Safe and Efficient Tetrazole Synthesis in a Continuous Flow Microreactor

Abstract

Safer flow: The synthesis of 5-substituted tetrazoles in flow (see scheme) is safe, efficient, scalable, requires no metal promoter, and uses a near-equimolar amount of NaN[subscript 3], yet nonetheless displays a broad substrate scope. The hazards associated with HN[subscript 3] are essentially eliminated, shock-sensitive metal azides such as Zn(N[subscript 3])[subscript 2] are avoided, and residual NaN[subscript 3] is quenched in-line with NaNO[subscript 2].