Facile access to 3,5-symmetrically disubstituted 1,2,4-thiadiazoles through phosphovanadomolybdic acid catalyzed aerobic oxidative dimerization of primary thioamides.

In the presence of Keggin-type phosphovanadomolybdic acids, e.g., H6PV3Mo9O40, oxidative dimerization of various kinds of primary thioamides including aromatic, heterocyclic, and aliphatic ones efficiently proceeded to give the corresponding 3,5-disubstituted 1,2,4-thiadiazoles in excellent yields.