Synthesis of New ۲-Azetidinone Derivatives and Related Schiff Bases from ۳-Phenyl-۲,۳,۶,۷-tetrahydroimidazo [۲,۱-b] Thiazolo [۵,۴-d] Isoxazole

۲-Azetidinones, commonly known as β-lactams, are well-known heterocyclic compounds. Herein we described the synthesis of a series of novel β-lactams. The efficient and rapid synthesis of novel β-lactams has been established in good yields starting from (R)-۳-phenyl-۲, ۳, ۶, ۷-tetrahydroimidazo [۲', ۱':۲, ۳] thiazolo [۵, ۴-d] isoxazole ۱. First, (R)-۳-phenyl-۲, ۳, ۶, ۷-tetrahydroimidazo [۲', ۱':۲, ۳] thiazolo [۵, ۴-d] isoxazole ۱ on condensation with ethylchloro acetate yielded Ethyl (R) ۲-(۳-phenyl- ۶, ۷-dihydroimidazo [۲', ۱':۲,۳] thiazolo [۵, ۴-d] isoxazole-۲(۳H)-yl) acetate ۲, which on amination with hydrazine hydrate yielded (R) ۲-(۳-phenyl- ۶, ۷-dihydroimidazo [۲', ۱':۲, ۳] thiazolo [۵, ۴-d] isoxazol -۲(۳H)-yl) acetohydrazide ۳. Then, condensation between compound ۳ and various aromatic aldehydes give Schiff base derivatives ۴a-j, which upon dehydrative annulation in the presence of chloroacetyl chloride and triethylamine yielded N-((۳S, ۴S)-۳-chloro-۲-oxo-۴-phenylazetidin-۱-yl)-۲-((R)-۳-(Aryl)-۶, ۷-dihydroimidazo [۲', ۱':۲, ۳] thiazolo [۵, ۴-d] isoxazol -۲(۳H)-yl) acetamide ۵a-j. All synthesized compounds were characterized by elemental analyses, IR, ۱H-NMR and ۱۳C-NMR data.

Keywords:

Condensation , Synthesis , Schiff bases , ۲-Azetidinones , β-Lactam