Synthesis of 5-chloro-2, 4-diphenylpyrimidine

Abstract

The invention relates to the technical field of organic chemistry, and particularly discloses a synthesis method of 5-chloro-2, 4-diphenylpyrimidine, which comprises the following steps: dissolving 5-amino-2, 4-diphenylpyrimidine in a mixed solution of an organic solvent and water, adding acid, stirring, cooling, adding nitrite, and stirring to form a first reaction system; and dropwise adding the 5-chloro-2, 4-diphenylpyrimidine into an acidic salt solution of chloride to form a second reaction system, and reacting to obtain the 5-chloro-2, 4-diphenylpyrimidine. The yield and purity of the 5-chloro-2, 4-diphenylpyrimidine are remarkably improved, then the performance of an organic electronic device constructed based on the organic light-emitting technology is optimized, and the 5-chloro-2, 4-diphenylpyrimidine can be applied to the fields of display, illumination, optoelectronics and the like.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemistry and specifically discloses a method for synthesizing 5-chloro-2,4-diphenylpyrimidine. Background Art

[0002] Organic light emitting phenomenon is a phenomenon that uses organic materials to efficiently convert electrical energy into light energy. Organic light emitting technology is an electrically controlled light emitting technology that uses organic materials to release energy through the recombination of electrons and holes under the action of an external electric field and radiate in the form of light. It has the characteristics of simple preparation, low cost, high luminous efficiency and good flexibility, and is widely used in display, lighting and optoelectronics. The structure of organic electronic devices built based on organic light emitting technology exquisitely includes an anode, a cathode and an organic material layer between the two. These organic material layers are usually carefully selected from a series of specific compounds. As the core components of the organic layer, they play a decisive role in the performance of the device. For example, patents KR20190011463A and KR20180041482A respectively introduce in detail an innovative organic electronic device, whose organic layer is embedded with a special compound, and 5-chloro-2,4-diphenylpyrimidine is the indispensable starting material for the synthesis of this key compound.

[0003] However, the current methods for synthesizing 5-chloro-2,4-diphenylpyrimidine have several shortcomings: multiple steps, complex operations, increased production difficulty and cost, and reliance on expensive raw materials. For example, although patent KR2016065298 reports a synthetic route, the method suffers from overreaction and selective coupling problems, resulting in low product purity and low synthesis efficiency.

[0004] In view of the above-mentioned defects in the prior art, the present invention aims to develop a new synthesis method that is more efficient, economical and easy to operate to improve the yield and purity of 5-chloro-2,4-diphenylpyrimidine. Summary of the invention

[0005] In order to solve the above problems, the first aspect of the present invention provides a method for synthesizing 5-chloro-2,4-diphenylpyrimidine, as follows: 5-amino-2,4-diphenylpyrimidine is dissolved in a mixture of an organic solvent and water, an acid is added, stirred, cooled, and then nitrite is added and stirred to form a first reaction system; then, the mixture is added dropwise to an acidic salt solution of chloride to form a second reaction system, and reacted to obtain 5-chloro-2,4-diphenylpyrimidine.

[0006]

[0007] In some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1 L of organic solvent is 505-910 mmol, preferably 505 mmol.

[0008] In some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 550mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 600mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 650mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 700mmol; In some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 750 mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 800 mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 850 mmol; in some specific embodiments of the first aspect, the amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 900 mmol.

[0009] In some specific embodiments of the first aspect, the amount of acid added per 1 L of organic solvent is 2020-4040 mmol, preferably 2020 mmol.

[0010] In some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2050mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2100mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2150mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2200mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2250mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2300mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2300mmol; In some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2350mmol; in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2400mmol; in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2450mmol; in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2500mmol, in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2550mmol; in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2600mmol; in some specific embodiments of the first aspect, the amount of acid added to each 1L of organic solvent is 2650mmol; In some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2700mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2750mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2800mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2850mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2900mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2950mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 2900mmol. In some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3000mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3050mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3100mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3150mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3200mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3250mmol; in some specific embodiments of the first aspect, the amount of acid in each 1L of organic solvent is 3300mmol;In some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3350mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3400mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3450mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3500mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3550mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3600mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3650mmol; In some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3700mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3750mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3800mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3850mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3900mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 3950mmol; in some specific embodiments of the first aspect, the amount of acid added per 1L of organic solvent is 4000mmol. ;

[0011] In some specific embodiments of the first aspect, the amount of nitrite added per 1 L of the organic solvent is 555-1110 mmol, preferably 555 mmol.

[0012] In some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 600mmol; in some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 650mmol; in some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 700mmol; in some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 750mmol; in some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 800mmol; in some specific embodiments of the first aspect, the amount of nitrite in each 1L of the organic solvent is 800mmol; The amount of nitrite added to the solvent is 850 mmol; in some specific embodiments of the first aspect, the amount of nitrite added to each 1L of the organic solvent is 900 mmol; in some specific embodiments of the first aspect, the amount of nitrite added to each 1L of the organic solvent is 950 mmol; in some specific embodiments of the first aspect, the amount of nitrite added to each 1L of the organic solvent is 1000 mmol; in some specific embodiments of the first aspect, the amount of nitrite added to each 1L of the organic solvent is 1050 mmol; in some specific embodiments of the first aspect, the amount of nitrite added to each 1L of the organic solvent is 1100 mmol.

[0013] In some specific embodiments of the first aspect, the molar ratio of 5-amino-2,4-diphenylpyrimidine to nitrite is (505-910): (555-1110).

[0014] In some specific embodiments of the first aspect, the molar ratio of 5-amino-2,4-diphenylpyrimidine to nitrite is 505:555.

[0015] In some specific embodiments of the first aspect, the molar ratio of the acid to the nitrite is (2020-4040): (555-1110).

[0016] In some specific embodiments of the first aspect, the molar ratio of the acid to the nitrite is 2020:555.

[0017] In some specific embodiments of the first aspect, the acid is selected from hydrochloric acid, sulfuric acid, nitric acid, or a mixture thereof.

[0018] In some specific embodiments of the first aspect, the nitrite is sodium nitrite.

[0019] In some specific embodiments of the first aspect, the acidic salt solution of chloride is an acidic cuprous chloride solution.

[0020] In some specific embodiments of the first aspect, the reaction temperature of the first reaction system is -10 to 0°C, preferably -5°C.

[0021] In some specific embodiments of the first aspect, the reaction temperature of the first reaction system is -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C or 0°C.

[0022] In some specific embodiments of the first aspect, the reaction temperature of the second reaction system is 60-80°C, preferably 70°C.

[0023] In some specific embodiments of the first aspect, the reaction temperature of the second reaction system is 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C.

[0024] The second aspect of the present invention provides a method for synthesizing 5-amino-2,4-diphenylpyrimidine, as follows: 5-amino-2,4-dichloropyrimidine, phenylboric acid, potassium carbonate and bistriphenylphosphine palladium dichloride are added to a mixed solution of an organic solvent and water, and reacted under an inert gas atmosphere to obtain 5-amino-2,4-diphenylpyrimidine.

[0025]

[0026] In some specific embodiments of the second aspect, the molar amount of 5-amino-2,4-dichloropyrimidine in each 1 L of the organic solvent is 142.5 to 162.5 mmol, preferably 152.5 mmol.

[0027] In some specific embodiments of the second aspect, the molar amount of 5-amino-2,4-dichloropyrimidine fed per 1 L of the organic solvent is 152.5 mmol.

[0028] In some specific embodiments of the second aspect, the molar amount of phenylboric acid fed per 1 L of the organic solvent is 452.5 to 462.5 mmol, preferably 457.5 mmol.

[0029] In some specific embodiments of the second aspect, the molar amount of phenylboric acid fed into each 1 L of the organic solvent is 457.5 mmol.

[0030] In some specific embodiments of the second aspect, the molar amount of potassium carbonate fed to each 1 L of the organic solvent is 452.5 to 462.5 mmol, preferably 457.5 mmol.

[0031] In some specific embodiments of the second aspect, the molar amount of potassium carbonate fed to each 1 L of the organic solvent is 457.5 mmol.

[0032] In some specific embodiments of the second aspect, the molar amount of bistriphenylphosphine palladium dichloride in each 1 L of the organic solvent is 2.5-3.5 mmol, preferably 3.0 mmol.

[0033] In some specific embodiments of the second aspect, the molar amount of bistriphenylphosphine palladium dichloride in each 1 L of the organic solvent is 3.0 mmol.

[0034] In some specific embodiments of the second aspect, the molar ratio of 5-amino-2,4-dichloropyrimidine to phenylboric acid is (142.5-162.5): (452.5-462.5).

[0035] In some specific embodiments of the second aspect, the molar ratio of 5-amino-2,4-dichloropyrimidine to phenylboric acid is 152.5:457.5.

[0036] In some specific embodiments of the second aspect, the molar ratio of potassium carbonate to bistriphenylphosphine palladium dichloride is (452.5-462.5): (2.5-3.5).

[0037] In some specific embodiments of the second aspect, the molar ratio of potassium carbonate to bis(triphenylphosphine)palladium dichloride is 457.5:3.0.

[0038] In some specific embodiments of the second aspect, the organic solvent is selected from one or a mixture of DMF, toluene, xylene, acetonitrile, acetic acid, NMP, alcohols, and dichloromethane, and the inert atmosphere is one or a mixture of argon and nitrogen.

[0039] In some specific embodiments of the second aspect, the reaction temperature is 60-100°C, preferably 80°C.

[0040] In some specific embodiments of the second aspect, the reaction temperature is 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C.

[0041] The present invention has the following advantages: The present invention provides a new synthesis method that is more efficient, economical and easy to operate, so as to significantly improve the yield and purity of 5-chloro-2,4-diphenylpyrimidine, thereby optimizing the performance of organic electronic devices constructed based on organic light-emitting technology, and providing more powerful support for applications in the fields of display, lighting and optoelectronics. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : Hydrogen spectrum NMR data of 5-amino-2,4-diphenylpyrimidine of the present invention; Figure 2 : Hydrogen spectrum NMR data of 5-chloro-2,4-diphenylpyrimidine of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0044] The synthetic route of the present invention is summarized as follows:

[0045] 5-amino-2,4-dichloropyrimidine, phenylboric acid, potassium carbonate and bistriphenylphosphine palladium dichloride are added to a mixed solution of an organic solvent and water, and reacted under an inert gas atmosphere to obtain 5-amino-2,4-diphenylpyrimidine; 5-amino-2,4-diphenylpyrimidine is dissolved in a mixed solution of an organic solvent and water, and hydrochloric acid and nitrite are added, and stirred to form a reaction system; and then the solution is added dropwise to an acidic salt solution of chloride and kept warm for reaction to obtain 5-chloro-2,4-diphenylpyrimidine.

[0046] Example 1: Synthesis of 5-amino-2,4-diphenylpyrimidine The chemical reaction equation is as follows:

[0047] Compound 1 (5 g, 30.5 mmol), phenylboronic acid (11.15 g, 91.5 mmol), potassium carbonate (12.6 g, 91.5 mmol) and bistriphenylphosphine palladium dichloride (0.42 g, 0.6 mmol) were added to the reaction flask, followed by toluene (160 mL), ethanol (40 mL) and water (20 mL), and nitrogen was replaced three times; the temperature was raised to 80°C and refluxed for 16 hours; TLC spot plate showed that the reaction was complete. Water was added to the reaction solution to quench, and ethyl acetate was extracted to retain the organic phase. The organic phase was brushed on a silica gel column, and the filtrate was concentrated to obtain a crude product. The crude product was then crystallized with ethyl acetate and petroleum ether to obtain compound 2, 4.9 g, with a yield of 65%.

