A simple and environmentally benign room temperature synthesis of 1,2,4-triazolidine-3- thiones is described using Envirocat EPZ-10R as a solid acid catalyst in the aqueous medium. The use of Envirocat EPZ-10R as a green catalyst, reusability of the catalyst, water as a universal solvent and good yields of the product are the attractive features of the present method.
An environmentally benign, simple, rapid synthesis of 1,2,4-triazolidine-3-thiones at room temperature is reported using amino acid-derived Brønsted acidic ionic liquid L-proline nitrate [Pro+NO3 -] from aldehyde and thiosemicarbazide in an aqueous medium. A cost-effective and energy-efficient catalyst with the reusability of up to five cycles without significant loss in the catalytic activity makes this protocol superior. A faster reaction and easy work-up with excellent yields are the added advantages of this protocol.