1,3-bis(3-aminophenoxy)benzene and a method for preparing the same

Abstract

This invention relates to the field of organic synthesis, specifically to a method for preparing 1,3-di(3-aminophenoxy)benzene. The method involves a nucleophilic reaction (S1): m-aminophenol and triethylamine are dissolved in dichloromethane, cooled to below 10°C, and trimethylchlorosilane is added dropwise. After the reaction, the mixture is separated to obtain a crude N,O-bistrimethylsilyl-m-aminophenol intermediate. A coupling reaction (S2) involves adding the crude intermediate, m-dibromobenzene, an acid-binding agent, a catalyst, and a catalyst ligand to N,N-dimethylformamide. After the reaction, the mixture is cooled to room temperature and filtered. Hydrochloric acid is added to form a salt, and the mixture is filtered again to obtain a wet 1,3-di(3-aminophenoxy)benzene hydrochloride. The wet hydrochloric acid salt is added to water, and the pH is adjusted to 9-10 with sodium hydroxide solution, precipitating a solid to obtain 1,3-di(3-aminophenoxy)benzene. This preparation process has low energy consumption and mild reaction conditions.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis, and more specifically, to a 1,3-bis(3-aminophenoxy)benzene and its preparation method. Background Technology

[0002] Polyimide (PI) film possesses advantages such as high heat resistance, high strength, and good dimensional stability, hence its nickname "golden film." Electronic-grade PI film is primarily used in the manufacture of flexible copper-clad laminates (FCCL), which in turn are used in the manufacture of flexible printed circuit boards (FPC), a major type of printed circuit board (PCB). FPCs are widely used in consumer electronics products such as mobile phones, tablets, and displays. These electronic products require PI films with the lowest possible dielectric constant (Dk) and loss factor (Df). A low Dk in insulating materials results in strong signal penetration; a low Df in insulating materials results in low energy loss and, consequently, low heat generation. Adding a portion of 1,3-bis(3-aminophenoxy)benzene (TPE-M) to PI film, replacing other diamines, significantly reduces the Dk and Df of the PI film and improves its flexibility. Therefore, TPE-M is one of the essential diamine monomers indispensable for manufacturing high-grade electronic-grade PI films.

[0003] Patent CN109956877A discloses a method for preparing TPE-M by using m-dinitrobenzene as a raw material, anhydrous carbonates (potassium, sodium, cesium, lithium) as catalysts, and a mixture of DMAC or DMF and toluene or xylene as a reaction medium, with the dropwise addition of resorcinol to generate the intermediate 1,3-bis(3-nitrophenoxy)benzene. This intermediate (dinitro compound) is then hydrogenated under high pressure (0.5-3 MPa) using palladium on carbon as a catalyst and ethanol as a solvent to obtain TPE-M. In this synthetic method, the palladium on carbon catalyst for the hydrogenation reaction is costly, and the high-pressure hydrogenation reaction carries certain risks.

[0004] Patent CN1221733A discloses a method for synthesizing TPE-M by reacting m-aminophenol as a raw material with a basic substance in a polar aprotic solvent (such as sulfolane, dimethyl sulfoxide, etc.) to generate sodium (potassium) aminophenol intermediate, followed by reaction of the intermediate with m-dibromobenzene using copper powder or cuprous salt as a catalyst. This synthesis method requires high temperature (150-240℃), consumes a lot of energy, and may trigger side reactions.

[0005] Therefore, there is an urgent need to provide a preparation method with low energy consumption and mild reaction conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing 1,3-bis(3-aminophenoxy)benzene, using N,O-bistrimethylsilyl-m-aminophenol as a coupling agent, which increases the stability of the reaction substrate and makes it less prone to deterioration. The coupling reaction is sensitive to water; by using N,O-bistrimethylsilyl-m-aminophenol as the coupling agent, the trimethylsilyl groups of the phenolic hydroxyl and amino groups act as protecting groups, and their hydrolysis can absorb water in the reaction, allowing the reaction to proceed smoothly.

[0007] Another object of the present invention is to provide a 1,3-bis(3-aminophenoxy)benzene, the preparation process of which has low energy consumption and mild reaction conditions.

[0008] The technical problem solved by this invention is achieved by the following technical solution.

[0009] On one hand, embodiments of the present invention provide a 1,3-bis(3-aminophenoxy)benzene, comprising the following steps: For the S1 nucleophilic reaction, m-aminophenol and triethylamine were first dissolved in dichloromethane and cooled to below 10°C. Trimethylchlorosilane was then added dropwise. After the reaction was completed, the mixture was separated. The organic phase was washed with saturated brine, dried, filtered, and evaporated to dryness to obtain crude N,O-bistrimethylsilyl-m-aminophenol intermediate. In the S2 coupling reaction, the crude intermediate, m-dibromobenzene, acid-binding agent, catalyst, and catalyst ligand are added to N,N-dimethylformamide. After the reaction is complete, the mixture is cooled to room temperature and filtered. The organic phase is concentrated under reduced pressure, and the concentrate is dissolved in methanol. Hydrochloric acid is added to form a salt, and the mixture is filtered to obtain wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The wet hydrochloric acid salt is added to water, and the pH is adjusted to 9-10 with sodium hydroxide solution. A solid precipitates out, which is filtered, washed, and dried to obtain 1,3-bis(3-aminophenoxy)benzene.

[0010] In some embodiments of the present invention, in S1, the molar ratio of m-aminophenol, trimethylchlorosilane, and triethylamine is 1:(2-3):(2-3). In some embodiments of the present invention, the acid-binding agent includes at least one of potassium phosphate, potassium dihydrogen phosphate, and potassium carbonate. In some embodiments of the present invention, the catalyst includes at least one of cuprous iodide, cuprous bromide, and cuprous chloride. In some embodiments of the present invention, the catalyst ligand includes at least one of 2-pyridinecarboxylic acid, triphenylphosphine, and 1,10-phenanthroline.

[0011] In some embodiments of the present invention, in step S2, the reaction temperature is 120-125°C and the reaction time is 16-18h.

[0012] In some embodiments of the present invention, the molar ratio of crude intermediate, m-dibromobenzene, acid-binding agent, catalyst, and catalyst ligand is 1:(0.45-0.47):(2.0-2.1):(0.105-0.11):(0.19-0.20).

[0013] In some embodiments of the present invention, in step S2, the concentration of hydrochloric acid is 20-30 wt%.

[0014] In some embodiments of the present invention, in S2, the concentration of the sodium hydroxide solution is 20-30 wt%.

[0015] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: By generating the N,O-bistrimethylsilyl-m-aminophenol intermediate, a steric barrier is formed by the double protection of the phenolic hydroxyl and amino groups. This not only prevents the oxidation and decomposition of the active groups but also prevents the self-polymerization of the raw materials during storage and the early stages of the reaction, reducing impurity generation from the source and significantly improving the controllability of the reaction system. The trimethylsilyl protecting group is not only suitable for water-sensitive coupling reactions but also compatible with a wider range of reaction substrates containing easily hydrolyzable functional groups, providing more possibilities for subsequent derivatization reactions and expanding its applicability.

[0016] The preparation method of this invention features mild reaction temperature and atmospheric pressure conditions. The lower reaction temperature reduces energy consumption and avoids harmful byproducts that may be generated at high temperatures. Compared with the large yield fluctuations of traditional processes, the reaction of this invention has better reproducibility and minimal quality differences. In the production of electronic-grade PI films, it can ensure the consistency of the final product performance and reduce the scrap rate of finished products due to fluctuations in raw material quality. Moreover, the low-cost synthesis route can reduce the market price of TPE-M, thereby driving down the costs of downstream PI film manufacturers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a synthetic route diagram of TPE-M in an embodiment of the present invention; wherein, compound 1 is m-aminophenol, compound 2 is trimethylchlorosilane, compound 3 is crude N,O-bistrimethylsilyl m-aminophenol intermediate, compound 4 is m-dibromobenzene, and compound 5 is 1,3-bis(3-aminophenoxy)benzene.

[0019] Figure 2 The 1H NMR spectrum of TPE-M prepared in Example 1 ( 1 H NMR). Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to specific embodiments.

[0022] This invention provides a 1,3-bis(3-aminophenoxy)benzene, comprising the following steps: For the S1 nucleophilic reaction, m-aminophenol (compound 1) and triethylamine were first dissolved in dichloromethane and cooled to below 10°C. Trimethylchlorosilane (compound 2) was then added dropwise. After the reaction was complete, the mixture was separated. The organic phase was washed with saturated brine, dried, filtered, and evaporated to dryness to obtain crude N,O-bistrimethylsilyl-m-aminophenol intermediate (compound 3). The molar ratio of m-aminophenol, trimethylchlorosilane, and triethylamine was 1:(2-3):(2-3). In the S2 coupling reaction, the crude intermediate (compound 3), m-dibromobenzene (compound 4), acid-binding agent, catalyst, and catalyst ligand were added to N,N-dimethylformamide. The reaction temperature was 120-125℃, and the reaction time was 16-18 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The organic phase was concentrated under reduced pressure, and the concentrate was dissolved in methanol. 20-30 wt% hydrochloric acid was added to form a salt, and the mixture was filtered to obtain wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The wet hydrochloric acid salt was added to water, and the pH was adjusted to 9-10 with 20-30 wt% sodium hydroxide solution. A solid precipitated, which was filtered, washed, and dried to obtain 1,3-bis(3-aminophenoxy)benzene (compound 5).

[0023] The acid-binding agent includes at least one of potassium phosphate, potassium dihydrogen phosphate, and potassium carbonate. The catalyst includes at least one of cuprous iodide, cuprous bromide, and cuprous chloride. The catalyst ligand includes at least one of 2-pyridinecarboxylic acid, triphenylphosphine, and 1,10-phenanthroline.

[0024] The molar ratio of crude intermediate, m-dibromobenzene, acid-binding agent, catalyst, and catalyst ligand is 1:(0.45-0.47):(2.0-2.1):(0.105-0.11):(0.19-0.20).

[0025] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0026] Example 1 Triethylamine (20.2 g, 200 mmol) and 200 ml (265 g) of dichloromethane were added to a three-mouthed simmering pan equipped with a stirrer, thermometer, and dropping apparatus. Stirring was started, followed by the addition of m-aminophenol (10.9 g, 100 mmol). After complete dissolution, the mixture was cooled to below 10°C, and trimethylchlorosilane (21.8 g, 200 mmol) was added dropwise over 30 minutes. The reaction mixture was then kept at this temperature for 1 hour. The reaction was quenched with 100 ml of pure water, and the mixture was separated. The organic phase was washed once with 100 ml of saturated brine, dried, filtered, and evaporated to dryness to obtain 25.4 g of crude N,O-bistrimethylsilyl-m-aminophenol, with a 100% yield. This crude product was added directly to the next step without further purification.

[0027] 100 ml (94.8 g) of N,N-dimethylformamide (DMF) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, followed by the addition of crude N,O-bis(trimethylsilyl)-m-aminophenol (25.4 g), m-dibromobenzene (10.6 g, 45 mmol), potassium phosphate (42.4 g, 200 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol). The reaction was carried out at 120 °C for 18 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with 20 ml of methanol to obtain 24 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. A solid precipitated, which was filtered. The filter cake was washed with 20 ml of pure water and dried to obtain 10.6 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.1 °C and a yield of 81% (based on m-dibromobenzene). The 1H NMR spectrum of TPE-M is shown below. 1 HNMR) such as Figure 2 As shown.

[0028] Example 2 The first step is the same as in Example 1.

[0029] N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, followed by the addition of crude N,O-bis(trimethylsilyl)-m-aminophenol (25.4 g), m-dibromobenzene (11.1 g, 47 mmol), potassium phosphate (42.4 g, 200 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol). The reaction was carried out at 125 °C for 16 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with 20 ml of methanol to obtain 23 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. The solid precipitated, filtered, and the filter cake was rinsed with 20 ml of pure water and dried to obtain 10.4 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.0 °C and a yield of 76% (based on m-dibromobenzene).

[0030] Example 3 The first step is the same as in Example 1.

[0031] N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, followed by the addition of crude N,O-bis(trimethylsilyl)-m-aminophenol (25.4 g), m-dibromobenzene (10.6 g, 45 mmol), potassium phosphate (42.4 g, 200 mmol), cuprous iodide (2.0 g, 10.5 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol). The reaction was carried out at 120 °C for 18 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with 20 ml of methanol to obtain 24 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. The solid precipitated, filtered, and the filter cake was rinsed with 20 ml of pure water and dried to obtain 10.5 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 107.9 °C and a yield of 80% (based on m-dibromobenzene).

[0032] Example 4 The first step is the same as in Example 1.

[0033] N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, followed by the addition of crude N,O-bis(trimethylsilyl)-m-aminophenol (25.4 g), m-dibromobenzene (10.6 g, 45 mmol), potassium phosphate (42.4 g, 200 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.3 g, 19 mmol). The reaction was carried out at 123 °C for 17 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with 20 ml of methanol to obtain 22 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. The solid precipitated, filtered, and the filter cake was washed with 20 ml of pure water and dried to obtain 10.3 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.1 °C and a yield of 78% (based on m-dibromobenzene).

[0034] Example 5 The first step is the same as in Example 1.

[0035] N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, followed by the addition of crude N,O-bis(trimethylsilyl)-m-aminophenol (25.4 g), m-dibromobenzene (10.6 g, 45 mmol), potassium phosphate (44.5 g, 210 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol). The reaction was carried out at 120 °C for 18 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with 20 ml of methanol to obtain 23.5 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. A solid precipitated out, which was filtered. The filter cake was washed with 20 ml of pure water and dried to obtain 10.5 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.0 °C and a yield of 80% (based on m-dibromobenzene).

