Molecular-Iodine-Catalyzed One-Pot Synthesis of 1,5-Benzodiazepine Derivatives under Solvent-Free Conditions

Abstract

2,3-Dihydro-1H-1,5-benzodiazepines have been syn­thesized from o-phenylenediamine (OPDA) and ketones under ­solvent-free conditions in the presence of a catalytic amount of ­molecular iodine. All of the ketones, including cyclic ketones and acyclic ketones, reacted smoothly with OPDA to furnish products. Compared to other reaction conditions, this new protocol has the ­advantage of excellent yield and short reaction time at room temperature.