The A3-thiazoline-2-thiones 1 a, b eliminate sulfur thermally, photolytically, or with trimethyl phosphite to give the vinyl isothiocyanates 2a, b. Compound 2a forms a thiosemicarbazone 3a which cyclizes thermally to 4. This easily splits off the isopropyl group to give the triazolinethione 5. The vinyl isothiocyanate 2 b rearranges thermally or photochemically to the isoquinoline-lthione 7 which itself is photolabile.
