2-Bromo-5-iodotoluene was synthesized from o-toluidine by iodination with sodium periodate and I2 to give 2-amino-5-iodotoluene which reacted with sodium nitrite by diazotization, followed by Gat- termann reaction with copper powder in 48% hydrobromic acid with an overall yield of 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 I2 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: = 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.%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3h；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0.5h；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.
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