1. Department of Chemistry, Yazd University, Yazd 89195‐741, Iran;2. Department of Chemistry, Isfahan University, Isfahan 81746‐73441, Iran
Abstract:
Alumina supported 12‐tungstophosphoric acid catalyzes efficiently the reaction of o‐phenylenediamine with ketones under solvent‐free condition to afford the corresponding 1,5‐benzodiazepines in good to excellent yields. The catalyst can be recovered and reused.