5,6,7,8-Tetrahydroguinolines. 4. Antiulcer and antisecretory activity of 5,6,7,8-tetrahydroquinolinenitriles and -thioamides.

A number of 5,6,7,8-tetrahydroquinoling-8-nitriles and -8-thioamides and related compounds have been found to be potent inhibitors of basal gastric secretion in the pylorus-ligated rat and to afford protection against gastric erosions induced in rats by cold-restraint stress. Molecular manipulation has proved useful in determining factors necessary for such activity and structure-activity relationships are discussed. It has been shown that the most necessary requirements for activity are a pyridine nitrogen with its available lone pair and a primary or secondary thioamide. Also desirable is a six-membered carbocyclic ring with relative freedom from steric hinderance around the 8 position.