Synthesis Some of New Substituted 1,3,4-Thiadiazole and 1,2,4-Triazole

Abstract

The aim of this paper, the synthesis of new series of substituted 1,3,4-thaidiazole and 1,2,4-triazol from reaction of the carboxylic acid (2-naphthoic acid,4-methyl benzoic acid) with absolute ethanol in the presence of concentrated sulfuric acid to give esters. the above synthesis ester were converted to acid hydrazide by their reaction with hydrazine hydrate in ethanol, which then reacted with ammonium thiocyanate and hydrochloric acid in ethanol or with phenylisothiocyanate in absolute ethanol to give substituted thiosemicarbazides compounds. the substituted thiosemicarbazides then uses to synthesis of many hyterocyclic compounds like substituted 1,3,4-thiadiazole and 1,2,4-triazole by its reaction with concentrated sulfuric acid and sodium hydroxide respectively. the substituted thiosemicarbazides then cyclization to substituted 3,4-diamine-1,2,4-triazole when treated with hydrazine hydrate. And finally the N- acetyl-N-substituted hydrazide compounds synthesis by treated hydrazide with acetyl chloride in anhydrous tetrahydrofuran which then cyclized to 2-methyl substituted-1,2,4-thiadiazole by their reaction with diphosphorus pentoxide in xylene. The structure of the synthesized compounds were confirmed By physcical & spectroscopic techniques infrared (IR) and (1H-NMR) data.