Viral Polymerase Inhibitors

A compound of formula (I), salts, N-oxides, solvates, hydrates, racemates, enantiomers or diastereomers thereof:

• wherein
• Z1 and Z2 are each independently selected from C—H, C-halo, C—C1-4alkylhalo, C—C1-4alkoxy, C—C1-4alkoxyhalo and N;
• R1 is selected from H, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C1-6alkoxy, halo, C1-4alkylhalo, C1-4alkoxyhalo, C3-7cycloalkyl, C3-7cycloalkenyl, 5-6-membered heterocyclyl and 5-6 membered heteroaryl and wherein alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, heterocyclyl and heteroaryl in each occurrence may be optionally substituted;
• R2 is H or an optional substituent;
• R3 is an optionally substituted 6-membered heteroaryl group containing N in the 2-(ortho) ring position with reference to the point of attachment or R3 is an optionally substituted 5-membered heteroaryl group containing N in the ring position adjacent to the point of attachment;
• R4 is H, C1-4alkyl, C2-4alkenyl, C2-4alkynyl, or C3-7cycloalkyl;
• R5 in each occurrence is independently H or optionally substituted C1-6 alkyl;
• m represents an integer selected from 0, 1, 2, 3, 4, 5 and 6;
• and
• each (CH2) moiety when present may be independently optionally substituted with one or two substituents;
• and further when m is an integer selected from 1, 2, 3, 4, 5 and 6 then one or more (CH2) may be replaced with O, C═O, NH, optionally substituted NC1-6alkyl, S, S═O or SO2.