The invention discloses a preparation method of p-chlorobenzotrifluoride, and belongs to the technical field of
fluorine-containing carbocyclic compounds, the preparation method comprises the following steps: preparation of carbazolyl
copolymer microspheres, chlorination reaction, fluorination reaction and rectification; according to the invention, a four-
tower series continuous chlorination
reaction system is adopted, each reaction
tower independently controls the
ultraviolet light power and temperature, and the chlorination reaction is intensified in a segmented manner, so that high-efficiency reaction in the front, middle and later stages is realized; the first
tower is mainly used for monochlorination, the second tower is used for deepening dichlorination, the third tower and the fourth tower are used for realizing efficient conversion of polychlorinated products, the reaction time is shortened, the generation of
side reaction impurities is reduced, the
energy consumption is reduced, the yield and purity of target products are improved, the temperature rise in the reaction process is easier to control, and the safety of the reaction process is further improved. The purity of the parachlorobenzotrifluoride prepared by the method disclosed by the invention is 99.61 to 99.72 percent, and the two-step yield of the parachlorobenzotrifluoride is 96.48 to 96.65 percent.