Pyridine biphenyl derivative as well as preparation method and application thereof

Abstract

The invention discloses a pyridine biphenyl derivative as well as a preparation method and application thereof, 3-bromo-5-nitropyridine and 4-hydroxy-4 '-nitrobiphenyl are taken as raw materials, under the action of a solvent and an acid-binding agent, an intermediate product is obtained through condensation reaction, and the intermediate product is reduced under the action of a catalyst and hydrogen to obtain a final product. The product is the pyridine biphenyl derivative, and the method has the advantages of high purity, high yield, few by-products, mild conditions, single solvent and repeated recovery and reuse of the catalyst, is suitable for industrial mass production, and has a wide application range.

Description

Technical Field

[0001] This invention relates to a pyridine biphenyl derivative, its preparation method and application, belonging to the field of organic synthesis technology. Background Technology

[0002] The information disclosed in this background section is intended only to enhance some understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art.

[0003] Pyridine-biphenyl derivatives are an important class of heterocyclic aromatic compounds. Their molecular structure consists of a pyridine ring (a nitrogen-containing six-membered heterocycle) and a biphenyl group linked by covalent bonds, exhibiting significant π-π conjugation and a rigid planar structure. The core characteristic of these compounds lies in the coordination ability provided by the nitrogen atom of the pyridine ring, while the biphenyl moiety provides hydrophobicity and steric extension. By modifying the substitution sites of the pyridine ring (such as the 2-, 3-, and 4- positions) or the functional groups on the biphenyl group (such as halogens, alkyl groups, and carboxyl groups), their electron distribution, solubility, and intermolecular interactions can be controlled. In application fields, pyridine biphenyl derivatives are widely used due to their unique properties: 1) Optoelectronic materials, as electron transport or light-emitting layer materials for organic light-emitting diodes (OLEDs), such as 4-(4-pyridyl)biphenyl, which can improve device efficiency; 2) Pharmaceutical chemistry, where their structure can serve as pharmacophores for kinase inhibitors or antibacterial agents, for example, some derivatives exhibit antitumor activity; 3) Coordination chemistry, as ligands for metal-organic frameworks (MOFs) for gas adsorption or catalytic reactions; 4) Analytical detection, using fluorescence properties for sensing heavy metal ions or biomolecules; 5) Pesticide development, where some derivatives have insecticidal or herbicidal efficacy. Furthermore, they also have potential value in liquid crystal materials, corrosion inhibitors, and polymer modification. Current research focuses on balancing their stability and functionality through structural optimization and exploring green synthetic pathways to promote industrial applications. Overall, pyridine biphenyl derivatives represent a multifunctional molecular platform with strong structural designability and broad interdisciplinary application prospects.

[0004] Currently, there are few reports on pyridine biphenyl derivatives. The synthetic methods yield low amounts and purities, are difficult to separate reaction byproducts, require harsh reaction conditions, exhibit low catalytic efficiency, and involve complex post-processing. Furthermore, existing synthetic methods are not optimized for the needs of the rubber industry, limiting the application of pyridine biphenyl derivatives in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a pyridine biphenyl derivative, its preparation method, and its applications. This product is a novel pyridine biphenyl derivative. The method produces a product with high purity, high yield, few byproducts, mild conditions, a single solvent, and a reusable catalyst, making it suitable for large-scale industrial production. Furthermore, it develops new applications for pyridine biphenyl derivatives in high-performance rubber materials, demonstrating significant industrial value.

[0006] The technical solution adopted in this invention is as follows: In a first aspect of the present invention, a pyridine biphenyl derivative is provided, the chemical structural formula of which is as follows: .

[0007] In a second aspect of the present invention, a method for preparing the above-mentioned pyridine biphenyl derivative is provided, the method comprising the following steps: Using 3-bromo-5-nitropyridine and 4-hydroxy-4'-nitrobiphenyl as raw materials, an intermediate product is obtained through a condensation reaction in the presence of a solvent and an acid-binding agent. The intermediate is then reduced in the presence of a catalyst and hydrogen to obtain the final product.

