A kind of synthetic method of bisphenols

Abstract

The invention discloses a method for synthesizing bisphenol S, which comprises the following steps: (1) while stirring, under nitrogen protection, phenol and a catalyst are heated to 120-140° C., and 98wt% concentrated sulfuric acid is added dropwise thereto. , the dropwise addition time is 2.5-3.5h; continue to keep the reaction for 2-3h, heat up to 160-190°C, and keep the temperature for 5-6h until the system becomes molten to obtain the crude product. (2) dissolving the obtained crude product in dilute alkali solution, adjusting pH to be 8.5~9.5, obtaining mother liquor after decolorization heat filtration, adjusting the pH of the mother liquor to 5~6 with dilute hydrochloric acid, dissolving the separated monosodium salt in water, continue The pH is adjusted to 2-3, the product is precipitated in solid form, and 4,4'-dihydroxydiphenyl sulfone is obtained after filtration and drying. The invention reduces the reaction temperature, improves the reaction safety, simplifies the operation process, reduces the reaction cost, and increases the content of 4,4'-dihydroxydiphenyl sulfone in the fine product.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a synthesis technology of bisphenol S. Background technique [0002] Bisphenol S, the Chinese name is 4,4'-dihydroxydiphenyl sulfone; 4,4'-dihydroxydiphenyl sulfone; 4,4'-sulfonyl diphenol; bisphenol S; 4,4'-dihydroxy Diphenylsulfone; 4-hydroxyphenylsulfone; p,p-dihydroxydiphenylsulfone; 4,4'-sulfonyldiphenol; bis(4-hydroxyphenyl)sulfone. It is mainly used as a monomer for the synthesis of polysulfone resin, and can also be directly used in coatings, leather modifiers, dye intermediates, metal plating brighteners, etc. The molecule contains two hydroxyl groups and a strong electron-withdrawing sulfone group, so the acidity is stronger than other phenols. It has heat resistance, oxidation resistance and light stability. [0003] At present, the synthesis technology of bisphenol S in the prior art is to synthesize bisphenol S at a high temperature of 230°C by using phe...

AI Technical Summary

Problems solved by technology

The reaction requires the heat transfer oil to be at a high temperature of 230°C for a long time. Generally, the best use temperature of the heat transfer oil is below 200°C. Long-term high temperature may reduce the service life of the heat transfer oil, and the use of the heat transfer oil in the open air during the small test may cause fire hazards.

[0005] 2. The reaction will evaporate the solvent, which needs to be condensed immediately, and has higher requirements for the condensing device

[0006] 3. High temperature reaction, more trihydroxytriphenyldisulfone may appear in the reaction process

[0008] Therefore, the current bisphenol S synthesis method has many problems such as complex process, high cost, low product yield and harsh equipment requirements, which restricts the industrial production of bisphenol S