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CN-121990878-A - Synthesis method of 4,4' -dihydroxybiphenyl

CN121990878ACN 121990878 ACN121990878 ACN 121990878ACN-121990878-A

Abstract

The invention discloses a synthesis method of 4,4' -dihydroxybiphenyl. Mixing 4,4 '-dinitrobiphenyl, a metal catalyst and an organic solvent, and introducing hydrogen to perform hydrogenation reduction reaction to obtain 4,4' -diaminobiphenyl; mixing 4,4 '-diaminobiphenyl and a silicon dioxide grafted and modified multi-branched carboxylic acid polymer, heating the mixture for reaction, removing a solvent from a reaction solution to obtain 4,4' -dihydroxybiphenyl, taking the 4,4 '-dinitrobiphenyl as a substrate for reaction, obtaining an intermediate 4,4' -diaminobiphenyl after hydrogenation reduction, the silicon dioxide grafted and modified multi-branched carboxylic acid polymer is used as a hydrolysis reagent to synthesize the target product 4,4 '-dihydroxybiphenyl, so that the efficiency and selectivity of the reaction for preparing the 4,4' -dihydroxybiphenyl are effectively improved, the reaction condition is mild, the operation process is simple and convenient, and the method has wide industrialized application potential.

Inventors

  • XING WENGUO
  • ZHANG CHENYANG
  • ZHANG LIPENG
  • DONG MINGYAN
  • CHENG YUANZHI
  • CHEN GUIJUN
  • YUE TAO

Assignees

  • 青岛科技大学

Dates

Publication Date
20260508
Application Date
20260112

Claims (10)

  1. 1. A method for synthesizing 4,4' -dihydroxybiphenyl, which is characterized by comprising the following steps: (1) Mixing 4,4 '-dinitrobiphenyl, a metal catalyst and an organic solvent, and introducing hydrogen to carry out hydrogenation reduction reaction to obtain 4,4' -diaminobiphenyl; (2) Mixing 4,4 '-diaminobiphenyl and a silicon dioxide grafted and modified multi-branched carboxylic acid polymer, heating for reaction, and removing a solvent from a reaction solution to obtain 4,4' -dihydroxybiphenyl.
  2. 2. The synthesis method according to claim 1, wherein in the step (1), 4 '-dinitrobiphenyl and an organic solvent are stored in a storage tank to obtain a mixed solution, and the mixed solution is introduced into a hydrogenation reduction reactor filled with a metal catalyst to perform hydrogenation reduction reaction to obtain 4,4' -diaminobiphenyl.
  3. 3. The synthesis method according to claim 2, wherein the organic solvent is at least one selected from methanol, ethanol, isopropanol and tetrahydrofuran, and the mass ratio of the 4,4' -dinitrobiphenyl to the organic solvent is 0.25-0.5:1.
  4. 4. The synthesis method according to claim 2, wherein the mixed solution has a feed rate of 0.04-0.065 kg/min, a hydrogen feed rate of 0.75-1.1 g/min, a heating temperature of the hydrogenation reduction reactor of 25-100 ℃, and the metal catalyst is selected from palladium, platinum or ruthenium.
  5. 5. The synthesis method according to claim 1, wherein in the step (2), 4' -diaminobiphenyl is pumped into a two-stage serial tower reactor filled with a silica graft modified multi-branched carboxylic acid polymer to react, the obtained 4,4' -dihydroxybiphenyl reaction solution is subjected to solvent removal by a desolventizing tank to obtain refined 4,4' -dihydroxybiphenyl, and the removed solvent is recycled.
  6. 6. The synthetic method of claim 5 wherein the silica graft modified multi-branched carboxylic acid polymer is a silica graft of at least two of the compounds having the structural formula A, B, C; Wherein A is structural formula Or (b) B is structural formula Or (b) C is shown in the structural formula 。
  7. 7. The synthetic method of claim 6 wherein the silica graft modified multi-branched carboxylic acid polymer is prepared by the process of: Dispersing silicon dioxide and a silane coupling agent in toluene, adding sulfonic benzoic acid and dicarboxylic acid, heating and refluxing under the protection of nitrogen, spin-drying the obtained product, washing with an organic solvent and deionized water in sequence, and drying to obtain the silicon dioxide grafted modified multi-branched carboxylic acid polymer.
  8. 8. The synthesis method according to claim 7, wherein the silane coupling agent is KH-550, the sulfonic acid-containing benzoic acid is added with 2-sulfobenzoic acid or 2-hydroxy-5-sulfobenzoic acid, the dicarboxylic acid is succinic acid or terephthalic acid, the molar ratio of the silicon dioxide, the sulfonic acid-containing benzoic acid and the dicarboxylic acid is 1:2-3:3-4, and the addition amount of the silane coupling is 0.5-1% of the mass of the silicon dioxide.
  9. 9. The synthesis method according to claim 5, wherein the pumping pressure is 1.0-1.2 Mpa, and the temperature of the two-stage series-connected tower reactor is 60-85 ℃.
  10. 10. Use of the method of any one of claims 1 to 9 in at least one of the following 1) to 3): 1) The synthesis time of 4,4' -dihydroxybiphenyl is shortened; 2) The selectivity of the 4,4' -dihydroxybiphenyl is improved; 3) Reduce the impurity in the reaction liquid of 4,4 '-dihydroxybiphenyl and improve the yield of 4,4' -dihydroxybiphenyl.

