Synthetic and Mechanistic Studies on the Preparation of Pyridyl-Substituted Imidazothiazoles

Article abstract of DOI:10.1021/jo00253a012

A new method is presented for the introduction of the 4'-pyridyl substituent into 6-aryl-2,3-dihydroimidazo<2,1-b>thiazoles.The method involves treatment of the imidazothiazolines with the reactive complex of pyridine and ethyl chloroformate and oxidative deethyl carboxylation of the dihydropyridine adducts formed.Sulfur in refluxing mesitylene was found most suitable for the latter reaction, but chromium trioxide in pyridine or KtBuO and air were also effective.