Method for producing 2,6-dichlorotoluene and 2,3-dichlorotoluene by utilizing 2-chlorotoluene to directionally chloridize

Abstract

The invention relates to a method for producing 2,6-dichlorotoluene and 2,3-dichlorotoluene by utilizing 2-chlorotoluene to directionally chloridize, which comprises the following steps: 1) adding a directional chlorination catalyst; 2) reacting chlorine with 2-chlorotoluene; 3) stopping reaction; and 4) separating components. According to the method, under the action of the directional catalyst (CY-2), the 2-chlorotoluene reacts with the chlorine, and a rectifying column for different components is professionally designed and is used for separating unreacted raw materials and products from by-products, so that the required products, namely, the 2,6-dichlorotoluene and the 2,3-dichlorotoluene, are obtained. According to the method, the adverse factors of high cost and serious pollution of a technology for producing the 2,6-dichlorotoluene according to a traditional diazotization method are eliminated; the ideal reaction products can be obtained by controlling reaction temperature and reaction depth; and different components can be obtained from the reaction products through a rectifying technology according to a boiling point difference of the components.

Description

technical field [0001] The invention relates to a method for industrial production of 2,6-dichlorotoluene and 2,3-dichlorotoluene by directional chlorination of 2-chlorotoluene: 2,6-dichlorotoluene and 2,3-dichlorotoluene in the chlorination product The mass percentages of chlorotoluene are above 40±2% and 20±2%, respectively, and the rest is unreacted 2-chlorotoluene and a small amount of other high-boiling point (>220°C) polychlorinated toluene by-products (about 2%). Background technique: [0002] 2,6-dichlorotoluene and 2,3-dichlorotoluene are important raw materials for organic synthesis, and are widely used in medicine, pesticides, and dye industries. There are many derivatives, which can produce dichlorobenzaldehyde, dichlorobenzonitrile and so on. The traditional industrial production process route of 2,6-dichlorotoluene is the production of diazotization method, which first generates 2.6-dinitrobenzene, and then further reacts to generate 2,6-dichlorotoluene. ...

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Problems solved by technology

The cost of this process is high, and there is heavy pollution, waste gas and waste water are difficult to deal with, and the market competitiveness of products produced by this method is low

[0003]The traditional production process of 2,3-dichlorotoluene uses o-toluidine as a raw material, and after nitration, Sandmeyer reaction, reduction of iron powder, and then a Sandmeyer reaction to obtain 2 , 3-dichlorotoluene, the total yield is 25.8%. This process is not only costly, but also has high risk and serious corrosion to equipment

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