CHLORINATION OF 2-CHLORO-6-(TRICHLOROMETHYL)-PYRIDINE

摘要

The relative amounts of 5,6-dichloro-2-(trichloromethyl)pyridine and 3,6-dichloro-2-(trichloromethyl)pyridine obtained in the chlorination of 2-chloro-6-(trichloromethyl)pyridine in the liquid phase at temperatures of 160 DEG C to 220 DEG C and in the presence of a metal halide catalyst, such as ferric chloride are controlled by regulating the amount of hydrogen chloride present in the system, adding hydrogen chloride to obtain a mixture enriched in 5,6-dichloro-2-(trichloromethyl)pyridine or removing hydrogen chloride, usually by passing excess chlorine or an inert gas through the system, to obtain a mixture enriched in 3,6-dichloro-2-(trichloromethyl)pyridine.