申请人:——
公开号:US20040002610A1
公开(公告)日:2004-01-01
Process for the synthesis of R(+)&agr;-lipoic acid comprising the following stages: a) Salifying of racemic 6,8-halo-octanoic acid with S(−)&agr;-methylbenzylamine; b) separation by filtration of the crystallized diastereoisomeric salt of R(+)6,8-di-halo-octanoic acid-S(−)&agr;-methylbenzylamine; c) purification by re-crystallization of the diastereoisomeric salt of R(+)6,8-di-halo-octanoic acid-S(−)&agr;-methylbenzylamine; (d) separation of the diastereoisomeric salt to obtain R(+)6,8-di-halo-octanoic acid by reation of said salt with strong mineral acids in an aqueous solution with a dilution between 2 and 10% by weight; e) esterification of R(+)6,8-di-halo-octanoic acid to obtain the corresponding alkyl ester; f) reaction of the alkyl ester of R(+)6,8-di-halo-octanoic acid in an organic solvent with an aqueous solution of alkali disulfide in presence of a compound for phase transfer catalysis; g) hydolysis of the ester of R(+)&agr;-lipoic acid.
合成R(+)-α-硫辛酸的过程包括以下阶段:a)用S(-)-α-甲基苄胺对外消旋6,8-卤代辛酸进行盐化;b)通过过滤分离结晶的R(+)6,8-二卤代辛酸-S(-)-α-甲基苄胺的二对映异构盐;c)通过再结晶纯化R(+)6,8-二卤代辛酸-S(-)-α-甲基苄胺的二对映异构盐;d)通过将该盐与强矿酸在含有2至10%重量的水溶液中反应来分离二对映异构盐,以获得R(+)6,8-二卤代辛酸;e)酯化R(+)6,8-二卤代辛酸以获得相应的烷基酯;f)在有机溶剂中,将R(+)6,8-二卤代辛酸的烷基酯与碱性二硫化物的水溶液在相转移催化剂的存在下反应;g)水解R(+)-α-硫辛酸的酯。