The present invention relate to a preparation method of high-purity L-carnitine which belongs to an important technique of quality control in different steps of chiral medicine production. The method comprises the following steps of: monitoring the content of the L-isomer impurity in chiral material S-epichlorohydrin by gas chromatography and chiral column and controlling the content of the L-isomer impurity in chiral raw material in the definite range; monitoring and controlling the specific optical rotation of the chiral intermediate L-3-chloro-2-hydroxy-N,N,N-trimethyl-propanaminium in the definite ranges using a polarimeter; monitoring the content of the R-isomer in the intermediate L-3-cyano-2-hydroxy-N,N,N-trimethyl-propanaminium using derivation agent (+)α-methyl-6-methoxy-2-naphthaleneaceyl chloride by HPLC and controlling the content of the isomer in the intermediate in the definite range; and measuring the final product L-carnitine using derviation agent (+)α-methyl-6-methoxy-2-naphthaleneaceyl chloride by HPLC. This method gives the high-purity L-carnitine in which the content of L-isomer may be more than 97% and that of R-isomerless than 2%.
本发明涉及高纯度
L-肉碱的制备方法,属于手性药物生产不同步骤的质量控制的重要技术。该方法包括以下步骤:通过气相色谱和手性柱监测手性原料S-
环氧氯丙烷中L-异构体杂质的含量,并控制手性原料中L-异构体杂质的含量在一定范围内;使用旋光仪监测和控制手性中间体L-3-
氯-2-羟基-N,N,N-三甲基
丙胺在一定范围内的比旋光度;通过HPLC使用衍生剂(+)α-甲基-6-甲氧基-2-
萘乙酰氯监测中间体L-3-
氰-2-羟基-N,N,N-三甲基
丙胺中R-异构体的含量,并控制中间体中异构体的含量在一定范围内;通过HPLC使用衍生剂(+)α-甲基-6-甲氧基-2-
萘乙酰氯测量最终产品
L-肉碱。该方法可得到高纯度的
L-肉碱,其中L-异构体的含量可达97%以上,R-异构体的含量小于2%。