Dual pro-drugs of 2′-C-methyl guanosine monophosphate as potent and selective inhibitors of hepatitis C virus

We have previously reported the power of combining a 5'-phosphoramidate ProTide, phosphate prodrug, motif with a 6-methoxy purine pro-drug entity to generate highly potent anti-HCV agents, leading to agents in clinical trial. We herein extend this work with the disclosure that a variety of alternative 6-substituents are tolerated. Several compounds exceed the potency of the prior 6-methoxy leads, and in almost every case the ProTide is several orders of magnitude more potent than the parent nucleoside. We also demonstrate that these agents act as pro-drugs of 2'-C-methyl guanosine monophosphate. We have also reported the novel use of hepatocyte cell lysate as an ex vivo model for ProTide metabolism. (C) 2011 Elsevier Ltd. All rights reserved.