Synthesis of 5-Substituted-1H-Tetrazoles from Nitriles and Azides in a Betaine-Diol-Based Deep Eutectic Solvent

摘要

Devising a simple, environmentally friendly, and reusable route for the 3+2 cycloaddition reaction of azides and nitriles to form tetrazoles is undoubtedly a challenging issue. Herein, a facile synthesis method for 5-substituted-1H-tetrazoles was developed by treating nitriles with NaN3 in a betaine-diol-based deep eutectic solvent. This protocol offers products in very high yields, an easy work-up procedure devoid of harmful organic solvents, and recyclability of the deep eutectic solvent, thereby making it environmentally benign.