Method for preparing 4,4'-diaminodiphenyl sulfone

Abstract

The invention discloses a method for preparing 4,4'-diaminodiphenyl sulfone. The method comprises the following steps: 1) 4,4'-Dichlorodiphenyl sulfone, an aminating agent and a cuprous chloride catalyst are fed into a pipeline reactor in a mixed manner or a separate manner, continuous ammonolysis reaction is carried out under a reaction pressure of 9.5-14 MPa and at a temperature of 220-250 DEG C, and the retention time ranges from 20 minutes to 35 minutes; 2) continuous discharge is performed at a reduced pressure, excessive ammonium hydroxide is recycled, and materials are separated and dehydrated to obtain a crude 4,4'-diaminodiphenyl sulfone product; 3) the crude 4,4'-diaminodiphenyl sulfone product is dissolved in hydrochloric acid, the solution is decolorized, filtered and cooled to below 10 DEG C, the pH value is adjusted between 2 and 2.5, and the solution is filtered centrifugally, neutralized through washing, and dried to obtain a pure 4,4'-diaminodiphenyl sulfone product. According to the method, the reaction can be continuous, the reaction time is short, the productivity is improved, energy consumption is greatly reduced, reaction yield and product purity are high, the manufacturing of equipment is simple and the investment is reduced.

Description

Technical field: [0001] The invention relates to a method for preparing 4,4'-diaminodiphenylsulfone, in particular to a pipelined preparation method of 4,4'-diaminodiphenylsulfone. technical background: [0002] 4,4'-diaminodiphenyl sulfone, also known as dapsone, is a widely used chemical substance, which can be used not only as a curing agent in epoxy resin curing, but also as a treatment for human or animal bacterial infections Therapeutic agent for , has been approved as an antibiotic by the Food and Drug Administration since 1963. With regard to its use in human medicine, 4,4'-diaminodiphenylsulfone is in fact an effective antibiotic used initially in the treatment of leprosy and later also as an inhibitor of dermatitis herpetiformis. Dapsone has recently been used as an effective antibiotic for the prophylaxis of Pneumocystis carinii pneumonia (PCP), an opportunistic disease in HIV infection usually diagnosed when the disease is severe and often occurs in, and appears...

AI Technical Summary

Problems solved by technology

[0010] This kind of ammonolysis reaction is generally carried out in a high-pressure reactor. The kettle-type ammonolysis process is relatively mature, but there are defects: first, intermittent reaction, long operation time and small output; second, the reaction time of kettle-type ammonolysis Long, high temperature and high pressure, the by-product ammonium chloride is extremely corrosive to the equipment, and there are potential safety hazards; third, the investment is large, and the autoclave is made of special steel, which is difficult to manufacture

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