由对二氯苯合成3,4-二氟氯苯的研究

The Synthesis of 3, 4-Difluorochlorobenzene from p-Dichlorobenzene

报道了由对二氯苯一步直接氟化制备3,4 二氟氯苯的方法。将对二氯苯用硝硫混酸硝化获得2,5 二氯硝基苯,并以氟化钾为氟化剂,在四苯基溴化膦催化下于环丁砜等高沸点溶剂中直接进行氟化,经水蒸气蒸馏和分馏提纯获得产品。硝化收率95%以上,氟化精馏收率49 8%,产品纯度98%以上。

The synthesis method of 3, 4-difluorochlorobenzene was reported by one step direct fluoration of p-dichlorobenzene 2, 5 dichloronitrobenzene was synthesized by nitrating p-dichlorobenzene with nitric acid and sulfuric acid. In the process of direct fluoration, tetraphenyl phosphonium bromide, potassium fluoride and sulfolane was used as catalyst, fluorating agent, and high boiling point agent respectively. The terminal product was gotten by distillation in water vapor, fractionation, and purification. The yields for nitration and rectification to fluorating product are over 95% and 49.8% respectively. The purity is over 98%.