-tolylureido) phenyll-acetylamino)-acetyl)-pentyl-amino]-propionic acid, Compound AL; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-octyl-amino]-propionicacid, Compound AM; 3-[[2-(2h-indol-3-yl)-ethyl]-({2-[3-methoxy-4-(3-o-tolylurei do)phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound AN; 3-[(2,3-dimethoxy-benzyl)-({2-[3-methoxy-4-(3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound AO; 3-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetylamino}-acetyl)-prop-1-yl-amino]-propionic acid, Compound AP; 3-[(3,3-diphenyl-prop-1-yl)-({2-[3-methoxy-4-(3-o-tolylureid o)phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound AQ; 3-[(2,2-diphenyl-ethyl)-({2-[3-methoxy-4-(3-o-tolylureido)ph enyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound AR; <BR> <BR> 3- [ [2- (5-methoxy-2h-indol-3-yl)-ethyl]- (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol- acetyl)-amino]-propionic acid, Compound AS; 3- [ (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol-acetyl)- (4-phenyl-butyl)-amino]- propionic acid, Compound AT; <BR> <BR> 3- [hexyl- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol-acetyl)-amino]-propionic acid, Compound AU; <BR> <BR> 3- [benzo [1,3] dioxol-5-ylmethyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound AV; <BR> <BR> 3- [ (2-acetylamino-ethyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound AW; 3-{({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-[2-(4-nitro-phenyl)-ethyl]- amino}-propionic acid, Compound AX; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(2-oxo-azepan-3-yl)-amino]- propionic acid, Compound AY; 3- [ (3, 5-dimethoxy-benzyl)- (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino)-acetyl)- amino]-propionic acid, Compound AZ; <BR> <BR> 3- [ (3-dimethylamino-prop-1-yl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound BA; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-naphthalen-1-ylmethyl- amino]-propionic acid, Compound BB;

3- [ (1-cyclohexyl-ethyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound BC; 3-[N-(3,4-dimethoxybenzyl)-2-{2-[3-methoxy-4-(3-o-tolylureid o)phenyl]acetylamino}acetamido]- propionic acid, alternative name: 3- [ (3, 4-dimethoxy-benzyl)- ( (2- [3-methoxy-4- (3-o-tolyl-ureido)- phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound BD; 3- [ (2-diethylamino-ethyl)- (12- [3-methoxy-4- (3-o-tolylureido) phenyll-acetylaminol-acetyl)- amino]-propionic acid, Compound BE; 3- [ (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino)-acetyl)- (4-nitro-benzyl)-aminol- propionic acid, Compound BF; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(2-piperidin-1-yl-ethyl)- amino]-propionic acid, Compound BG; <BR> <BR> 3- [benzyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound BH; <BR> <BR> 3- [cyclohexyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound BI; 3-[isobutyl-({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl amino}-acetyl)-amino]-propionic acid, Compound BJ; 3{(3-imidazol-1-yl-prop-1-yl)--[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid, Compound BK; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(4-trifluoromethyl-benzyl)- amino]-propionic acid, Compound BL; 3- [ (2-methoxy-ethyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]- propionic acid, Compound BM; <BR> <BR> 3- { ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- [2- (7-methyl-2h-indol-3-yl)- ethyl]-amino}-propionic acid, Compound BN; 3-[(4-dimethylamino-benzyl)-({2-[3-methoxy-4-(3-o-tolylureid o)phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound BO; <BR> <BR> 3- [isopropyl- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound BP; 3-[(6-chloro-2-phenoxy-phenylmethyl)-({2-[3-methoxy-4-(3-o-t olylureido)phenyl]-acetylamino}- acetyl)-amino]-propionic acid, Compound BQ; <BR> <BR> 3- [ ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-phenethyl-amino]-propionic acid, Compound BR; 3-[({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(1-methyl-2-phenoxy-ethyl)- amino]-propionic acid, Compound BS;

3-[[2-(5-methoxy-2H-indol-3-yl)-ethyl]-({2-[3-methoxy-4-(3-o -tolylureido)phenyl]-acetylamino}- acetyl)-amino]-propionic acid, Compound BT; <BR> <BR> 3- [ ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- (3-phenyl-prop-1-yl)-amino]- propionic acid, Compound BU; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-prop-1-y lamino)-acetyl]-[3-(2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}-propionic acid, Compound BV; Compounds BW to KV; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-(3-carboxy-prop-1- yl)-amino}-propionic acid; Compound KW; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-[2-(2-oxo- pyrrolidin-1-yl)-ethyl]-amino}-propionic acid; Compound KX; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-(3-carboxy-prop-1-yl)- amino}-propionic acid; Compound LA; 3-{[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]-[2-(2-oxo- pyrrolidin-1-yl)-ethyl]-amino}-propionic acid; Compound LB; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-(2-carboxy-ethyl)-amino}- propionic acid; Compound LC; 3-{(2, 3-dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid; Compound AO; 3-{[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-phenyl-amino}-propionic acid; Compound LD; <BR> <BR> 3-{(3-ethoxy-4-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido) phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid; Compound LE; <BR> <BR> 3-{(3, 4-diethoxy-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid; Compound LF; 3-{(4-benzyloxy-3-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolyl ureido)phenyl]-acetyl}-amino)- acetyl]-amino}-propionic acid; Compound LG; 3-{[(1,4-benzodioxan-6-yl)-methyl]-[({[3-methoxy-4-(3-o-toly lureido)phenyl]-acetyl}-amino)- acetyl]-amino}-propionic acid; Compound LH; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-(3-methanesulphonylamino- prop-1-yl)-amino}-propionic acid; Compound LI; <BR> <BR> 3- [ (4-dimethylamino-benzyl)- [ (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetvl)-amino)-acetyl]- N-methylamino]-propionic acid; 3-{(3-nitro-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl] -acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LJ;

3-{(2-thienylmethyl)({[3-methoxy-4-(3-o-tolylureido)phenyl]- acetyl}-N-methylamino}-acetyl)- amino}-propionic acid, Compound LK; 3-{(2-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)pheny l]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid; Compound LL; <BR> <BR> 3-{(4-methyl-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LM; 3-{(3,4-methylenedioxy-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido)phenyl]-acetyl}- N-methylamino)-acetyl]-amino}-propionic acid, Compound LN; 3-{(3,5-dimethoxy-benzyl)-{({[3-methoxy-4-(3-o-tolylureido)p henyl]-acetyl}-N-methylamino)- acetyl]-amino}-propionic acid, Compound LO; <BR> <BR> 3-{(2-pyridylmethyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LP; <BR> <BR> 3-{(2-furanylmethyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LQ; <BR> <BR> 3-{(2-ethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LR; <BR> <BR> 3-{(2-thienylmethyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LS; 3-{(4-pyridylmethyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl ]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LT; 3-{(2-pyridylmethyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl ]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LU; 3-{(3-nitro-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl] -acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LV; 3-{(3-pyridylmethyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl ]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LW; 3- { (4- [1,2,3-thiadiazol-4-yl]-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}- N-methylamino)-acetyl]-amino}-propionic acid, Compound LX; <BR> <BR> 3-{(4-pyridylmethyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LY; <BR> <BR> 3-{ (benzyl)-[( { [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]-amino}- propionic acid, Compound LZ; 3-{(2-bromo-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl] -acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound MA;

3-{(2-bromo-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound MB; 3-{(2-chloro-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound MC; 3-{(4-methanesulphonyl-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido)phenyl]acetyl}- N-methylamino)-acetyl]-amino}-propionic acid, Compound MD; and their prodrugs, and pharmaceutically acceptable salts and solvates (e. g. hydrates) of such compounds and their prodrugs.

Preferred compounds of the invention include: 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-[3-(2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}-propionic acid, Compound A; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-[3-(3-imidazol-1-yl)- prop-1-yl]-amino}-propionic acid, Compound B; 3-{(3,4-dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)p henyl]-acetyl}-N-methylamino)- acetyl]-amino}-propionic acid, Compound C; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-[3-(2-oxo-pyrrolidin-1-yl)- prop-1-yl]-amino}-propionic acid, Compound D; 3- [allyl- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)-amino]-propionic acid, Compound Z; 3-{({2-[3-methoxy-4-(3-o-tolylureido)phenyl]-acetylamino}-ac etyl)-(3-phenyl-prop-1-yl)-amino]- propionic acid, Compound AC; 3- [ (2, 3-dimethoxy-benzyl)- ( (2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol-acetyl)- amino]-propionic acid, Compound AO; 3- [ (12- [3-methoxy-4- (3-o-tolylureido) phenyll-acetylamino)-acetyl)- (4-phenyl-butyl)-amino]- propionic acid, Compound AT; 3- [N- (3, 4-dimethoxybenzyl)-2- {2- [3-methoxy-4- (3-o-tolylureido) phenyl] acetylamino} acetamido]- propionic acid, Compound BD; 3 {(3-imidazol-1-yl-prop-1-yl)--[({[3-methoxy-4-(3-o-tolylurei do) phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid, Compound BK; 3- [ (4-dimethylamino-benzyl)- ( {2- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylamino}-acetyl)- amino]-propionic acid, Compound BO; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-(3-carboxy-prop-1- yl)-amino}-propionic acid; Compound KW;

3-{[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]-[2-(2-oxo- pyrrolidin-1-yl)-ethyl]-amino}-propionic acid; Compound KX; 3-{(3, 4-dimethoxy-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid; Compound KY; 3-{ [({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-(3-carboxy-prop-1-yl)- amino}-propionic acid; Compound LA; 3-{[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-(2-carboxy-ethyl)-amino}- propionic acid; Compound LC; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-phenyl-amino}-propionic acid; Compound LD; 3-{(3-ethoxy-4-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido)phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid; Compound LE; <BR> <BR> 3-{(3, 4-diethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid; Compound LF; 3-{(4-benzyloxy-3-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolyl ureido)phenyl]-acetyl}-amino)- acetyl]-amino}-propionic acid; Compound LG; 3-{[(1,4-benzodioxan-6-yl)-methyl-[({[3-methoxy-4-(3-o-tolyl ureido)phenyl]-acetyl}-amino)- acetyl]-amino}-propionic acid; Compound LH; <BR> <BR> 3-{ [({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-(3-methanesulphonylamino- prop-1-yl)-amino}-propionic acid; Compound LI; 3-{(3-nitro-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LJ; 3-{(2-thienylmethyl)-({[3-methoxy-4-(3-o-tolylureido)phenyl] -acetyl}-N-methylamino}-acetyl)- amino}-propionic acid, Compound LK; 3-{(2-methoxy-benzyl)-{({[3-methoxy-4-(3-o-tolylureido)pheny l]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid; Compound LL; 3-{(4-methyl-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl ]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LM; 3-{(3,4-methylenedioxy-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido)phenyl]-acetyl}- N-methylamino)-acetyl]-amino}-propionic acid, Compound LN; 3-{(3,5-dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)p henyl]-acetyl}-N-methylamino)- acetyl]-amino}-propionic acid, Compound LO; 3-{(2-pyridylmethyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl ]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LP;

3-{ (2-furanylmethyl)-[({ [3-methoxy-4-(3-o-tolylu reido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LQ; 3-{(2-ethoxy-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- amino}-propionic acid, Compound LR; 3-{(2-thienylmethyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LS; 3-{(4-pyridylmethyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]-amino}- propionic acid, Compound LT; and their prodrugs, and pharmaceutically acceptable salts and solvates (e. g. hydrates) of such compounds and their prodrugs.

Especially preferred compounds of the invention include: 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-[3-(2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}-propionic acid, Compound A; 3-{(3, 4-dimethoxy-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)- acetyl]-amino}-propionic acid, Compound C; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-a cetyl]-[3-(2-oxo-pyrrolidin-1-yl)- prop-1-yl]-amino}-propionic acid, Compound D; 3- [ (2, 3-dimethoxy-benzyl)- (12- [3-methoxy-4- (3-o-tolylureido) phenyl]-acetylaminol-acetyl)- amino]-propionic acid, Compound AO; 3- [N- (3, 4-dimethoxybenzyl)-2- {2- [3-methoxy-4- (3-o-tolylureido) phenyl] acetylamino} acetamido]- propionic acid, Compound BD; 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-(3-carboxy-prop-1- yl)-amino}-propionic acid; Compound KW; 3-{(3-ethoxy-4-methoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylure ido)phenyl]-acetyl}-amino)-acetyl]- amino}-propionic acid; Compound LE; 3-{(3,4-diethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)ph enyl]-acetyl}-amino)-acetyl]-amino}- propionic acid; Compound LF; and their prodrugs, and pharmaceutically acceptable salts and solvates (e. g. hydrates) of such compounds and their prodrugs.

The compounds of the invention exhibit useful pharmacological activity and accordingly are incorporated into pharmaceutical compositions and used in the treatment of patients suffering from certain medical disorders. The present invention thus provides, according to a further

aspect, compounds of the invention and compositions containing compounds of the invention for use in therapy.

Compounds within the scope of the present invention block the interaction of the ligand VCAM-1 to its integrin receptor VLA-4 (a4ßl) according to tests described in the literature and described in vitro and in vivo procedures hereinafter, and which tests results are believed to correlate to pharmacological activity in humans and other mammals. Thus, in a further embodiment, the present invention provides compounds of the invention and compositions containing compounds of the invention for use in the treatment of a patient suffering from, or subject to, conditions which can be ameliorated by the administration of an inhibitor of o4pl mediated cell adhesion. For example, compounds of the present invention are useful in the treatment of inflammatory diseases, for example joint inflammation, including arthritis, rheumatoid arthritis and other arthritic conditions such as rheumatoid spondylitis, gouty arthritis, traumatic arthritis, rubella arthritis, psoriatic arthritis and osteoarthritis.

