Method for continuously synthesizing perchloromethyl mercaptan

Abstract

The invention provides a method for continuously synthesizing perchloromethyl mercaptan. Liquid chlorine, carbon disulfide and a hydrochloric acid solution are adopted as raw materials and react in the continuous flow reactor under certain temperature and pressure conditions through a full-liquid-phase reaction among the materials, so that the reaction efficiency is greatly improved; meanwhile, back mixing can be effectively avoided by adopting continuous flow reaction, further reaction of total chlorine, chlorine and other byproducts is reduced, and the reaction selectivity is improved. Besides, compared with the prior art, the method has the advantages that the liquid chlorine gasification procedure is omitted, so that the problem of dissolution heat release during chlorine reaction isavoided, the total heat release in the reaction process is reduced, and the production energy consumption is reduced; moreover, high-toxicity chlorine and extremely flammable carbon disulfide need tobe used for synthesizing total chlorine, while the continuous reactor is used in the invention, so that the material amount in a reaction system can be greatly reduced, the reaction safety and controllability are improved, and the harm to the health of workers or other dangers caused by running, emitting, dripping, leaking and the like can be effectively avoided.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a method for continuously synthesizing perchloromethanethiol. Background technique [0002] Perchloromethanethiol is an intermediate in organic synthesis of synthetic dyes and pesticides, such as the pesticide fungicides folpet and captan. Therefore, the synthesis of perchloromethanethiol is of great significance. [0003] At present, the synthesis method of perchloromethanethiol mostly adopts intermittent gas-liquid kettle synthesis, using carbon disulfide and hydrochloric acid as raw materials, passing chlorine gas at a temperature of 10-30°C for a period of time to complete the reaction, and then separating liquids to obtain perchloromethanethiol. For example, in the Chinese patent application with the publication number CN103360295A, two reactors are used, carbon disulfide and hydrochloric acid are added to the two reactors, and then chlorine is synthesized, and pe...

AI Technical Summary

Problems solved by technology

This type of synthetic method mainly has the following disadvantages: (1) the reaction time is long, and it takes up to 22 hours to complete the reaction; the longer reaction time increases labor costs and reduces the output per unit time

(2) The product perchlorine and chlorine will further undergo series side reactions. Using a tank reactor, back mixing will cause an increase in series side reactions and reduce selectivity

(3) Most of the synthesis reaction devices are batch kettles, and the amount of reaction materials is large

Carbon disulfide is extremely flammable, chlorine gas is highly toxic, and has a high risk of reaction. It is easy to run, run, drip, and leak materials, which will cause great harm to the health of workers.

(4) The heat of the reaction is large, and the heat needs to be removed in time. The large reactor reduces the heat transfer area, and more costs need to be invested in heat exchange to maintain the reaction temperature

This method can realize the continuous production of perchloromethanethiol, but there are still problems of slow reaction speed, large amount of material in the container, and poor heat exchange capacity of the equipment. It is necessary to increase the external circulation system to enhance the heat exchange capacity, and the equipment cost is high.

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