Tricyclic 3-(2H)-pyridazinone derivatives : synthesis and evaluation of their antisecretory and antiulcer activity

A new series of benzopyranopyridazinones (1b-e) either unsubstituted at the amide nitrogen or substituted by an alkyl thiourea, as well as two benzocinnolinone derivatives (2b, f) have been synthesized and tested for their antiulcer and antisecretory activity. All the test compounds showed statistically significant antiulcer properties in the EtOH model, 1b being the most active. On the contrary, in die ASA model only 1b and 1d were found weakly active. In the pylorus-ligated rat model, 1b and 1e displayed significant antisecretory activity, though only 1b proved to be able to reduce the acidity of the gastric secretion.