Discovery of cyclic guanidines as potent, orally active, human glucagon receptor antagonists

In the course of the development of an aminobenzimidazole class of human glucagon receptor (hGCGR) antagonists, a novel class of cyclic guanidine hGCGR antagonists was discovered. Rapid N-dealkylation resulted in poor pharmacokinetic profiles for the benchmark compound in this series. A strategy aimed at blocking oxidative dealkylation led to a series of compounds with improved rodent pharmacokinetic profiles. One compound was orally efficacious in a murine glucagon challenge pharmacodynamic model and also significantly lowered glucose levels in a murine diabetes model.