[0048] Hydrogen NMR spectrum of 5-amino-2,4-diphenylpyrimidine: 1 H NMR (400 MHz, Chloroform-d) δ 8.51- 8.33 (m, 3H), 7.90 (d, J = 7.2 Hz, 2H), 7.50 (m, 6H), 3.97 (s, 2H). Example 2: Synthesis of 5-chloro-2,4-diphenylpyrimidine The chemical reaction equation is as follows:

[0049] Compound 2 (4.5 g, 18.2 mmol) was added to a mixture of DMF (18 mL), acetic acid (18 mL) and water (9 mL) and stirred to dissolve. Then, dilute hydrochloric acid (7.4 g, 72.8 mmol) was added and stirred at room temperature for 30 min, and then the temperature was lowered to -5°C. Sodium nitrite (1.4 g, 20.0 mmol) was added in batches, and the mixture was stirred for 30 min after addition. Then, it was added dropwise to a 70°C mixture of dilute hydrochloric acid (7.4 g, 72.8 mmol) and cuprous chloride (0.54 g, 5.5 mmol), and the temperature was controlled to be above 60°C. After addition, the mixture was kept at 70°C for 1 hour. TLC showed that the reaction was complete, and water was added to the reaction solution and filtered to obtain a solid. The solid was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and concentrated by column. The crude product was crystallized from petroleum ether and ethyl acetate to obtain compound 3, 3.2 g, with a yield of 66%.

[0050] Hydrogen NMR spectrum of 5-chloro-2,4-diphenylpyrimidine: 1H NMR (400 MHz, Chloroform-d) δ 8.84(s, 1H), 8.55 - 8.49 (m, 2H), 8.06- 8.00 (m, 2H), 7.59 - 7.51 (m, 6H). Example 3: Synthesis of 5-chloro-2,4-diphenylpyrimidine Compound 2 (5 g, 20.2 mmol) was added to a mixture of DMF (20 mL), acetic acid (20 mL) and water (10 mL) and stirred to dissolve. Then 80% sulfuric acid (9.9 g, 80.8 mmol) was added and stirred at room temperature for 30 min, then cooled to -5°C; sodium nitrite (1.5 g, 22.2 mmol) was added in batches, and the mixture was stirred for 30 min after addition. Then it was added dropwise to a 70°C mixture of dilute hydrochloric acid (8.1 g, 80.8 mmol) and cuprous chloride (0.60 g, 6.1 mmol), and the temperature was controlled above 60°C; after addition, the mixture was kept at 70°C for 1 hour. TLC showed that the reaction was complete, and water was added to the reaction solution and filtered to obtain a solid. The solid was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and concentrated by column. The crude product was crystallized from petroleum ether and ethyl acetate to obtain compound 3, 3.1 g, with a yield of 57.6%.

[0051] Example 4: Synthesis of 5-chloro-2,4-diphenylpyrimidine Compound 2 (4.5 g, 18.2 mmol) was added to a mixture of acetone (20 mL) and water (10 mL) and stirred to dissolve. Then 80% sulfuric acid (9.9 g, 80.8 mmol) was added and stirred at room temperature for 30 min, then cooled to -5°C; sodium nitrite (1.5 g, 22.2 mmol) was added in batches, and the mixture was stirred for 30 min after addition. Then it was added dropwise to a 70°C mixture of dilute hydrochloric acid (8.1 g, 80.8 mmol) and cuprous chloride (0.60 g, 6.1 mmol), and the temperature was controlled above 60°C; after addition, the mixture was kept at 70°C for 1 hour. TLC showed that the reaction was complete, and water was added to the reaction solution and filtered to obtain a solid. The solid was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and concentrated by column. The crude product was crystallized from petroleum ether and ethyl acetate to obtain compound 3, 2.7 g, with a yield of 56.1%.

[0052] Example 5: Synthesis of 5-chloro-2,4-diphenylpyrimidine Compound 2 (3 g, 12.13 mmol) was added to a mixture of acetonitrile (12 mL), acetic acid (12 mL) and water (6 mL) and stirred to dissolve. Then, dilute hydrochloric acid (4.9 g, 48.5 mmol) was added and stirred at room temperature for 30 min, and then the temperature was lowered to -5°C. Sodium nitrite (0.9 g, 13.34 mmol) was added in batches, and the mixture was stirred for 30 min after addition. Then, it was added dropwise to a 70°C mixture of dilute hydrochloric acid (4.9 g, 48.5 mmol) and cuprous chloride (0.36 g, 3.67 mmol), and the temperature was controlled to be above 60°C. After addition, the mixture was kept at 70°C for 1 hour. TLC showed that the reaction was complete, and water was added to the reaction solution and filtered to obtain a solid. The solid was dissolved in dichloromethane, dried over anhydrous sodium sulfate, and concentrated by column. The crude product was crystallized from petroleum ether and ethyl acetate to obtain compound 3, 1.8 g, with a yield of 55.7%.

