Novel 6,8-dibromo-4(3H)-quinazolinone derivatives of promising anti-inflammatory and analgesic properties

Abstract

A new series of the title compounds incorporated into diverse N and O heterocyclic moieties of pharmacoavailability as anti-inflammatory and analgesic agents, were synthesized starting with 6,8-dibromo-2-phenyl-4H-3,1-enzoxazin-4- one (I) by its fusion with p-aminoacetophenone to give the new intermediate compound, 6,8-dibromo-2-phenyl-3-(4-acetylphenyl)-4(3H)-quinazolinone (II). The one pot reaction of II with the appropriate aromatic aldehydes and anhyd. ammonium acetate in the presence of either ethyl cyanoacetate or malononitrile afforded the corresponding 2(1H)-pyridones III or 2(1H)-iminopyridines IV, respectively, while its reaction with malononitrile and aromatic aldehydes in piperidine gave 2-aminopyrans V. Also, reaction of the acetyl derivative II with aromatic aldehydes afforded the corresponding 1,3-propen-1-one derivatives VI which underwent cyclization with hydrazine to give the corresponding pyrazolines VII and with urea and/or thiourea to give the corresponding tetrahydropyrimidin-2-ones and/or tetrahydropyrimidin-2-thiones VIII . Some representative examples of the new compounds showed promising anti-inflammatory and analgesic activities in experimental animals.