Additionally, the compounds are useful in the treatment of acute synovitis, autoimmune diabetes, autoimmune encephalomyelitis, collitis, atherosclerosis, peripheral vascular disease, cardiovascular disease, multiple sclerosis, asthma, psoriasis restenosis, myocarditis, inflammatory bowel disease and melanoma cell division in metastasis.

A special embodiment of the therapeutic methods of the present invention is the treating of asthma.

Another special embodiment of the therapeutic methods of the present invention is the treating of joint inflammation.

Another special embodiment of the therapeutic methods of the present invention is the treating of inflammatory bowel disease.

According to a further feature of the invention there is provided a method for the treatment of a human or animal patient suffering from, or subject to, conditions which can be ameliorated by the administration of an inhibitor of the interaction of the ligand VCAM-1 to its integrin receptor VLA-4 (a4ßl), for example conditions as hereinbefore described, which comprises the administration to the patient of an effective amount of compound of the invention or a composition containing a compound of the invention."Effective amount"is meant to describe

an amount of compound of the present invention effective in inhibiting the interaction of the ligand VCAM-1 to its integrin receptor VLA-4 (o4j3l), and thus producing the desired therapeutic effect.

References herein to treatment should be understood to include prophylactic therapy as well as treatment of established conditions.

The present invention also includes within its scope pharmaceutical compositions comprising at least one of the compounds of the invention in association with a pharmaceutically acceptable carrier or excipient.

Compounds of the invention may be administered by any suitable means. In practice compounds of the present invention may generally be administered parenterally, topically, rectally, orally or by inhalation, especially by the oral route.

Compositions according to the invention may be prepared according to the customary methods, using one or more pharmaceutically acceptable adjuvants or excipients. The adjuvants comprise, inter alia, diluents, sterile aqueous media and the various non-toxic organic solvents.

The compositions may be presented in the form of tables, pills, granules, powders, aqueous solutions or suspensions, injectable solutions, elixirs or syrups, and can contain one or more agents chosen from the group comprising sweeteners, flavourings, colourings, or stabilisers in order to obtain pharmaceutically acceptable preparations. The choice of vehicle and the content of active substance in the vehicle are generally determined in accordance with the solubility and chemical properties of the active compound, the particular mode of administration and the provisions to be observed in pharmaceutical practice. For example, excipients such as lactose, sodium citrate, calcium carbonate, dicalcium phosphate and disintegrating agents such as starch, alginic acids and certain complex silicates combined with lubricants such as magnesium stearate, sodium lauryl sulphate and talc may be used for preparing tables. To prepare a capsule, it is advantageous to use lactose and high molecular weight polyethylene glycols. When aqueous suspensions are used they can contain emulsifying agents or agents which facilitate suspension.

Diluents such as sucrose, ethanol, polyethylene glycol, propylene glycol, glycerol and chloroform or mixtures thereof may also be used.

For parenteral administration, emulsions, suspensions or solutions of the products according to the invention in vegetable oil, for example sesame oil, groundnut oil or olive oil, or

aqueous-organic solutions such as water and propylene glycol, injectable organic esters such as ethyl oleate, as well as sterile aqueous solutions of the pharmaceutically acceptable salts, are used. The solutions of the salts of the products according to the invention are especially useful for administration by intramuscular or subcutaneous injection. The aqueous solutions, also comprising solutions of the salts in pure distilled water, may be used for intravenous administration with the proviso that their pH is suitably adjusted, that they are judiciously buffered and rendered isotonic with a sufficient quantity of glucose or sodium chloride and that they are sterilised by heating, irradiation or microfiltration.

For topical administration, gels (water or alcohol based), creams or ointments containing compounds of the invention may be used. Compounds of the invention may also be incorporated in a gel or matrix base for application in a patch, which would allow a controlled release of compound through the transdermal barrier.

For administration by inhalation compounds of the invention may be dissolved or suspended in a suitable carrier for use in a nebuliser or a suspension or solution aerosol, or may be absorbed or adsorbed onto a suitable solid carrier for use in a dry powder inhaler.

Solid compositions for rectal administration include suppositories formulated in accordance with known methods and containing at least one compound of the invention.

The percentage of active ingredient in the compositions of the invention may be varied, it being necessary that it should constitute a proportion such that a suitable dosage shall be obtained.

Obviously, several unit dosage forms may be administered at about the same time. The dose employed will be determined by the physician, and depends upon the desired therapeutic effect, the route of administration and the duration of the treatment, and the condition of the patient.

In the adult, the doses are generally from about 0.001 to about 50, preferably about 0.001 to about 5, mg/kg body weight per day by inhalation, from about 0.01 to about 100, preferably 0.1 to 70, more especially 0.5 to 10, mg/kg body weight per day by oral administration, and from about 0.001 to about 10, preferably 0.01 to 1, mg/kg body weight per day by intravenous administration. In each particular case, the doses will be determined in accordance with the factors distinctive to the subject to be treated, such as age, weight, general state of health and other characteristics which can influence the efficacy of the medicinal product.

The compounds according to the invention may be administered as frequently as necessary in order to obtain the desired therapeutic effect. Some patients may respond rapidly to a higher or lower dose and may find much weaker maintenance doses adequate. For other patients, it may be necessary to have long-ter treatments at the rate of 1 to 4 doses per day, in accordance with the physiological requirements of each particular patient. Generally, the active product may be administered orally 1 to 4 times per day. Of course, for some patients, it will be necessary to prescribe not more than one or two doses per day.

Compounds of the invention may be prepared by the application or adaptation of known methods, by which is meant methods used heretofore or described in the literature, for example those described by R. C. Larock in Comprehensive Organic Transformations, VCH publishers, 1989.

In the reactions described hereinafter it may be necessary to protect reactive functional groups, for example hydroxy, amino, imino, thio or carboxy groups, where these are desired in the final product, to avoid their unwanted participation in the reactions. Conventional protecting groups may be used in accordance with standard practice, for examples see T. W. Greene and P. G. M. Wuts in"Protective Groups in Organic Chemistry"John Wiley and Sons, 1991.

Thus, for example, compounds of formula (I), wherein RI, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is carboxy, may be prepared by hydrolysis of esters of formula (I), wherein RI, Xl, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is-CO2R12 group (in which R12 is alkyl, alkenyl or arylalkyl). The hydrolysis may conveniently be carried out by alkaline hydrolysis using a base, such as an alkali metal hydroxide, e. g. lithium hydroxide, or an alkali metal carbonate, e. g. potassium carbonate, in the presence of an aqueous/organic solvent mixture, using organic solvents such as dioxan, tetrahydrofuran or methanol, at a temperature from about ambient to about reflux. The hydrolysis of the esters may also be carried out by acid hydrolysis using an inorganic acid, such as hydrochloric acid, in the presence of an aqueous/inert organic solvent mixture, using organic solvents such as dioxan or tetrahydrofuran, at a temperature from about 50°C to about 80°C.

As another example compounds of formula (1), wherein RI, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is carboxy, may be prepared by acid catalysed removal of the tert-butyl group of tert-butyl esters of formula (I), wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is-CO2R12 (in which R12 is -CO2tBu), using standard reaction conditions.

In a process A compounds of formula (1), wherein Rl, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is carboxy, may be prepared by coupling of an acid (or an acid halide) with an amine to give an amide bond within R3 using standard peptide coupling procedures as described hereinafter.

As an example of process A, compounds of formula (I), wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is carboxy, may be prepared by:- (i) treating Wang resin (4-hydroxymethylphenoxylated styrene/divinylbenzene copolymer) with acryloyl chloride, in the presence of a tertiary amine, such as diisopropylethylamine, in an inert solvent, such as dichloromethane, at a temperature at about room temperature, to give Resin A: 0 0 0 acryolyl chloride 0 HO 0 (Wang Resin) (Resin A)

where represents the polymeric core comprising polystyrene crosslinked with 1% to 2% divinylbenzene.

(ii) reaction of Resin A with amines of formula (II), wherein R4 is as defined hereinbefore, in the presence of a base, such as a tertiary organic base, for example diisopropylethylamine, in dimethylformamide and at a temperature at about room temperature, to give Resin 1, in which R4 and definedhereinbefore: are as

(Resin A) (Resin 1) (iii) reaction of Resin 1 with compounds of formula (III)

wherein R1, X1, X2 and X6 are as hereinbefore defined, one of X7, X8 and X9 represents CR14 [in which R14 is -L1-(CH2)n-CO2H (in which L1 and n are as

hereinbefore defined)], and the others independently represent N or CR2 (in which R2 is as hereinbefore defined), in the presence of 0- (7-azabenzotriazol-1-yi)- 1,1,3,3-tetramethyluronium hexafluorophosphate and diisopropylethylamine in dimethylformamide, at room temperature, to give resin 2 wherein R4, R9, n and are as hereinbefore defined and R15 represents a monovalent radical derived from (III) in which R1, X1, X2 and X6 are as hereinbefore defined, one of X7, X8 and X9 represents CH and the others independently represent N or CR2 (in which R2 is as hereinbefore defined) by removing one of the hydrogen atoms from X7, X8 or X9:

(Resin 2) (iv) Resin 2 may then be treated with trifluoroacetic acid in an inert solvent such as dichloromethane and at a temperature at about room temperature.

As another example of process A, compounds of formula (I), wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the L1 and Y moieties within one of X3, X4 and X5 are-R9-C (=O)-NH- (where R9 is as hereinbefore defined) and carboxy respectively, may be prepared by:-

(i) treating Resin 1, wherein R4 and are as hereinbefore defined, with a suitably protected amino-acid of formula (IV), wherein R13 is a suitable amino protecting group (such as 9-fluorenylmethoxycarbonyl, FMOC) and n is as hereinbefore defined, in the presence of 0- (7-azabenzotriazol-1-yl)-1, 1,3,3- tetramethyluronium hexafluorophosphate and diisopropylethylamine in dimethylformamide, at room temperature to give Resin 3, wherein R4 and are as hereinbefore defined:

(Resin 3) (ii) The resulting Resin 3, may then be deprotected, for example by treating with piperidine in dimethylformamide, at room temperature, to give Resin 4, wherein R4, n and are as hereinbefore defined:

(Resin 4) (iii) Resin 4 may then be treated with compounds of general formula (III), wherein RI, XI, X2 and X6 are as hereinbefore defined, one of X7, x8 and X9 represents CR14 [in which R14 is-R9-CO2H (where R9 is as hereinbefore defined)], and the others independently represent N or CR2 (in which R2 is as hereinbefore defined), using standard peptide coupling procedures, for example those described hereinabove, to give resin 5, wherein R4, R9, R15, n and are as hereinbefore defined: (Resin 5)

(iv) Resin 5 may then be treated with trifluoroacetic acid in an inert solvent such as dichloromethane and at a temperature at about room temperature.

As another example of process A, compounds of formula (1), wherein Ri, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the L1 and Y moieties within one of X3, X4 and X5 are-R9-C (=O)-(NR1l)- (where R9 and Rll is as hereinbefore defined) and carboxy respectively, may be prepared by:- (i) treating Resin 1, wherein R4 and are as hereinbefore defined, with compounds of formula (V), wherein n is as hereinbefore defined and X10 is a halogen atom, preferably bromine, using standard peptide coupling procedures, for example those described hereinabove, to give Resin 6: (Resin 6) (ii) Reaction of Resin 6 with amines of formula (VI), wherein RII is as hereinbefore defined, in an inert solvent such as dimethyl sulphoxide, and at a temperature at about 80°C. to give Resin 7, wherein R4, R1l n and are as hereinbefore defined:

(Resin 7) (iii) Resin 7 may then be treated with compounds of general formula (III), wherein RI, Xl, X2 and X6 are as hereinbefore defined, one of X7, X8 and X9 represents CR14 [in which R14 is-R9-CO2H (where R9 is as hereinbefore defined)], and the others independently represent N or CR2 (in which R2 is as hereinbefore defined), using standard peptide coupling procedures, for example those described hereinabove, to give resin 8 wherein R4, R9, Rll, R15, n and are as hereinbefore defined: (Resin 8)

(iv) Resin 8 may then be treated with trifluoroacetic acid in an inert solvent such as dichloromethane and at a temperature at about room temperature.

Esters of formula (I), wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined and where Y moiety within one of X3, X4 and X5 is a-CO2R12 group (in which R12 is as hereinbefore defined), may be prepared by reaction of compounds of formula (III), wherein R1, X1, X2 and X6 are as hereinbefore defined, one of X7, X8 and X9 represents C-R14 [in which R14 is -L1-(CH2) n-C (=O) X" (where L1 and n are as hereinbefore defined and X11 is a hydroxy group, or a halogen, preferably chlorine, atom)] and the others independently represent N or CR2 (where R2 is as hereinbefore defined), with amines of formula (VII):- R4-HN-CH2-CH2-Co2R12 (VII) wherein R4 and R12 are as hereinbefore defined. When X11 is a hydroxy group the reaction may be carried out using standard peptide coupling procedures as described hereinbefore.

When X11 is a halogen atom the reaction may be carried out with the aid of a base, such pyridine, preferably in a solvent such as tetrahydrofuran and at a temperature at about room temperature.

According to a further process B compounds of the invention may be prepared by interconversion of other compounds of the invention.

For example compounds of formula (I) wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is-C (=O)-NHOH, may be prepared by reaction of compounds of formula (1), wherein R1, X1, X2, X3, X4, X5 and X6 are as hereinbefore defined, and where the Y moiety within one of X3, X4 and X5 is carboxy, with hydroxylamine using standard peptide coupling procedures such as treatment with a carbodiimide, for example dicyclohexylcarbodiimide, in the presence of triethylamine, in an inert solvent such as dichloromethane or tetrahydrofuran and at a temperature at about room temperature. The coupling may also be carried out using 1-hydroxybenzotriazole and 1- (3-dimethylaminopropyl)-3-ethycarbodiimide in dichloromethane at room temperature. The preparation may also be carried out using an O-protected hydroxylamine such as

0- (trimethylsilyl) hydroxylamine, 0- (t-butyidimethylsilyl)-hydroxylamine, or 0- (tetrahydropyranyl) hydroxylamine followed by treatment with acid.

