PREPARATION OF 3, 6 - DICHLORO -2 - TRICHLOROMETHYLPYRIDINE BY VAPOR PHASE CHLORINATION OF 6 -CHLORO-2-TRICHLORMETHYLPYRIDINE

摘要

An improved process for chlorinating 6-chloro-2-trichloromethylpyridin (I) in the vapor phase at elevated temperatures to obtained a chlorination mixture containing 5,6-dichloro-2-trichloromethylpyridine (II) and 3,6-dichloro-2-trichloromethylpyridine (III) wherein the improvement comprises contacting the 6-chloro-2-trichloromethylpyridine (I) with chlorine in the presence of a Type L zeolite catalyst to obtain a mixture enriched in 3,6-dichloro-2-trichloromethylpyridine (III).