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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence