Concise Approach toward Tetrazolo[1,5-a][1,4]benzodiazepines via a Novel Multicomponent Isocyanide-Based Condensation

A novel and efficient method for the synthesis of heteroannulated [1,4]benzodiazepines via an isocyanide-based multicomponent reaction is reported. The tetrazolo[1,5-a][1,4]benzodiazepines were obtained by a facile azide Ugi five-center four-component reaction (U-5C-4CR) using ketones, sodium azide, ammonium chloride, and corresponding isocyanide. The aforementioned tetrazolodiazepines represent a notable class of compounds with proven platelet aggregation inhibitory and cholecystokinin agonist activities.