Preparation method of improved 4,4-dichlorodiphenylsulfone

Abstract

The invention discloses a preparation method of improved 4,4-dichlorodiphenylsulfone. The method comprises steps that: (1) Al2Cl3 is adopted as a catalyst; chlorobenzene, thionyl chloride are adopted as reaction materials; the materials are subject to a Friedel-Crafts reaction; a mother liquor obtained after the reaction is hydrolyzed; the hydrolyzed mother liquor is refluxed for 45 to 60min under a temperature of 95 to 100 DEG C; after refluxing, the mother liquor is cooled to below 20 DEG C, such that the liquor is divided into an organic phase and a water phase; the organic phase is processed through reduced-pressure distillation and centrifugal washing until the organic phase turns neutral, and the organic phase is preserved as a product M for later use, wherein a main component in the product M is 4,4-dichlorodiphenylsulfone; (2) the product M and an oxidizing agent of hydrogen peroxide are adopted as raw materials, and 1,2-dichloropropane is adopted as an organic solvent; an oxidizing reaction is carried out upon the main component 4,4-dichlorodiphenylsulfone in the product M under the effect of a composite catalyst, such that a 4,4-dichlorodiphenylsulfone crude product is synthesized, wherein the composite catalyst is phosphotungstic acid or silicotungstic acid loaded on active carbon. Therefore, the method provided by the invention has advantages of high yield and good product quality. With the method, wastewater can be circulated and reused.

Description

technical field [0001] The invention relates to a preparation method of 4.4-dichlorodiphenyl sulfone. Background technique [0002] 4.4-Dichlorodiphenylsulfone, referred to as DDS, is a white crystal, sublimable, easily soluble in benzene, chlorobenzene, DMF and other organic solvents; slightly soluble in ethanol and methanol; insoluble in water. Its flash point is 233°C and its boiling point is 397°C. [0003] 4.4-Dichlorodiphenyl sulfone is widely used in the field of engineering plastics and fine chemicals. It is the main raw material for the preparation of engineering plastics such as polysulfone and polyethersulfone, and is also an intermediate for medicine, dyes, and pesticides. [0004] Using chlorobenzene, thionyl chloride, and hydrogen peroxide as raw materials to synthesize 4.4-dichlorodiphenylsulfone is as follows: using AlCl3 as a catalyst to promote the Friedel-Crafts reaction between chlorobenzene and thionyl chloride to generate 4.4-dichlorodiphenylsulfone s...

AI Technical Summary

Problems solved by technology

[0005] It can be seen that this process has the following defects: (1) the amount of acetic acid is large; (2) the discharge of waste water is large; (3) the waste acetic acid after oxidation needs to be rectified, which seriously corrodes the equipment, and the equipment for rectifying acetic acid Large investment; (4) The product quality is poor, and it is difficult to purify and separate after treatment, otherwise it is difficult to meet the quality standards of polysulfone and polyethersulfone; (5) The product yield is low