L-4-Nitrophenylalanine methyl ester hydrochloride

67-56-1

949-99-5

17193-40-7

Thionyl chloride (1.03 mL, 14.2 mmol) was slowly added dropwise to a suspension of (S)-2-amino-3-(4-nitrophenyl)propionic acid (0.995 g, 4.73 mmol) dissolved in 10 mL of methanol at 0 °C. After the dropwise addition, the reaction system was gradually warmed up to room temperature. Subsequently, the reaction mixture was heated to reflux the reaction overnight. Upon completion of the reaction, the reaction solution was concentrated by distillation under reduced pressure. The crude product was purified by recrystallization using a mixed solvent of methanol/ethyl acetate, and finally 1.012 g of (S)-4-nitrophenylalanine methyl ester hydrochloride was obtained in 95% yield.