Reaction of chloroacetylenephosphonates with 5-thiotetrazoles

A method is developed for the synthesis of new condensed phosphorylated heterocycles, [1,3]thiazolo[3,2-d][1,2,3,4]tetrazol-7-ium chlorides and some related zwitterions, based on the regioselective condensation of chloroacetylenephosphonates with 1-substituted 5-thio-1H-1,2,3,4-tetrazoles as heterocyclic binucleophiles.