Synthesis and Antimicrobial Screening of Novel Azetidin-2-ones Derived from Pyromellitic Diimide via [2+2]-Cycloaddition Reaction

A series of novel 2-azetidinone derivatives have been obtained starting from pyromellitic dianhydride. Pyromellitic dianhydride was converted to pyromellitic diimide using sodium cyanate, and the diimide was alkylated with ethyl chloroacetate. The resulting diester was treated with hydrazine hydrate to obtain dihydrazide which reacted with substituted pyridine-2-carbaldehydes to give the corresponding Schiff bases, and [2+2]-cycloaddition of the latter with chloroacetyl chloride in the presence of triethylamine afforded the target azetidin-2-one derivatives. The newly synthesized compounds showed high antimicrobial activities against some bacterial and fungal strains.