Bronsted acid catalyzed cyclization of propargylic alcohols with thioamides. Facile synthesis of di- and trisubstituted thiazoles

A general and efficient method is described for preparing 2,4-di- and trisubstituted thiazoles through p-TsOH.[H.sub.2]O-catalyzed cyclization of trisubstituted propargylic alcohols with thioamides. The reaction is achieved in under mild conditions that has not required the exclusion of air and moisture and has provided a convenient route to the synthetically useful aromatic heterocycle.