2-溴-5-碘甲苯的合成工艺改进  

Improvement of synthetic process for 2-bromo-5-iodotoluene

作　　者：刘长春[1] 贺新[1] 张頔[1] 臧寿楠[1] 

机构地区：[1]常州工程职业技术学院化工系,江苏常州213164

出　　处：《应用化工》2012年第7期1291-1293,共3页Applied Chemical Industry

基　　金：2010大学生实践创新课题(CX2010-15)

摘　　要：以邻甲苯胺为起始原料,高碘酸钠为氧化剂,单质碘取代得2-氨基-5-碘甲苯,再经重氮化及Gattermann反应,得2-溴-5-碘甲苯,总收率66.1%(以邻甲苯胺计)。结果表明,较佳的工艺条件为:碘化过程中邻甲苯胺、高碘酸钠和碘的摩尔比为1∶0.6∶0.45,反应温度为25～30℃,反应时间3 h;在重氮化、溴代反应中,以亚硝酸钠为重氮化试剂,2-氨基-5-碘甲苯与亚硝酸钠和浓硫酸的摩尔比为1∶1∶7.5,反应温度为0～5℃,溴代反应时间为0.5 h;经精馏所得产物含量超过98%(GC法)。改进后的工艺原料易得,操作简便,适合工业化生产。2-Bromo-5-iodotoluene was synthesized from o-toluidine by iodination with sodium periodate and 12 to give 2-amino-5-iodotoluene which reacted with sodium nitrite by diazotization, followed by Gat- termann reaction with copper powder in 48% hydrobromie acid with an overall yield o1＇ 66.1% （based on o-toluidine）. The results showed that the optimum process are ： in iodination, the molar ratio of o-toluid- ine, sodium periodate and 12 was 1 ： 0.6 ： 0.45, reaction temperature was 25-30℃, iodination time was 3 h ; in diazotization and bromination, sodium nitrite was used as diazotization reagent, the molar ratio of 2- amino-5-iodotoluene, sodium nitrite and sulfuric acid was 1 ： 1 ： 7.5, reaction temperature was 0 -5 ℃, bromination time was 0.5 h, the purity of the target after distilling is more than 98 % （ GC）, the improved process is practical, easy to operate, suitable for industrial production.

关 键 词：2-氨基-5.碘甲苯 2-溴-5.碘甲苯 邻甲苯胺 工艺改进 

分 类 号：TQ242.1[化学工程—有机化工] O625[理学—有机化学]