As another example of the interconversion process, compounds of formula (I) containing sulphoxide linkages may be prepared by the oxidation of corresponding compounds containing -S-linkages. For example, the oxidation may conveniently be carried out by means of reaction with a peroxyacid, e. g. 3-chloroperbenzoic acid, preferably in an inert solvent, e. g. dichloromethane, preferably at or near room temperature, or alternatively by means of potassium hydrogen peroxomonosulphate in a medium such as aqueous methanol, buffered to about pH5, at temperatures between about 0°C and room temperature. This latter method is preferred for compounds containing an acid-labile group.

As another example of the interconversion process, compounds of formula (I) containing sulphone linkages may be prepared by the oxidation of corresponding compounds containing-S- or sulphoxide linkages. For example, the oxidation may conveniently be carried out by means of reaction with a peroxyacid, e. g. 3-chloroperbenzoic acid, preferably in an inert solvent, e. g. dichloromethane, preferably at or near room temperature.

It will be appreciated that compounds of the present invention may contain asymmetric centres.

These asymmetric centres may independently be in either the R or S configuration. It will be apparent to those skilled in the art that certain compounds of the invention may also exhibit geometrical isomerism. It is to be understood that the present invention includes individual geometrical isomers and stereoisomers and mixtures thereof, including racemic mixtures, of compounds of formula (I) hereinabove. Such isomers can be separated from their mixtures, by the application or adaptation of known methods, for example chromatographic techniques and recrystallisation techniques, or they are separately prepared from the appropriate isomers of their intermediates.

According to a further feature of the invention, acid addition salts of the compounds of this invention may be prepared by reaction of the free base with the appropriate acid, by the application or adaptation of known methods. For example, the acid addition salts of the compounds of this invention may be prepared either by dissolving the free base in water or aqueous alcohol solution or other suitable solvents containing the appropriate acid and isolating the salt by evaporating the solution, or by reacting the free base and acid in an organic solvent, in which case the salt separates directly or can be obtained by concentration of the solution.

The acid addition salts of the compounds of this invention can be regenerated from the salts by the application or adaptation of known methods. For example, parent compounds of the invention can be regenerated from their acid addition salts by treatment with an alkali, e. g. aqueous sodium bicarbonate solution or aqueous ammonia solution.

Compounds of this invention can be regenerated from their base addition salts by the application or adaptation of known methods. For example, parent compounds of the invention can be regenerated from their base addition salts by treatment with an acid, e. g. hydrochloric acid.

Compounds of the present invention may be conveniently prepared, or formed during the process of the invention, as solvates (e. g. hydrates). Hydrates of compounds of the present invention may be conveniently prepared by recrystallisation from an aqueous/organic solvent mixture, using organic solvents such as dioxan, tetrahydrofuran or methanol.

According to a further feature of the invention, base addition salts of the compounds of this invention may be prepared by reaction of the free acid with the appropriate base, by the application or adaptation of known methods. For example, the base addition salts of the compounds of this invention may be prepared either by dissolving the free acid in water or aqueous alcohol solution or other suitable solvents containing the appropriate base and isolating the salt by evaporating the solution, or by reacting the free acid and base in an organic solvent, in which case the salt separates directly or can be obtained by concentration of the solution.

The starting materials and intermediates may be prepared by the application or adaptation of known methods, for example methods as described in the Reference Examples or their obvious chemical equivalents.

Compounds of formula (III), wherein R1, X1, X2 and X6 are as hereinbefore defined, one of X7, X8 and X9 represents C-R14 (in which R14 is as described hereinabove, or a suitably protected derivative thereof) and the others independently represent N or CR10 (where R10 is as hereinbefore defined), may be prepared by the application or adaptation of methods described in prepared as described in the specification of International Patent Application Publication No.

WO 96/22966.

Intermediates of formulae (Resin 1), (Resin 2), (Resin 3), (Resin 4), (Resin 5), (Resin 6), (Resin 7) and (Resin 8) are novel compounds and, as such, they and their processes described herein for their preparation constitute further features of the present invention.

The present invention is further Exemplified but not limited by the following illustrative Examples and Reference Examples.

In the nuclear magnetic resonance spectra (NMR) the chemical shifts are expressed in ppm relative to tetramethylsilane. Abbreviations have the following significances: s = singlet; d = doublet; t = triplet; m = multiplet; dd = doublet of doublets; b = broad.

Mass spectra (MS) were recorded on a Micromass Platform II mass spectrometer fitted with an Electrospray source and an HP1100 liquid chromatograph; using a mixture of acetonitrile and water (1: 1, v/v) as the mobile phase, a flow rate of 0.3 ml/minute, an injection volume of 20R1, a run time of 2.0 minutes, a scan range of 150-850 Daltons Positive/Negative, a scan time of 2.0 seconds, an ESI voltage of 3.5Kv, an ESI pressure of 20n/m2 Nitrogen. Abbreviations have the following significances: w = weak.

EXAMPLE 1 Compounds A, B and C A solution of ({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetic acid [0.80g, Reference Example 1] and 3- [3- (2-oxo-pyrrolidin-1-yl)-prop-1-ylamino]-propionic acid ethyl ester [0.51g, Reference Example 2 (c)] in dimethylformamide (25ml) was treated with [0- (7-azabenzotriazol-1-yl)-1, 1,3,3,-tetramethyluronium hexafluorophosphate] (0.80g) and diisopropylethylamine (0.75m !). After stirring at room temperature for 2 hours the reaction mixture was treated with water (100ml) then extracted three times with ethyl acetate. The combined organic extracts were washed with hydrochloric acid (1M), then with brine, then dried over magnesium sulphate and then evaporated. The residual oil was subjected to flash chromatography on silica eluting with a mixture of dichloromethane and methanol (25: 1, v/v) to give 3- ( [ (1 [3-methoxy-4- (3-o-tolylureido) phenyll-acetyl)-N-methylamino)-acetyll- [3- (2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}-propionic acid ethyl ester as a colourless oil (0.76g). The ester was dissolved in tetrahydrofuran (50mi) and then treated with lithium hydroxide hydrate (0.065g) in water (lOml). After stirring at room temperature for 2 hours the mixture was concentrated to remove the tetrahydrofuran. The residual aqueous residue was washed with ethyl acetate then acidified by addition of hydrochloric acid (1M) and then extracted three times

with dichloromethane. The combined organic extracts were washed with brine, then dried over magnesium sulphate and then evaporated to give 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]- acetvl}-N-methvlamino)-acetvll-3- (2-oxo-pvrrolidin-1-vl)-prop-1-yll-aminol-propionic acid as a white solid (0.58g, Compound A), m. p. 73-76°C. [Elemental analysis:- C, 60.69; H, 6.85; N, 11.79%.

Calculated for C3oH39N507 sO. 67H20 :- C, 60.69; H, 6.69; N, 11.58%]. MS: 580 [MH]-. HPLC: RT=9.72 minutes (gradient elution using a mixture of acetonitrile and water 1: 4 to 4: 1).

(b) By proceeding in a manner similar to Example 1 (a) but using 3- (3-imidazol-1-yl-prop-1- ylamino)-propionic acid ethyl ester [Reference Example 2 (b)] there was prepared 3-{[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methyl amino)-acetyl]-[3-(3-imidazol-1-yl)- prop-1-vll-amino-propionic acid as a white solid (Compound B), m. p. 58-62°C. MS: 563 [MH]-.

HPLC: RT=9.70 minutes (gradient elution using a mixture of acetonitrile and water 1: 4 to 4: 1).

(c) By proceeding in a manner similar to Example 1 (a) but using 3- (3, 4-dimethoxy-benzylamino)- propionic acid ethyl ester [Reference Example 2 (a)] there was prepared 3-{(3,4-dimethoxy- benzvl)-f (f f3-methoxv-4- (3-o-tolvlureido) phenvll-acetyl-N-methvlamino)-acetvll-amino- propionic acid as a white solid (Compound C), m. p. 104-106°C. [Elemental analysis:- C, 62.19; H, 6.43; N, 8. 94% Calculated for C32H38N408 0.67H20:- C, 62.13; H, 6.40; N, 9.05%].

MS: 605 [MH]-. HPLC: RT=11.92 minutes (gradient elution using a mixture of acetonitrile and water 1: 4 to 4: 1).

EXAMPLE 2 Compounds D to BU Step 1. Wang resin (3.0g, 0.92mmol/g) was allowed to swell in dichloromethane (30mi) for 15 minutes, then treated with diisopropylethylamine (1.8ml) followed by acryloyl chloride (0. 9ml), The mixture was kept at room temperature for 3 hours with occasional gentle shaking then filtered to give resin A which was washed (i) three times with dichloromethane (15ml), (ii) three times with methanol (15moi), (iii) three times with dimethylformamide (15ml), (iv) three times with methanol (15ml), (v) three times with dichloromethane (15ml) and then dried in a desiccator under high vacuum for 2 hours.

Step 2. Resin A (40mg) was placed in a Jones tube, suspended in dimethylformamide (lml) and then treated with 1- (3-aminoprop-1-yl)-2-pyrrolidinone (50mg). After standing at room

temperature for 90 minutes the mixture was filtered to give resin B which was washed (i) four times with dimethylformamide (5ml), (ii) three times with methanol (5ml), (iii) dimethylformamide (5ml).

Step 3. Resin B from step 2 was treated with a solution of ({[3-methoxy-4-(3-o- tolylureido) phenyl]-acetyl}-amino]-acetic acid (30mg, Reference Example 3) in dimethyformamide (lml), and then with a solution of [0- (7-azabenzotriazol-1-yl)-1,1,3,3,- tetramethyluronium hexafluorophosphate] (30mg) in dimethylformamide (lml) and diisopropylethylamine (30ptl). After standing at room temperature for 3 hours with occasional agitation the mixture was filtered to give resin C which was washed (i) four times with dimethylformamide (5ml), (ii) three times with methanol (5ml), (iii) four times with dichloromethane (45ml) and then dried in a desiccator under vacuum for 2 hours.

Step 4. Resin C from step 3 was treated with a mixture of dichloromethane and trifluoroacetic acid (2ml, 1: 1 v/v). After standing at room temperature for 45 minutes the mixture was filtered, and the resin was washed with dichloromethane. The combined filtrate and washings were evaporated to give 3- (f3-methoxv-4- (3-o-tolvlureido) phenyll-acetvl}-amino)-acetvll-f3- (2-oxo- pyrrolidin-1-vl)-prop-1-vll-amino)-propionic acid (Compound D). MS: 568 [MH] +. HPLC: RT=3.11 minutes, area of main peak as a percentage of the total sample =96% (gradient elution using a mixture of acetonitrile and water 3: 7 to 17: 3 v/v).

By proceeding in a similar manner to Example 2, but using the appropriately substituted amines in step 2, there were prepared Compounds E to BU depicted in Table 1.

Table 1 Compound R4 MOLECULAR HPLC MH+ MH number FORMULA RT Me Compound E C33H41N506 4.5,95% 604 N (Et)- (CHZ) 2- [{ (CH) 2-C26H33N507 J 2.7,86% 528 526 1 --j Compound G C29H31C1N406 5. 4, 93% 567 565 H2 _ Compound H MeO- (CH)- C26H34N407 3. 6, 96% 515 513 Compound I aCH2-C29H38N406 5.7,98% 539 537 Compound J Me0 \ 5.0,85% 563 561 Compound K (CH3) ZCH-CHZ-C26H34N406 4. 6, 92% 499 497 Compound L \/CH (CH3)-C30H34N406 5.2,82 % 547w 545 S n Compound M I CH 2-C3lH32N606S 7.7,60% 617w 615 Zon Compound N Fß CH (CH3)-C30H33FN406 8.0,81% 565 563 omet OEt Compound O C31H36N407 5.6,97% Compound P \\- (CH- C29H33N506 2.7,96% 548 546 ZON Br Compound Q MeO C (CH2) 2-C31H35N4BrO7 5.8,95% 657 655 Met Compound R C30H34N407 5. 0, 89% 563 561 Chez- Compound S MeO- (CHZ) 2-C25H32N407 3.5,94 % 499 501 Compound T (CH3) 2CH- (CH2) 2- ; 2 w % 513 511 0ß3 (CH2) 2-_ Compound U C36H38N407 7.0,86% 639 637 Compound V O C31H34N408 7.8,68% 591 589 Compound W CH3- (CH2) 3-C26H34N406 4.7,97% 499 497 meo ompoundX 0\, H 2 z C32H38N408 5.4,88% 607 605 Met 0 Compound Y ¢CH2-C27H30N407 4.5,95% 523 521 Compound Z CH2=CH-CH2-C25H30N406 3.9,97% 483 481 N Compound AA (CH2-C28H31N506 2.6,95% 534 532 Compound AB C1- (CH2) 3-C25H31CIN406 4.5,95% 519 517 Compound AC < 2 3-C31H36N406 5.7,88% 561 559 OMe Compound AD C30H34N407 5.1,83% 563 561 cl 2- Compound AE -CH2 2.6,91% 556 554 Compound AF MeSO2 CH2-C30H34N408S 6.4,76% 611 609 Compound AG CH-C23H28N406 3. 2, 89% 455 Compound AH (n=\ C34H37N506 5.9,97% 612 610 5 (cx2 2) 2- Compound Al X Ici C32H38N408 5 3,96% 607 605 MeO OMe Compound AJ Et2N- (CH2) 2-C28H39N506 3. 0, 96% 542 540 Compound AK (CH3) zCH- (CHz) 3-CH (CH3)-C30H42N406 5. 3, 96% 555 553 Compound AL CH- (CH C27H36N406 5.2, >90% 513 511 Compound AM CHg- (CH- C30H42N406 7.4,93% 555 553 X- Compound AN C32H35N506 5.1,67% 586 584 han Han _ Compound AO C31H36N408 7.6,79% 593 591 MeO OMe Compound AP CH3- (CH2) 2-C25H32N406 4.1,98% 485 483 Compound AQ C37H40N406 6.9,96 % 637 635 (CH,),- Compound AR C36H38N406 6.4,96% 623 621 CH 2- OMe OMe Compound AS C33H37N507 5.0,82% 616 614 // CH2 - HN/ Compound AT //2) 4" C32H38N406 575 573 Compound AU CH 3- (CH 2) 5-C28H38N406 6. 0, >90% 527 525 CH 2- Compound AV C30H32N408 4.9,88% 577 575 0 Compound AW CH3C (=O) NH- (CH2) 2-C26H33N507 1.8,67% 528 526 Compound AX o2N (CH2) 2-C30H33NS08 7.9,74% 592 590 /-\CH Compound AY NA C28H35NS07 3.3, >95% 554 552 H O Met <-CH Compound AZ CHa-C31H36N408 5. 2,76% 593 591 MeO Compound BA Me 2N- (CH 2) 3- C27H37N506 2.6,93% 528 526 Compound BB C33H34N406 6.0,74% 583 581 CH2- Compound BC CH (CH3)-C30H40N406 A 553 552 MeO Compound BD Me0 CH- z C31 H36N408 4.7,87% 593 591 Compound BE Et2N- (CH2) 2 C28H39N506 I 9 % 542 540 Compound BF o2N ~ CH2-C29H31N508 7.7,76% 578 576 Compound BG N- (CHz) 2-C29H39N506 3.1,97% 554 552 Compound BH CHz-C29H32N406 5.0,96% 533 531 Compound BI \ CH-523 C28H36N406 5.0,97% 525 Compound BJ (CH3) 2CH-CH2-C26H34N406 4 6,95% 499 497 Compound BK N~N (CH2) 3-C28H34N606 2.6,98% 551 549 Nez Compound BL CF343CH2-C30H31F3N406 6.0,83% 601 599 Compound BM MeO- (cH2) 2-C25H32N407 35, 91 Y 501 499 i Me Compound BN CH2 2-C33H37N506 8.6,58% 598 HN// Compound BO Me2N/\ CHz-C31H37N506 1. 8, 83% 576 574 Compound BP (CH3) 2-CH-C25H32N406 3.9,95 % 485 483 OPh Compound BQ \ C35H35CIN407 6.7,88% 659 657 Cl Compound BR v (CH2) 2-C30H34N406 5.2,93 % 547 545 Compound BS 0-CH2-CH (CH3)-C31H36N407 5.5,88% 577 575 OMe i Compound BT CS C33H37N507 8.0,52% 614 (CH 2) 2- Compound BU CHa 8.4,85 % 561 559