[0008] Specifically, the following steps are included: (1) Mix the set amount of 3-bromo-5-nitropyridine with the solvent, stir at 45~50℃ until completely dissolved, turn on the cooling and lower to 15~25℃; mix the set amount of 4-hydroxy-4'-nitrobiphenyl with the solvent, stir at 55~60℃ until completely dissolved, turn on the cooling and lower to room temperature; add the set amount of acid-binding agent to the 4-hydroxy-4'-nitrobiphenyl solution, stir evenly, and start the dropwise addition. The temperature should not exceed 30℃ during the dropwise addition. After the dropwise addition is completed, keep warm for 4~5 hours. After the reaction is completed, drain the mother liquor, add the mother liquor dropwise to the precipitate, filter, rinse with water, dry, and obtain the intermediate product; (2) Dissolve the specified amount of intermediate in the solvent and stir until completely dissolved. After adding the catalyst, transfer the entire mixture to the hydrogenation reactor. Purge with nitrogen to 0.5 MPa and then evacuate. Repeat this process 3-5 times. Heat the hydrogenation reactor to 70°C and then introduce hydrogen at a pressure of 0.5-1 MPa. If the pressure is lower than 0.5 MPa during the reaction, add hydrogen to the reactor. The pressure of the hydrogen should not exceed 1 MPa. The reaction ends when the pressure remains constant. After the reaction, filter out the solid catalyst, add the mother liquor dropwise to the precipitate, filter, rinse with water, and dry to obtain the final product.

[0009] In step (1), the main reaction equation is: .

[0010] Preferably, in steps (1) and (2), the solvent is the same solvent, which is one or more of THF, 2-MeTHF, DMF, NMP, acetone, and 1,3-dimethyl-2-imidazolinone.

[0011] Preferably, in step (1), the mass ratio of 3-bromo-5-nitropyridine to the solvent is 1:4-6, and the mass ratio of 4-hydroxy-4'-nitrobiphenyl to the solvent is 1:4-6.

[0012] More preferably, the mass ratio of 3-bromo-5-nitropyridine to solvent is 5, and the mass ratio of 4-hydroxy-4'-nitrobiphenyl to solvent is 5.

[0013] Preferably, in step (1), the acid-binding agent is one of triethylamine, K2CO3, diethylamine hydrochloride, pyridine derivatives, etc., and its amount is 2.0-2.5 times the molar amount of 3-bromo-5-nitropyridine.

[0014] More preferably, the amount of the acid-binding agent is 2.3 times the molar amount of 3-bromo-5-nitropyridine.

[0015] Preferably, in step (1), the mass ratio of the mother liquor to the precipitate is 1:1.9-2.9.

[0016] More preferably, the mass ratio of the mother liquor to the precipitate is 1:2.5.

[0017] Preferably, in step (1), the precipitate is an ethanol-water mixture with a volume ratio of 4:6 for ethanol and water.

[0018] Preferably, in step (1), the reaction dropping rate is 1-5 ml / min, and the reaction is kept at a constant temperature for 2-6 h.

[0019] Preferably, in step (1), the molar ratio of 3-bromo-5-nitropyridine to 4-hydroxy-4'-nitrobiphenyl is 1:1.04-1.11.

[0020] More preferably, the molar ratio of 3-bromo-5-nitropyridine to 4-hydroxy-4'-nitrobiphenyl is 1:1.05-1.10.

[0021] Preferably, in step (1), the mother liquor is added at a rate of 1-9 ml / min.

[0022] In step (2), the main reaction equation is:

[0023] Preferably, in step (2), the mass ratio of the intermediate to the solvent is 1:7.8-9.5.

[0024] Preferably, in step (2), the mass ratio of the intermediate to the solvent is 1:7.8-9.5.

[0025] More preferably, the mass ratio of the intermediate to the solvent is 1:8.1.

[0026] Preferably, in step (2), the catalyst is palladium on carbon (Pd / C), and its mass is 2-5% of the intermediate.

[0027] More preferably, the amount of the catalyst is 2% of the intermediate.

[0028] Preferably, in step (2), the mass of the precipitate is 1-5 times that of the hydrogenation mother liquor.

[0029] More preferably, the mass of the precipitate is 2.5 times that of the hydrogenation mother liquor.

[0030] Preferably, in step (2), the precipitate is a mixed solution of ethanol, water and acetic acid, with a volume ratio of ethanol:water:acetic acid = 30:66:4.

[0031] Preferably, in step (2), the mother liquor is added at a rate of 1-9 ml / min.

