Reaktion #73966

Reaktionsgleichung

ethyl 2-(triphenylphosphoranylidene)propionate

3,4,5-trifluorobenzaldehyde

→

title compound

Ausbeute 93.0%

(E)-ethyl 2-methyl-3-(3,4,5-trifluorophenyl)acrylate

Ausbeute 93.0%

Lösungsmittel

DMF

—

Hexanes

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeat room temperature
2. 2
   Sonstigethe solvent was removed by rotary evaporation
3. 3
   Sonstigethe precipitate removed by filtration
4. 4
   Waschenwashed with additional MBTE (3×50 mL)
5. 5
   EinengenAfter concentration

Vorschrift

To a solution of dry DMF (50 mL) under N2 was added 3,4,5-trifluorobenzaldehyde (4.26 g, 26.6 mmol) followed by ethyl 2-(triphenylphosphoranylidene)propionate (10.6 g, 29.3 mmol) in portions, keeping the solution at room temperature. After 1 hour, TLC (10% EtOAC in Hexanes) showed complete conversion, and the solvent was removed by rotary evaporation. The resulting material was brought up in 50 mL methyl t-butyl ether (MBTE) and the precipitate removed by filtration and washed with additional MBTE (3×50 mL). After concentration, the resulting filtrate was applied onto a silica gel column (25% EtOAc in hexanes) resulting in 6.0 g of the title compound (93%) as a white powder.

Quelle