EXAMPLE 3 Compounds BV to FJ T Step 1. Resin B from Step 2 Example 2 was treated with bromoacetic acid (0.47g) in dimethylformamide (7ml) and diisopropylcarbodiimide (0. 67ml). After standing at room temperature for 1.5 hours the mixture was filtered to give resin D which was washed.

Step 2. Resin D (100mg) was swelled with dimethyl sulphoxide (1.5ml) and then treated with propylamine (10 equivalents). After heating for 2 hours at 80°C the mixture was filtered to give resin E which was washed (i) three times with dimethylformamide, (ii) three times with tetrahydrofuran, (iii) three times with dichloromethane.

Step 3. Resin E was treated with a solution of [3-methoxy-4- (3-o-tolylureido) phenyl]-acetic acid (70 mg, Reference Example 5) in dimethylformamide (lml), a solution of [0- (7-azabenzotriazol- 1-yl)-1,1,3,3,-tetramethyluronium hexafluorophosphate] (75 mg) in dimethylformamide (lml), and diisopropylethylamine (100R1). After standing at room temperature for 2 hours with

occasional agitation the mixture was filtered to give resin F which was washed (i) four times with dimethylformamide, (ii) three times with methanol, (iii) three times with dichloromethane and then dried under vacuum.

Step 4. Resin F was treated with a mixture of dichloromethane and trifluoroacetic acid (2ml, 1: 1 v/v) and allowed to stand for 45 minutes. The mixture was filtered and the resin was washed with dichloromethane. The combined filtrate and washings were evaporated to give 3-j ( (f3-methoxv-4- (3-o-tolvlureido) phenvll-acetvl-prop-l-vlamino)-acetvll-f3- (2-oxo- pyrrolidin-1-vl)-prop-1-vll-amino}-propionic acid (Compound BV).

By proceeding in a similar manner to Example 3, but using the appropriately substituted amines in step 1 and the appropriately substituted amines step 3, there were prepared Compounds BW to FJ depicted in Table 2.

Table 2 Compound RII R4 MOLECULAR HPLC MH+ MH- Number FORMULA RT O-- Compound r ß CH2=CH-CH2-C32H41N507 2.7,80% 625 BW N- 3 (M+18) + Compound CH3C (=O)-NH- (CH2) 2-CX2=CH-CH2-C29H37N507 2. 5,78% 568 BX CON Compound/\ CH2-CHZ=CH-CH2-C31H35N506 2. 8,68%574 | BY _ l---] Compound CH3- (CH2) 2-CHz=CH-CHz-C28H36N406 6.7,100% 542 BZ BZ [M+18] + Compound CN (CH2) 2-CH2=CH-CH2-C31H41N506 2.0,100% 580 CA _ _ S C0nCPBUnd | O (CR,) 2-| CE22=CH-CH-| C32H 7NSO6 35I40% | 588 | INE 1 < (CH) I C ; 22=CN-CII-I CIIH38N O6 I 3 0 5% | SYI | ICompound (CH 2) 2-CH 2=CH-CH 2-C32H37N506 3. 5, 40% 588 CB Nez Cl CC O Compound CH3C (=O)-NH- (CHZ) z-C33H44N608 2.3,77% cn, N (CH2) 3- Com pou nd CH3C (=O)-NFi- (CH2) 2-CH3C (=O)-NH- (CHZ) 2-C30H40N608 2, 2, 79 %630 | f CE [M+181+ CN-- Compound/\ CH2-CH3C (=O)-NH- (CHZ) 2-C32H38N607 2. 4, 81 %619 | I CF Compound CH3- (CH2) 2-CFi3C (=O)-NH- (CH2) 2-C29H39N507 1.8,100% 570 CG Compound CN- (CHZ) 2-Cg3C =O)-NH- (CHZ) 2-C32H44N607 2. 4, 81 % 625 CH CL Compound (CH 2) 2- CH 3C (=O)-NH- (CH 2) 2- C33H4ON607 2. 3, 75% 633 NE N% Cri CJ ce Compound HO- (0=) C- (CH 2) 3- (CH 2) 2- C36H44N4010 6. 7,100%690 CKz MeOOMe 0 Compound (CH 2) 2- C39H49N509 6.8,100% 730 CL, N (CH2) 3 MeO OMe Compound CH 3C (=O)-NH- (CH2) 2- (CH 2) 2- C36H45N509 6.3,100% 689 CM MeOOMe .... _ Compound SCH2-¢T (CH2) 2- C38H43N508 6.8,81% 698 CN MeOOMe Compound CH 3- (CH 2) 2- (CH 2) 2- C35H44N408 8.5,100% 666 CO [M+18] + MeO OMe Compound N (CHZ) 2- \ (CFi2) 2-C38H49N508 6.9,100% 704 CP MeOOMe CN Compound (CH 2) 2- (CH2) 2-C39H45N508 6.7,89%712 | CQz Met orme N Compound J- (CH) 3-I S-(CH)-| C38H46N60 | 6 1 69% 715 CR Met orme - Compound Ho- (o=) C- (CHZ) 3- \ CHZ-C32H37N508 2. 1,22% 620 CS Cum ound CHz-C35H42N607 1. 8,82%657 Cl 2) 3- Zon Compound CH3C (=O)-NH- (CH)-y-CH-| C32H38N607 | 2.2,18% 619 CU 2 2-c Compound \ CHZ- \ CH- zC34H36N606 2. 2, 50% 625 CV N \ Compound CH3-(CH2) 2-<--CH2-C31H37N506 576 CW N Compound CN- (CHz) z- CH2-C34H42N606 2.1,16%631 f f CX _. _ Com ound/\ (CH)- P 2 Z-CHa-C35H38N606 639 CY j N Compound I, N (CHZ) 3-CHZ-C34H39N706 2.1,40% 642 CZ Compound HO- (O=) C- (CHZ) 3-/\ CHz'C33H37CIN408 7. 0, 100% 651 DU ci 0 Compound/\ CHa-C36H42CIN507 7.0,55% 709 D B N- (CHZ) 3- Cl [M+18] + Compound CH3C (=O)-NH- (CH2) -/\ CH2-C33H38CIN507 6. 6, 30°l0 650 DC \ 2.6,70% Cl C1 Compound/ CHZ-/\ CHz-C35H36CIN506 7.0,62% 566 | ; DD \ ci Compound CH3- (CHz) 2-/\ CHZ-C32H37C1N406 6. G, 64% 566 Du 8.7,46% Cl Compound CN- (CHa) z-/\ CHs-C35H42CIN506 7. 0, 50% 664 DF C1 ci Cl Compound/\CH2) 2-CH2 C36H38CIN506 6.8,53% 672 DG Cl Cl NS\ _ Compound W/N (CH2) 3-SCH2-C35H39CIN606 6.4,23% 675 Dix ci Cl O Compound HO- (O=) C- (CHz) 3-C33H43N509 2.5,46% 612 652 DI- (CH 2) 3- Compound C C36H48N608 710 DJ C ZN (CH2) 3-I (CH2) 3- (m+is) + 0 Compound CH3C (=0)-NH- (CH2),-< C33H44N608 2.3,86% 670 DK- (CH 2) 3- (M+1s+ _ Compound CHz-C35H42N607 2. 6,67% 659 DL CN- (CH 2) 3- DL N- (CHz) 3- O. Compound CH3- (CH2) 2-CY C32H43N507 2.0,61% 627 D M N- (CH) 3- 0 Compound CN- (CH 2) 2- C35H48N607 2.6,72% 665 | DN (CH 2) 3- Compound (CH 2) 2- C36H44N607 2. 5,67%673 UO N- (CH) 3 _ N- Cg _ Com ound s C35H45N707 5. 4, 76% 676 DP UN- (CH 2) 3- Compound HO- (O=) C- (CH2) 3-Me0/\ (CH=) s C35H42N4010 5.5,30% 612 DU Me0 0 Compound Me0/\ (CH 2) 2- C38H47N509 5. 4, 67% 701 DR N- (CH) 3 _ MeO Compound CH3C (=O)-NH- (CHz) Z- Me0/\ (CH3)- C35H43N509 678 DU Mes N Compound/ cHz-Me0/\ (CH3) C37H41N508 684 DT Me0 CompoundCH3- (CH2) 2- Me0/ (CH) DU/ [M+t8} + ne Meo IM+18] + CompoundCN- (CH 2) 2-meo (CH 2) 2- C37H47N508 5. 6, 50% 690 DV Me0 _, 84% 698 Compound/\ WHZ) Z-Me0, (CH)- MeO Du Me0 N Compound (,, N- (CHZ) 3-Me0 (CH2) z C37H44N608 2. 1, 100% 701 DX MeO Me0 N CompoundHO- (O=) C- (CHa) 3-I _. N- (CHa) 3-C32H40N608 2.3,41%, 637 DY dry N CompoundN- (CH2) 3-C35H45N707 2. 4, 55%, 676 DZ- (CH,),--- N Compound CH3C (=O)-NH- (CIiz) z-N- (CHZ) 3-C32H41N707 2. 2,55%636 EA Compound/\ CH2-I _, N- (CHs) 3-C34H39N706 2.2,34%, 642 _ EB N% ! Compound CH3- (CH2) 2-4XN (CH2) 3-C31H40N606 1.7,100% 593 EC N% ! Compound CN- (CHZ) 2-\ N- (CHZ) 3-C34H45N706 6.0,26%, 648 ED ex Compound (CH 2) 1- N- (CH 2) 3 C35H4lN706 2.1,72% 656 EE - Compound CN (CH2) 3-CN (CH2) 3-C34H42N806 2.1,66% 659 EF EF Compound__ _ _ _ EG8. 5, 34% EG 8. 5, 34% Compound (CFI)- \ z 3 C38H47N507 7. 4, 65 °la 703 EH N- CHz) 3 _ ... __ C35H43N507 7.0,71% 646 CompoundCH3C (=O)-NH- (CH2) 2- (CH)- El EI //C37H41N506 7.5,50%, 652 Compound CH 2 (CH 2) 3- 7. 8, 24%, EJ 8. 6, 27% 8.6,27% C34H42N406 8.9,72% 620 CompoundCH 3- (CH2) 2- (CH 2) 3- [M+181+ z 3 [M+18] + EK _ _ C37H47N506 7.5,5, S6% 658 Compound CN- (CHZ) z-/\ (CH2) 3-8. 6 38% EL /\ C38H43N506 7.3,65%, 666 Compound(CH 2) 2- (CH2) 3- 8. 6, 35% EM N=\ C3iH44N606 6.8,64%, 669 Compound , N- (CHz) a- 36% EN Compound S CH2-MeO X CH1 C38H42N408 14.1,89% 683 681 EX Me0 Compound CFi2-Meo/\ CFiz-C38H48N408 15.3,92% 689 687 EP EP/ MeO (,'onipound (CH 2) 2- MeO CH2-C39H44N408 14.5,84% 697 ___ EQ MeO Compound (CHi2) 3-Me0 \ CHz-C40H46N408 15.0,83% 711 709 ER MeOMe0 /\ CompoundCHZ-C36H431Y507 13. 4, 87% 658 656 ES N- (CHZ) 3 _ O Compound CHz-C36H49N507 14.5,88% 664 662 ET \ O Compound (CHZ) z'C37H45N507 13. 9,89% 672 670 Eu u \ O Compound/\ (CHz) 3-C38H47N507 686 684 EV"N- (CH,),- \ nez Compound CH 2-N- (CH2) 3- C35H4ON606 12.8,81% 641 639 EW ex Compound CHZ-. N- (CH2) 3-C35H46N606 13.9,30% 647 645 EX EX Compound/\ (CHZ) z-, N- (CHZ) 3-C36H42N606 13.2,51% 655 653 EY NS\ /\ nu Compound (CH2) 3-_, N- (CHa) 3-C37H44N606 13.7,45% 669 667 EZ Compound \ CH2-/\ (CH2) 3-C38H42N406 16.8,92% | I 0 FA Compound O-CH 2- (CH 2) 3- C38H48N406 18.1,92% 657 655 FB Compound (CHz) 2-/\ (CH2) 3-C39H44N406 17. 2,92% 665 663 FC Compound (CH 2) 3- (CH 2) 3- C40H46N406 17. 7, 86% 679 677 FD 0 Compound CH2-C38H47N509 13.4,73% 718 716 FE N- (cxz) 3 _ met oye 0 Compound CHZ-C38H42N408 15.9,82% 683 681 FFN- (CHz) 3 _ °mFPFOUnd 1 N--(CH) 3- {-CH3-| C38H42N40 | 15 9 82% | 683 | 681 |Compound [N (CH2) 3-X CH2-C38H48N408 17. 1, 83% 689 687MeO OMe 0 Compound CH 2-C38H48N408 17. 1, 83% 689 687 FGN- (CH,),- met oye Me0 OMe O Compound CH2-C39H44N408 16.5,82% 697 695 EH(CH 2) 3- p- Me0OMe Compound'- (CH 2) 2--CH 2-C38H43N508 13. 0,85% 698 696 FlOMe Me0OMe Compound 0- (CH 2) 3- CH 2-C40H46N408 16.8,70% 711 709 Fi/\ F, J Me0 OMe