[0032] In a third aspect of the invention, the use of the pyridine biphenyl derivative in the preparation of rubber additives, particularly in vulcanization accelerators, is provided.

[0033] Compared with the related technologies known to the inventors, one of the technical solutions of the present invention has the following beneficial effects: (1) The pyridine biphenyl derivative provided by this invention exhibits multifunctionality due to its unique structure and has broad application prospects. In particular, when used as a rubber vulcanization accelerator, it has fast vulcanization efficiency and high crosslinking density; the amino and pyridine groups contained in this compound can accelerate the vulcanization reaction and improve the vulcanization efficiency, thereby resulting in a higher degree of vulcanization; it has good aging mechanical properties and high retention rate; these active groups play a catalytic role in the vulcanization process, promoting the crosslinking of sulfur and rubber molecular chains.

[0034] (2) The preparation method provided by the present invention uses DMF as a single solvent. Through its strong solubility, aprotic polarity and mild reactivity, it solves the problem that a single solvent is difficult to balance solubility and reactivity. K2CO3 has a dual mechanism of acid binding agent and catalyst. On the one hand, it can act as an acid binding agent to reduce side reactions and promote the forward shift of reaction equilibrium. On the other hand, it can act as a catalyst to increase the reaction rate with halogenated pyridine. It has high catalytic efficiency and realizes in-situ catalysis. While ensuring high purity and high yield, it is also in line with green environmental protection.

[0035] (3) The technical solution of the present invention is simple to synthesize and the reaction conditions are mild, which greatly reduces the production cost.

[0036] (4) The solvents, catalysts and reagents used in the post-processing of this invention can all be recycled and reused. Attached Figure Description

[0037] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0038] Figure 1 This is the 1H NMR spectrum of the pyridine biphenyl derivative of this invention. Detailed Implementation

[0039] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, 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.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0041] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0042] Unless otherwise specified, all raw materials used in the following examples are commercially available products.

[0043] Example 1: 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of DMF were added to a three-necked flask and stirred at 50 °C for 30 min until completely dissolved. Cooling was then initiated until the temperature dropped to 20 °C. 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of DMF and stirred at 55 °C for 30 min until completely dissolved. Cooling was then initiated until the temperature dropped to room temperature. 186.64 g (K₂CO₃) was added to the solution of 4-hydroxy-4'-nitrobiphenyl. After stirring the liquid thoroughly, the mixture was added dropwise using a plunger pump at a rate of 4 ml / min. The temperature during the addition process should not exceed 30°C. After the addition was complete, the mixture was kept at this temperature for 4 hours. Once the reaction was finished, the mother liquor was drained, and the mother liquor was added dropwise to 2.5 times the volume of the precipitate (the precipitate was an ethanol-water mixture with a volume ratio of 4:6) at a rate of 5 ml / min. The mixture was then filtered, washed 2-3 times with deionized water, and dried at 80°C to obtain 208.48 g of the intermediate product, with a yield of 96.58% and a purity of 99.11%. 208.48 g of the intermediate was dissolved in 1688.69 g of DMF and stirred until completely dissolved. 4.17 g of Pd / c was added, and the entire mixture was transferred to a hydrogenation reactor. Nitrogen gas was introduced to 0.5 MPa, followed by vacuuming. This process was repeated 3-5 times. The reactor was heated to 70°C, and hydrogen gas was introduced at a pressure of 0.5-1 MPa. If the pressure dropped below 0.5 MPa during the reaction, hydrogen gas was added to the reactor, with the pressure not exceeding 1 MPa. The reaction ended when the pressure stabilized. After the reaction, the solid catalyst was filtered out. The mother liquor was added dropwise to 2.5 times the volume of the precipitate (a mixture of ethanol, water, and acetic acid in a volume ratio of ethanol:water:acetic acid = 30:66:4) at a rate of 5 ml / min. The mixture was filtered, washed 2-3 times with deionized water, and dried at 80°C to obtain the final product. The NMR information is as follows: 1 H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), as Figure 1 The yield was 97.38%, and the purity was 99.75%.

[0044] Example 2: The operation steps are the same as in Example 1, except that 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of DMF were added to a three-necked flask and stirred at 50 °C for 30 min until completely dissolved. Cooling was then initiated until the temperature dropped to 20 °C. 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of DMF, and instead, 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of NMP were added to the three-necked flask. The mixture was stirred at 50 °C for 30 min until completely dissolved. Cooling was then initiated until the temperature dropped to 20 °C. 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of NMP. The final product was obtained, and the NMR information is as follows: 1 ¹H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), yield 97.21%, purity 99.32%.

[0045] Example 3: The operation steps are the same as in Example 1, except that 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of DMF were added to a three-necked flask and stirred at 50°C for 30 min until completely dissolved. The temperature was then lowered to 20°C. 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of DMF, and 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of DMSO were added to the three-necked flask. The mixture was stirred at 50°C for 30 min until completely dissolved. The temperature was then lowered to 20°C. 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of DMSO. The final product was obtained, and the NMR information is as follows: 1 ¹H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), yield 97.25%, purity 99.39%.

[0046] Example 4: The operation steps are the same as in Example 1, except that after stirring evenly, the mixture is added dropwise using a plunger pump at a rate of 4 ml / min. The temperature during the dropwise addition must not exceed 30°C. After the dropwise addition is completed, the mixture is kept at this temperature for 4 hours. Alternatively, after stirring evenly, the mixture is added dropwise using a plunger pump at a rate of 5 ml / min. The temperature during the dropwise addition must not exceed 30°C. After the dropwise addition is completed, the mixture is kept at this temperature for 4 hours. The final product is obtained, and the NMR information is as follows: 1 ¹H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), yield 97.08%, purity 99.13%.

[0047] Example 5: The operation steps are the same as in Example 1, except that instead of dissolving 208.48g of the intermediate in 1688.69g of DMF and stirring until completely dissolved, 208.48g of the intermediate was dissolved in 1688.69g of NMP and stirred until completely dissolved to obtain the final product. The NMR information is as follows: 1 ¹H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), yield 97.18%, purity 99.22%.

[0048] Example 6: The operation steps are the same as in Example 1, except that after adding 4.17g of Pd / c, all the product is transferred to a hydrogenation reactor. Nitrogen gas is purged to 0.5MPa, and then a vacuum is drawn. This process is repeated 3-5 times. After heating the reactor to 70°C, hydrogen gas is introduced at a pressure of 0.5-1MPa. Alternatively, after adding 3.24g of Pd / c, all the product is transferred to a hydrogenation reactor. Nitrogen gas is purged to 0.5MPa, and then a vacuum is drawn. This process is repeated 3-5 times. After heating the reactor to 75°C, hydrogen gas is introduced at a pressure of 0.5-1MPa. The final product is obtained. The NMR information is as follows: 1 ¹H NMR (DMSO): δ: 5.24 (s, 2H), 6.58 (d, 2H), 6.72 (s, 2H), 6.89 (s, H), 7.08 (d, 2H), 7.44 (d, 2H), 7.65 (d, 2H), 7.80 (s, H), 7.93 (s, H), yield 97.12%, purity 99.07%.

[0049] Comparative Example 1: The procedure is the same as in Example 1, except that 130g (0.64mol) of 3-bromo-5-nitropyridine and 650g of DMF are added to a three-necked flask and stirred at 50°C for 30 minutes until completely dissolved. Cooling is then initiated until the temperature drops to 20°C. 147.42g (0.685mol) of 4-hydroxy-4'-nitrobiphenyl is added to a beaker containing 737.1g of DMF and stirred at 55°C for 30 minutes until completely dissolved. Cooling is then initiated until the temperature drops to room temperature. 186.64g of K2CO3 is added to the 4-hydroxy-4'-nitrobiphenyl solution. After thorough mixing, the solution is added dropwise using a plunger pump at a rate of 4ml / min. The temperature must not exceed [a certain value] during the addition process. At 30°C, after the addition was complete, the mixture was kept at this temperature for 4 hours. Then, 130 g (0.64 mol) of 3-bromo-5-nitropyridine and 650 g of DMF were added to a three-necked flask, and the mixture was stirred at 50°C for 30 minutes until completely dissolved. The temperature was then lowered to 25°C. Next, 147.42 g (0.685 mol) of 4-hydroxy-4'-nitrobiphenyl was added to a beaker containing 737.1 g of DMF, and the mixture was stirred at 55°C for 30 minutes until completely dissolved. The temperature was then lowered to room temperature, and the mixture was added dropwise using a plunger pump at a rate of 7 ml / min. The temperature during the addition process should not exceed 35°C. After the addition was complete, the mixture was kept at this temperature for 2 hours to obtain the final product, with a yield of 87.12% and a purity of 89.36%.

