Synthesis method of 3, 3 ', 4, 4'-tetraaminobiphenyl

Abstract

The invention belongs to the field of organic synthesis, and relates to a preparation method of a material intermediate, in particular to a synthesis method of 3, 3 ', 4, 4'-tetraaminobiphenyl. The synthetic route comprises the following steps: (1) taking 4, 4 '-diaminobiphenyl as a raw material, and carrying out diazo coupling reaction on the 4, 4'-diaminobiphenyl and aromatic diazonium salt under an alkaline or neutral condition to form an intermediate 4, 4 '-diaminobiphenyl diazo compound as shown in a formula (I); and (2) carrying out catalytic hydrogenation reduction reaction on the intermediate obtained in the step (1) to obtain a finished product 3, 3 ', 4, 4'-tetraaminobiphenyl. The method has the advantages of short process route, no dangerous nitration reaction and no generation of nitric acid waste liquid. According to the method, conversion is achieved through three-step reaction, the molar yield can reach 87.7%, operation is easy, reaction conditions are mild, and therefore the effects of low cost and low pollution are achieved.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis and relates to a preparation method of a material intermediate, in particular to a preparation method of a synthesis method of 3,3',4,4'-tetraaminobiphenyl. Background Art

[0002] 3,3′,4,4′-Tetraaminobiphenyl, referred to as DAB, is a white or brown solid with the molecular formula: C 12 H 14 N4, relative molecular weight: 214.27, CAS number: 91-95-2, structural formula is as follows:

[0003]

[0004] 3,3′,4,4′-Tetraaminobiphenyl is an important organic intermediate and an important monomer for the synthesis of polybenzimidazole, which can form fibers known for their chemical and thermal stability and is widely used in many industries such as aviation, aerospace, military industry, and construction. In addition, its water-soluble tetrahydrochloride is also used for immunohistochemical staining of nucleic acids and proteins. At present, there are two main methods for synthesizing 3,3′4,4′-tetraaminobiphenyl: 1) Using 4,4′-diaminobiphenyl as a raw material, the amino group is protected, nitrated, deprotected, and the nitro group is reduced in four steps to obtain the product (CN108191674, Chem. Commun. 1999, 10, 929, etc.); 2) Using dichlorobiphenyl diamine as a raw material, copper-catalyzed high-temperature aminolysis (CN1580038A, CN102173994, etc.). Among them, method 1) requires a large amount of nitric acid and involves a relatively dangerous nitration reaction. In addition, the process route is long and requires amino protection and deprotection, which is relatively complicated and not in line with atom economy. The preparation of the raw material dichlorobiphenyl diamine in the above method 2) is relatively complicated and expensive. The aminolysis reaction requires a high temperature reaction (over 200°C) and a large amount of copper salt as a catalyst, which is not easy to remove. In addition, there are some reports on the preparation through heavy metal catalytic coupling reaction, but it requires a more complicated process and more expensive raw materials and catalysts, which is not suitable for industrial production.

[0005] Summary of the invention

[0006] The invention aims to provide a method for synthesizing 3,3',4,4'-tetraaminobiphenyl, which has the advantages of simple preparation operation, mild conditions, high yield and environmental friendliness.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for synthesizing 3,3',4,4'-tetraaminobiphenyl, wherein the synthesis reaction formula is

[0009]

[0010] (1) using 4,4′-diaminobiphenyl as a raw material, and carrying out a diazo coupling reaction with an aromatic diazonium salt under alkaline or neutral conditions to form an intermediate 4,4′-diaminobiphenyl diazo compound represented by formula (I);

[0011]

[0012] (2) The intermediate obtained in step (1) is subjected to catalytic hydrogenation reduction reaction to obtain the finished product 3,3′,4,4′-tetraaminobiphenyl.

[0013] In step (1), the molar ratio of 4,4'-diaminobiphenyl to aromatic diazonium salt is 1:2 to 1:2.5.

