RESEARCH ON HETEROCYCLIC-COMPOUNDS .38. SYNTHESIS AND PHARMACOLOGICALACTIVITY OF IMIDAZO[1,2-B]PYRIDAZINE-2-CARBOXYLIC DERIVATIVES

A series of imidazo[1,2-b]pyridazine-2-carboxylic acids, esters and am ides was synthesized and tested fbr antiinflammatory, analgesic and ul cerogenic activities. The ethyl esters were prepared by cyclocondensat ion of some 3-aminopyridazines with ethyl bromopyruvate, followed by h ydrolysis or ammonolysis in order to obtain the corresponding acids an d amides. The inhibitory activity on the carrageenan-induced edema in the rat paw and on writhes induced by acetic acid in mice was evaluate d, as well as the ulcerogenic action on the rat gastric mucosa. The ph armacological activity was discussed in terms of structure-activity re lationships. In particular, the analgestic activity shown by these car boxylic derivatives was compared with that found in other series of im idazo[1,2-b]pyridazine analogues previously examined.