SYNTHESIS OF SOME NEW FUSED SPIROHETEROCYCLIC SYSTEMS RELATED TO THIAZOLOPYRANS, THIAZOLOTHIOPYRANS AND THIAZOLOPYRIDINES

Abstract

1-Oxa-4-thiaspiro[4.4]nonan-2-one and/or 1-oxa-4-thiaspiro[4.5]decan-2-one were reacted with aniline to give the corresponding spirothiazolidinones(1a, b). Reaction of 1a, b with chalcones yielded 2-(α-aracylbenzyl)-4-phenyl-1-thia-4-azaspiro[4.4]nonan-3-one and 2-(α-aracylbenzyl)-4-phenyl-1-thia-4-azaspiro[4.5]decan-4-one (2a–h). Compounds 2a–h were reacted with acetic anhydride, phosphorus pentasulfide and ammonium acetate to give spirothiazolopyrans 3a–h, spirothiazolothiopyrans 4a–h and spirothiazolodihyropyridines 5a–h respectively. All the synthesized spiroheterocycles derivatives were identified by conventional methods (IR, ¹H-NMR) and elemental analyses.

Key Words:

• Spirothiazolopyrans
• Spirothiazolothiopyrans
• Spirothiazolodihyropyridines
• Spiroheterocycles
• NMR