Rigid congeners of arylpyridazinones. IV. Synthesis and activity of derivatives of the new heterocyclic system 9H-indeno[2,1-c]pyridazine

Representative terms of the new heterocyclic system 9H-indeno[2,1-c]pyridazine have been synthesized. Their antiinflammatory, analgesic and antipyretic activities were evaluated, in order to compare the pharmacological profiles with those of the isomeric series of 5H-indeno[1,2-c]pyridazine previously investigated. The new compounds were, in general, equiactive as analgesic but less active as antiinflammatory and antipyretic agents with respect to their 5H-isomers.