EXAMPLE 4 Compounds FK to KV Step 1. Resin A from Step 1 Example 2 was suspended in dimethylformamide (30ml) and then treated with phenethylamine (10 eqivalents). After standing at room temperature overnight the mixture was filtered to give resin G which was washed with (i) dimethylformamide, (ii) tetrahydrofuran, (iii) dichloromethane and then dried in a desiccator under high vacuum for 2 hours.

By proceeding in a similar manner but replacing phenethylamine by allylamine, isobutylamine, (cyclohexyl) methylamine, 3-(2-oxo-1-pyrrolydinyl) prop-1-ylamine, 4-phenyl-1-butylamine, piperonylamine, 3- (1-imidazolyl) prop-1-ylamine, 3- (2-methyl-1-piperdinyl) prop-1-ylamine, 2- (2-pyridinyl) ethylamine, (2-acetamido) ethylamine or 2-methoxybenzylamine there were prepared resins H to R.

A library of 144 compounds were prepared from resins H to R, using an ACT496 robot (96 well plate format), in the following manner.

Step 2. The appropriate resin (40mg, resins H to S prepared as described above) was placed in each well and treated with dimethylformamide (1.2ml) for 5 minutes and then drained.

Dimethylformamide (0.35 ml) was added to each well, the system was warmed to 30°C, and each well was treated with (i) a solution of diisopropylethylamine in dimethylformamide (0. 5ml, 0.66M), (ii) a solution of N- (9-fluorenylmethoxycarbonyl) glycine in dimethylformamide (0.375ml, 0.294M) and (iii) a solution of [0-(7-azabenzotriazol-1-yl)-1, 1,3,3,-tetramethyluronium hexafluorophosphate] in dimethylformamide (0.375ml, 0.294M). After standing at 30°C for 2 hours with mixing the wells were drained and the resins in each well were then washed five times with dimethylformamide (1.2ml) with mixing for 5 minutes. Further batches of resins H to S were similarly modified by replacing N- (9-fluorenylmethoxycarbonyl) glycine with N- (9-fluorenylmethoxycarbonyl)-3-aminopropionic acid, N- (9-fluorenylmethoxycarbonyl)-4- aminobutyric acid, N- (9-fluorenylmethoxycarbonyl) sarcosine or N- (9-fluorenylmethoxycarbonyl)-4-N-methylaminobutyric acid.

Step 3. The resins from Step 2 in each well were then treated with 20% piperidine in dimethylformamide (1. 2ml) with mixing for 5 minutes, the wells were drained and the procedure repeated. The resins in each well were then washed (with mixing for 5 minutes) seven times with dimethylformamide (1. 2ml).

Step 4. Dimethylformamide (0.35 ml) was added to the resin in each well followed by (i) a solution of diisopropylethylamine in dimethylformamide (0.5mt, 0.44M), (ii) a solution of 4- (phenylureido) phenylacteic acid in dimethylformamide (0.375ml, 0.196M), (iii) a solution of [0- (7-azabenzotriazol-1-yl)-1, 1,3,3,-tetramethyluronium hexafluorophosphate] in dimethylformamide (0.375ml, 0.196M). After mixing for 2 hours the wells drained and each well was washed (with mixing for 5 minutes) (i) three times with dimethylformamide (1.2ml), (ii) five times with tetrahydrofuran (1.2ml), (iii) seven times with dichloromethane (1.2ml). Further batches of resins from Step 3 were similarly modified by replacing [4-(phenylureido) phenyl]- acetic acid with [4- (3-o-tolylureido) phenyl]-acetic acid, [4- (phenylureido) phenyl]-propionic acid, [3-(phenylureido) phenyl]-acetic acid, [3-methoxy-4- (3-o-tolyl-ureido) phenyl]-acetic acid or [3-methoxy-4- (3-o-tolyl-ureido) phenyl]-propionic acid.

Step 5. The system heating was switched off. The resins in each well were treated with a mixture of trifluoroacetic acid and dichloromethane (2ml, 1: 1 v/v) for 45 minutes, the filtrate was collecte and the procedure repeated once more. The combined nitrates were evaporated on a turbovap evaporator (vortexed N2 gas) to give Compounds FK to KV depicted in tables 3 to 15.

The retention times (RT), and area of main peak as a percentage of the total sample, shown in tables 3 to 15 were determined under HPLC conditions using as elutant (i) mixture of 0.05% trifluoroacetic acid in acetonitrile and 0.05% trifluoroacetic acid in water (1: 19, v/v) for 2 minutes (ii) a mixture of 0.05% trifluoroacetic acid in acetonitrile and 0.05% trifluoroacetic acid in water (1: 19 to 19: 1, v/v) gradient elution over 10 minutes, (iii) a mixture of 0.05% trifluoroacetic acid in acetonitrile and 0. 05% trifluoroacetic acid in water (19: 1, v/v) for 2 minutes, (iv) a mixture of 0.05% trifluoroacetic acid in acetonitrile and 0. 05% trifluoroacetic acid in water (19: 1 to 1: 19, v/v) gradient elution over 2 minutes.

Table 3 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound S (CH2) 2-C29H32N405 14.0, >75% 517 FK Compound CH2 =CH-CH2-C24H28N405 12.0, >90 % 453 FL Compound (CH3) ZCH-CH2-C25H32N405 13. 1, >90% 469 Compound CHa-C28H36N405 14.8, >90% 509 FN Compound N- (CH2) 3-C28H35N506 11.0, >90% 560 FO [M+Na] + Compound v (CH2) 4~ C31H36N405 15.2, >90% FP Compound o vCH2~ C29H30N407 13.6, >75% 569 FQ O [M+Na] + C\ CompoundN- (CH2) 3-C27H32N605 10. 0, >75 % 521 FR FR Me Compound C30H41N505 11.3, >90 % 552 _ FS 9 N (CH2) 3-. FUS Compound [X- (CH,),-C2SH31N505 10.2, >90 % 518 For Compound CH3C (=O) NH- (CFi2) 2-C25H31N506 10.1, >90% 498 FU OMe Compound C29H32N406 13.7, >75% 533 FV V_' Table 4

Compound R4 MOLECULAR HPLC C MH+ MH- number FORMULA RT Compound \\//-<CH)- C30H34N405 10. 3, >75% 531 FW Compound CH2 =CH-CH2-C25H30N405 13.9, >50% 467 FX Compound (CHCH-CH-C26H34N405 14. 7, >50% 483 FY Compound O-CH 2-C29H38N405 11. 0, <50% 537 FZ N- (cx2) 3- Compound C29H37N506 13.7, >75 % 550 GA 0 Compound (CH 2) 4- C32H38N405 10.8, >75% 559 GB Compound O GC L/ "0 Compound non (CH 2) 3- C28H34N605 8. 4, >75 % 533 Go Me Me Compound/C31H43N505 8.8, >75% 564 GE \ N (CH2) 3- GE Compound \ CHZ 2-C29H33N505 8.5, >75% 530 GF-" Compound CH3C (=O) NH- (CH2) 2-C26H33N506 8. 5, >75 % 510 GG OMe Compound C30H34N406 10.0, >75 % 545 GH \/CH2-

Table 5 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound 9 (CH2) 2-C29H32N405 ItU >75% 517 GI Compound CH2=CH-CH2 ~ C24H28N405 12.0, >90% 453 GJ Compound (CH3) ZCH-CH2-C25H32N405 13. 1, >90% 469 GK Compound SCH2-C28H36N405 14.8, >90% 509 GL _ N- (CH j- Compound Z 3 C28H35N506 11.0, >90% 560 GM o [M+Na] + O Compound (CH 2) 4- C3lH36N405 15. 2, >90% GN Compound ° g CH2-C29H30N407 13.6, >75 % 569 GO I- [M+Na] + 0 Compound \N (CH2) 3-C27H32N605 10. 0, >75 % 521 Nez GP Me Compound C30H41N505 11.3, >90% 552 GQ N- (CH2) 3 _ Compound 1 v (CH2) 2-C28H31N505 10 2, >90% 518 GR- Compound CH3C (=O) NH (CH2), C25H31N506 10.1, >90% 498 GS OMe Compound/ C29H32N406 13.7, >75 % 533 GT vCH2- Table 6

Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound a (CH 2) 2- C30H34N405 13.8, >90 % 531 GU Compound CH2=CH-CH2 ~ C25H30N405 11.9, >90% 52 467 GV Compound (CH3) 2CH-CHZ-C26H34N405 12.8, >90% 483 _ GW Compound SCH2-C29H38N405 14.3, >90% 523 GX N- (cx2) 3- Compound C2) 3-C29H37N506 11.5, >90% 614 GY O [M+Na] + O Compound a (CH2) 4~ C32H38N405 15.7, >95 % 621 GZ [M+Na] + Compound o XCH2~ C30H32N407 14.0, >90% 623 [M+Na] + O Compound N~N (CH2) 3-C28H34N605 10.6, >90% 575 NEZ HB Me Compound C31H43N505 8.9, >75% 564 HC N- (CH2) 3- Compound \ (CHz 8.4, >75 % 530 HD Compound CH3C (=O) NH (CH2) 2-C26H33N506 8.5, >90% 510 HE OMe Compound C30H34N406 10.1, >90% 545 HF C-CH 2- Table7 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound 9 (CH2) 2-C31H36N405 10.7, >90% 545 HG Compound CH2=CH-CH 2-C26H32N405 14. 1, >75% 481 HH Compound (CH3) zCH-CH2-C27H36N405 9.9, >75% 497 HI Compound aCH2-C30H40N405 11.1, >75% 537 HJ Compound N- (CHZ) 3-C30H39N506 8.8, >75 % 564 HK 0 Compound (Cli2) a-C33H40N405 10.8, >90% 571 HL Compound CH-5 C31H34N407 i 10.0, >90% 573 HM L./ '0 Compound \ N- (CH- C29H36N605 8.5, >75 % 547 HN Me Me C32H45N505 8.9, >90% 578 Compound N- (CH2) 3- HO Compound P 2) 2- C30H35N505 8. 5, >90 % 544 HP-" Compound CH3C (=0) NH- (CH2) 2- C27H35N506 8. 6, >90% 524 HQ je Compound C31H36N406 8.2, >95 559 ,, CH2 _ Table 8

Compound R4 MOLECULAR HPLC C MH+ MH- number FORMULA RT Compound 0- (CH 2) 2- C29H32N405 14.2, >75 % 517 j X HS Compound CIi2=CH-CHZ-C24H28N405 12. 0, >90% 453 HT lCompound (CH3) ZCH-CH2-C25H32N405 13.1, >90% 469 HU Compound | vCH2-C28H36N405 14.9, >90% 509 HV N- (CHZ) 3- Compound C28H35N506 11.0, >90% 560 HW O [M+Na] + Compound (CH 2) 4- C3lH36N405 15.4, >90% 567 HX [M+Na] + Compound o X CH2 ~ C29H30N407 13.7, >75 % 569 HY L,-0 [M+Na] + O Compound (\N- (CH)-C27H32N605 1oS 7s 521 NEZ HZ Me N- (CH2) 3- Compound C30H41N505 11.2, >90% 552 JA Compound \ (CH 2-) C28H31N505 10.2, >90% 518 Compound CH3C (=0) NH- (CH2) 2-C25H31N506 10.0, >90 % 498 JC OMe Compound C29H32N406 13.7, >75% 533 r _ JD /cx2_ Table 9 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound (CH 2) 2-C30H34N405 13.8, >90% 531 JF Compound CH =CH-CH2-C25H30N405 11. 9, >90% 467 JG Compound (CH3) ZCH-CH2-C26H34N405 12.8, >90% 483 JIS Compound O-CH 2-C29H38N405 14. 5, >90 % 523 . __ _ Compound N- (CH2) 3-C28H37N506 11. 5, >90% 614 0O [M+Na+CH3CN] + Compound \/CHa >95% | l l JK Compound O X CH2-C30H32N407 14.0, >90% 623 ,1 L JLt0 [M+Na+CH3CNS+ / N 2 3 z 3 Compound C28H34N605 10.3, >90% 575 . IM . JM [M+CH3CN] + Me 564 Compound d- (CH 2) 3-C3lH43N505 8.9, >50% 564 JN Compound (\//-2) (CHz C29H33N505 8.6, >50% 530 , 1 O Compound CH3C (=O) NH- (CH2) 2 C26H33N506 8.6, >75% 510 OMe Compound C30H34N406 10.1, >90% 545 , IC Table 10 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound/ CHa z-C31H36N405 10. 7, >75 % 545 JR Compound CH2=CH-CH2-C26H32N405 14.0, >75% 481 JS Compound (CHCH-CH-C27H36N405 10.0, >50% 497 JT Compound CHa-C30H40N405 11. 1, >75% 537 JU j- CH2 3 _ Compound C 3-C30H39N506 8.9, >75% 564 JV \ 0 Compound \/ CHa 10.9, >90% 571 JW Compound 0 CH 2-C3lH34N407 10.0, >75% 573 JE 0 / (\N- (CH2) 3 ~ NEZ Compound C29H36N605 8.6, >75% 547 JY Me Au Compound C 3-C32H45N505 9.0, >75% 578 JZ Compound (CH 2) 2- C30H35N505 8. 6, >75 % 544 VA'-" Compound CH3C (=O) NH- (CH2) 2- C27H35N506 8.7, >75 % 524 KB OMe Compound C31H36N406 10. 1, >95% 559 KC \/cl2 _ v i Table 11 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound v (CH2) 3~ C32H38N406 8.0,100% 575 573 KD Compound Me2N \/CHZ-C32H39N506 2. 8, 100% 588 KF KF Table 12

Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT N- (CH2) 3- Compound C31H41N507 2.7,95% 596 594 KG 0 Compound - (CH) g- C33H40N406 7.6,97% 588 KH Compound Met CH 2-C33H4ON408 5.8,83% 620 KI Me0 Compound Me2N \/CHZ-C33H41N506 2. 5,97% 602 KJ Table 13 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound N- (CH2) 3-C30H39N507 2.7,96% 582 580 KK 0 Compound X (CHz) 3-C32H38N406 7.5,97% 575 573 KL Compound MeO X CH2-C32H38N408 5.9,70 % 607 KA KA Me0 Compound Me2N \/CHz-C32H39N506 2. 4, 93% 590 KN

Table 14

Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT N- (CHZ) 3- Compound C32H43N507 3.0,100% 610 609 KO \\ O Compound / CHz2 s'C34H42N406 8.0,85 % 603 KP Compound meo \/CH2-C34H42N408 6.3,65% 635 KQ MeO Compound Me2 X CH2-C34H43N506 2.6,90% 618 KR Table 15 Compound R4 MOLECULAR HPLC MH+ MH- number FORMULA RT Compound C31H41N507 3.7,96% 595 KS < O Compound -<CH-C33H40N406 8.4,100% 590 587 KT Compound MeO CH2-C33H40N408 6.8,100% 621 KA KU Me0 Compound Me2N \/CHz-C33H41N506 3. 0, 88% 603 KV KV

EXAMPLE 5 Compounds C, KW and KX A solution of 3- { (3,4-dimethoxy-benzyl)-[({ [3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N- methylamino)-acetyl]-amino}-propionic acid ethyl ester [2.0g, Reference Example 4 (a)] in ethanol (50m1) was treated with sodium hydroxide (3. 5ml, 1M). After stirring at room temperature for 3 hours the mixture was concentrated to dryness. The residue was dissolved in water (12ml) and the pH of the solution was adjusted tol. O by addition of concentrated hydrochloric acid (0. 25ml) and then extracted three times with dichloromethane. The resultant solid was collecte and recrystallised twice from 20% aqueous isopropanol to give

3-1(3,4-dimethoxv-benzvl)-f (f3-methoxv-4- (3-o-tolvlureido) phenvll-acetyl}-N-methvlamino)- acetyl]-amino}-propionic acid (Compound C) as a white solid (0.25g,), m. p. 183-187°C.

[Elemental analysis:- C, 63.2; H, 6.3; N, 9.2% Calculated for C32H3gN40g :-C, 63.4; H, 6.3; N,9.2%].

MS: 605 [MH]-. HPLC: RT=11.92 minutes (gradient elution using a mixture of acetonitrile and water 1: 4 to 4: 1).

(b) By proceeding in a manner similar to Example 5 (a) but using 3- { [ ( { [3-methoxy-4- (3-o- tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- (3-carboxy-prop-1-yl)-amino}-propionic acid ethyl ester [Reference Example 4 (b)] there was prepared 3-f {f ( {f3-methoxv-4- (3-o- tolylureido)phenyl]-acetyl}-N-methylamino)-acetyl]-(3-carbox y-prop-1-yl)-amino}-propionic acid (Compound KW) as a white foam. [Elemental analysis:- C, 57.2; H, 6.5; N, 9.9%. Calculated for C27H34N40g'HO :- C, 57. 2; H, 6.3; N, 9.8%]. MS: 543 [MH] +.

(c) By proceeding in a manner similar to Example 5 (a) but 3-{[({[3-methoxy-4-(3-o- tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]-[2-(2-oxo-pyrrolidin- 1-yl)-ethyl]-amino}- propionic acid ethyl ester [Reference Example 4 (c)] there was prepared 3-{[({[3-methoxy-4-(3-o- tolylureido)phenyl]-acetyl}-N-methylamino)-acetyl]-[2-(2-oxo -pyrrolidin-1-yl)-ethyl]-amino}- propionic acid (Compound KX) as a yellow foam. [Elemental analysis:- C, 59.5; H, 6.5; N, 11.9%.

Calculated for C29H37N507H20:- C, 59.5; H, 6.7; N, 11.95%]. MS: 568 [MH] +.

EXAMPLE 6 Compounds BD, D, LA, LB. LC, AO, AC and LD to LH (a) Step 1. A solution of ({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-aceti c acid [50g, Reference Example 3] and 3- (3, 4-dimethoxy-benzylamino)-propionic acid ethyl ester [36g, Reference Example 2 (a)] in dimethylformamide (500mut) was treated with [0- (7-azabenzotriazol- 1-yl)-1, 1,3,3,-tetramethyluronium hexafluorophosphate] (53.2g) and diisopropylethylamine (59ml). After stirring at ambient temperature for 3 hours the reaction mixture was evaporated to dryness and the residue was treated with water (3L). The mixture was extracted twice with ethyl acetate (1L) and then concentrated to dryness. The residue was subjected to flash chromatography on silica eluting initially with ethyl acetate and then with a mixture of ethyl acetate and methanol (9: 1, v/v) to give 3- [N- (3, 4-dimethoxybenzyl)-2- {2- [3-methoxy-4- (3-o- tolylureido) phenyl] acetylamino} acetamido] propionic acid ethyl ester as a yellow oil (49g).

Step 2. This material was treated with methanol (1L) and sodium hydroxide (160ml, 1. OM) and the reaction mixture was heated at 40°C for 2 hours. After this time, the reaction mixture was cooled then evaporated and then treated with water (1.5L). The aqueous solution was washed twice with ethyl acetate (500ml) and then acidified to pH 1.0 by addition of concentrated hydrochloric acid. The resultant solid was collected, washed with water and dried under vacuum. This material was recrystallised from 10% aqueous methanol to give 3-rN-(3. 4-dimethoXv-benzvl)-2-f 2-r3-methoxv-4-(3-o-tolvlureido) phenvllacetvlaminoT- acetamidolpropionic acid (Compound BD) as a white solid (33g), m. p. 172-174°C. [Elemental analysis:- C, 62.4; H, 6.2; N, 9.5%. Calculated for C31H36N40g :-C, 62.8; H, 6.1; N, 9.45%].

MS: 593 [MH] +.

(b) By proceeding in a manner similar to Example 6 (a) but using 3-(3-imidazol-1-yl-prop-1- ylamino)-propionic acid ethyl ester [Reference Example 2 (b)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3{(3-imidazol-1-yl-prop-1-yl)- -[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-ace tyl]-amino}-propionicacid (Compound BK) as a white foam. MS: 551 [MH] +.

(c) By proceeding in a manner similar to Example 6 (a) but using 3- [3- (2-oxo-pyrrolidin-l- yl)-prop-1-ylamino]-propionic acid ethyl ester [Reference Example 2 (c)] to replace 3- (3, 4-dimethoxy-benzylamino)-propionic acid ethyl ester, there was prepared 3-f [3-methoxv- 4-(3-o-tolylureido)phenyl]-acetyl}-amino)-acetyl]-[3-(2-oxo- pyrrolidin-1-yl)-prop-1-yl]-amino}- propionic acid (Compound D) as a white foam. [Elemental analysis:- C, 58.9; H, 6.2; N, 11.5%.

Calculated for C29H37N5O7#H2O:- C, 59.5; H, 6.7; N, 11.95%]. MS: 586 [MH] +.

(d) By proceeding in a manner similar to Example 6 (a) but using 3- (3-carboxy-prop-l- ylamino)-propionic acid di-ethyl ester [Reference Example 2 (d)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-{[({[3-methoxy-4-(3-o- tolvlureido) phenvll-acetyll-amino)-acetvll- (3-carboxy-prop-l-vi)-aminol-propionic acid (Compound LA) as a white solid, m. p. 179-181°C. [Elemental analysis:- C, 59.0; H, 6.1; N, 10.55%. Calculated for C26H32N40g :-C, 59.1; H, 6.1; N, 10.6%]. MS: 529 [MH] +.

(e) By proceeding in a manner similar to Example 6 (a) but using 3-[2-(2-oxo-pyrrolidin-1- yl)-ethylamino]-propionic acid ethyl ester [Reference Example 2 (e)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-t 3-methoxv-4-(3-o-

tolylureido)phenyl]-acetyl}-amino)-acetyl]-[2-(2-oxo-pyrroli din-1-yl)-ethyl]-amino}-propionic acid (Compound LB) as a white foam. [Elemental analysis:- C, 58.2; H, 6.5; N, 12.0% Calculated for C28H35N5O7eH20 :- C, 58.8; H, 6.5; N, 12.25%]. MS: 553 [MH] +.

(f) By proceeding in a manner similar to Example 6 (a) but using 3- (2-carboxy-ethylamino)- propionic acid di-ethyl ester [Reference Example 2 (f)] to replace 3- (3, 4-dimethoxy-benzylamino)- propionic acid ethyl ester, there was prepared 3-ff (ff3-methoxv-4-(3-o-tolvlureido) Phenvll- acetvli-amino)-acetvll-(2-carboxv-ethvl)-aminoT-Propionic(2- carboxv-ethvl)-aminoT-Propionic acid (Compound LC) as a white solid, m. p. 117-121°C. [Elemental analysis :- C, 56.5; H, 5.85; N, 10.6% Calculated for C25H30N4O8#H2O:- C, 56.4; H, 6.1; N, 10.5%]. MS: 533 [MH] +.

(g) By proceeding in a manner similar to Example 6 (a) but using 3- (2,3-dimethoxy- benzylamino)-propionic acid ethyl ester [Reference Example 2 (g)] to replace 3- (3, 4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-f (2,3-dimethoxv-benzvl)-f ( [3- methoxv-4- (3-o-tolvlureido) phenyll-acetyll-amino)-acetvll-amino-propionic acid (Compound AO) as a white solid, m. p. 134-136°C. [Elemental analysis:- C, 63.0; H, 6.6; N, 9.6% Calculated for C31H36N4O8:- C, 62.8; H, 6.1; N, 9.45%]. MS: 593 [MH] +.

(h) By proceeding in a manner similar to Example 6 (a) but using 3- (3-phenyl-prop-l- ylamino)-propionic acid ethyl ester [Reference Example 2 (h)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-f ({[3-methoxy-4-(3-o- tolvlureido) phenvll-acetyl}-amino)-acetvll- (3-phenvl-prop-1-vl)-amino}-propionic acid (Compound AC) as a white solid, m. p. 149-150°C. [Elemental analysis:- C, 65.65; H, 6.1; N, 9.7% Calculated for C31H36N4o6 C,66. 4; H, 6.5; N, 10.0%]. MS: 561 [MH] +.

(i) By proceeding in a manner similar to Example 6 (a) but using 3- (phenylamino)-propionic acid ethyl ester (prepared according to the procedure described by Kano, Shinzo; Ebata, Tsutomu; Shibuya, Shiroshi. J. Chem. Soc., Perkin Trans. 1 (1980), Issue 10,2105-11) to replace 3- (3, 4-dimethoxy-benzylamino)-propionic acid ethyl ester, there was prepared 3-{[({[3-methoxy- 4-(3-o-tolvlureido) Phenvll-acetvl}-amino)-acetvll-phenvl-aminol-propionic(3-o-t olvlureido) Phenvll-acetvl}-amino)-acetvll-phenvl-aminol-propionic acid (Compound LD) as a beige solid. MS: 519 [MH] +.

(k) By proceeding in a manner similar to Example 6 (a) but using 3- (3-ethoxy-4-methoxy- benzylamino)-propionic acid ethyl ester [Reference Example 7 (a)] to replace 3- (3,4-dimethoxy-

benzylamino)-propionic acid ethyl ester, there was prepared 3-{(3-ethoxy-4-methoxy-benzyl)- [({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-acet yl]-amino}-propionicacid (Compound LE) as a white solid, m. p. 187-189°C. [Elemental analysis:- C, 63.1; H, 6.5; N, 9.2% Calculated for C32H3gN40g :- C, 63.35; H, 6.3; N, 9.2%]. MS: 607 [MH] +.

(1) By proceeding in a manner similar to Example 6 (a) but using 3- (3,4-diethoxy- benzylamino)-propionic acid ethyl ester [Reference Example 7 (b)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-f (3,4-diethoxv-benzvl)-[(ff3- methoxv-4- (3-o-tolvlureido) phenvll-acetvll-amino)-acetvll-amino-propionic acid (Compound LF) as a white solid, m. p. 197-198°C. [Elemental analysis :- C, 63.95; H, 6.4; N, 8.9% Calculated for C33H40N40g :-C, 63.9; H, 6.5; N, 9.0%]. MS: 621 [MH] +.

