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

Temperatur

0 °C

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.

1. customkept under nitrogen at 0° C
2. temperaturecooled to -70° C
3. additionwas slowly added
4. stirringThe mixture was then stirred at -70° C. for an hour
5. customto rise above -65° C
6. temperatureThe mixture was then warmed to room temperature
7. extractionIt was extracted with diethyl ether (3×500 ml)
8. washthe purified organic phase washed with sodium hydrogen carbonate
9. dry with materialdried over magnesium sulphate
10. concentrationconcentrated in a rotary evaporator
11. customThe residue was recrystallised from ethanol

ORD-Eintrag

ord-4750a94f93504a98841f53d9de765b37

Quelldatensatz

uspto-grants-1989_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04888340