十二烷基硫酸钠催化合成氯乙酸异丙酯

Synthesis of Isopropyl Chloroacetate Catalyzed by Sodium Dodecyl Sulfate

研究了十二烷基硫酸钠催化氯乙酸与异丙醇酯化反应中各种因素对酯化率的影响.在醇酸摩尔比1 2/1、催化剂用量1.0%(以酸的摩尔数计量)、反应时间2.5h、反应温度为回流温度以及5mL苯作为带水剂的反应条件下,酯化率可达97.2%.与其他酯化催化剂相比较,十二烷基硫酸钠的催化活性与硫酸氢钠、对甲苯磺酸等Br nsted酸相当,比大多数Lewis酸的催化活性高.由FTIR方法推测出十二烷基硫酸钠水解生成的硫酸氢钠在催化过程中起到了关键性作用.

Isopropl chloroacetate was synthesized by esterification of chloroacetic acid with isopropanol using sodium dodecyl sulfate as catalyst. Various factors affecting the esterification have been investigated. Under the condition of 1.2/1 molar ratio of isopropanol to chloroacetic acid, 1.0% catalyst (molar percent of chloroacetic acid), 2.5 h reaction time, 5 mL benzene as watercarrying agent and reflux temperature as reaction temperature, the yield of isopropyl chloroacetate reaches 97.2%. Compared with other catalysts, the catalytic activity of sodium dodecyl sulfate is almost equal to Brnsted acids, such as sodium hydrosulfate or ptoluene sulfonic acid. Its catalytic activity is greater than that of most Lewis acids. Using FTIR spetrum, it is concluded that the effect of sodium hydrosulfate,produced from sodium dodecyl sulfate hydrolysis,is essential in the catalytic esterification.