[0050] Comparative Example 2: The operation steps are the same as in Example 1, except that 208.48g of intermediate is dissolved in 1688.69g of DMF and stirred until completely dissolved. After adding 4.17g of Pd / c, the mixture is transferred to a hydrogenation reactor. Nitrogen gas is introduced to 0.5MPa and then a vacuum is drawn. This process is repeated 3-5 times. After the reactor is heated to 70°C, hydrogen gas is introduced at a pressure of 0.5-1MPa. During the reaction, if the pressure is lower than 0.5MPa, hydrogen gas is added to the reactor. The hydrogen gas pressure does not exceed 1MPa. The reaction ends when the pressure remains constant. The method was to dissolve 208.48 g of the intermediate in 1688.69 g of DMF, stirring until completely dissolved. Then, 4.17 g of Raney nickel was added, and the mixture was transferred to a hydrogenation reactor. Nitrogen gas was introduced to 0.5 MPa, followed by vacuuming. This process was repeated 3-5 times. The reactor was then heated to 50°C, and hydrogen gas was introduced at a pressure of 0.5-1 MPa. If the pressure dropped below 0.5 MPa during the reaction, hydrogen gas was added to the reactor, with the pressure not exceeding 1 MPa. The reaction ended when the pressure stabilized. The final product was obtained with a yield of 90.73% and a purity of 91.38%.

[0051] Comparative Example 3: The operation steps are the same as in Example 1, except that 186.64g of (K2CO3) was added to the 4-hydroxy-4'-nitrobiphenyl solution, instead of 151.77g of (triethylamine) was added to the 4-hydroxy-4'-nitrobiphenyl solution, to obtain the final product with a yield of 91.55% and a purity of 92.88%.

[0052] Application example: Product preparation: The pyridine biphenyl derivative product synthesized in Example 1 was dissolved in DMSO and stirred until homogeneous. The additive system was then atomized through a high-pressure nozzle and injected into a mixer containing insoluble sulfur semi-finished product via a metering tank. The mass ratio of insoluble sulfur semi-finished product, naphthenic oil, and pyridine biphenyl derivative product was 80:20:0.4. The mixture was stirred at 90°C for 30 minutes at a stirring speed of 90 rpm and a blade speed of 1400 rpm. After 30 minutes, the naphthenic oil was atomized through a high-pressure nozzle and injected into the mixer via a metering tank. The mixture was stirred at 85°C for 20 minutes at a stirring speed of 80 rpm and a blade speed of 1200 rpm. After 20 minutes, the remaining naphthenic oil was added to make up the difference. The mixture was stirred at 75°C for 10 minutes at a stirring speed of 60 rpm and a blade speed of 900 rpm. After vacuum devolatilization, the mixture was cooled to 60°C and placed into a silo. The product was then packaged by sieving. To obtain insoluble sulfur products.

[0053] Application Experiment:

[0054] First stage of intensive mixing: initial temperature 80℃, rotation speed 50rpm, add glue in 20s, mix with a grinding wheel for 60s, lift the grinding wheel for 10s, add small ingredients and carbon black, mix with a grinding wheel for 80-100s, clean in the middle position for 10s, mix with a grinding wheel for 40-60s, repeat 3 times, and discharge glue (total 390s).

[0055] Two-stage open mill: Adjust the roller gap of the open mill so that there is an appropriate amount of accumulated rubber above the open mill, then roll and mix for about 1 minute. Add HMMM-55, DZ, and insoluble sulfur (after adding the additives). After the material is fully absorbed, cut the left and right sides three times and then extrude the sheet. Adjust the roller gap of the open mill to the appropriate level, make 3 triangular wraps and 5 rolls, then adjust the roller gap and extrude the sheet for testing.

[0056] The application performance test results are as follows: 1. Sulfur rheometer test

[0057] The table shows that the addition of additives resulted in better vulcanization than the blank, with faster vulcanization efficiency and higher crosslinking density. The compound contains amino and pyridine groups, which can accelerate the vulcanization reaction, improve vulcanization efficiency, and thus achieve a higher degree of vulcanization. These active groups play a catalytic role in the vulcanization process, promoting the crosslinking of sulfur with rubber molecular chains.

