对溴苯异氰酸酯的合成研究

Synthesis of 4-Bromophenyl Isocyanate

研究以对溴苯胺和三光气为原料合成对溴苯异氰酸酯,重点讨论溶剂、反应温度、反应时间和原料配比等对合成工艺的影响。研究表明:以乙酸乙酯为溶剂,滴液温度-5～0℃,回流温度78℃,反应时间为5.0 h,三光气∶对溴苯胺=1∶2(摩尔比),对溴苯异氰酸酯的收率可达90.4%。

4-Bromophenyl isocyanate was prepared from triphosgene and 4-bromoaniline.The effects of solvents,reaction temperature,reaction time and the mole ratio of raw materials on the yield of 4-bromophenyl isocyanate were studied.The optimum reaction conditions were obtained as follows： the solvent ethyl acetate,titration temperature-5~0℃,the refluxing temperature 78℃,the mole ratio of 4-bromoaniline to triphosgene 2∶1 and reaction time 4.5 h.The results of parallel tests showed that under such optimum condition the yield of 4-bromophenyl isocyanate could reach 90.4%.