Preparation method of 4, 4 '-dichlorodiphenyl sulfone

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of high-purity 4, 4-dichlorodiphenyl sulfone. The preparation method of the high-purity 4, 4-dichlorodiphenyl sulfone comprises the following steps: firstly, mixing molybdate, organic dicarboxylic acid and hydrogen peroxide, dropwise adding the mixture into a mixed solution of 4, 4-dichlorodiphenyl sulfoxide and a solvent for reaction, and after the reaction is completed, performing post-treatment to obtain the high-purity 4, 4-dichlorodiphenyl sulfone and residual filtrate; the residual filtrate is directly used for the next round of reaction after being layered; the molar ratio of the 4, 4-dichlorodiphenyl sulfoxide to the molybdate to the organic dicarboxylic acid to the hydrogen peroxide is 1: (0.01-0.05): (0.02-0.1): (1-3). The invention provides the preparation method of the high-purity 4, 4-dichlorodiphenyl sulfone, the catalyst is low in cost, the preparation steps are simple, the post-treatment steps are simple, the reaction residual filtrate is circularly and efficiently utilized, the purity is high, and the yield is high.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of 4,4'-dichlorodiphenyl sulfone. Background technique [0002] 4,4´-dichlorodiphenyl sulfone is an important chemical raw material. There are many methods for industrial production of 4,4´-dichlorodiphenyl sulfone. Regarding the preparation of 4,4´-dichlorodiphenyl sulfone by sulfoxide oxidation There are also many reports on chlorodiphenyl sulfone. [0003] Hydrogen peroxide is used as an oxidant in the traditional sulfoxide oxidation method, but the purity of the obtained 4,4´-dichlorodiphenyl sulfone is low; after further improvement, many industrial productions use a large amount of sulfuric acid to enhance the acidity of the system, mixed with acetic acid or Peroxyacid has an oxidation effect, but a large amount of mixed acid is used, which has a high degree of corrosion to equipment, and it is difficult to treat the mixed waste l...

AI Technical Summary

Problems solved by technology

[0003] Hydrogen peroxide is used as an oxidant in the traditional sulfoxide oxidation method, but the purity of the obtained 4,4´-dichlorodiphenyl sulfone is low; after further improvement, many industrial productions use a large amount of sulfuric acid to enhance the acidity of the system, mixed with acetic acid or Peroxyacid has an oxidation effect, but a large amount of mixed acid is used, which has a high degree of corrosion to equipment, and it is difficult to treat the mixed waste liquid of mixed acid and solvent, and the separation of acid and solvent is relatively difficult. The separation cost is high, and the prepared 4 ,4´-dichlorodiphenyl sulfone post-treatment steps are more cumbersome, the process is more complicated, which virtually increases the production cost of the enterprise

[0004] As a further improvement, the quaternary ammonium phosphotungstic acid catalyst was used in the research, but the matching special quaternary ammonium salt phase transfer agent is expensive. As a cost consideration, enterprises are limited in its promotion and application

[0005] CN107540581A adopts formic acid or glacial acetic acid, and corresponding peroxyacid as medium reaction, but obtains lower purity

[0006] CN106349126A adopts concentrated sulfuric acid catalyst, chlorobenzene and glacial acetic acid as solvent, hydrogen peroxide oxidation, the prepared 4,4'-dichlorodiphenyl sulfone, although the mixed solvent can be used next time, but the purity and yield are all low

[0007] CN108047101A mentions that the mixture of hydrogen peroxide and acetic acid or concentrated sulfuric acid is used in the oxidation stage, the yield is low, and the mixed acid is difficult to handle

[0008] The use of concentrated sulfuric acid, organic peroxyacids, and a large amount of mixed acids used in the above patents will lead to corrosion of equipment, difficulty in waste liquid separation, and acid crystallization of 4,4´-dichlorodiphenyl sulfone, which is difficult to use with alkali The liquid is completely cleaned and the purity is low

[0009] In CN105732447B, phosphotungstic heteropolyacid quaternary ammonium salt is used as catalyst, benzene is solvent, hydrogen peroxide is oxidant, and the molar ratio of hydrogen peroxide to 4,4'-dichlorodiphenyl sulfoxide is 4~6:1. 4,4´-dichlorodiphenylsulfoxide is oxidized to 4,4´-dichlorodiphenylsulfone, and the catalyst can be reused, but the preparation process of the catalyst is complex and expensive, and the amount of hydrogen peroxide used is large and strong The carcinogen benzene is used as the problem of the solvent, and the yield of the product is low

Images