高效杀虫剂原料2,6-二氟苯胺合成工艺的研究

[目的]优化2,6-二氯苯甲腈法合成2,6-二氟苯胺的最佳工艺。[方法]采用2,6-二氯苯甲腈法合成2,6-二氟苯胺,通过单因素试验,研究各工艺参数对氟代反应、水解反应和霍夫曼重排反应产率的影响。[结果]氟代反应的最佳工艺条件为:DCBN/KF为1.0∶2.8,反应前期温度170~180℃,时间2 h;反应后期温度230~240℃,时间4 h,该条件下,反应产率为88%~90%。水解反应的最佳工艺条件为:硫酸浓度85%,反应温度70℃,反应时间4 h,该条件下,水解产率为98.4%。霍夫曼重排反应的最佳工艺条件为:反应温度60~70℃,反应时间2 h,溴用量16.5~17.0 g。[结论]在最佳工艺条件下,2,6-二氯苯甲腈法合成2,6-二氟苯胺的产率达68.5%,且易于实现工业化。

Study on Synthesis Technology of 2,6-dlfluoroaniline Material for High Efficient Insecticide

[Objective] The aim was to optimize the best technology of synthesis of 2,6-difluoroaniline with 2,6-Dichloro-cyanobenzene method.[Method] The 2,6-difluoroaniline was synthesized by using 2,6-Dichloro-cyanobenzene,the effect of each process parameter on the yields for reaction of fluoridation,hydrolysis,and Hofmann rearrangement was studied through single factor test.[Result] The optimal process conditions of fluoridation reaction were: DCBN/KF was 1.0∶2.8,temperature 170-180 ℃ in the early stage for 2 h,temperature 230-240 ℃ in the later stage for 4h,and reaction yield was 88%-90% under these conditions.The best process conditions of hydrolysis reaction were: the sulfuric acid concn.of 85%,reaction temperature 70 ℃,reaction time 4h,and the hydrolysis yield was 98.4% under these conditions.The optimal process conditions of Hofmann rearrangement reaction were: reaction temperature 60-70 ℃,reaction time 2h,bromine dosage 16.5-17.0 g.[Conclusion] Under the best process conditions,the yield for 2,6-difluoroaniline synthesized by 2,6-Dichloro-cyanobenzene was up to 68.5%,which was easy to realize industrialization.