Non-steroidal anti-inflammatory agents: synthesis of novel benzopyrazolyl, benzoxazolyl and quinazolinyl derivatives of 4(3 H)-quinazolinones.

Four novel series of 4(3 H)-quinazolinone derivatives have been synthesized by cyclization of the intermediate 3-aryl-2-(6-aryl-2-cyclohexen-1-on-5-yl)-4(3 H)-quinazolinones 3a-f with hydrazine, phenylhydrazine, hydroxylamine and thiourea. The products are 3-aryl-2-(6-aryl-3-methyl-1 H-4,5-dihydrobenzo[d]pyrazol-4-yl)-4(3 H)-quinazolinones 4a-f; 3-aryl-2-(6-aryl-3-methyl-1-phenyl-1 H-4,5-dihydrobenzo[d]pyrazol-4-yl)-4(3 H)-quinazolinones 4g-1; 3-aryl-2-(6-aryl-3-methyl-4,5-dihydrobenzo[d]-1,2-oxazol-4-yl)-4(3 H)-quinazolinones 5a-f, and 3-aryl-2-(7-aryl-4-methyl-5,6-dihydro-2(1 H)thioxoquinazolin-5-yl)-4(3 H)-quinazolinones 6a-f. Some of these compounds showed anti-inflammatory activity comparable to or higher than that of the reference compound proquazone.