Abstract 2-Substituted 1, 3-dithiol-2-yl azides, on thermolysis in refluxing toluene, give 3- substituted 1, 4, 2-dithiazines which thermally extrude sulfur atom of the 4-position selectively to yield 3-substituted isothiazoles, while 2-unsubstituted 1, 3-dithiol-2-yl azides undergo both ring expansion yielding 1, 4, 2-dithiazines and peculiar thermal dissociation into 1, 3-dithiol-2-ylidene carbenes and hydrogen azide.
