Synthesis and anti-inflammatory activity of 3,3a-dihydro-2H,9H-isoxazolo [3,2-b] [1,3]benzoxazin-9-ones and related compounds.

A series of 3,3a-dihydro-2H,9H-isoxazolo[3,2-b]-[1,3]benzoxazin-9-ones was synthesized and evaluated for anti-inflammatory, antipyretic and analgesic activity. Since many of these compounds exhibited promising activity, particularly in the anti-inflammatory tests, a number of homologous 2,3,4,4a-tetrahydro-10H-1,2-oxazino[3,2-b]-[1,3]benzoxazin-10-ones and one 3,4,5,5a-tetrahydro-2H, 11H,-1,2-oxazepino [3,2-b][1,3]benzoxazin-11-one, the 9-chloro analog, were also prepared and evaluated. The expanded ring members were generally less active than the tricyclic compounds containing the isoxazolidine ring.