[C-2 basically substituted thiazoles with H2-antagonistic action. 21. H2-antihistaminics]

In studies on structure-activity relationships of histamine H2-receptor antagonists, C-2 basically substituted thiazoles were prepared and tested for their H2-antihistaminic activity on the isolated guinea-pig atrium and on the histamine stimulated acid secretion of the anaesthetized rat. As a basic substituent the dimethylaminomethyl group is especially suitable, while cyclic guanidines lead to lower H2-antagonistic activity.