Ehidence is reported for production of nitrile sulfides as reactive intermediates in the thermolysis of 1, 3, 4-oxathi-azol-2-ones. The nitrile sulfides were trapped with dimethyl acetylenedicarboxylate to give good yields of dimethyl 3-sribstituted-4, 5- isothiazoledicarboxylates 6a-t. The diacids 7a-r were readily converted to 3-substituted-4- isothiazolecarboxylic acids Sa-r by thermal decarboxylation. 3-Aryl-4- ...