[0014] In step (1), the aromatic diazonium salt is an aromatic diazonium hydrochloride salt, an aromatic diazonium sulfate salt or an aromatic diazonium tetrafluoroborate salt.

[0015] In step (1), the raw material is coupled with an aromatic diazonium salt at 0 to 20° C. under alkaline or neutral conditions; the molar ratio of the base to 4,4′-diaminobiphenyl is 3:1 to 10:1; wherein the base is an inorganic base or an organic amine.

[0016] The base is sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, diethylamine, triethylamine, tert-butylamine, diisopropylethylamine.

[0017] In step (2), the intermediate obtained in step (1) is subjected to a catalytic hydrogenation reduction reaction at 20 to 120° C. to obtain the finished product 3,3′,4,4′-tetraaminobiphenyl.

[0018] The solvent used in the catalytic hydrogenation reduction reaction is methanol, ethanol, isopropanol or n-butanol.

[0019] In step (2), the catalyst used in the catalytic hydrogenation reduction reaction is palladium carbon, platinum carbon or Raney nickel, and the amount of the catalyst used is 0.5% to 5% of the weight of the intermediate.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) The process route of the present invention is short, there is no dangerous nitration reaction, and no nitric acid waste liquid is generated.

[0022] (2) The raw materials of the present invention are cheaper, and no high temperature reaction is required. Only a small amount of catalyst is needed and can be recycled.

[0023] (3) The aromatic amines produced in the synthesis of the present invention are all recovered and reused, which is more in line with atom economy.

[0024] (4) The present invention realizes conversion through three-step reaction, and the molar yield can reach 87.7%. The operation is simple and the reaction conditions are mild, thus achieving the effect of low cost and low pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the ESI-MS spectrum of the intermediate (I) diazo compound prepared in Example 1.

[0026] Figure 2 This is the ESI-MS spectrum of 3,3′,4,4′-tetraaminobiphenyl prepared in Example 1.

[0027] Figure 3 This is the DSC spectrum of 3,3′,4,4′-tetraaminobiphenyl prepared in Example 1. DETAILED DESCRIPTION

[0028] The specific implementation modes of the present invention are further described below in conjunction with examples. It should be noted that the specific implementation modes described here are only for illustrating and explaining the present invention, and are not limited to the present invention.

[0029] The present invention first uses 4,4'-diaminobiphenyl as a raw material, performs a diazo coupling reaction with an aromatic diazonium salt, and then performs hydrogenation reduction to obtain 3,3',4,4'-tetraaminobiphenyl, and recovers aromatic amine. The present invention has simpler operation steps, higher yield, and avoids nitration reaction or catalytic high-temperature ammonolysis reaction in the existing process. The reaction conditions are mild, more environmentally friendly, and easy to achieve industrial production.

[0030] Embodiment 1:

[0031] Step (1): Add aniline (103.6 g, 1.11 mol), 450 mL of deionized water, and concentrated hydrochloric acid (240.7 g, 37%, 2.44 mol) to a 2000 mL three-necked flask in sequence and stir to dissolve. Cool to 0-5°C, slowly drop sodium nitrite (74.9 g, 1.09 mol) aqueous solution (200 mL), control the temperature not to exceed 10°C, and drip it in about 40 minutes. Stir at 0-5°C for 15 minutes to obtain an aqueous solution of benzene diazonium hydrochloride. Then drop 4,4′-diphenylenediamine (100 g, 0.543 mol) in ethanol (250 mL), control the temperature not to exceed 20°C, and drip it in about 1 hour, and solid precipitates. Sodium hydroxide was added to adjust the pH value of the reaction system to neutral, and the mixture was stirred for 2 hours. A large amount of solid precipitated and was filtered. The filter cake was rinsed with a small amount of water and ethanol and dried to obtain 192.4 g of a dark red intermediate (I) diazo compound with a purity of 99.0% and a molar yield of 90.3%.

