The invention provides compounds of the formula (I): or a salt, N-oxide or tautomer thereof, wherein A is CH, CF or nitrogen； E is CH, CF or nitrogen； and R0 is hydrogen or C1-2 alkyl； R1a is selected from CONH2； CO2H； an optionally substituted acyclic C1-8 hydrocarbon group； and an optionally substituted monocyclic carbocyclic or heterocyclic group of 3 to 7 ring members, of which 0, 1, 2, 3 or 4 are heteroatom ring members selected from O, N and S； R2 is selected from hydrogen and a group R2a； R2a is selected from an optionally substituted acyclic d-8 hydrocarbon group； an optionally substituted monocyclic carbocyclic or heterocyclic group of 3 to 7 ring members, of which 0, 1 or 2 ring members are heteroatom ring members selected from O, N and S； and an optionally substituted bicyclic heterocyclic group of 9 or 10 ring members, of which 1 or 2 ring members are nitrogen atoms； wherein at least one of R1 and R2 is other than hydrogen； R3 is an optionally substituted 3- to 10-membered monocyclic or bicyclic carbocyclic or heterocyclic ring containing 0, 1, 2 or 3 heteroatom ring members selected from N, O and S； R4a is selected from halogen； cyano； C1-4 alkyl optionally substituted with one or more fluorine atoms； C1-4 alkoxy optionally substituted with one or more fluorine atoms； hydroxy-C1-4 alkyl； and C1-2 alkoxy-C1-4 alkyl； R5 is selected from hydrogen and a substituent R5a； and R5a is selected from C1-2 alkyl optionally substituted with one or more fluorine atoms； C1-3 alkoxy optionally substituted with one or more fluorine atoms； halogen； cyclopropyl； cyano； and amino, The compounds have activity against hepatitis C virus and can be used in the prevention or treatment of hepatitis C viral infections.L'invention concerne des composés de formule (I), ou leur sel, N-oxyde ou tautomère, dans laquelle A est CH, CF ou azote； E est CH, CF ou azote； et R0 est hydrogène ou alkyle C1-2； R1a est choisi parmi CONH2, CO2H, un groupe hydrocarboné C1-8 acyclique éventuelleme
