申请人:EMCURE PHARMACEUTICALS LIMITED
公开号:US20170275229A1
公开(公告)日:2017-09-28
The present invention provides a process for preparation of (2E,4E,6E,8E)-9-(4-methoxy-2,3,6-trimethyl)phenyl-3,7-dimethyl-nona-2,4,6,8}tetraenoate, an acitretin intermediate of formula (VI) with trans isomer≧97%, comprising of reacting 3-formyl-crotonic acid butyl ester of formula (V), substantially free of impurities, with 5-(4-methoxy-2,3,6-trimethylphenyl)-3-methyl-penta-2,4-diene-1-triphenyl phosphonium bromide of formula (IV) and isolating resultant compound of formula (VI), treating the filtrate with iodine for isomerization of the undesired cis intermediate and finally obtaining acitretin (I), with desired trans isomer≧97%.
本发明提供了一种制备(2E,4E,6E,8E)-9-(4-甲氧基-2,3,6-三甲基)苯基-3,7-二甲基-壬-2,4,6,8-四烯酸}酯化物的方法,该化合物是维甲酸类似物的中间体,其反式异构体≧97%。该方法包括将公式(V)的3-甲酰基巴豆酸丁酯与公式(IV)的5-(4-甲氧基-2,3,6-三甲基苯基)-3-甲基戊-2,4-二烯-1-三苯基膦溴反应,分离得到公式(VI)的化合物,用碘处理滤液以异构化不需要的顺式中间体,最终获得所需的反式异构体≧97%的维甲酸。