(m) By proceeding in a manner similar to Example 6 (a) but using 3- (4-benzyloxy-3-methoxy- benzylamino)-propionic acid ethyl ester [Reference Example 7 (c)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-f (4-benzvloxy-3-methoxv- benzyl)-[({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-ami no)-acetyl]-amino}-propionicacid (Compound LG) as a white solid, m. p. 160-162°C. [Elemental analysis :- C, 65.7; H, 5.9; N, 8.35% Calculated for C37H40N4O8#0. 26H20:- C, 66.0; H, 6.1; N, 8.3%]. MS: 669 [MH] +.

(n) By proceeding in a manner similar to Example 6 (a) but using 3- [ (1, 4-benzodioxan-6-yl)- methylamino]-propionic acid ethyl ester [Reference Example 7 (d)] to replace 3- (3,4-dimethoxy- benzylamino)-propionic acid ethyl ester, there was prepared 3-{[(1,4-benzodioxan-6-yl)-methyl]- [({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-acet yl]-amino}-propionicacid (Compound LH) as a white solid, m. p. 175-178°C (with decomposition). [Elemental analysis:- C, 62.0; H, 6.1; N, 9.5%. Calculated for C31H34N40g0.55H20:- C, 62.0; H, 5.9; N, 9.3%].

MS: 591 [MH] +.

EXAMPLE 7 CompoundLI Stepl. By proceeding in a manner similar to step 1 of Example 6 (a) but using 3- (3-tert- butoxycarbonylamino-prop-1-ylamino)-propionic acid ethyl ester [Reference Example 2 (i)] to replace 3- (3, 4-dimethoxy-benzylamino)-propionic acid ethyl ester, there was prepared 3-{[({[3- <BR> <BR> <BR> <BR> methoxy-4- (3-o-tolylureido) phenyl]-acetyl}-amino)-acetyl]- (3-tert-butoxycarbonylamino-prop-1- yl)-amino}-propionic acid ethyl ester.

Step2. A solution of this material (0.75g) in dichloromethane (lOml) was treated with trifluoracetic acid (1. 75ml) and stirred at ambient temperature for 2.5 hours. The reaction mixture was evaporated to give 3- { [ ( { [3-methoxy-4- (3-o-tolylureido) phenyl]-acetyll-amino)- acetyl]- (3-amino-prop-1-yl)-amino}-propionic acid ethyl ester trifluoroacetate salt (1.0g) which was treated with dichloromethane (lOml). The resulting solution was cooled to 0°C and then treated with triethylamine (1.8ml) followed by methanesulphonyl chloride (O. lml). The reaction mixture was stirred for 3 hours at ambient temperature then diluted with dichloromethane (lOml) and washed with hydrochloric acid (lOml, 1M), then with water (10ml), then with saturated sodium bicarbonate solution (lOml) and then with brine. The organic layer was dried over magnesium sulphate and evaporated. The residue was subjected to flash chromatography on silica eluting with a mixture of ethyl acetate and methanol (9: 1, v/v) to give a white foam (0.63g). This material was hydrolyse according to the procedure described in step 2 of Example 3 (a) to give 3-ff{f3-methoxv-4- (3-o-tolvlureido) phenyll-acetvl}-amino)-acetvll- (3- methanesulphonvlamino-prop-1-yl)-amino}-propionic acid (Compound LI) as a colourless foam (0.43g). MS: 578 [MH] +.

EXAMPLE 8 Compounds LJ to MD By proceeding in a similar manner to Example 3, but using the appropriately substituted amines in step 2 and ({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N-methylamino)-acetic acid (Reference Example 1) or ({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-amino)-acetic acid (Reference Example 3) in step 3 there were prepared Compounds LJ to MD depicted in Table 16.

Table 16 Compound Rll R4 MOLECULAR MH+ MH- number FORMULA 02N 578 576 Compound H C29H31N508 Lj CH 2- Compound CH3 I CH2-C28H32N406S LK 577 575 Compound CH3 CH 2-C3lH36N407 LL \ OMe 561 559 Compound CH3 Me oCH2-C31H36N406 LM O 591 589 Compound Cg3 , Cg2- LN MeO 607 605 Compound CH3/=\ LO CH 2-C32H38N408 Met -N 534 532 Compound H SCH2-C28H31N506 LP Compound 537 535 LQ CH3 IL >-2) C28H32N407 0 Compound 591 589 LR CH3 < CH2-C32H38N407 OEt Compound 539 537 LS H t \<CH2-C27H30N406S S Compound 534 532 LT H N/CH2-C28H31N506 Compound/= 548 546 LU CH3 vCH2-C29H32N506 Compound 02N 592 LV CH3 C30H33N508 Compound N-548 546 LWCH3 \\//-2'C29H33N506 Compound s 631 629 LX CH3 N = CH2-C32H34N606S N Compound 548 546 LY CH3 N< CH2-C29H33N506 Compound 547 545 LZ CH3 (< CH2-C30H34N406 Compound Br 624 MA CH3 C30H33BrN406 Compound Br 613 611 MB H C29H31BrN406 Compound C1 581 579 MC CH3 C30H33CIN406 /CHZ _ Compound 625 623 MD CH3 MeSO2 \/CH2-C31H36N408S "_y

EXAMPLE 9 (a) 3-{(3,4-Dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido)p henyl]-acetyl}-N- methvlamino)-acetvll-amino}-propionic acid sodium salt A solution of 3-{(3, 4-dimethoxy-benzyl)-[({[3-methoxy-4-(3-o-tolylureido) phenyl]-acetyl}-N- methylamino)-acetyl]-amino}-propionic acid [17g, Example 5 (a)] in ethanol (170ml) was treated with sodium hydroxide solution (23. 3ml, 1N). After stirring at ambient temperature for 24 hours the reaction mixture was filtered through a short pad of diatomaceous earth and then evaporated. The residue was triturated with hot ethyl acetate (200ml) and dried under vacuum.

The resultant foam was dissolved in water (200ml) and freeze dried for 40 hours to yield the title compound as a white solid (15.4g), m. p. 225°C (with decomposition). [Elemental analysis:- C, 57.8; H, 6.05; N, 8.2; Na, 3. 5%. Calculated for C32H37N4NaO8o2H20 :- C, 57.8; H, 6.2; N, 8.4; Na,3.5%].

(b) By proceeding in a manner similar to Example 9 (a) but using 3-{[({[3-methoxy-4-(3-o- tolylureido) phenyl]-acetyl}-N-methylamino)-acetyl]- [3- (2-oxo-pyrrolidin-1-yl)-prop-1-yl]- amino}-propionic acid [Example 1 (a)], there was prepared 3- {[({[3-methoxy-4-(3-o- tolvlureido)phenvll-acetvl f-N-methvlamino)-acetvll-f3- (2-oxo-pvrrolidin-1-vl)-prop-1-vll- amino)-propionic acid sodium salt, m. p. 213°C (with decomposition). [Elemental analysis :- C, 57.55; H, 6.4; N, 10.85; Na, 3. 5% Calculated for C30H3gNsNaO7oH20:- C, 57.95; H, 6.5; N, 11.25; Na, 3.7%].

(c) By proceeding in a manner similar to Example 9 (a) but using 3-{(3, 4-dimethoxy-benzyl)- [({ [3-methoxy-4-(3-o-tolyl-ureido)-phenyl]-acetyl}-amino)-acety l]-amino}-propionic acid [Example 6 (a)], there was prepared 3-{[({[3-methoxy-4-(3-o-tolyl-ureido)-phenyl]-acetyl}- amino)-acetvll-r3- (2-oxo-pvrrolidin-1-vl)-prop-l-vll-amino-propionic acid sodium salt, m. p.

>250°C (with decomposition).

REFERENCE EXAMPLE 1 ({[3-Methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methylamin o)-aceticacid A solution of [3-methoxy-4- (3-o-tolylureido) phenyl]-acetic acid (2.50g, Reference Example 5) and sarcosine ethyl ester hydrochloride (1.23g) in dimethylformamide (75ml) was treated with [0- (7-azabenzotriazol-1-yl)-1, 1,3,3,-tetramethyluronium hexafluorophosphate] (3.03g) and diisopropylethylamine (4. 30ml). The reaction mixture was stirred at room temperature for 2 hours, then treated with water (200mut) and then filtered. The white solid was suspended in tetrahydrofuran (100ml) and the mixture was then treated with lithium hydroxide hydrate (0.45g) in water (20ml). After stirring for 45 minutes the mixture was concentrated to remove the tetrahydrofuran. The remaining aqueous phase was washed with ethyl acetate then acidified by addition of hydrochloric acid (1M), then extracted three times with ethyl acetate. The combined organic extracts were washed with brine, then dried over magnesium sulphate and then evaporated to yield the title compound (2.24g) as a white solid, m. p. 125-130°C (with decomposition). HPLC: RT=10.83 minutes (gradient elution using a mixture of acetonitrile and water 1: 4 to 4: 1 v/v). MS (-ve) [M-1]-384.

REFERENCE EXAMPLE 2 (a) 3- (3, 4-dimethoxv-benzvlamino)-propionic acid ethvl ester A mixture of 3, 4-dimethoxy-benzylamine (100g) and ethyl acrylate (65ml) in ethanol (2L) and cylcohexane (1L) was stirred at room temperature for 20 hours then evaporated to give the title compound as a colourless oil (154g). MS: 268 [MH] +.

(b) By proceeding in a manner similar to Reference Example 2 (a) but using 1-(3-aminoprop-1- yl)-imidazole there was prepared 3- 3-imidazol-l-vl-prop-1-vlamino)-propionic acid ethvl ester.

MS: 226 [MH] +.

(c) By proceeding in a manner similar to Reference Example 2 (a) but using 1-(3-aminoprop-1- yl)-2-pyrrolidinone there was prepared 3- 3- (2-oxo-pvrrolidin-l-vl)-prop-l-vlaminol-propionic acid ethvl ester. MS: 243 [MH] +.

(d) By proceeding in a manner similar to Reference Example 2 (a) but using 4-amino- butanoic acid ethyl ester there was prepared 3- 3-carboxv-prop-1-vlamino)-propionic acid di- ethyl ester.

(e) By proceeding in a manner similar to Reference Example 2 (a) but using 1- (2- aminoethyl)-2-pyrrolidinone there was prepared, 3-[2-(2-oxo-pvrrolidin-1-yl)-ethvlaminol- propionic acid ethyl ester.

(f) By proceeding in a manner similar to Reference Example 2 (a) but using (3-alanine ethyl ester there was prepared 3- (2-carboxv-ethvlamino)-propionic acid di-ethvl ester.

(g) By proceeding in a manner similar to Reference Example 2 (a) but using 2,3-dimethoxy- benzylamine, there was prepared 3- (2, 3-dimethoxv-benzvlamino)-propionic acid ethvl ester.

(h) By proceeding in a manner similar to Reference Example 2 (a) but using 3-phenyl-prop-1- ylamine, there was prepared 3- (3-Phenvl-Prop-1-vlamino)-propionic acid ethyl ester.

(i) By proceeding in a manner similar to Reference Example 2 (a) but using 3- (tert- butoxycarbonylamino) prop-1-ylamine (prepared according to the procedure described by Muller, Dan; Zeltser, Irena; Bitan, Gal; Gilon, Chaim. J. Org. Chem. 1997,62, page 411-416), there was prepared 3- (3-tert-butoxvcarbonvlamino-prop-1-vlamino)-propionic acid ethvl ester.

REFERENCE EXAMPLE 3 (f f3-Methoxv-4- (3-o-tolvlureido) phenvll-acetvl-amino)-acetic acid A stirred solution of [3-methoxy-4- (3-o-tolylureido) phenyl]-acetic acid (7.53g, Reference Example 5) in a mixture of dimethylformamide (15ml) and dichloromethane (150ml) was treated with 1- (3-dimethylaminoprop-1-yl)-3-ethylcarbodiimide (4.98g), then with 1- hydroxybenzotriazole (3.57g), then with glycine methyl ester hydrochloride (3.01g) and then with diisopropylethylamine (4.10ml). After stirring at room temperature for 20 hours the reaction mixture was diluted with water (100mi). The organic phase was washed with saturated sodium bicarbonate (100moi), then with hydrochloric acid (1M) and then with brine, then dried over magnesium sulphate and then evaporated. The residue was triturated with petroleum ether and the resulting cream coloured solid (6.25g) was dissolved in tetrahydrofuran (200ml). The solution was treated with water (50ml) and then with lithium hydroxide hydrate (0.75g). The mixture was stirred at room temperature for 4 hours and then the tetrahydrofuran was removed

under vacuum. The aqueous phase was acidified by addition of hydrochloric acid (12M). The resulting solid was washed with diethyl ether and then dried to give the title compound (5.76g), m. p. 130-134°C (with decomposition). MS: 370 [M-1]-. HPLC: RT=10.16 minutes (gradient elution using a mixture of acetonitrile and water 4: 1 to 1: 4 v/v).

