A method for producing 2,6-dichlorobenzylidene dichloride while by-producing 2,6-dichlorotoluene

Abstract

The invention discloses a method for producing 2,6-dichloro benzal chloride with a byproduct of 2,6-dichlorotoluene. Through a chlorination-rectification-chlorination process, the method is capable ofmeeting a purpose of continuous reactions. The method comprises the following steps: by adopting a backpack type reaction rectification coupling mode and 2-chlorine-6-nitrotoluene as a raw material,adding the raw material and a catalyst into a chlorination reactor coupled with a rectification tower, and introducing chlorine to implement a chlorination reaction; transferring the material after the chlorination reaction into a #1 rectification tower, backflowing a top part of the tower, and discharging the material from the tower top to obtain 2,6-dichlorotoluene; transferring the residual material after the chlorination reaction into a #2 rectification tower, backflowing the top part of the tower, and discharging the material from the tower top to obtain 2-chloro-6-nitrotoluene, mixing the 2-chloro-6-nitrotoluene with a fresh raw material, circulating, transferring into the chlorination reactor, collecting residual liquid at the bottom of the #2 rectification tower as 2-chloro-6-nitrobenzyl chloride and 2,6-dichloro monobenzyl chloride, further mixing the product with the fresh raw material, feeding back to the chlorination reactor coupled with the rectification tower, and carrying out deep chlorination to obtaining 2,6-dichloro benzal chloride.

Description

technical field

[0001] The invention relates to a method for producing chemical raw materials, more specifically to a method for producing 2,6-dichlorobenzylidene dichloride while by-producing 2,6-dichlorotoluene. Background technique

[0002] 2,6-dichlorobenzylidene dichloride, also known as 2,6-dichlorobenzylidene dichloride, is used as an intermediate of 2,6-dichlorobenzaldehyde and 2,6-dichlorobenzonitrile in industrial production The deep chlorination reaction is carried out with 2,6-dichlorotoluene or 2-chloro-6-nitrotoluene as the raw material. The reaction mechanism is a free radical reaction. The chlorination temperature is high and the time is long. In addition to 2,6-dichlorobenzylidene dichloride, there are polychlorinated products such as 2,6-dichlorobenzyl chloride and 2,6-dichlorobenzylidene trichloride. Therefore, for green production, researchers Continuous research and improvement has been carried out.

[0003] Chen Qun et al. (Chen Qun, chlorination proc...

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