HALOGEN CARBON SULFUR-COMPOUNDS - SYNTHESIS AND MODES OF REACTIONS OF 4,5-BIS(TRIFLUOROMETHYL)-1,3-DITHIOLE DERIVATIVES

The chemistry of the bis(trifluoromethyl)-1,3-dithiole system is thoroughly investigated starting from the 2-thione 6. By its oxidation the sulfine 2 and the ketone 7 are obtained. Further oxidation of 2 leads to the spiro compound 3. By chlorination of 6 the 2-sulfenyl chloride 5 is obtained, which can be desulfurized by PCl3 to the 2,2-dichloro compound 10. The best method for the preparation of the latter is the reaction of 6 with PCl5. Hydrolysis of 10 yields again the ketone 7. By reaction of 1,2-ethanedithiol with 10 the spiro compound 11 is obtained, the reaction of which with hexafluoro-2-butyne also affords 3. 10 reacts with primary amines to the 2-imines 9a and 9b, whereas 5 under similar conditions reacts via the thione S-imides 4a and 4b to 9a (with sulfur extrusion) or in a rearrangement reaction to the 1,2,4-trithiine 1. The preparation of the tosyl hydrazone 12 does not open an access to the diazo compound 16, neither does the reaction of 10 with hydrazine, which yields the ketazine 14. The homogeneous reaction of disilylhydrazine and 10 produced the tetrazene 17, which is a dimer of 16 and decomposes at its high melting point to the ketazine 14.