Compounds of formula (IA) or (IB) have antibacterial activity: wherein W is ═CH— or ═N—; Ri and R2 are independently selected from hydrogen, fluoro and chloro, provided that Ri and R2 are not each hydrogen when W is ═CH—; n is 0 or 1; X is —O—, —S—, or —CH
2
—; and Q is (i) a phenyl radical, a naphthyl radical, a monocyclic carbocyclic or heteroaryl radical having 3 to 6 ring atoms, or a bicyclic heteroaryl radical having 5 to 10 ring atoms, any of which radicals being optionally substituted; or (ii) an optionally substituted C
1
-C
6
alkyl, C
2
-C
6
alkenyl, or C
2
-C
6
alkynyl radical, which may optionally be interrupted by —O—, —S—, —S(O)—, —S(O
2
)—, —NH—, —N(CH
3
)—, —N(CH
2
CH
3
)—, —C—K═Oh or —C(═O)—O—.
Compounds of formula (IA) or (IB) have antibacterial activity: wherein W is ═CH— or ═N—; Ri and R2 are independently selected from hydrogen, fluoro and chloro, provided that Ri and R2 are not each hydrogen when W is ═CH—; n is 0 or 1; X is —O—, —S—, or —CH2—; and Q is (i) a phenyl radical, a naphthyl radical, a monocyclic carbocyclic or heteroaryl radical having 3 to 6 ring atoms, or a bicyclic heteroaryl radical having 5 to 10 ring atoms, any of which radicals being optionally substituted; or (ii) an optionally substituted C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl radical, which may optionally be interrupted by —O—, —S—, —S(O)—, —S(O2)—, —NH—, —N(CH3)—, —N(CH2CH3)—, —C—K═Oh or —C(═O)—O—.
Compounds of formula (IA) or (IB) have antibacterial activity: wherein W is =CH- or =N-; Ri and R2 are independently selected from hydrogen, fluoro and chloro, provided that Ri and R2 are not each hydrogen when W is =CH-; n is 0 or 1; X is -O-, -S-, or -CH2-; and Q is (i) a phenyl radical, a naphthyl radical, a monocyclic carbocyclic or heteroaryl radical having 3 to 6 ring atoms, or a bicyclic heteroaryl radical having 5 to 10 ring atoms, any of which radicals being optionally substituted; or (ii) an optionally substituted C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl radical, which may optionally be interrupted by -O-, -S-, -S(O)-, -S(O2)-, -NH-, -N(CH3)-, -N(CH2CH3)-, - C-K=Oh or -C(=O)-O-.