A novel fragmentation of an isothiazoline ring is reported. Nitroketene aminals 1 react with benzoyl isothiocyanate to form the adducts 3. These adducts can be converted to the 3, 3- diamino-2-nitroacrylonitriles 2 in two discrete steps—first to an isothiazoline (4, 7) by oxidation, and then to the nitriles by base-induced fragmentation; alternatively the adducts (3c, 11) can be directly treated with alkaline hydrogen peroxide to provide the nitriles in ...
