Sulfuric Acid → N-carbobenzyloxy-beta-chloro-L-alanine

Temperatur

60 °C

L-Serine hydrochloride (0.4 g, 2.84 mmol) and 0.029 g (0.28 mmol) of triethylamine were suspended in 4 ml of diethylene glycol dimethyl ether. Thereto was added dropwise 0.67 g (5.68 mmol) of thionyl chloride at room temperature in a nitrogen gas atmosphere. After 2 hours of stirring at 60° C., 8 ml of water was added while maintaining the reaction mixture inside at 15° C. or below, and the whole mixture was stirred at room temperature for 30 minutes. Further, 1.6 g of potassium carbonate was added to make the pH about 10 and, thereafter, 0.956 g (5.68 mmol) of benzyl chloroformate was added dropwise. After overnight standing at room temperature, the reaction mixture was washed with ethyl acetate, the aqueous layer obtained was cooled with ice and acidified with 50% sulfuric acid and then extracted with ethyl acetate. The solvent was distilled off and the residue was purified by column chromatography to give 0.3 g (1.16 mmol, 41%) of N-carbobenzyloxy-β-chloro-L-alanine.

1. temperaturewhile maintaining the reaction mixture inside at 15° C. or below
2. stirringthe whole mixture was stirred at room temperature for 30 minutes
3. waitAfter overnight standing at room temperature
4. washthe reaction mixture was washed with ethyl acetate
5. customthe aqueous layer obtained
6. temperaturewas cooled with ice
7. extractionextracted with ethyl acetate
8. distillationThe solvent was distilled off
9. customthe residue was purified by column chromatography

ORD-Eintrag

ord-5dcd566d7c1447328e619ff8cf742154

Quelldatensatz

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06372941B1