[0032] The ESI-MS spectrum of this intermediate is shown in Figure 1 ,Depend on Figure 1It can be seen that its molecular weight is 392 (M+H).

[0033] Step (2): Add the intermediate (I) (192.4 g, 0.490 mol) obtained in step (1), 1.2 L of n-butanol and 1.92 g of 3% palladium carbon (commercially available conventional commercial product, in which the metal palladium accounts for 3% of the palladium carbon content) into a 2 L pressure reactor. Replace nitrogen and hydrogen three times each, react at 0.8 MPa and 110°C for about 5 hours until no hydrogen is absorbed, and keep the temperature and pressure for about 30 minutes. Release the pressure, open the kettle and filter to remove the catalyst and apply it to the next batch of reactions. The filtrate is cooled to room temperature, and a large amount of white solid is precipitated. It is filtered and the filter cake is rinsed with a small amount of water. The wet product is vacuum dried at 80°C for 12 hours to obtain 94.8 g of a white final product with a melting point of 174.3-176.2°C ( Figure 3 ), purity 99.5%, step (2) molar yield: 90.3%.

[0034] The total molar yield of the two steps is 81.5%. The mother liquor obtained in the above step (1) is distilled to recover 80.2 g of aniline with a recovery rate of 87.8%.

[0035] The ESI-MS spectrum of the target product is shown in Figure 2 ,Depend on Figure 2 It can be seen that its molecular weight is 214 (M+H).

[0036] Embodiment 2:

[0037] Step (1): Add aniline (80.9 g, 0.868 mol) and 400 mL of deionized water into a 2000 mL three-necked flask, and slowly add a 40% tetrafluoroboric acid aqueous solution (429 g, 1.95 mol) while stirring. After the addition is complete, cool to 0-5°C, slowly add sodium nitrite (59.9 g, 0.868 mol) in batches, control the temperature not to exceed 10°C, and add it in about 1 hour. Stir at 0-5°C for 20 minutes to obtain an aqueous solution of tetrafluoroborate benzene diazonium salt. Prepare another 2000 mL three-necked flask, add 4,4′-diphenylenediamine (80 g, 0.434 mol) and methanol (250 mL), cool to 0-5°C, slowly drip the tetrafluoroborate benzene diazonium salt aqueous solution obtained above, control the temperature not to exceed 20°C, and drip it in about 1 hour, and solid precipitates. Sodium hydroxide was added to adjust the pH value of the reaction system to neutral, and the mixture was stirred for 2 hours. A large amount of solid precipitated and was filtered. The filter cake was rinsed with a small amount of water and methanol and dried to obtain 161.6 g of a dark red intermediate (I) diazo compound with a purity of 99.3% and a molar yield of 94.89%.

[0038] Step (2): Add the intermediate (I) (161.6 g, 0.412 mol) obtained in step (1), 480 mL DMF and 1.62 g 3% palladium on carbon into a 1 L pressure reactor. Replace nitrogen and hydrogen three times each, react at 0.8 MPa and 80° C. for about 3 hours until no hydrogen is absorbed, and keep the temperature and pressure for about 30 minutes. Release the pressure, filter and remove the catalyst by opening the reactor and apply it to the next batch of reactions. The filtrate is cooled to room temperature and poured into 700 mL deionized water. A large amount of white solid precipitates, which is filtered and the filter cake is rinsed with a small amount of water. The wet product is vacuum dried at 80° C. for 12 hours to obtain 81.6 g of a white final product with a purity of 99.3%. The molar yield of step (2) is 92.4%. The total molar yield of the two steps is 87.7%.

