Antiviral 2,5-disubstituted imidazo[4,5-c]pyridines: Further optimization of anti-hepatitis C virus activity

Substituted 5-beiizyl-2-phenyl-5H-imidazo[4,5-c]pyridines represent a novel class of compounds with activity against pestiviruses and the hepatitis C virus (HCV). Several series of analogues with modifications of the substituents in positions 2 and 5 were prepared. These efforts resulted in the discovery of several compounds with potent antiviral activity of which 2-(2,3-difluorophenyl)5-[4-(trifluoromethyl)beiizyl]-5H-imidazo[4,5-c]pyridine (46) was most potent against HCV (EC50 of 0. 10 mu M and a selectivity index of 1080). (c) 2007 Elsevier Ltd. All rights reserved.