REFERENCE EXAMPLE 4 (a) 3 (3,4-Dimethoxv-benzvl)-[(f r3-methoxv-4-(3-o-tolvlureido) phenvll-acetvl}-N- methvlamino)-acetvll-amino-propionic acid ethyl ester A solution of ({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-N-methylamin o)-acetic acid [18.4g, Reference Example 1] and 3- (3,4-dimethoxy-benzylamino)-propionic acid ethyl ester [13.4g, Reference Example 2 (a)] in dimethylformamide (400ml) was treated with [0- (7-azabenzotriazol- 1-yl)-1,1,3,3,-tetramethyluronium hexafluorophosphate] (19. lg) and diisopropylethylamine (10.5ml). After stirring at ambient temperature for 20 hours the reaction mixture was evaporated to dryness. The residue was treated with water (800ml) followed by hydrochloric acid (175ml, 1 M) and the mixture was extracted twice with ethyl acetate (500ml). The combined organic extracts were washed with hydrochloric acid (500ml, 1M), then with water (400ml), then with saturated aqueous sodium bicarbonate solution (500ml), then dried over magnesium sulphate and then evaporated. The residual oil was subjected to flash chromatography on silica eluting with a mixture of dichloromethane and methanol (49: 1, v/v) to give the title compound as a fawn coloured foam (26.4g), m. p. 97-105°C. [Elemental analysis:- C, 63.4; H, 6.7; N, 8.7% % Calculated for C34H42N408'0.5H20:- C, 63.3; H, 6.8; N, 8.8%].

(b) By proceeding in a manner similar to Reference Example 4 (a) but using 3- (3-carboxy- prop-1-ylamino)-propionic acid di-ethyl ester [Reference Example 2 (d)] to replace 3- (3,4-dimethoxy-benzylamino)-propionic acid ethyl ester, there was prepared 3- {f ( {f3-methoxv- 4-(3-o-tolvlureido) phenvll-acetvl T-N-methvlamino)-acetvll-(3-carboxv-prop-1-vl)-amino}- propionic acid ethvl ester.

(c) By proceeding in a manner similar to Reference Example 4 (a) but using 3- [2- (2-oxo- pyrrolidin-1-yl)-ethylamino]-propionic acid ethyl ester [Reference Example 2 (e)] to replace 3- (3,4-dimethoxy-benzylamino)-propionic acid ethyl ester, there was prepared 3-{ (tf3-methoxv- 4-(3-o-tolvlureido) phenvll-acetvll-N-nlethvlamino)-acetvll-r2-(2-oXo-pvrrolidin -l-vl)-eth amino}-propionic acid ethvl ester.

REFERENCE EXAMPLE 5 [3-Methoxv-4- (3-o-tolvlureido) phenvllacetic acid A suspension of [3-methoxy-4- (3-o-tolylureido) phenyl]-acetic acid methyl ester (19.43g, Reference Example 6) in methanol (195ml) was treated with sodium hydroxide solution (65ml, IN) and the mixture was heated at reflux for 1 hour giving a clear solution. The reaction mixture was cooled to room temperature and then filtered. The filtrate was diluted to 390ml with water, then heated to 50°C and then acidified to pH 1 by the addition of hydrochloric acid (80ml, 1N) over 1 hour. The resulting suspension was stirred for a further 30 minutes at 50°C, then allowed to cool to room temperature and then filtered. The solid was washed with twice with water (200ml) then dried to give the title compound (15.72g) as a white solid, m. p. 179- 181°C (with decomposition).

REFERENCE EXAMPLE 6 [3-methoxv-4- (3-o-tolvlureido) phenvll-acetic acid methyl ester A suspension of potassium t-butoxide (1.44kg) in dimethylformamide (6.61), cooled to-5°C to -10°C, was treated with a mixture of 2-nitroanisole (690g) and methyl dichloroacetate (915g) over 4 hours, whilst maintaining the temperature below-5°C. The reaction mixture was then treated with acetic acid (770moi), then with water (6.61) and then extracted three times with tert-butyl methyl ether (5.51). The combined extracts were washed with water (5.51), then with saturated sodium bicarbonate solution (5.51), then with saturated brine (5.51) and then dried over magnesium sulphate to give a solution of methyl a-chloro-3-methoxy-4-nitrophenylacetate.

This solution was concentrated to half volume under reduced pressure and then treated with tetrahydrofuran (21), followed by triethylamine (751ml), followed by 10% palladium on charcoal (58.4g) and the mixture was hydrogenated under a pressure of 50psi hydrogen at 50°C for 8 hours. The mixture was cooled to room temperature and filtered. The filtrate was dried over magnesium sulphate to give a solution of methyl 4-amino-3-methoxyphenylacetate which was heated to reflux and then treated with o-tolyl isocyanate (598.5g) over 30 minutes. After heating at reflux temperature for a further 3 hours, during which time a solid was deposited, the mixture was cooled to room temperature. The solid was collecte, washed twice with tert-butyl methyl ether (41), then dried in a vacuum oven at 60°C to give the title compound (764.8g) as a white solid, m. p. 167-168°C.

REFERENCE EXAMPLE 7 (a) 3- (3-Ethoxv-4-methoxv-benzvlamino)-propionic acid ethyl ester A mixture of P-alanine ethyl ester hydrochloride (1.6g), 3-ethoxy-4-methoxybenzaldehyde (1.8g), sodium cyanoborohydride (0.42g) and powdered 3A molecular seives (2.5g) in ethanol (25ml) was stirred at ambient temperature for 24 hours. A further aliquot of sodium cyanoborohydride (0.42g) was added and stirring was continued for a further 24 hours. The reaction mixture was filtered and the filtrate was evaporated. The residue was treated with ethyl acetate (100ml) and the solution was washed with 10% aqueous potassium carbonate (sol), then twice with water (25ml), then with brine (25ml), then dried over magnesium sulphate and then evaporated. The residual oil was subjected to flash chromatography on silica eluting with a mixture of dichloromethane and methanol (95: 5, v/v) to give the title compound as a colourless oil (l. lg).

(b) By proceeding in a manner similar to Reference Example 7 (a) but using 3,4-diethoxy- benzaldehyde, there was prepared 3- (3, 4-diethoxy-benzvlamino)-propionic acid ethvl ester.

(c) By proceeding in a manner similar to Reference Example 7 (a) but using 4-benzyloxy-3- methoxy-benzaldehyde, there was prepared 3- (4-benzvloxy-3-methoxv-benzvlamino)-propionic acid ethvl ester.

(d) By proceeding in a manner similar to Reference Example 7 (a) but using 1,4-benzodioxan- 6-carboxaldehyde, there was prepared 3-r (ls4-benzodioxan-6-vl)-methvlaminol-propionic acid ethylester.

IN VITRO AND IN VIVO TEST PROCEDURES 1. Inhibitory effects of compounds on VLA4 dependent cell adhesion to Fibronectin and VCAM.

1.1 Metabolic labelling of RAMOS cells.

RAMOS cells (a pre-B cell line from ECACC, Porton Down, UK) are cultured in RPMI culture medium (Gibco, UK) supplemented with 5 % foetal calf serum (FCS, Gibco, UK). Prior to assay the cells are suspended at a concentration of 0.5 X 106 cells/ml RPMI and labelled with 400tCi/100mis of [3H]-methionine (Amersham, UK) for 18 hours at 37°C.

1.2 96 well plate preparation for adhesion assay.

Cytostar plates (Amersham, UK) were coated with 50F1/well of either 3Rg/ml human soluble VCAM-1 (R&D Systems Ltd, UK) or 28.8) lg/mt human tissue Fibronectin (Sigma, UK). In control non-specific binding wells 50R1 phosphate buffered saline was added. The plates were then left to dry in an incubator at 25°C, overnight. The next day the plates were blocked with 200R1/well of Pucks buffer (Gibco, UK) supplemented with 1 % BSA (Sigma, UK). The plates were left at room temperature in the dark for 2 hours. The blocking buffer was then disposed of and the plates dried by inverting the plate and gently tapping it on a paper tissue. 50F1/well of 3.6% dimethyl sulphoxide in Pucks buffer supplemented with 5mM manganese chloride (to activate the integrin receptor Sigma, UK) and 0.2% BSA (Sigma, UK), was added to the appropriate control test binding and non-specific binding assay wells in the plate. 50, uVwell of the test compounds at the appropriate concentrations diluted in 3.6% dimethyl sulphoxide in Pucks buffer supplemented with 5mM manganese chloride and 0.2% BSA, was added to the test wells.

Metabolically labelle cells were suspended at 4 x 106 cells/ml in Pucks buffer that was supplemented with manganese chloride and BSA as above. 50RI/well of cells in 1.8% dimethyl sulphoxide in Pucks buffer and supplements was added to all plate wells.

The same procedure exists for plates coated with either VCAM-1 or fibronectin and data is determined for compound inhibition of cell binding to both substrates.

1.3 Performance of assay and data analysis.

The plates containing cells in control or compound test wells are incubated in the dark at room temperature for 1 hour.

The plates are then counted on a Wallac Microbeta scintillation counter (Wallac, UK) and the captured data processed in Microsoft Excel (Microsoft, US). The data was expressed as an IC50, namely the concentration of inhibitor at which 50% of control binding occurs. The percentage binding is determined from the equation: {[(CTB-CNS)-(CI-CNS)]/(CTB-CNS)} X 100 = % binding where CTg are the counts bound to fibronectin (or VCAM-1) coated wells without inhibitor present, CNS are the counts present in wells without substrate, and CI are the counts present in wells containing a cell adhesion inhibitor.

Compound data of this invention is expressed for ICsos for inhibition of cell adhesion to both fibronectin and VCAM-1.

Compound data of this invention is expressed as ICsos for inhibition of cell adhesion to both fibronectin and VCAM-1. Particular compounds of the invention inhibit cell adhesion to fibronectin and VCAM-1 with IC50s in the range 100 micromolar to 0.01 nanomolar. Preferred compounds of the invention inhibit cell adhesion to fibronectin and VCAM-1 with IC50s in the range 1.0 micromolar to 0.01 nanomolar. Especially preferred compounds of the invention inhibit cell adhesion to fibronectin and VCAM-1 with IC50s in the range 100 nanomolar to 0.01 nanomolar.

2. Inhibition of antigen-induced airway inflammation in the mouse and rat.

2.1 Sensitization of the animas.

Rats (Brown Norway, Harland Olac, UK) are sensitized on days 0,12 and 21 with ovalbumin (100 pg, intraperitoneally [i. p], Sigma, UK) administered with aluminium hydroxide adjuvant (lOOmg, i. p., Sigma, UK) in saline (lml, i. p.).

In addition mice (C57) are sensitized on days 0 and 12 with ovalbumin (10pg, i. p.) administered with aluminium hydroxide adjuvant (20mg, i. p.) in saline (0.2ml, i. p.).

2.2 Antigen challenge.

Rats are challenged on any one day between days 28-38, while mice are challenged on any one day between days 20-30.

The animals are challenged by exposure for 30 minutes (rats) or 1 hour (mice) to an aerosol of ovalbumin (long/1) generated by an ultrasonic nebulizer (deVilbiss Ultraneb, US) and passed into an exposure chamber.

2.3 Treatment protocols.

2.3 Treatment protocols.

Animals are treated as required before or after antigen challenge. The aqueous-soluble compounds of this invention can be prepared in water (for oral, p. o. dosing) or saline (for intratracheal, i. t. dosing). Non-soluble compounds are prepared as suspensions by grinding and sonicating the solid in 0.5 % methyl cellulose/0.2 % polysorbate 80 in water (for p. o. dosing, both Merck UK Ltd., UK) or saline (for i. t. dosing). Dose volumes are: for rats lml/kg, p. o. or 0.5mg/kg, i. t.; for mice 10ml/kg, p. o. or lml/kg, i. t.

2.4 Assessment of airway inflammation.

The cell accumulation in the lung is assessed 24 hours after challenge (rats) or 48-72 hours after challenge (mice). The animals are euthanized with sodium pentobarbitone (200mg/kg, i. p., Pasteur Merieux, France) and the trachea is immediately cannulated. Cells are recovered from the airway lumen by bronchoalveolar lavage (BAL) and from the lung tissue by enzymatic (collagenase, Sigma, UK) disaggregation as follows.

BAL is performed by flushing the airways with 2 aliquots (each 10 ml/kg) RPMI 1640 medium (Gibco, UK) containing 10 % fetal calf serum (FCS, Serotec Ltd., UK). The recovered BAL aliquots are pooled and cell counts made as described below.

Immediately after BAL, the lung vasculature is flushed with RPMI 1640/FCS to remove the blood pool of cells. The lung lobes are removed and cut into 0.5 mm pieces. Samples (rats: 400mg; mice: 150mg) of homogenous lung tissue are incubated in RPMI 1640/FCS with collagenase (20 U/ml for 2 hours, then 60 U/ml for 1 hour, 37°C) to disaggregate cells from the tissue. Recovered cells are washed in RPMI 1640/FCS.

Counts of total leukocytes recovered from the airway lumen and the lung tissue are made with an automated cell counter (Cobas Argos, US). Differential counts of eosinophils, neutrophils and mononuclear cells are made by light microscopy of cytocentrifuge preparations stained with Wright-Giemza stain (Sigma, UK). T cells are counted by flow cytometry (EPICS XL, Coulter Electronics, US) using fluophore-labelled antibodies against CD2 (a pan-T cell marker used to quantify total T cells), CD4, CD8 and CD25 (a marker of activated T cells). All antibodies were supplied by Serotec Ltd., UK) 2.5 Data analysis.

The cell data was expressed as mean cell numbers in unchallenged, challenged and vehicle treated, and challenged and compound treated groups, including the standard error of the means. Statistical analysis of the difference among treatment groups was evaluated using one- way analysis of variance via the Mann-Whitney test. Where p < 0.05 no statistical significance existed. The inhibitors of the invention caused a statistically significant reduction in eosinophil and lymphocyte numbers in the BAL and airway tissue. The inhibitors of the invention caused a statistically significant reduction in eosinophil and lymphocyte numbers in the BAL and airway tissue at doses within the range 100 mg/kg to 0.01 mg/kg.

3. Inhibition of Antizen Induced Airwav Sensitivitv in Allergic Sheep The experiment was performed essentially as described in W. M. Abraham et al, J. Clin. Invest., (1994) Vol 93,776-787. The experiment used allergic sheep which had been previously shown to develop early and late phase responses to inhaled challenge with Ascaris suum antigen. The inhibitors of the invention were delivered as an aerosol to the sheep and caused a statistically significant reduction of Ascaris suum induced airway responses when dosed at lmg/kg.