[0039] Example 3 (aniline recovery experiment):

[0040] Step (1): Add the aniline (80.2 g, 0.86 mol) recovered in Example 1, 350 mL of deionized water, and concentrated hydrochloric acid (186.3 g, 37%, 1.89 mol) into a 2000 mL three-necked flask in sequence and stir to dissolve. Cool to 0-5°C, slowly drop sodium nitrite (58.0 g, 0.84 mol) aqueous solution (150 mL), control the temperature not to exceed 10°C, and drip it in about 30 minutes. Stir at 0-5°C for 15 minutes, then drop 4,4′-diphenylenediamine (77.4 g, 0.42 mol) ethanol solution (200 mL), control the temperature not to exceed 20°C, and drip it in about 1 hour. Sodium hydroxide was added to adjust the pH value of the reaction system to neutral, and the mixture was stirred for 2 hours. A large amount of solid precipitated and was filtered. The filter cake was rinsed with a small amount of water and ethanol and dried to obtain 146.0 g of a dark red intermediate (I) diazo compound with a purity of 99.1% and a molar yield of 88.5%.

[0041] Step (2): Add the intermediate (I) (146.0 g, 0.372 mol) obtained in step (1), 1.0 L of n-butanol and 1.46 g of palladium carbon recovered in Example 1 into a 2 L pressure reactor. Replace nitrogen and hydrogen three times each, react at 0.8 MPa and 110° C. for about 5 hours until no hydrogen is absorbed, and keep the temperature and pressure for about 30 minutes. Release the pressure, filter and remove the catalyst by opening the reactor and apply it to the next batch of reactions. The filtrate is cooled to room temperature, a large amount of white solid precipitates, filtered, the filter cake is rinsed with a small amount of water, and the wet product is vacuum dried at 80° C. for 12 hours to obtain 71.2 g of a white final product with a purity of 99.4%. The molar yield of step (2) is 89.4%.

[0042] The total molar yield of the two steps is 81.5%. The mother liquor obtained in the above step (1) is distilled to recover 80.2 g of aniline with a recovery rate of 87.8%.

Claims

1. A method for synthesizing 3,3',4,4'-tetraaminobiphenyl, characterized in that: (1) using 4,4'-diaminobiphenyl as a raw material, and carrying out a diazo coupling reaction with an aromatic diazonium salt under alkaline or neutral conditions to form an intermediate 4,4'-diaminobiphenyl diazo compound represented by formula (I); (2) The intermediate obtained in step (1) is subjected to catalytic hydrogenation reduction reaction to obtain the finished product 3,3',4,4'-tetraaminobiphenyl.

2. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to claim 1, characterized in that: In step (1), the molar ratio of 4,4'-diaminobiphenyl to aromatic diazonium salt is 1:2 to 1:2.

5.

3. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to claim 1, characterized in that: In step (1), the aromatic diazonium salt is an aromatic diazonium hydrochloride salt, an aromatic diazonium sulfate salt or an aromatic diazonium tetrafluoroborate salt.

4. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to any one of claims 1 to 3, characterized in that: In step (1), the raw material is coupled with an aromatic diazonium salt at 0 to 20° C. under alkaline or neutral conditions; the molar ratio of the base to 4,4'-diaminobiphenyl is 3:1 to 10:1; wherein the base is an inorganic base or an organic amine.

5. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to any one of claims 1 to 3, characterized in that: The base is sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, diethylamine, triethylamine, tert-butylamine, diisopropylethylamine.

6. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to claim 1, characterized in that: In step (2), the intermediate obtained in step (1) is subjected to a catalytic hydrogenation reduction reaction at 20 to 120° C. to obtain the finished product 3,3',4,4'-tetraaminobiphenyl.

7. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to claim 1, characterized in that: The solvent used in the catalytic hydrogenation reduction reaction is methanol, ethanol, isopropanol or n-butanol.

8. The method for synthesizing 3,3',4,4'-tetraaminobiphenyl according to claim 1, characterized in that: In step (2), the catalyst used in the catalytic hydrogenation reduction reaction is palladium carbon, platinum carbon or Raney nickel, and the amount of the catalyst used is 0.5% to 5% of the weight of the intermediate.

Images