US Patent 7557130 Bicyclic heteroaromatic alanines

Compounds of formula (1) are described: in which X is an —O— or —S— atom or —N(R2)— group and R1 is a group Ar1L2Ar2Alk- in which Ar1 is an optionally substituted aromatic or heteroaromatic group, L2 is a covalent bond or a linker atom or group, Ar2 is an optionally substituted bicyclic heteroarylene group and Alk is a chain —CH2—CH(R)—, —CH═C(R)—, OR—CH(CH2R)— in which R is a carboxylic acid (—CO2H) or a derivative or biostere thereof. The compounds are selective inhibitors of alpha 4 integrins such as α4β1 and are of use in modulating cell adhesion for the prophylaxis or treatment of inflammatory diseases or disorders, such as rheumatoid arthritis, in which the extravasculation of leukocytes plays a role.