A Novel Approach To The Transformation of Pyrazole-4-Carbonitriles to Novel 3-Aryl-1-Phenyl-1H-Pyrazole-4-Carbothioamide Using Thioacetamide as a Sulfur Source

Abstract

New protocol designed for the synthesis of novel pyrazole-4-carbothioamide by the reaction of pyrazole-4-carbonitrile using thioacetamide in the presence of Amberlyst-15 as a catalyst in ethanol. Various methods are adopted for the synthesis of 3-Aryl-1-phenyl-1H-pyrazole-4-carbothioamides such as Amberlyst-15 method, Citric acid method, BF3-Etherate method and Dowex DR-2030 method. But Amberlyst-15 method offered highly pure product with excellent yield. Here, thioacetamide employed as sulfur source and avoid use of hazardous Lawesson’s Reagent, Na2S, H2S gas. Novel Pyrazole-4-Carbothioamides are synthesized and characterized by using 1H NMR, 13C NMR and Mass spectral techniques. It’s a rapid, single step and clean synthetic protocol for the synthesis of Pyrazole-4-carbonitriles with excellent yield (97-99%).