This invention discloses an improved process for the preparation of high purity citalopram base and its hydrobromide salt of formulae (I) and (Ia): which comprises: i. Isolation of crude citalopram base after water work up of the reaction into a non polar aromatic or dialkyl ether solvent. ii. Extraction of the citalopram base into aqueous organic acid. iii. Neutralization of acid layer with organic base to a controlled pH (7.0-8.0) iv. Extraction of the pure base into a non-polar aromatic or dialkyl ether solvent and crytallization form the same solvent after concentrating to certain volume under reduced pressure. v. Preparation of high purity citalopram hydrobromide in a non-polar aromatic or dialkyl ether solvent using 40-50 % HBr in acetic acid as HBr source and crystallizing out form the same solvent. Alternatively preparation of HBr salt in aqueous medium using aqueous HBr and crystallizing out from the same medium at 0 10 °C. vi. Recrystallization of high purity citalopram hydrobromide salt of pharmaceutically acceptable grade form a mixture of alcoholic solvent.
这项发明揭示了一种改进的高纯度
西酞普兰碱及其盐的制备过程,其
化学式为(I)和(Ia):包括:i. 在反应
水处理后将粗
西酞普兰碱分离到非极性
芳香烃或二烷基醚溶剂中。ii. 将
西酞普兰碱萃取到含
水有机酸中。iii. 用有机碱将酸层中和至控制的pH值(7.0-8.0)。iv. 将纯碱萃取到非极性
芳香烃或二烷基醚溶剂中,并在减压下浓缩至一定体积后从相同溶剂中结晶。v. 在非极性
芳香烃或二烷基醚溶剂中使用40-50%HBr
乙酸中的HBr作为HBr来源制备高纯度
西酞普兰盐,并从相同溶剂中结晶出来。或者在
水介质中使用
水溶性HBr制备HBr盐,并在0-10°C下从相同介质中结晶出来。vi. 从醇溶剂混合物中重新结晶出药用级高纯度
西酞普兰盐。