Green synthesis of 1,2,4-triazole-3-thione derivatives in natural deep eutectic solvents

Heterocyclic compounds containing heteroatoms N, S and O represents important place in medical chemistry. Triazole ring is present in many natural products and biologically active compounds. For example, triazole derivatives were considered as antifungal and antiviral agants [1,2]. Deep eutectic solvents play an essential key in green chemistry. They are nontoxic, reusable, eco-friendly and environmentally organic compounds. Deep eutectic solvents act as catalysts in many reactions [3]. In this project, various hydrazide derivatives were reacted with alkyl or aryl isothiocyanates under optimized conditions in a deep eutectic solvents including glycerol-potassium carbonate to afford novel 1,2,4-triazole-3-thione derivatives (scheme. 1). The progress of the reaction was checked by TLC. The chemical structures of all compounds were confirmed by IR and 1H NMR and 13C NMR spectral data. Simple work‐up, mild reaction conditions, short reaction times, use of a green eutectic solvent, and excellent product yields are advantages of this method.