Synthesis, Characterization and Antifungal Activity of Some 5-Substituted 4-Amino-1,2,4-triazole-3-thiols

Abstract

A series of 5-substituted 4-amino-1,2,4-triazole-3-thiols (4a-i) was synthesized by refluxing substituted organic acids (a-i) with methanol to the corresponding esters (1a-i). These esters were then converted to hydrazides (2a-i) by reaction with hydrazine hydrate in the presence of absolute ethanol. The hydrazides were then converted to 5-substituted 1,3,4-oxadiazole-2-thiols (3a-i) by cyclization reaction with carbon disulfide and KOH which was followed by reaction with hydrazine hydrate in the presence of absolute ethanol. Structure of the synthesized compounds was established by physico-chemical and spectral data analysis. Synthesized compounds were subjected to antifungal activity. Antifungal activity analysis was performed against Aspergillus flavus, Mucor species, Aspergillus niger and Aspergillus fumigates, with test compounds at a concentration of 200 μg/mL. Terbinafine was used as the standard drug.