Perfluoroalkyl derivatives of sulphur. Part VIII. Synthesis and reactions of perfluoroethylenesulphonyl fluoride

Abstract

Perfluoroethylenesulphonyl fluoride, prepared from chlorotrifluoroethylene or perfluoropropene in six and three stages, respectively, reacts with aqueous sodium hydroxide to give sodium perfluoroethylenesulphonate, with methanol at 0° to give 1,2,2-trifluoro-2-methoxyethanesulphonyl fluoride, with diethylamine at –30° to provide 2-diethylamino-1,2,2-trifluoroethanesulphonyl fluoride, and with anhydrous hydrogen fluoride at 60° to yield 1,2,2,2-tetrafluoroethanesulphonyl fluoride. The last product is also obtained by treatment of perfluoroethylenesulphonyl fluoride with anhydrous potassium fluoride in formamide at 35°. Thus the olefin is polarised in the sense [graphics omitted]·SO₂F. The compounds CF₂Br·CHF·SO₂F, CF₂Br·CFBr·SO₂F, and CF₂Cl·CFCl·SOF are obtained in high yield by free-radical hydrobromination, bromination, and chlorination, respectively, of perfluoroethylenesulphonyl fluoride. Reaction of perfluoroethylenesulphonyl fluoride with trifluoronitrosomethane yields a 1 : 1 alternating copolymer.