三聚氯氰催化液相重排合成ε-己内酰胺

Synthesis of ε-Caprolactam by Liquid Phase Beckmann Rearrangement of Cyanuric Chloride

以甲苯和三氟乙酸为混合溶剂,极少量的三聚氯氰(CNC)作催化剂,实现了温和条件下由环己酮肟液相贝克曼重排制备ε-己内酰胺的反应。对溶剂种类、反应温度、催化剂用量、反应时间、混合溶剂比例、混合溶剂用量等因素对重排反应的影响进行了考察,并得到了最佳的反应条件:环己酮肟1.0 mol%,反应温度80℃,三聚氯氰1.0mol%,反应时间2.5h,甲苯∶三氟乙酸=4∶5(体积比),混合溶剂8m L,环己酮肟的转化率达98.6%,ε-己内酰胺的选择性达93.8%,主要副产物为环己酮。该法具有对环境无害,反应条件温和,催化剂廉价易得,溶剂可重复使用等优点。

Applied a very small amount of CNC(cyanuric chloride)as catalyst,trifluoroacetic acid and toluene as mixed solvent,ε-caprolactam was synthesized by liquid phase Beckmann rearrangement of cyclohexanone oxime under mild conditions.The effect of different solvent,reaction temperature,the dosage of catalyst,reaction time,the proportion of mixed solvent and the amount of mixed solvent on the Beckmann rearrangement were mainly studied.The Beckmann rearrangement of cyclohexanone oxime was almost completely performed(98.6%)under the optimized reaction conditions of1.0mol%of cyanuric chloride(CNC)in a5:4mixed solvent of trifluoroacetic acid and toluene at80℃for2.5h,ε-caprolactam yield was reach in93.8%and the mainly by-product was cyclohexanone.