Zinc chloride catalyzed synthesis of 5-substituted 1H-tetrazoles under solvent free condition

Zinc chloride is an efficient and safe catalyst in the [3 + 2] cycloaddition reaction of organic nitriles with sodium azide in solventless condition. The corresponding 5-substituted 1H tetrazoles were obtained under mild conditions. This method can overcome disadvantages such as: the use of toxic metals and expensive reagents, drastic reaction conditions, water sensitivity and the presence of dangerous hydrazoic acid.