Benzimidazole derivatives as novel nonpeptide luteinizing hormone-releasing hormone (LHRH) antagonists. Part 2: Benzimidazole-5-sulfonamides

Abstract The 2-cyclopropyl substituted benzimidazole 2 has been used as a starting point for further optimization of an LHRH antagonist series. SAR studies revealed that a tert -butyl urea fragment connected through a simple carbon chain would improve activity. Further modification of the benzylsulfonamide moiety led to the discovery of 23 (IC 50 : 4.2 nM).