Synthesis method of 2-chloro-5-chloromethyl pyridine

Abstract

A process for synthesizing 2-chloro-5-chloromethyl pyridine includes such steps as adding 2-chloro-5-methyl pyridine and CC4 solvent into airlift recirculating reactor, spraying dry N2 into the reactor from its bottom under micro negative pressure, adding azadiisobutylnitrie as catalyst, heating to 70-80 deg.C, continuously introducing N2 for 2-10 min, stopping the introduction of N2, and introducing dry chlorine gas and in-line detection with gas-phase chromatograph. Its advantages are less consumption of chlorine gas and short time of supplying chlorine gas.

Description

technical field [0001] The invention relates to a synthesis method of 2-chloro-5-chloromethylpyridine. technical background [0002] Currently, 3-methylpyridine insecticides represented by imidacloprid, acetamiprid, fluazifop-p-butyl, and valalifop, have systemic , broad spectrum, high efficiency, long duration, good safety and other advantages, has been widely used at home and abroad, and 2-chloro-5 chloromethylpyridine is the key intermediate for the synthesis of the above pesticides. [0003] Known synthetic method of producing 2-chloro-5-chloromethylpyridine, it takes 2-chloro-5-methylpyridine as raw material, through catalytic chlorination, directly synthesizes 2-chloro-5-chloromethylpyridine, traditional Most of the reactors used in the process are stirred tank reactors, which have poor sealing performance, high noise, high energy consumption, unsatisfactory yield, and difficult uniform mixing of materials. ...

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Problems solved by technology

[0003] Known synthetic method of producing 2-chloro-5-chloromethylpyridine, it takes 2-chloro-5-methylpyridine as raw material, through catalytic chlorination, directly synthesizes 2-chloro-5-chloromethylpyridine, traditional Most of the reactors used in the process are stirred tank reactors, which have poor sealing performance, high noise, high energy consumption, unsatisfactory yield, and difficult material mixing.

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