间甲基苯腈的硝化及产物的结构表征

以浓硝酸为硝化剂硝化间甲基苯腈得到3种硝基间甲基苯腈的异构体。在n(间甲基苯腈)∶n(发烟硝酸)=1∶10,反应时间2 h,反应温度18~20℃的条件下,冰浴中将浓硝酸缓慢滴加到间甲基苯腈中,得3种硝基间甲基苯腈异构体,粗品总收率92%。经柱层析和重结晶,从粗产物中分离出3种纯异构体,分别为3-甲基-4-硝基苯腈、3-甲基-6-硝基苯腈和3-甲基-2-硝基苯腈,以间甲基苯腈计,收率分别为43%、37%和12%。应用核磁共振、红外和气质联用技术,表征了3种纯异构体的结构,对硝化反应的位置选择性进行了初步分析。

Nitration of m-Tolunitrile and Identification of the Products

Three nitro isomers of m-tolunitrile were obtained in 92% total yield via nitration of m-tolunitrile with concentrated nitric acid(≥98%) under the following conditions:n(m-tolunitrile)∶n(nitric acid)=1∶10,reaction time 2 h,reaction temperature 18～20 ℃ and dropping nitric acid to m-tolunitrile in ice bath.Column chromatography followed by recrystallization gave three pure isomers (5-cyano)-2-nitrotoluene,3-cyano-4-nitrotoluene and 3-cyano-2-nitrotoluene in 43%,37% and 12% yield respectively,based on m-tolunitrile.Structure of the pure isomers was characterized by IR,~1HNMR and GS/MS.Regioselectivity of the nitration was discussed.