Method for preparing biphenyl-4-sulfonic acid

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing biphenyl-4-sulfonic acid, which is characterized in that by controlling reaction conditions and reactant proportion, biphenyl is sulfated by sulfur trioxide to generate high-purity biphenyl-4-sulfonic acid. The method provided by the invention is simple to operate, simple and convenient in flow and suitable for industrial production, and a new scheme is provided for industrial preparation of the biphenyl-4-sulfonic acid.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, and specifically relates to a method for preparing biphenyl-4-sulfonic acid. Background Technology

[0002] Biphenyl-4-sulfonic acid (C 12 H 10 Biphenyl-4-sulfonic acid (SO3S) is an organic compound formed by the combination of a biphenyl group and a sulfonic acid group (-SO3H). This compound is typically a white crystalline solid, readily soluble in water and polar solvents. Due to the strong electron-withdrawing effect of the sulfonic acid group, it exhibits strong acidity approaching that of sulfuric acid. Its unique properties have made it a subject of continuous interest in the fields of chemistry and materials science. Biphenyl-4-sulfonic acid has wide applications in organic synthesis, serving as an acidic catalyst or intermediate in the development of pharmaceuticals (such as antiviral agents) and functional materials. It can also be used as a precursor in the preparation of high-performance materials such as ion exchange resins and proton exchange membranes, making it an important industrial product.

[0003] Currently, the synthesis of biphenyl-4-sulfonic acid mainly involves the sulfonation reaction of biphenyl with concentrated sulfuric acid. For example, patent CN117945857A discloses a method for preparing biphenyl-4-sulfonic acid as an intermediate in the preparation of 4-hydroxybiphenyl: biphenyl and concentrated sulfuric acid are reacted at 110~160℃ to obtain biphenyl-4-sulfonic acid with a purity of 91.0% and a yield of 52.1%. This method has a low yield, which is not conducive to industrial production. In addition, patent CN100497280C discloses a method for preparing biphenyl-4-sulfonic acid as an intermediate in the preparation of p-phenylphenol: biphenyl and chlorosulfonic acid are dissolved in o-nitrobenzene and reacted at 80℃ for 2 hours to obtain biphenyl-4-sulfonic acid. This method is suitable for small-scale laboratory production. By strictly controlling the ratio of reactants, the amount of reactants added, and the reaction conditions, high-purity biphenyl-4-sulfonic acid can be obtained. However, in large-scale industrial production, due to insufficient contact between a large number of reactants and the promotion of high temperature, more by-products, such as disulfonation by-products, will be generated, resulting in a decrease in purity and affecting product quality.

[0004] Therefore, it is of great significance to provide a method for preparing biphenyl-4-sulfonic acid with good yield, high purity, and suitability for large-scale industrial production. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing biphenyl-4-sulfonic acid.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows: This invention provides a method for preparing biphenyl-4-sulfonic acid, comprising the following steps: S1: Dissolve biphenyl in dibutyl phthalate, add boron trifluoride diethyl ether complex to obtain mixture A; S2: Add sulfur trioxide to 1,2,4-trichlorobenzene at 20~30℃, add boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture B and mixture A dropwise into 1,2-dichloroethane, heat to 100~130℃, and react for 2~4h; then cool to 30~50℃ at a rate of 1~3℃ / min and continue the reaction for 0.5~2h to obtain the crude product solution; S4: Add water to the crude product solution, add alkali to adjust the pH while stirring, discard the organic phase, add salt to the aqueous phase until all the solid precipitates, filter, wash and dry to obtain the product.

[0007] As a further embodiment of the present invention, the molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:0.8~1:0.8~2.

[0008] As a further embodiment of the present invention, the molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:0.8~1:1~1.5.

[0009] As a further embodiment of the present invention, the molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:1:1.2.

[0010] As a further embodiment of the present invention, the ratio of biphenyl and dibutyl phthalate in S1 is 1 mol: 200~600 ml.

[0011] As a further embodiment of the present invention, the mass ratio of sulfur trioxide and 1,2,4-trichlorobenzene in S2 is 1:1~3.

