Antibacterial agents

Compounds of formula (I) have antibacterial activity: wherein R represents hydrogen or 1, 2 or 3 optional substituents; W is ═C(R 1 )— or ═N—; R 1 is hydrogen or an optional substituent and R 2 is hydrogen, methyl, or fluorine; or R 1 and R 2 taken together are —CH 2 —, —CH 2 CH 2 —, —O—, or, in either orientation, —O—CH 2 — or —OCH 2 CH 2 —; R 3 is a radical of formula -(Alk 1 ) m -(Z) p -(Alk 2 ) n -Q wherein m, p and n are independently 0 or 1, provided that at least one of m, p and n is 1, Z is —O—, —S—, —S(O)—, —S(O 2 )—, —NH—, —N(CH 3 )—, —N(CH 2 CH 3 )—, —C(═O)—, —O—(C═O)—, —C(═O)—O—, or an optionally substituted divalent monocyclic carbocyclic or heterocyclic radical having 3 to 6 ring atoms; or an optionally substituted divalent bicyclic heterocyclic radical having 5 to 10 ring atoms; Alk 1 and Alk 2 are optionally substituted C 1 -C 6 alkylene, C 2 -C 6 alkenylene, or C 2 -C 6 alkynylene radicals, which may optionally terminate with or be interrupted by —O—, —S—, —S(O)—, —S(O 2 )—, —NH—, —N(CH 3 )—, or —N(CH 2 CH 3 )—; and Q is hydrogen, halogen, nitrile, or hydroxyl or an optionally substituted monocyclic carbocyclic or heterocyclic radical having 3 to 6 ring atoms; or an optionally substituted bicyclic heterocyclic radical having 5 to 10 ring atoms.