Thiadiazole compounds useful as 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 an electronegative group.