Inventors:
Richard K. Helling - Martinez CA
Philip D. Grover - Concord CA
Thomas J. Dietsche - Berkeley CA
Mark L. Garibaldi - Martinez CA
Assignee:
The Dow Chemical Company - Midland MI
International Classification:
C07D21361
Abstract:
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 about 160. degree. C. to about 220. degree. 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.