Synthesis of Some Novel Fused Substituted 3-(4-substitutedphenyl)-6,6-diphenyl-3,3a dihydroimidazo[2',1':2,3][1,3] thiazolo[4,5-c][1,2] isoxazoles

The present study describes the synthesis of some novel arylidene cyclic chalcones 2-(4-substituted benzylidene)-6,6-diphenylimidazo[2,1-b][1,3]thiazole-3,5-diones and their transformation to 3-(4-substitutedphenyl)-6,6-diphenyl-3,3a- dihydroimidazo[2',1':2,3][1,3]thiazolo[4,5-c][1,2]oxazol-7(6H)-ones via cyclization using hydroxylamine hydrochloride. The starting chalcones have been synthesized by the condensation of various aromatic aldehydes and methylene entity of synthesized imidazothiazole-3,5-diones which were obtained by the cyclization of 5,5-diphenyl-2-thioxoimidazolidin-4-ones and chloroacetic acid. The intermediate 5,5-diphenyl-2-thioxoimidazolidin-4-ones have been synthesized by the condensation of α-diketone (benzil) with thiourea in presence of ethanolic alkali followed by Pinacol-Pinacolone rearrangement. Structures of all the newly synthesized compounds were confirmed by chemical, analytical and spectral data.