Expedient Access to Novel Bis-tetrazolopiperazines via Ugi-azide Reactions

A one-pot four-component synthesis of bis-tetrazolopiperazines in moderate to high yields is described. The reaction consists of condensation of aldehydes or cyclic ketones with piperazine, trimethylsilyl azide, and isocyanides. High reaction efficiency, short reaction time, mild reaction condition, use of simple experimental procedure, and prompt isolation of the products are some advantages of this protocol.