Dichloromethane → 3-Chloro-4-phenylthio-1,1,2-trifluoro-1-butene

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Reaction Steps

To a solution of 1,1,2-trifluoro-1,3-butadiene (8.0 g. 74 mmol) and calcium carbonate (50 mg) in 85 mL of dichloromethane at -40° C. in a round-bottom 250 mL flask was added a solution of phenylsulfenyl chloride (7.1 g, 49 mmol) in 20 mL of dichloromethane over 2 hours. The reaction mixture was left to stand overnight at room temperature and poured into ice water. The organic layer was washed with aqueous 5% sodium metabisulfite solution and brine, then dried over anhydrous magnesium sulfate. Evaporation of solvent followed by distillation gave 12.1 g (97.5%) of 3-chloro-4-phenylthio-1,1,2-trifluoro-1-butene as a light yellow oil, bp 84°-86° C. (1.0 mm Hg). 1H-NMR (300 MHz, CDCl3): δ 3.39(2H, d, J=8 Hz), 4.58(1H, ttd, J=1.5, 8, 33 Hz), 7.2-7.4(5H, phenyl protons). Mass spectrum: m/e=252,254 (M+). 19F-NMR (300 MHz, CDCl3): φ F3 =-11.8, F2 =116.7, F1 =99.3. J(F12 =64.5, J(F23)=111.2, J(F13)=33.0, J(F3H)=26.4.

Provenance & Evidence