L-脯氨酰胺的合成工艺改进

Improved synthesis of L-prolinamide

以L-脯氨酸为原料合成了L-脯氨酰胺,改用将溶剂全部蒸除直接用于下步反应的方法,解决了因L-脯氨酸甲酯盐酸盐吸湿造成的结晶困难,用AR级甲醇代替无水甲醇进行L-脯氨酸甲酯盐酸盐的制备,省去了甲醇的无水处理环节。优化的最佳工艺条件如下:n(L-脯氨酸)∶n(氯化亚砜)=1∶1.1,滴加氯化亚砜温度为-10℃以下,保温反应0.5 h,室温反应9 h;氨化反应在常压0℃进行,时间为24 h。L-脯氨酰胺总产率达94.1%,光学纯度达到98.0%。

We have synthesized L-prolinamide with the material of L-proline. After steaming out all the solvent, the L-proline methyl ester hydrochloride was direct for the next reaction. This method avoids the crystallization difficulty caused by moisture. The process of drying the methanol was reduced by using the AR methanol instead of the anhydrous methanol to synthesis L- proline methyl ester hydrochloride. The optimum conditions were found： reacting at less than -10 ℃, 0. 5 h , rt,9 h with n （L-proline） ： n（SOCl2） = 1 ：P 1. 1, for ammoniation at normal pressure and 0 ℃,24 h. The total yield of L-prolinamide was 94. 1%, and the optical purity was up to 98.0%.