An efficient and expeditious synthesis of 1,2,4-triazolidine-3-thiones using meglumine as a reusable catalyst in water

A simple, convenient, and eco-friendly procedure has been developed using meglumine (15 mol%) as a green catalyst for the synthesis of 1,2,4-triazolidine-3-thiones under one-pot condition. Variously substituted aldehydes or ketones reacted well with thiosemicarbazide to give desired compounds in extremely good quantity. The developed protocol offers several advantages such as shorter reaction times, mild reaction conditions, easy workup, simple purification procedures, water as a solvent, and wide substrate scope tolerance. Further, the catalyst was recycled (up to 4 cycles) without compromising the yield of the final products.

Graphical abstract

The current protocol demonstrates the synthesis of 1,2,4-triazolidine-3-thiones from variously substituted aldehydes or ketones with thiosemicarbazide under aqueous conditions. A simple stirring of the reaction at room temperature in the presence of the catalytic amount of meglumine quickly gave the desired product an excellent yield. The method is operationally simple and eco-friendly.