Highly regioselective heterocyclization reactions of 1H-1,2,4-triazole-3-thiols with chloroacetylenephosphonates

A method is developed for the synthesis of new condensed phosphorylated heterocycles and related zwitterions based on the regioselective condensation of chloroacetylenephosphonates with the heterocyclic binucleophiles, 3-substituted 1H-1,2,4-triazole-3-thiols, in anhydrous acetonitrile.