Patent ID: 10577326

Abstract:
The present invention relates to a method for preparing 2-chloro-6-trichloromethylpyridine with product purity greater than or equal to 99.0% by using trifluoromethyl chlorobenzene as a solvent for reaction between 2-methylpyridine with chlorine gas, in which 2-methylpyridine and chlorine gas are used as starting materials, trifluoromethyl chlorobenzene is used as a solvent, 2-methylpyridine is prepared into a liquid raw material by using the solvent trifluoromethyl chlorobenzene, and the liquid raw material is continuously fed to perform liquid phase photochlorination reaction at temperature of 160-240° C. under irradiation of ultraviolet light to obtain 2-chloro-6-trichloromethylpyridine solution. Advantages: the selectivity of reaction for the production of 2-chloro-6-trichloromethylpyridine is improved, the content of components such as isomers and pentachloromethylpyridine in the crude product is decreased significantly, the crude product is easy to be purified to obtain the 2-chloro-6-trichloromethylpyridine product with purity greater than or equal to 99.0%, and the industrial production is facilitated; and secondly, not only can the reuse of the separated solvent in the preparation process of the 2,6-dichloropyridine product with purity greater than or equal to 99.0% be realized, but also the purposes of low pollution, low energy consumption and low cost in the preparation process are realized.