2,3-Dichloro-5-(trifluoromethyl)pyridine

69045-83-6

69045-84-7

General procedure for the synthesis of 2,3-dichloro-5-trichloromethylpyridine from 2,3-dichloro-5-trichloromethylpyridine: 26.5 g (0.1 mol) of 2,3-dichloro-5-trichloromethylpyridine and 0.2 g of tungsten hexachloride were added to a reactor, which was heated to 170 °C under atmospheric pressure. Subsequently, about 20 g of hydrogen fluoride was slowly added. The reaction was terminated when the composition of the reaction product no longer changed. The unreacted hydrogen fluoride was recovered by condensation and the generated hydrogen chloride was removed by absorption. The reaction solution was cooled to room temperature and then transferred to an autoclave, heated to 180°C, maintained at a pressure of 0.2 MPa, and reacted for 5 hours. After completion of the reaction, the reaction mixture was cooled and sampled for analysis. The results showed that the product contained 94% of 2,3-dichloro-5-trifluoromethylpyridine and 92% purity.