Research on heterocyclic compounds. XVIII. Imidazo[2,1-b]-1,3,4-thiadiazole derivatives

The synthesis of a series of 6-carbethoxy-, 6-carbethoxy-methyl-, and 5-carbethoxy-6-methylimidazo[2,1-b]-1,3,4-thiadiazoles was accomplished by reacting some 2-amino-1,3,4-thiadiazoles with ethyl bromopyruvate, 4-chloroacetoacetate, and 2-chloroacetoacetate, respectively; such carbethoxy derivatives afforded the corresponding carboxylic acids by hydrolysis. The antiinflammatory, analgesic, antipyretic and ulcerogenic activities were studied on three of the new acidic compounds.