Novel HCV NS5B polymerase inhibitors derived from 4-(1′,1′-dioxo-1′,4′-dihydro-1′λ6-benzo[1′,2′,4′]thiadiazin-3′-yl)-5-hydroxy-2H-pyridazin-3-ones. Part 5: Exploration of pyridazinones containing 6-amino-substituents

Abstract: The synthesis of 4-(1′,1′-dioxo-1′,4′-dihydro-1′λ6-benzo[1′,2′,4′]thiadiazin-3′-yl)-5-hydroxy-2H-pyridazin-3-ones bearing 6-amino substituents as potent inhibitors of the HCV RNA-dependent RNA polymerase (NS5B) is described. Several of these agents also display potent antiviral activity in cell culture experiments (EC50 <0.10μM). In vitro DMPK data (microsome t 1/2, Caco-2 P app) for many of the compounds are also disclosed, and a crystal structure of a representative inhibitor complexed with the NS5B protein is discussed. [Copyright &y& Elsevier]