Process for the preparation of pure 2,5-dichloropyridine and the isolation of 2,3-dichloropyridine which is formed as a by-product

摘要

The invention relates to a novel process for the preparation of 2,5-dichloropyridine as an isomer-free product from 2-chloropyridine or 2-bromopyridine. The novel process also includes the recovery and preparation in pure form of the by-products chlorinated in the 3-position.