Process for producing 2,3,5,6-tetrachloropyridine and 2,3,6-trichloropyridine

摘要

Vapor phase chlorination of 2,6-dichloropyridine produces 2,3,6-trichloropyridine selectively over isomeric 2,4,6-trichloropyridine and of 2,3,6-trichloropyridine produces 2,3,5,6-tetrachloropyridine in high selectivity over isomeric 2,3,4,6-tetrachloroyridine at temperatures of 300 DEG C to 450 DEG C. The products are intermediates for insecticides and herbicides.