Viral polymerase inhibitors

A compound of formula (I):

• wherein:
• either A or B is N and the other B or A is C, wherein ----- between two C-atoms represents a double bond and ----- between a C-atom and a N-atom represents a single bond;
• R1 is H or (C1-6)alkyl;
• R2 is (C1-6)alkyl, (C2-6)alkynyl, —C(═O)—(C1-6)alkyl, aryl or Het;
• the aryl and Het being optionally substituted with R21;
• wherein R21 is one, two or three substituents each independently selected from (C1-6)alkyl, (C3-7)cycloalkyl, Het, —CN, —NH2, —NH(C1-6)alkyl, —N((C1)alkyl)2, halo, —O—(C1-6)alkyl, —S—(C1-6)alkyl, —SO—(C1-6)alkyl and —SO2—(C1-6)alkyl;
• wherein the (C1-6)alkyl, —O—(C1-6)alkyl, —S—(C1-6)alkyl, —SO—(C1-1)alkyl and —SO2—(C1-6)alkyl are each optionally substituted with one, two or three halo substituents;
• R3 is (C5-6)cycloalkyl, optionally substituted with from one to four halo substituents;
• R5 is selected from H, (C1-6)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C3-7)cycloalkyl, (C3-7)cycloalkyl-(C1-6)alkyl-, Het and Het-(C1-6)alkyl-;
• wherein the (C1-6)alkyl is optionally substituted with from one to three substituents each independently selected from halo, cyano, (C1-6)alkoxy, —NH(C1-6)alkyl, —N((C1-6)alkyl)2 and —NHSO2(C1-6)alkyl;
• and
• wherein each of the Het and the Het portion of the Het-(C1-6)alkyl- is optionally substituted with (C1)alkyl;
• and
• R6 is selected from H, (C1-6)alkyl and halo;
• or
• R5 and R6 are linked such that the group of the subformula
• is a group of formula
• wherein n is 0, 1 or 2;
• and wherein R50 is selected independently in each instance from H, halo, cyano, (C1-6)alkoxy, (C1-)alkyl, (C2-6)alkenyl, (C2-6)alkynyl, (C3-7)cycloalkyl, (C3-7)cycloalkyl-(C1-6)alkyl-, Het and Het-(C1-6)alkyl-;
• wherein the (C1-6)alkyl is optionally substituted with from one to three substituents each independently selected from halo, cyano, (C1-6)alkoxy, —NH(C1-6)alkyl, —N((C1-6)alkyl)2 and —NHSO2(C1-6)alkyl;
• and wherein each of the Het and the Het portion of the Het-(C1-6)alkyl- is optionally substituted with (C1-6)alkyl;
• R7 is selected from H, (C1-)alkyl, (C1-6)alkoxy, (C1-6)alkylthio, —NH2, —NH(C1-6)alkyl, —N((C1-6)alkyl)2 and halo;
• R9 and R10 are each independently selected from (C1-6)alkyl;
• or R9 and R10 are covalently bonded together to form (C3-7)cycloalkyl, (C5-7)cycloalkenyl or a 4-, 5- or 6-membered heterocycle having from 1 to 3 heteroatoms each independently selected from O, N, and S;
• wherein the cycloalkyl, cycloalkenyl or heterocycle is optionally substituted with (C1-4)alkyl;
• wherein Het is defined as a 4- to 7-membered heterocycle having 1 to 4 heteroatoms each independently selected from O, N and S, which may be saturated, unsaturated or aromatic, and which is optionally fused to at least one other cycle to form a 7 to 14-membered heteropolycycle having wherever possible 1 to 5 heteroatoms, each independently selected from O, N and S, the heteropolycycle being saturated, unsaturated or aromatic;
• or an enantiomer, diastereoisomer or tautomer thereof, including a salt, ester or derivative thereof.