Design, synthesis and identification of novel benzimidazole derivatives as highly potent NPY Y5 receptor antagonists with attractive in vitro ADME profiles

Optimization of our HTS hit 1, mainly focused on modification at the C-2 position of the benzimidazole core, is described. Elimination of the flexible and metabolically labile -S-CH2- part and utilization of less lipophilic pyridone substructure led to identification of novel NPY Y5 receptor antagonists 6, which have low to sub-nanomolar Y5 receptor binding affinity with improved CYP450 inhibition profiles, good solubilities and high metabolic stabilities.