Acetic Acid → Benzyl 4-(2,2-difluorovinyloxy)phenyl ketone

Participants

Reaction Conditions

Reaction Steps

Butyllithium (190 ml; 1.6N) in hexane was added, dropwise, to diisopropylamine (30.4 g; 0.3 mol) in tetrahydrofuran (400 ml) kept under nitrogen at 0° C. The mixture was stirred for 30 minutes at 0° C. and then cooled to -70° C. At this temperature benzyl 4-(2,2,2-trifluoroethoxy)phenyl ketone, dissolved in tetrahydrofuran (70 ml) was slowly added, dropwise, to the reaction mixture. The solution became deep red. The mixture was then stirred at -70° C. for an hour and acetic acid (20 ml) was added, dropwise, without allowing the temperature of the reaction mixture to rise above -65° C. The mixture was then warmed to room temperature and added to ice-water (2000 ml). It was extracted with diethyl ether (3×500 ml) and the purified organic phase washed with sodium hydrogen carbonate, dried over magnesium sulphate and concentrated in a rotary evaporator. The residue was recrystallised from ethanol to give pure benzyl 4-(2,2-difluorovinyloxy)phenyl ketone.

Provenance & Evidence