Synthesis and antimicrobial activities of 2-azetidinyl-4-quinazolinone derivatives of diclofenac analogue

A new class of 2-azetidinyl-4-quinazolinones 6a–k was synthesized by multi-step process, starting from 2-2-(2,6-dichlorophenyl)amino]phenyl acetic acid 1. Acid 1 was easily converted to acid chloride 2, which on cyclization reaction with 5-bromo anthranilic acid yielded benzoxazinone 3. The condensation reaction of 3 with benzene-1,4-diamine afforded 4-quinazolinone 4. Finally the title compound 6a–k was synthesized from 4-quinazolinone 4 by Schiff base formation 5a–k with aromatic aldehyde and then cyclization reaction with chloroacetylchloride. The in vitro antimicrobial activity of compounds 5a–k and 6a–k were tested. These compounds showed pronounced antimicrobial activity when 4-Cl and 4-OCH ₃ groups were present.