[0036] Comparative Example 1 N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, and m-aminophenol (10.9 g, 100 mmol) and sodium hydroxide (4 g, 100 mmol) were added. The mixture was reacted at 180 °C for 2 hours, cooled to room temperature, and then m-dibromobenzene (10.6 g, 45 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol) were added. The mixture was reacted at 160 °C for 18 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), stirred for 1 hour, filtered, and the filter cake was washed with 20 ml of methanol to obtain 19.2 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. The solid precipitated, filtered, and the filter cake was washed with 20 ml of pure water and dried to obtain 8.5 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.0 °C and a yield of 65% (based on m-dibromobenzene).

[0037] Comparative Example 2 N,N-dimethylformamide (DMF) (100 ml) was added to a three-necked sintering pan equipped with a stirrer, thermometer, and dropping device. Stirring was started, and m-aminophenol (10.9 g, 100 mmol) and sodium hydroxide (4 g, 100 mmol) were added. The mixture was reacted at 180 °C for 2 hours, cooled to room temperature, and then m-dichlorobenzene (6.6 g, 45 mmol), cuprous iodide (2.1 g, 11 mmol), and pyridine-2-carboxylic acid (2.5 g, 20 mmol) were added. The mixture was reacted at 160 °C for 18 hours. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with DMF. The resulting organic phase was concentrated under reduced pressure. The residue was added to 50 ml of methanol and 20 ml of hydrochloric acid (30% concentration), stirred for 1 hour, filtered, and the filter cake was washed with 20 ml of methanol to obtain 13.4 g of wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The hydrochloride salt was added to 100 ml of pure water, and the pH was adjusted to 10 with 30% sodium hydroxide solution. A solid precipitated, which was filtered. The filter cake was washed with 20 ml of pure water and dried to obtain 5.9 g of 1,3-bis(3-aminophenoxy)benzene (TPE-M), with a melting point of 108.1 °C and a yield of 45% (based on m-dichlorobenzene). The reactivity of m-dichlorobenzene is lower than that of m-dibromobenzene.

[0038] In summary, the synthetic route of this invention, using N,O-bistrimethylsilyl-m-aminophenol for coupling, increases the stability of the reaction substrate and makes it less prone to deterioration. Secondly, the coupling reaction is sensitive to water; using N,O-bistrimethylsilyl-m-aminophenol for coupling, with the trimethylsilyl groups of the phenolic hydroxyl and amino groups acting as protecting groups, allows the hydrolysis of these groups to absorb water in the reaction, ensuring smooth reaction progress.

[0039] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for preparing 1,3-bis(3-aminophenoxy)benzene, characterized in that, Includes the following steps: S1 nucleophilic reaction First, m-aminophenol and triethylamine were dissolved in dichloromethane and cooled to below 10°C. Trimethylchlorosilane was then added dropwise. After the reaction was completed, the mixture was separated. The organic phase was washed with saturated brine, dried, filtered, and evaporated to dryness to obtain crude N,O-bistrimethylsilyl-m-aminophenol intermediate. S2 coupling reaction The crude intermediate, m-dibromobenzene, acid-binding agent, catalyst, and catalyst ligand were added to N,N-dimethylformamide. After the reaction was completed, the mixture was cooled to room temperature and filtered. The organic phase was concentrated under reduced pressure, and the concentrate was dissolved in methanol. Hydrochloric acid was added to form a salt, and the mixture was filtered to obtain wet 1,3-bis(3-aminophenoxy)benzene hydrochloride. The wet hydrochloric acid salt was added to water, and the pH was adjusted to 9-10 with sodium hydroxide solution. A solid precipitated out, which was filtered, washed, and dried to obtain 1,3-bis(3-aminophenoxy)benzene.

2. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 1, characterized in that, In S1, the molar ratio of m-aminophenol, trimethylchlorosilane, and triethylamine is 1:(2-3):(2-3).

3. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 1, characterized in that, The acid-binding agent includes at least one of potassium phosphate, potassium dihydrogen phosphate, and potassium carbonate.

4. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 1, characterized in that, The catalyst includes at least one of cuprous iodide, cuprous bromide, and cuprous chloride.

5. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 1, characterized in that, The catalyst ligand includes at least one of 2-pyridinecarboxylic acid, triphenylphosphine, and 1,10-phenanthroline.

6. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 1, characterized in that, In step S2, the reaction temperature is 120-125℃ and the reaction time is 16-18 h.

7. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 6, characterized in that, The molar ratio of crude intermediate, m-dibromobenzene, acid-binding agent, catalyst, and catalyst ligand is 1:(0.45-0.47):(2.0-2.1):(0.105-0.11):(0.19-0.20).

8. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 6, characterized in that, In step S2, the concentration of hydrochloric acid is 20-30 wt%.

9. The method for preparing 1,3-bis(3-aminophenoxy)benzene according to claim 6, characterized in that, In S2, the concentration of sodium hydroxide solution is 20-30 wt%.

10. A 1,3-bis(3-aminophenoxy)benzene, characterized in that, It is prepared by the preparation method according to any one of claims 1-9.

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