Discovery of 4′-azido-2′-deoxy-2′-C-methyl cytidine and prodrugs thereof: A potent inhibitor of Hepatitis C virus replication

4′-Azido-2′-deoxy-2′-methylcytidine (14) is a potent nucleoside inhibitor of the HCV NS5B RNA-dependent RNA polymerase, displaying an EC50 value of 1.2 μM and showing moderate in vivo bioavailability in rat (F = 14%). Here we describe the synthesis and biological evaluation of 4′-azido-2′-deoxy-2′-methylcytidine and prodrug derivatives thereof.