Design and synthesis of novel anthranilic acid analogs as HCV polymerase inhibitors

ORGN 658

Kevin J. Curran, currank@wyeth.com1, Thomas Nittoli, Shabana Insaf1, Amar S. Prashad, Prashaa@wyeth.com1, M. Brawner Floyd1, Mark Orlowski2, Anita Howe2, Rajiv Chopra1, Atul Agarwal1, and Jonathan Bloom1. (1) Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965, (2) Infectious Diseases, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965
We have identified a series of novel anthranilic acid derivatives that are potent, reversible inhibitors of Hepatitis C virus (HCV) NS5B polymerase, an essential enzyme for viral replication. The micromolar NS5B polymerase inhibitors belong to the N-phenoxyacetylanthranilic acid chemotype. X-ray crystallography determined that the inhibitors bind to a site on NS5B between the thumb and palm regions adjacent to the active site. Guided by crystallography, subsequent modifications to the hydrogen bonding and lipophilic regions of the inhibitors resulted in greatly improved activity against NS5B. Further SAR studies revealed a second, more potent sub-series where the phenoxy group was replaced by an anilino group. Analogs in both sub-series showed antiviral activity in a cell-based replicon model of HCV.