A green one-pot synthesis of 3(5)-substituted 1,2,4-triazol-5(3)-amines as potential antimicrobial agents

Abstract

An efficient procedure was proposed for the synthesis of 3(5)-substituted 1,2,4-triazol-5(3)-amines via a one-pot reaction of thiourea, dimethyl sulfate and various hydrazides. 1,2,4-Triazole derivatives were prepared in aqueous media under mild conditions while adhering to some principles of green chemistry. The products were easily isolated in 83–95% yields without any need for further purification. Inhibitory activities of all synthetic compounds were assessed against a variety of Gram-positive and Gram-negative pathogenic bacteria as well as some fungal pathogens. The best antibacterial effects were observed with 3(5)-phenyl-1H-1,2,4-triazol-5(3)-amine according to its MIC values (4–8 μg mL−1). All compounds were successful in blocking the growth of fungi. Acceptable antioxidant properties were observed only with 3(5)-(4-nitrophenyl)-1H-1,2,4-triazol-5(3)-amine. 3(5)-Substituted 1,2,4-triazol-5(3)-amines were efficiently prepared via a one-pot reaction of thiourea, dimethyl sulfate and various hydrazides in water as the solvent. Inhibitory activity of all synthesized derivatives was proved according to their MIC, MBC and MFC values. It is found that they are potential antifungal agents.