Trifluoromethanesulfonic anhydride → (4-(Pentafluorophenyl)-2,3,5,6-tetrafluorophenyl}bis(triflyl)methane

Participants

Reaction Conditions

Reaction Steps

A tert-butyl magnesium chloride (5 mL, 10 mmol, 2.0 M diethylether solution) was added to a diethylether (120 mL) solution dissolved with {4-(pentafluorophenyl)-2,3,5,6-tetrafluorophenyl}(triflyl)methane (4.6 g, 10 mmol), at −78° C. under argon atmosphere. After the reaction solution was stirred for 0.5 hour at −78° C., it was further stirred for 0.5 hour at 0° C. Then, the solution was cooled again to −78° C., trifluoromethane sulfinic acid anhydride (0.84 mL, 5 mmol) was added, and the resultant solution was stirred for 2 hours at room temperature. Further, tert-butyl magnesium chloride (3.75 mL, 7.5 mmol, 2.0 M diethylether solution) was added at −78° C. After the reaction solution was stirred at −78° C. for 0.5 hour, it was stirred at 0° C. for 0.5 hour. The solution was cooled again to −78° C., trifluoromethanesulfonic acid anhydride (0.84 mL, 5 mmol) was added, and the resultant solution was stirred for 2 hours at room temperature. After the reaction was completed, water was added, further neutralized with 1 M hydrochloric acid water, and the water phase was washed with hexane. Then, said water phase was acidified with 4 M hydrochloric acid water, and extracted with diethylether. The organic phase was dried with magnesium sulfate, filtrated, and the solvent was removed under reduced pressure. The crude product was sublimated (8 to 9 Pa, 150° C., and the aimed {4-(pentafluorophenyl)-2,3,5,6-tetrafluorophenyl}bis(triflyl)methane (2.79 g, 4.7 mmol, 47% yield) was isolated. 1H NMR (CDCl3, 300 MHz) δ 6.32 (s, 1H, CH), 19F NMR (CDCl3, 282 MHz) δ−75.1 (s, 6F, 2CF3), −127.72 to −127.58 (m, 1F), −133.43 (dt, J=10.2, 21.3 Hz, 1F), −134.60 (dt, J=9.4, 21.3 Hz, 1F), −137.08 to −137.35 (m, 2F), −140.07 (br, 1F), −148.38 (t, J=21.3 Hz, 1F), −160.01 (dt, J=6.2, 21.3 Hz, 2F).

Provenance & Evidence