Proton pump inhibitors

Novel thiadiazole compounds are provided, which are effective as proton pumps inhibitors, useful in treating peptic ulcers by inhibition of the proton pump enzyme H+/K+-ATPase. The compounds are 3-substituted 1,2,4-thiadiazolo [4,5- alpha ]benzimidazole and 3-substituted imidazo[1,2-d]-1,2,4-thiadiazoles corresponding to the general formula: where X and Z either represent an optionally substituted benzene ring fused to the diazole nucleus, or represent a variety of independent chemical groupings (hydrogen, lower alkyl, halo, etc.) and Y is selected from a wide range, e.g. heterocyclics and carbonyl groups.