Method for co-producing o-chlorobenzyl chloride, o-chlorobenzyl dichloride and o-chlorobenzyl trichloride through chlorination of o-chlorotoluene

Abstract

The invention relates to the technical field of chemical production, in particular to a method for co-producing o-chlorobenzyl chloride, o-chlorobenzyl dichloride and o-chlorobenzyl trichloride by chlorination of o-chlorotoluene, which comprises the following steps of: performing chlorination reaction on o-chlorotoluene serving as a raw material and chlorine, sampling, analyzing and controlling the content of components in the reaction material, rectifying and co-producing to obtain o-chlorobenzyl chloride, o-chlorobenzyl dichloride and o-chlorobenzyl trichloride. According to the method, benzoyl peroxide is taken as an initiator, and a metal ion masking agent is added into the raw material before chlorination reaction, so that metal ions in the raw material can be removed, side reaction can be inhibited, and the catalytic efficiency of the initiator is improved. The method is low in reaction temperature, mild in reaction, easy to control, high in reaction conversion rate, few in by-product and high in product purity.

Description

technical field [0001] The invention relates to the technical field of chemical production, in particular to a method for the chlorination of o-chlorotoluene to co-produce o-chlorobenzyl, o-chlorodichlorobenzyl and o-chlorotrichlorobenzyl. Background technique [0002] O-chlorobenzyl, o-chlorodichlorobenzyl and o-chlorotrichlorobenzyl are important fine chemical products, which are widely used in the fields of medicine, pesticides, dyes, etc. Trichlorobenzyl as raw material can be used to synthesize a series of intermediates or products with high value. [0003] There are many synthetic routes of ortho-chlorobenzyl, ortho-chlorodichlorobenzyl and ortho-chlorotrichlorobenzyl, currently based on the ortho-chlorotoluene side chain chlorination route. The specific chlorination methods of o-chlorotoluene include thermal chlorination, photochlorination and catalyst chlorination. Thermal chlorination has basically been eliminated due to its slow speed and many side reactions. Alt...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to aim at the deficiencies in the prior art, and provide a kind of method that o-chlorotoluene chlorination co-produces o-chlorobenzyl, o-chlorodichlorobenzyl and o-chlorotrichlorobenzyl, it solves the existing chlorination process Among them, the reaction conversion rate is low, the reaction conditions are inconvenient to control, the product purity is not high, and there are many by-products, etc.