水热条件提高α-氯代十二酸氨解产率合成α-氨基十二酸的研究

Improving aminating yield of α-amino dodecanoic acid from α-chlorododecanoic acid by hydrothermal technology

摘要:

从十二酸制备α-氯代十二酸( CDA )，再与氨水通过氨解反应合成了α-氨基十二酸( ADA )，用FTIR、ESI-MS和1H-NMR对产物ADA进行结构表征。实验考察了反应温度、反应时间、催化剂用量和投料比等因素的影响，由于氨解反应受到水解副反应竞争而使ADA产率偏低，采用常温-水热程序升温工艺有效地抑制了水解副反应，使之成为一个有实用性的合成反应。在n( NH3 ) :n( CDA ) = 20 :1，70 ℃下反应12 h然后100 ℃下反应4 h的程序升温优化条件下，ADA的产率可以从非水热条件下的80%左右上升到 91%。

Abstract:

α-Amino dodecanoic acid (ADA) was synthesized by the amination of α-chloro dodecanoic acid (CDA) derived from chlorination of natural dodecanoic acid, and the molecular structure of ADA was identified by FT-IR、ESI-MS and 1H-NMR. Effects of reaction temperatures, reaction times, dosages of catalyst and ratio of raw materials on the yield of ADA was investigated, unfortunately, the yield of ADA was lower in normal temperature technology which was accounted as the competition of the side hydrolysis reaction. A temperature programming of normal temperature followed by hydrothermal was applied to inhibit hydrolysis effectively, which evolved the amination a practical organic synthesis reaction. The yield of ADA was significantly improved from about 80% under the normal temperature technology to 91% under the optimal temperature programming technology when the amination was run with n(ammonia) :n(CDA) = 20 :1 at 70 ℃ for 12 h following 100 ℃ for 4 h.