Catalyst-free synthesis of N-rich heterocycles via multi-component reactions

Efficient and straightforward methods for the synthesis of 5-substituted 1H-tetrazoles via multi-component reaction of α-dicarbonyl compounds, 2,3-diaminomaleonitrile and sodium azide without any catalyst has been reported. These general protocols provide a wide variety of N-rich heterocyclic compounds (1H-tetrazole-5-yl) pyrazines and di(1H-tetrazole-5-yl) pyrazines, in good to excellent yields.