Discovery of benzimidazole-diamide finger loop (Thumb Pocket I) allosteric inhibitors of HCV NS5B polymerase: Implementing parallel synthesis for rapid linker optimization

Previously described SAR of benzimidazole-based non-nucleoside finger loop (Thumb Pocket I) inhibitors of HCV NS5B polymerase was expanded. Prospecting studies using parallel synthesis techniques allowed the rapid identification of novel cinnamic acid right-hand sides that provide renewed opportunities for further optimization of these inhibitors. Novel diamide derivatives such as 44 exhibited comparable potency (enzymatic and cell-based HCV replicon) as previously described tryptophan-based inhibitors but physicochemical properties (e. g., aqueous solubility and lipophilicity) have been improved, resulting in molecules with reduced off-target liabilities (CYP inhibition) and increased metabolic stability. (C) 2009 Elsevier Ltd. All rights reserved.