Syntheses and reactivity of zwitterionic bicyclic imidazo-thiazole derivatives

Abstract

Betaines of bicyclic imidazo-thiazoles were synthesized by the reaction of electrophiles such as phenyl isocyanate, phenyl isothiocyanate, methyl isocyanate, methyl isothiocyanate, allyl isothiocyanate, carbon disulfide and ketene, with 3-methyl-5,6-dihydroimidazo [2,1-b] thiazole and 3-phenyl-5,6-dihydroimidazo [2,1-b] thiazole. The corresponding betaines were obtained in excellent yields under mild conditions. The betaines reacted with methyl iodide to give quaternary ammonium salts. The reaction of the betaines of imidazo-thiazole derivatives with some $\alpha$-haloketone and $\alpha$-haloester was caused to transform to a new type of biheterocyclic compounds.