摘要
为提高(R)-α-硫辛酸(Ⅱ)合成收率,降低生产成本,以R体α-甲基苄胺拆分6,8-二氯辛酸得到的(R)-6,8-二氯辛酸(Ⅰ)为原料,在水相中采用一步法合成Ⅱ。讨论了摩尔比、反应温度、滴加时间等诸因素对产物收率及比旋光度的影响,获得了较优合成条件:拆分反应中,n(6,8-二氯辛酸)∶n〔(R)-α-甲基苄胺〕=1∶0.48,反应温度35℃,盐酸酸化;取代反应中,n(Ⅰ)∶n(二硫化钠)=1∶1.2,反应温度75℃,滴加时间3.0 h。在该优化条件下,Ⅱ的总收率为30.0%,并在该条件下,将6,8-二氯辛酸投料量扩大至600 g,Ⅰ投料量扩大至222.0 g,所得Ⅱ平均总收率可达34.3%。
To increase the yield of （R）-α-lipoic acid （ Ⅱ） and reduce its cost,an one-step synthesis of Ⅱ by using （R）-6,8-dichlorooctanoic acid （ Ⅰ ） as starting material was described. The synthesis steps involved chiral resolution of 6, 8-dichlorooctanoic acid by （R）-α-phenylethylamine and substitution reaction in water phase. The optimized parameters were as follow. In the chiral resolution, n （6,8-dichlorooctanic acid） ：n [ （R）-α-phenylethylamine ]= 1：0. 48, and reaction temperature is 35 ℃ ; in the substitution reaction, n （ Ⅰ ） ： n （ Na2S2 ） = 1 ： 1.2, the reaction temperature is 75℃, and the dropping time keeps 3.0 h. Under the optimal conditions, the total yield of Ⅱ was 30.0%. When starting material 6,8-dichlorooctanic acid was expanded to 600 g and Ⅰ was increased to 222.0 g, the total yield of Ⅱ was up to 34.3%.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2007年第10期991-995,共5页
Fine Chemicals
基金
贵州省工业攻关项目(黔科合2004GGY021)~~
