Silica Gel-Supported Sulfuric Acid Catalyzed Synthesis of 1,5-Benzodiazepine Derivatives

摘要

Silica gel-supported sulfuric acid has been found to be an efficient catalyst for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones in acetonitrile solvent. This method is simple, effective, and environmentally friendly and gives better yields. Compared to the classical reaction conditions, this new method consistently has the advantage of excellent yields (80-97%) and short reaction time (30-150 min) at room temperature.