Method for preparing 4.4-dichlorodiphenyl sulfone by using sulfoxide oxidation

Abstract

The invention discloses a method for preparing 4.4-dichlorodiphenyl sulfone by using sulfoxide oxidation. The method comprises the following steps of: (1) performing Frieldel-Crafts reaction at the temperature of 25-35 DEG C by taking AlCl3 as a catalyst and chlorobenzene and thionyl chloride as reaction raw materials; next, hydrolyzing mother liquor after the Frieldel-Crafts reaction is finished; refluxing at the temperature of 95-100 DEG C for 45-60 minutes after hydrolysis is finished; cooling to be below 20 DEG C to divide into an organic phase and a water phase after refluxing is finished; performing reduced pressure distillation and centrifugal washing on the organic phase to be neutral to serve as a product A for later use, wherein a main component in the product A is 4.4-dichlorodiphenyl sulfone; and (2) performing oxidation reaction on the 4.4-dichlorodiphenyl sulfone by taking the product A as the raw material, hydrogen peroxide as a catalyst and dichloromethane as a reaction solvent to synthesize a 4.4-dichlorodiphenyl sulfone rough product. Thus, the method has the advantages of mild reaction conditions, high product quality and low three wastes (waste water, waste gas and industrial residues).

Description

technical field [0001] The invention relates to a preparation method of 4.4-dichlorodiphenyl sulfone, in particular to a method for preparing 4.4-dichlorodiphenyl sulfone by oxidation of sulfoxide. 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] At present, the commonly used synthetic methods of 4.4-dichlorodiphenyl sulfone include: chlorosulfonic acid method, concentrated sulfuric acid method and sulfur trioxide method; wherein, t...

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Problems solved by technology

[0004] At present, the commonly used synthetic methods of 4.4-dichlorodiphenyl sulfone include: chlorosulfonic acid method, concentrated sulfuric acid method and sulfur trioxide method; wherein, the production cost of 4.4-dichlorodiphenyl sulfone prepared by chlorosulfonic acid method is high, and the three wastes Serious, and the product quality is relatively poor, it is difficult to meet the quality requirements stipulated in the production of polysulfone and polyethersulfone; the reaction temperature of the concentrated sulfuric acid method is high, the reaction time is long, the equipment is severely corroded, the product quality is poor, and the yield is low; The entire process route of the sulfur method is long, the Fuckers reaction temperature is high, the reaction time is long, and the refining process route is complicated