Antibacterial agents

A compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof

• R1 represents hydrogen, C1-C6 alkyl or C1-C6 alkyl substituted by one or more halogen atoms;
• R2 represents a group R10—(ALK)m—wherein
• R10 represents hydrogen, or a C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, a cycloalkyl, aryl, or heterocyclyl group, any of which may be unsubstituted or substituted by (C1-C6)alkyl, (C1-C6)alkoxy, hydroxy, mercapto, (C1-C6)alkylthio, amino, halo, trifluoromethyl, nitro, —COOH, —CONH2, —COORA, —NHCORA, —CONHRA, —NHRA, —NRARB, or —CONRARB wherein RA and RB are independently a (C1-C6)alkyl group,
• ALK represents a straight or branched divalent C1-C6 alkylene, C2-C6 alkenylene, C2-C6 alkynylene radical, and may be interrupted by one or more non-adjacent —NH—, —O— or —S— linkages, and
• m represents 0 or 1;
• A represents (i) a group of formula (IA), (IB), (IC) or (ID)
• wherein:
• in the case of (IA), (IB), and (IC) R3 and R4 when taken together with the nitrogen and carbon atoms to which they are respectively attached form an optionally substituted saturated heterocyclic ring of 5 to 8 atoms which ring is optionally fused to a carbocyclic or second heterocyclic ring and in the case of formula (IC), R3 may also represent hydrogen and R4 may represent the side chain of a natural or non-natural alpha amino acid;
• in the case of (ID), R5 and R6 when taken together with the nitrogen atom to which they are attached form an optionally substituted saturated heterocyclic ring of 3 to 8 atoms which ring is optionally fused to a carbocyclic or second heterocyclic ring, and in the case of (IA), R6 and R5 are as defined in relation to (ID) or independently represent hydrogen or optionally substituted C1-C8 alkyl, cycloalkyl, aryl(C1-C6)alkyl, non-aromatic heterocyclic or heterocyclic(C1-C6 alkyl);
• and
• R7 represents hydrogen, C1-C6 alkyl, or an acyl group.