A novel carbon-based solid acid catalyst (SC-GCa-800) was prepared by the high-temperature carbonization of calcium gluconate followed by sulfonation with 4-diazoniobenzenesulfonate at room temperature.
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.