Preparation method of 2, 3-dichloro-5-trichloromethylpyridine compound

The invention discloses a preparation method of a 2, 3-dichloro-5-trifluoromethylpyridine compound, which comprises the following steps: adding 2, 3-dichloro-5-trichloromethylpyridine and toluene into a reaction kettle, then adding a fixed amount of catalyst, finally adding potassium fluoride into the kettle, heating to 210-230 DEG C, and keeping the temperature for 8-12 hours; and cooling the reaction to 60-80 DEG C, carrying out suction filtration to separate solid-phase salt and an oil phase, recovering a byproduct potassium chloride with the content of more than 90%, recovering toluene from the oil phase under negative pressure, carrying out negative removal and heat preservation to obtain crude 2, 3-dichloro-5-trichloromethylpyridine, and rectifying to obtain refined 2, 3-dichloro-5-trichloromethylpyridine. The preparation method of the 2, 3-dichloro-5-trichloromethylpyridine is a normal-pressure one-pot method, is simple to operate, safe in process, high in yield and low in three wastes, and accords wit