新己烯的合成研究

Synthesis of Neohexene

采用加压方法,在无水AlCl3催化和少量助催化剂作用下,以乙烯、叔丁基溴为原料合成新己基溴;实验表明300g叔丁基溴,在35g催化剂的催化下,最佳的反应条件是150mL正己烷作溶剂,反应压力控制在0.9～1MPa、反应时间为2h,产物卤代新己烷的收率达到88%;N-甲基吡咯烷酮为溶剂,采用反应精馏的方法,溴代新己烷脱溴化氢制备新己烯,直接可得到纯度达98%的产品。溶剂和溴元素可以循环使用,节省了原料和减少了污染。

Neohexene was prepared through two steps from commercial tertbutyl bromide to 1neohexyl bromide via addition reaction of ethylene which was catalyzed by anhydrous AlCl3 along with the assistant catalysts and to neohexene via dehydrohalogenation of the intermediate neohexyl bromide in the solvent of 1methyl2pyrrolidone with reactiondistillation system. It has been showed that the optimum condition in the FriedelCrafts addition is that for 300g tertbutylbromide, 35g catalyst, 150mL nhexane is need with the reaction pressure of 0.9～1MPa and reaction time of 2 hours. The yield of product neohexyl halogens can be up to 88%, the purity of neohexene up to 98%. The solvent and bromide element can be reused in order to reduce the pollutign.