[0053] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for synthesizing 5-chloro-2,4-diphenylpyrimidine, as follows: Dissolving 5-amino-2,4-diphenylpyrimidine in a mixed solution of an organic solvent and water, adding an acid, stirring, cooling, and then adding a nitrite and stirring to form a first reaction system; then dropping the mixture into an acidic salt solution of a chloride to form a second reaction system, reacting to obtain 5-chloro-2,4-diphenylpyrimidine; 。 2. The method for synthesizing 5-chloro-2,4-diphenylpyrimidine according to claim 1, characterized in that: The amount of 5-amino-2,4-diphenylpyrimidine added per 1L of organic solvent is 505-910mmol, preferably 505mmol, and / or the amount of acid added per 1L of organic solvent is 2020-4040mmol, preferably 2020mmol, and / or the amount of nitrite added per 1L of the organic solvent is 555-1110mmol, preferably 555mmol.

3. The method for synthesizing 5-chloro-2,4-diphenylpyrimidine according to any one of claims 1 or 2, characterized in that: The molar ratio of the 5-amino-2,4-diphenylpyrimidine to the nitrite is (505-910): (555-1110), and / or the molar ratio of the acid to the nitrite is (2020-4040): (555-1110).

4. The method for synthesizing 5-chloro-2,4-diphenylpyrimidine according to any one of claims 1 to 3, characterized in that: The acid is selected from hydrochloric acid, sulfuric acid, nitric acid or a mixture thereof, and / or the nitrite is sodium nitrite, and / or the acidic salt solution of chloride is an acidic cuprous chloride solution, and / or the reaction temperature of the first reaction system is -10 to 0°C, preferably -5°C, and / or the reaction temperature of the second reaction system is 60 to 80°C, preferably 70°C.

5. A method for synthesizing 5-amino-2,4-diphenylpyrimidine, as follows: 5-amino-2,4-dichloropyrimidine, phenylboric acid, potassium carbonate and bistriphenylphosphine palladium dichloride are added to a mixed solution of an organic solvent and water, and reacted under an inert gas atmosphere to obtain 5-amino-2,4-diphenylpyrimidine; 。 6. The method for synthesizing 5-amino-2,4-diphenylpyrimidine according to claim 5, characterized in that: The molar amount of 5-amino-2,4-dichloropyrimidine per 1L of the organic solvent is 142.5-162.5 mmol, preferably 152.5 mmol, and / or the molar amount of phenylboronic acid per 1L of the organic solvent is 452.5-462.5 mmol, preferably 457.5 mmol.

7. The method for synthesizing 5-amino-2,4-diphenylpyrimidine according to any one of claims 5 or 6, characterized in that: The molar amount of potassium carbonate added per 1L of the organic solvent is 452.5-462.5 mmol, preferably 457.5 mmol.

8. The method for synthesizing 5-amino-2,4-diphenylpyrimidine according to any one of claims 5 to 7, characterized in that: The molar amount of bistriphenylphosphine palladium dichloride added per 1L of the organic solvent is 2.5 to 3.5 mmol, preferably 3.0 mmol.

9. The method for synthesizing 5-amino-2,4-diphenylpyrimidine according to any one of claims 5 to 8, characterized in that: The molar ratio of the 5-amino-2,4-dichloropyrimidine to phenylboric acid is (142.5-162.5): (452.5-462.5), and / or the molar ratio of potassium carbonate to bistriphenylphosphine palladium dichloride is (452.5-462.5): (2.5-3.5).

10. The method for synthesizing 5-amino-2,4-diphenylpyrimidine according to any one of claims 5 to 9, characterized in that: The organic solvent is selected from DMF, toluene, xylene, acetonitrile, acetic acid, NMP, alcohols, dichloromethane or a mixture thereof, the inert atmosphere is argon, nitrogen or a mixture thereof, and / or the reaction temperature is 60-100° C., preferably 80° C.

Images