Reaktion #483085

Reaktionsgleichung

hydrochloric acid

trimethylchlorosilane

benzaldehyde

methyl bromoacetate

→

Methyl 3-hydroxy-3-phenylpropionate

Lösungsmittel

isopropyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeAt room temperature, a three-necked flask fitted
2. 2
   Temperaturwith reflux condenser
3. 3
   TemperaturFollowing cooling to 60° C.
4. 4
   workup.ADDITIONwere added dropwise at 55° C.
5. 5
   Temperaturthe temperature being maintained at 55° C. by external cooling
6. 6
   Temperaturafter cooling to 0° C.
7. 7
   workup.STIRRINGstirred for 30 min
8. 8
   SonstigeExcess zinc was removed by filtration
9. 9
   Sonstigethe organic phase separated
10. 10
    workup.STIRRINGThe organic phase was then stirred at 0° C. with 40 ml of 0.5 N hydrochloric acid
11. 11
    Waschenfinally washed with 20 ml of saturated sodium hydrogen carbonate solution
12. 12
    SonstigeFollowing phase separation
13. 13
    Trocknendrying over sodium sulfate
14. 14
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure

Vorschrift

At room temperature, a three-necked flask fitted with reflux condenser, internal thermometer, dropping funnel and stirrer was charged, under nitrogen protective gas, with 5.7 g of zinc powder (87 mmol) in 35 ml of isopropyl acetate. After 1.65 ml of trimethylchlorosilane (13 mmol) had been added, the mixture was heated at 65° C. for 30 min. Following cooling to 60° C., 6.2 g of benzaldehyde (58 mmol) were added and, over the course of 4 min, 10.6 g of methyl bromoacetate (70 mmol) were added dropwise at 55° C., the temperature being maintained at 55° C. by external cooling. The mixture was then stirred at 55° C. for 5 min and, after cooling to 0° C., acidified with 40 ml of 2 N hydrochloric acid to a pH of 1 and stirred for 30 min. Excess zinc was removed by filtration and the organic phase separated. The organic phase was then stirred at 0° C. with 40 ml of 0.5 N hydrochloric acid and finally washed with 20 ml of saturated sodium hydrogen carbonate solution. Following phase separation and drying over sodium sulfate, the solvent was distilled off under reduced pressure. Methyl 3-hydroxy-3-phenylpropionate was obtained in a yield of 8.9 g (85% of theory) with a boiling point of 76° C. (0.07 mbar).

Quelle