Antihyperglycemic activity of novel substituted 3H-1,2,3,5-oxathiadiazole 2-oxides

A series of substituted 3H-1,2,3,5-oxathiadiazole-2-oxides (6) was prepared and tested for antihyperglycemic activity in the db/db mouse, a model for type 2 (non-insulin dependent) diabetes mellitus. The oxathiadiazoles 6 were synthesized by a two-step sequence: treatment of a substituted acetonitrile (4) with hydroxylamine to give the corresponding amidoxime (5) and cyclization with thionyl chloride to yield 6. In terms of potency, the 2-naphthalenylmethyl group (as in compound 3) was found to be the optimal substituent in this series. Compound 3 was approximately 5 times more potent than ciglitazone (1).