Concise route to a series of novel 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones

This Letter describes a novel three step solution phase protocol to synthesize 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones that utilizes the Ugi-Azide MCR followed by cyclization under acidic condition and immediate oxidation with TEMPO/CAN. The method was also expanded to produce a bis-benzodiazepine tetrazole.