Bicyclic heteroaromatic derivatives of formula (1) are described: F (1) where: the dashed line joining A and C(R.sup.a) is present and represents a bond and A is a --N.dbd. atom or a --C(R.sup.b).dbd. group, or the dashed line is absent and A is a --N(R.sup.b)--, or --C(R.sup.b)(R.sup.c)-- group; X is an --O--, --S-- or substituted nitrogen atom or a --S(O)--, --S(O.sub.2)-- or --NH-group; Y is a nitrogen or substituted carbon atom or a --CH.dbd. group; n is zero or the integer 1; Alk.sup.1 is an optionally substituted aliphatic or heteroaliphatic chain L.sup.1 is a covalent bond or a linker atom or group; Cy.sup.1 is a hydrogen atom or an optionally substituted cycloaliphatic, polycycloaliphatic, heterocycloaliphatic, polyheterocycloaliphatic, aromatic or heteroaromatic group; Ar is an optionally substituted aromatic or heteroaromatic group; and the remaining substituents are defined in the specification. The compounds are potent and selective inhibitors of p38 kinase and are of use in the prophylaxis and treatment of immune or inflammatory disorders. ##STR00001##