碳酸二甲酯法合成N,N-二甲基苯胺的研究

Synthesis of N,N-dimethyl anline form dimethyl carbonate

胺中亲核的氮原子的N-烷基化在实验室范围及批量范围有机合成中是一个非常常见的工序.传统的方法是Eschweiler-Clarke烷基化程序,采用甲酸和福尔马林进行胺的N-烷基化.提出了苯胺在碳酸二甲酯(DMC)作烷基化试剂,四乙基溴化铵(TEAB)催化下合成N,N-二甲基苯胺的新方法,讨论了物料比例、四乙基溴化铵、温度对反应结果的影响,确定了反应温度、四乙基溴化铵等的最佳用量最适宜的工艺条件是:反应温度为443 K,苯胺和碳酸二甲酯的摩尔比1∶1.2～1∶1.3,反应时间是2 h.在优选的条件下获得了产物N,N-二甲基苯胺,产率达93%,同时催化剂四乙基溴化胺得到很高的回收率.

N-methylation of nuclephilic nitrogen in amines is a common procedure in both lab-scale and bulk-scale organic synthesis.The conventional N-Alkylation of aniline is Eschweiler-Clarke methylation.It used toxic formalin and concentrated formic acid as methylating solution.Aniline is substrate,a new way was proved that of N-alkylation by DMC catalyzed by TEAB,and the influence factor was discussed that on the result such as reaction temperature,TEAB.The best yield（93%） of N,N-dimethyl anline were obtained under optimized conditions that the reaction temperature 443 K,n（aniline）∶ n（DMC）=1∶ 1.2～1∶ 1.3,the reaction time 2 h.The results show the recycling ability of TEAB is very well.