Description

Synthesis method of 4,4' -dihydroxybiphenyl Technical Field The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing 4,4' -dihydroxybiphenyl. Background The 4,4 '-dihydroxybiphenyl, namely 4,4' -biphenol, is an important organic intermediate with very wide application, is often used as a rubber anti-aging agent and a plastic antioxidant, and is used for medical latex products, rubber products for food packaging, colorless vulcanized rubber products and the like. 4,4' -dihydroxybiphenyl is also a dye intermediate and petroleum product stabilizer. 4,4' -dihydroxybiphenyl is often used as a modified monomer of high polymers such as polyester, polyurethane, polycarbonate, polysulfone, epoxy resin and the like to produce engineering plastics and composite materials because of excellent heat resistance. Currently, its high purity product is mainly used for the synthesis of liquid crystal polymers. The current method for synthesizing 4,4' -dihydroxybiphenyl mainly comprises the following steps: route 1 biphenyl sulphonation alkali fusion process ; Patent US6410238a adopts a method of sulfonation followed by hydrolysis to prepare 4,4' -dihydroxybiphenyl. The process has the advantages of simple synthetic route and higher yield. However, this route consumes a large amount of concentrated acid and strong alkali during the reaction, resulting in serious environmental pollution. In addition, side reactions frequently occur under the high-temperature condition, so that the prepared 4,4' -dihydroxybiphenyl has lower purity and is difficult to realize large-scale production; route 2, 6-Di-tert-butylphenol oxidative coupling reduction dealkylation method ; Patent CN117776875A discloses a method for preparing 4,4' -dihydroxybiphenyl finally by using 2, 6-di-tert-butylphenol as raw material and through oxidative coupling reaction and dealkylation. Although the method realizes continuous reaction and repeated use of the catalyst, and effectively reduces the emission of three wastes and the production cost, the whole process flow is complex, and the reaction steps are numerous, so that the final yield of the target product is directly influenced to a certain extent; Route 3 method of hydrolysis of halogenated biphenyls ; Patent US5196605A uses 4,4 '-dibromobiphenyl as a raw material, and hydrolyzes in an alkaline system under the action of a copper catalyst to generate 4,4' -dihydroxybiphenyl. The method has the advantages of strong toxicity and pollution of raw materials, high price, limited source channel and strict requirement on the purity of the raw materials. Therefore, the research and development of a production route of the 4,4' -dihydroxybiphenyl which is economically feasible, safe and efficient in production has important significance. Disclosure of Invention The invention aims to provide a method for synthesizing 4,4' -dihydroxybiphenyl. According to the invention, 4 '-dinitrobiphenyl is taken as a substrate of the reaction, the intermediate 4,4' -diaminobiphenyl is obtained after hydrogenation reduction, and the silicon dioxide grafted and modified multi-branched carboxylic acid polymer is taken as a hydrolysis reagent to synthesize the target product 4,4 '-dihydroxybiphenyl, so that the efficiency and selectivity of the reaction for preparing the 4,4' -dihydroxybiphenyl are effectively improved, the reaction condition is mild, the operation process is simple and convenient, and the method has wide industrial application potential. In order to achieve the above purpose, the invention adopts the following technical scheme: In a first aspect of the present invention, there is provided a method for synthesizing 4,4' -dihydroxybiphenyl, the method comprising the steps of: (1) Mixing 4,4 '-dinitrobiphenyl, a metal catalyst and an organic solvent, and introducing hydrogen to carry out hydrogenation reduction reaction to obtain 4,4' -diaminobiphenyl; (2) Mixing 4,4 '-diaminobiphenyl and a silicon dioxide grafted and modified multi-branched carboxylic acid polymer, heating for reaction, and removing a solvent from a reaction solution to obtain 4,4' -dihydroxybiphenyl. The synthetic route is as follows:。 Preferably, in the step (1), the 4,4 '-dinitrobiphenyl and the organic solvent are respectively added into a storage tank to obtain a mixed solution, and the mixed solution is introduced into a hydrogenation reduction reactor filled with a metal catalyst to perform hydrogenation reduction reaction to obtain the 4,4' -diaminobiphenyl. Preferably, the organic solvent is at least one selected from methanol, ethanol, isopropanol and tetrahydrofuran, and the mass ratio of the 4,4' -dinitrobiphenyl to the organic solvent is 0.25-0.5:1. Preferably, the feeding speed of the mixed solution is 0.04-0.065 kg/min, the feeding speed of hydrogen is 0.75-1.1 g/min, the heating temperature of the hydrogenation reduction reactor is 25-100 ℃, and the metal catalyst is selected from palla