[0012] As a further embodiment of the present invention, the boric acid in S2 is 0.1% to 1.0% of the mass of sulfur trioxide.

[0013] As a further embodiment of the present invention, the dripping time in S3 is 1~2h.

[0014] As a further embodiment of the present invention, the ratio of sulfur trioxide to water is 1 mol: 200~500 ml.

[0015] The beneficial effects of adopting the above technical solution are as follows: The preparation method provided by this invention has considerable purity and yield, and is suitable for large-scale industrial production. By adjusting the reaction conditions, the occurrence of side reactions is reduced while ensuring the yield. At the same time, a suitable solvent is selected to ensure proper contact of raw materials and reduce the generation of impurities. By making reasonable adjustments to each step in the reaction process and cooperating with each step, high yield and high purity of biphenyl-4-sulfonic acid production are achieved. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described clearly and completely below with reference to specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless otherwise specified, the experimental or testing methods involved in the embodiments of this invention are conventional methods in the prior art, and their names and / or abbreviations are conventional names in the art, clearly defined in their respective fields of application. Those skilled in the art can understand the conventional process steps and apply the corresponding equipment based on these names, implementing the methods under conventional conditions or conditions recommended by the manufacturer. The various instruments, equipment, raw materials, or reagents used in the embodiments of this invention are not subject to any special restrictions on their source; they are all conventional products that can be purchased through legitimate commercial channels and can be prepared according to conventional methods well known to those skilled in the art.

[0017] Sulfur trioxide (SO3, liquid) was purchased from Sigma Aldrich, product number 425478; Biphenyl was purchased from Aladdin Reagents, catalog number B110382; Boron trifluoride diethyl ether complex was purchased from Sigma Aldrich, product number 801647.

[0018] Example 1 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates. Filter, wash with ethanol and dry to obtain 232.35 g of solid, with a yield of 97.5% and a purity of 98.3%.

[0019] Example 2 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 113.5 g (0.8 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 64.05g (0.8mol) of sulfur trioxide to 128g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.38g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 300 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 227.36 g of solid, with a yield of 95.7% and a purity of 98.6%.

[0020] Example 3 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 283.9 g (2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 238.19 g of solid, with a yield of 96.8% and a purity of 95.2%.

[0021] Example 4 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture A and mixture B dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, raise the temperature to 130 °C and reflux for 2 h; then lower the temperature to 30 °C at a rate of 3 °C / min and continue the reaction for 2 h to obtain the crude product solution. S4: While stirring, add 35 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates. Filter, wash with ethanol and dry to obtain 236.75 g of solid, with a yield of 94.7% and a purity of 93.7%.

[0022] Example 5 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 100 °C and refluxed for 4 h; then the temperature is lowered to 50 °C at a rate of 1 °C / min and the reaction is continued for 0.5 h to obtain the crude product solution. S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates. Filter, wash with ethanol and dry to obtain 223.25 g of solid, with a yield of 93.3% and a purity of 97.9%.

[0023] Example 6 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 80g of 1,2,4-trichlorobenzene liquid at 30℃, then add 0.08g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture A and mixture B dropwise to 1500 ml of 1,2-dichloroethane over 60 min; after the addition is complete, heat to 120 °C and reflux for 3 h; then cool to 45 °C at a rate of 2 °C / min and continue the reaction for 1.5 h to obtain the crude product solution. S4: While stirring, add 200 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 239.78 g of solid, with a yield of 95.4% and a purity of 93.2%.

[0024] Example 7 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 240g of 1,2,4-trichlorobenzene liquid at 20℃, then add 0.80g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture A and mixture B dropwise to 1500 ml of 1,2-dichloroethane over 120 min; after the addition is complete, heat to 120 °C and reflux for 3 h; then cool to 45 °C at a rate of 2 °C / min and continue the reaction for 1.5 h to obtain the crude product solution. S4: While stirring, add 500 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 226.83 g of solid, with a yield of 91.7% and a purity of 94.7%.