[0058] 2. Physical and mechanical properties

[0059] The table shows that the added additives result in higher tensile strength, better aging performance, better mechanical properties, and higher retention rate compared to the blank. These active groups play a catalytic role in the vulcanization process, promoting the cross-linking of sulfur and rubber molecular chains, thereby improving the physical properties of the rubber.

[0060] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A pyridine biphenyl derivative, characterized in that, Its chemical structural formula is as follows: 。 2. A method for preparing a pyridine biphenyl derivative, characterized in that, The method includes the following steps: using 3-bromo-5-nitropyridine and 4-hydroxy-4'-nitrobiphenyl as raw materials, an intermediate product is obtained through a condensation reaction in the presence of a solvent and an acid-binding agent, and the intermediate is reduced in the presence of a catalyst and hydrogen to obtain the final product.

3. The method for preparing the pyridine biphenyl derivative as described in claim 2, characterized in that, Specifically, the following steps are included: (1) Mix the set amount of 3-bromo-5-nitropyridine with the solvent, stir at 45~50℃ until completely dissolved, turn on the cooling and lower to 15~25℃; mix the set amount of 4-hydroxy-4'-nitrobiphenyl with the solvent, stir at 55~60℃ until completely dissolved, turn on the cooling and lower to room temperature; add the set amount of acid-binding agent to the 4-hydroxy-4'-nitrobiphenyl solution, stir evenly, and start the dropwise addition. The temperature should not exceed 30℃ during the dropwise addition. After the dropwise addition is completed, keep warm for 4~5 hours. After the reaction is completed, drain the mother liquor, add the mother liquor dropwise to the precipitate, filter, rinse with water, dry, and obtain the intermediate product; (2) Dissolve the specified amount of intermediate in the solvent and stir until completely dissolved. After adding the catalyst, transfer the entire mixture to the hydrogenation reactor. Purge with nitrogen to 0.5 MPa and then evacuate. Repeat this process 3-5 times. Heat the hydrogenation reactor to 70°C and then introduce hydrogen at a pressure of 0.5-1 MPa. If the pressure is lower than 0.5 MPa during the reaction, add hydrogen to the reactor. The pressure of the hydrogen should not exceed 1 MPa. The reaction ends when the pressure remains constant. After the reaction, filter out the solid catalyst, add the mother liquor dropwise to the precipitate, filter, rinse with water, and dry to obtain the final product.

4. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In steps (1) and (2), the solvent is the same solvent, which is one or more of THF, 2-MeTHF, DMF, NMP, acetone, and 1,3-dimethyl-2-imidazolinone.

5. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In step (1), the mass ratio of 3-bromo-5-nitropyridine to solvent is 1:4-6, and the mass ratio of 4-hydroxy-4'-nitrobiphenyl to solvent is 1:4-6; The acid-binding agent is one of triethylamine, K2CO3, diethylamine hydrochloride, or a pyridine derivative, and its amount is 2.0-2.5 times the molar amount of 3-bromo-5-nitropyridine.

6. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In step (1), the mass ratio of the mother liquor to the precipitate is 1:1.9-2.9; The precipitate is an ethanol-water mixture with a volume ratio of 4:6 for ethanol and water. The reaction was added at a rate of 1-5 ml / min, and the reaction was maintained at this temperature for 2-6 hours.

7. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In step (1), the molar ratio of 3-bromo-5-nitropyridine to 4-hydroxy-4'-nitrobiphenyl is 1:1.04-1.

11.

8. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In step (2), the mass ratio of the intermediate to the solvent is 1:7.8-9.

5.

9. The method for preparing the pyridine biphenyl derivative as described in claim 3, characterized in that, In step (2), the mass of the precipitate is 1-5 times that of the hydrogenation mother liquor; The precipitate is a mixed solution of ethanol, water and acetic acid, with a volume ratio of ethanol:water:acetic acid = 30:66:

4. The mother liquor was added at a rate of 1-9 ml / min.

10. The use of the pyridine biphenyl derivative of claim 1 or the product prepared by any one of claims 2 to 9 in the preparation of rubber vulcanization accelerators.

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