通过动力学控制增强α-氯代十二酸与三甲胺的氨解反应

α-氯代十二酸(α-chlorododecanoic acid,α-CDA)与三甲胺(TMA)在水热条件下经氨解反应可以合成两性表面活性剂α-癸基甜菜碱(α-capric betaine,α-CB),但水解副反应的竞争使α-CB产率偏低。在优化了溶剂、投料比等因素的基础上,通过采用动力学控制手段——程序升温,有效地抑制了水解副反应,从而显著提高了产物α-CB的产率。当n(TMA)/n(α-CDA)=3时,以KI为催化剂,且m(KI)/m(α-CDA)=0.01,预先添加质量分数为0.5%的α-CB,于70℃反应8 h,再升温至100℃继续反应2 h后,α-CB的产率从非程序升温时的62.4%提高到程序升温后的92%。

Strengthen Amination of α-Chlorododecanoic Acid with Trimethylamine by Means of Kinetic Control

α-Capric betaine(α-CB),a new type of zwitterionic surfactant was synthesized by the amination of α-chlorododecanoic acid(α-CDA) with trimethylamine(TMA) under the hydrothermal condition,and the bothering was that the yield of α-CB was lower caused by the side effect of hydrolysis.Based on the optimal factors such as solvent,feed ratio,etc,the temperature program,a means of kinetic control,was applied to effectively inhibit hydrolysis and thus the yield of α-CB was significantly improved.When kept n(trimethylamine)/n(α-CDA)=3,0.01 of KI as catalyst and 0.5% of α-CB as solubilizer added in advance,the amination proceeded at 70 ℃ for 8 h following 100 ℃ for 2 h,the yield of α-CB was improved from 62.4% to 92%.