[0025] Comparative Example 1 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 85.2 g (0.6 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 40.03g (0.5mol) of sulfur trioxide to 80g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.24g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 200 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates. Filter, wash with ethanol and dry to obtain 142.81 g of solid, with a yield of 53.1% and a purity of 87.1%.

[0026] Comparative Example 2 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 283.9 g (2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 120.10g (1.5mol) of sulfur trioxide to 240g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.72g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 550 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates. Filter, wash with ethanol and dry to obtain 287.54 g of solid, with a yield of 83.1% and a purity of 67.7%.

[0027] Comparative Example 3 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture A and mixture B dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, heat to 200 °C and reflux for 4.5 h to obtain crude product solution; S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 267.26 g of solid, with a yield of 74.5% and a purity of 65.3%.

[0028] Comparative Example 4 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of dibutyl phthalate, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2,4-trichlorobenzene liquid at 25℃, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix solution A with 1500 ml of 1,2-dichloroethane and add it dropwise to the mixture over 90 min; after the addition is complete, heat to 120 °C and reflux for 3 h; then cool to 45 °C at a rate of 2 °C / min and continue the reaction for 1.5 h to obtain the crude solution. S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 246.07 g of solid, with a yield of 81.2% and a purity of 77.3%.

[0029] Comparative Example 5 S1: Dissolve 154.2 g (1 mol) of biphenyl in 400 ml of 1,2-dichloroethane, add 170.3 g (1.2 mol) of boron trifluoride diethyl ether complex to obtain mixture A; S2: Add 80.07g (1mol) of sulfur trioxide to 160g of 1,2-dichloroethane, then add 0.48g of boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, mix A and mix B are added dropwise to 1500 ml of 1,2-dichloroethane over 90 min; after the addition is complete, the temperature is raised to 120 °C and refluxed for 3 h; then the temperature is lowered to 45 °C at a rate of 2 °C / min and the reaction is continued for 1.5 h to obtain the crude product solution. S4: While stirring, add 350 ml of water to the crude product solution, then add sodium hydroxide to adjust the pH of the solution to 6-8. After standing and separating the layers, discard the organic phase. Add sodium chloride to the aqueous phase until all the solid precipitates out. Filter, wash with ethanol and dry to obtain 248.83 g of solid, with a yield of 76.8% and a purity of 72.3%.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing biphenyl-4-sulfonic acid, characterized in that the steps include... include: S1: Dissolve biphenyl in dibutyl phthalate, add boron trifluoride diethyl ether complex to obtain mixture A; S2: Add sulfur trioxide to 1,2,4-trichlorobenzene at 20~30℃, add boric acid, and stir thoroughly to obtain mixture B; S3: Under stirring, add mixture B and mixture A dropwise into 1,2-dichloroethane, heat to 100~130℃, and react for 2~4h; then cool to 30~50℃ at a rate of 1~3℃ / min and continue the reaction for 0.5~2h to obtain the crude product solution; S4: Add water to the crude product solution, add alkali to adjust the pH while stirring, discard the organic phase, add salt to the aqueous phase until all the solid precipitates, filter, wash and dry to obtain the product.

2. The method according to claim 1, characterized in that, The molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:0.8~1:0.8~2.

3. The method according to claim 1, characterized in that, The molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:0.8~1:1~1.

5.

4. The method according to claim 1, characterized in that, The molar ratio of the biphenyl, sulfur trioxide and boron trifluoride diethyl ether complex is 1:1:1.

2.

5. The method according to claim 1, characterized in that, The ratio of biphenyl to dibutyl phthalate in S1 is 1 mol: 200~600 ml.

6. The method according to claim 1, characterized in that, The mass ratio of sulfur trioxide to 1,2,4-trichlorobenzene in S2 is 1:1~3.

7. The method according to claim 1, characterized in that, The boric acid in S2 is 0.1% to 1.0% of the mass of sulfur trioxide.

8. The method according to claim 1, characterized in that, The dripping time described in S3 is 1~2 hours.

9. The method according to claim 1, characterized in that, The ratio of sulfur trioxide to water added is 1 mol: 200~500 ml.