A number of heterocyclic thiones react with ethyl azidoformate in boiling carbon tetrachloride to yield the corresponding iminocarboxylic esters. 4-Phenyl-1, 2-dithiole-2-thione is an exception and yields both a 1, 2, 3-dithiazine derivative and a urethane type product. 4- Phenyl-1, 2-dithiole-3-one yielded an isothiazolin-3-one product. The mechanisms are discussed briefly.
