The present invention is to provide a purification method of obtaining N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine of high quality in good yield with high productivity, which is accordingly suited for commercial scale application. An impurity-contaminated N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine is crystallized from a mixed solvent of alcohol and water in a volume ratio of alcohol/water being 1 to 20 to remove a contaminating impurity into a mother liquor and give crystals of N-(1(S)-ethoxycarbonyl-3-phenylpropyl)-L-alanine.
本发明旨在提供一种提纯方法,以高产率和高生产效率获得高质量的N-(1(S)-乙氧基羰基-3-苯基丙基)-
L-丙氨酸,该方法特别适用于大规模商业化应用。将含有杂质的N-(1(S)-乙氧基羰基-3-苯基丙基)-
L-丙氨酸从
酒精和
水的混合溶剂中结晶析出,其中
酒精与
水的体积比为1:20,从而将污染物杂质留在母液中,并得到N-(1(S)-乙氧基羰基-3-苯基丙基)-
L-丙氨酸的晶体。