Studies on Antiulcer Drugs. II. Synthesis and Antiulcer Activities of Imidazo[1,2-a]pyridinyl-2-alkylaminobenzoxazoles and 5,6,7,8-Tetrahydroimidazo[1,2-a]pyridinyl Derivatives

A series of imidazo[1,2-a]pyridinylbenzoxazoles (4) and 5,6,7,8-tetrahydroimidazo[1,2-a]pyridinylbenzoxazoles (5) were synthesized and tested for anti-stress ulcer activity in rats. Several compounds were found to be more active than the reference compounds, sucralfate, cimetidine and ranitidine. Some of them exhibited potent protective activity against ethanol-induced gastric lesion. The synthesis and structure-activity relationships of these compounds are discussed.