Reaktion #11019

Reaktionsgleichung

Thionyl chloride

(2S)-2-hydroxy-3-phenylpropionic acid

Water

→

(2R)-chloro-3-phenylpropionic acid

Ausbeute 90.1%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGof stirring
2. 2
   Extraktionthe mixture was extracted with 90 ml of ethyl acetate
3. 3
   WaschenThe organic phase was washed with 10 ml of a saturated aqueous solution of sodium chloride
4. 4
   Trocknendried over anhydrous sodium sulfate
5. 5
   workup.DISTILLATIONThe solvent was distilled off under reduced pressure

Vorschrift

Thionyl chloride (0.66 ml, 9.0 mmol) was added dropwise to a solution of (2S)-2-hydroxy-3-phenylpropionic acid (500 mg, 3.0 mmol, optical purity 100% ee (S)) in 5 ml of tetrahydrofuran at room temperature, and the mixture was stirred for 15 hours. To the reaction mixture was added 170 mg (0.60 mmol) of tetra-n-butylammonium chloride, and the mixture was heated at 40° C. for 4 hours. Water (5 ml) was added to the reaction mixture and, after 30 minutes of stirring, the mixture was extracted with 90 ml of ethyl acetate. The organic phase was washed with 10 ml of a saturated aqueous solution of sodium chloride and then dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to give 499 mg (yield 90%) of the desired (2R)-chloro-3-phenylpropionic acid.

Quelle