Nano silica sulfuric acid catalyzed facile synthesis of azothiadiazoles under cogrinding and solvent-free technique

Abstract

An efficient method for the use of nano silica sulfuric acid as a heterogeneous catalyst in the synthesis of thiadiazolecontaining azo dyes via diazo coupling of substituted amino thiazole under solvent-free conditions is described. The method presented is effective, green, inexpensive, and satisfactory to give the products in high yield with an excellent purity in short times under mortar–pestle grinding. The environmental friendliness and re-usability of the catalyst make this protocol attractive in organic synthesis.