Meta-ester aromatic diamines, their production method, and polyimides made from these meta-ester aromatic diamines

Abstract

To provide a novel meta-type ester-based aromatic diamine and a method for producing the same, and a polyimide synthesis.SOLUTION: For example, it is a compound (b) obtained by the following reaction.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to meta-ester aromatic diamines and derivatives thereof, which are useful as raw materials for highly functional polymers such as polyimides and various organic compounds, and to a method for producing the same. [Background technology]

[0002] Printed wiring boards and other devices used in the information and communications field are required to support high-speed, high-capacity communications, and as a result, higher frequency bands than ever before are expected to be used. However, higher frequencies pose a problem: increased transmission loss. Transmission loss can be divided into contributions from resistance loss and dielectric loss. Of these, resistance loss is characterized by being converted into heat in proportion to frequency, while dielectric loss is characterized by being proportional to frequency, dielectric loss tangent, and relative permittivity.

[0003] Materials that can withstand use in high-frequency bands are required to have not only heat resistance but also excellent electrical properties, particularly low dielectric constant and low dielectric loss tangent. Examples of materials known to have excellent high heat resistance include polyimide resin (PI) and polyamide resin (Non-Patent Documents 1 and 2). However, these resins contain highly polar imide or amide group structures within the molecule, and due to these factors, the dielectric constant (k) of many PIs typically exceeds 3.0. Another PI material known to have excellent electrical properties is polyesterimide resin (PEI) (Non-Patent Document 3). However, it suffers from problems such as poor thermoplasticity, poor fluidity when melted, poor solvent solubility, and poor processability. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Pathrick RAet,al “Journal of Applied Polymer Science”, vol.132, p.41684-41692, 2015. [Non-patent document 2] Akhter Z.et,al “Polymer Bulletin” vol.74, p.3889-3906, 2017. [Non-patent document 3] Masatoshi Hasegawa.et al. “Polymers”, vol.12, p.859, 2020. [Non-patent document 4] S. Tamai et al. "Polymer", vol.37, p.3683-3692, 1996. Summary of the Invention [Problem to be solved by the invention]

[0005] Reducing the dielectric constant of PI has been proposed as a material with excellent heat resistance and electrical properties. Due to the diverse design of its diamine monomer, PI is an attractive material for molecular design to reduce its dielectric constant. The basic concept for reducing the dielectric constant of PI is how to dilute (reduce) the concentration of imide groups, which contribute to its high dielectric constant. To reduce the concentration of imide groups in PI, it is effective to use diamines with three or more aromatic rings instead of dinuclear aromatic diamines such as oxydianiline, a typical aromatic diamine. Furthermore, introducing an ester moiety into the PI main chain reduces the hygroscopicity of PI and is effective in reducing the dielectric constant (Non-Patent Document 3). However, the aromatic diamines described in Non-Patent Document 3 increase the linearity of the PI main chain, which impairs the processability of the PI resin. Using meta-type aromatic diamines as raw materials is effective in improving PI processability (Non-Patent Document 4), but this does not contribute to reducing the dielectric constant of PI.

[0006] Therefore, to simultaneously achieve excellent heat resistance, electrical properties, and processability, it is effective to use meta-type ether-based aromatic diamines as raw materials for PI. However, the production of meta-type ether-based aromatic diamine precursors requires harsh reaction conditions of 145-150°C for 5 hours, or even 170-180°C for 18 hours (Non-Patent Document 4). On the other hand, ester-based aromatic diamine precursors can be synthesized under milder reaction conditions of room temperature for 12 hours. In view of the above circumstances, the present invention aims to provide easily produced meta-type ester-based aromatic diamine compounds and derivatives thereof that are useful as raw materials for resins such as polyimide resins, as well as electronic materials and their intermediates and raw materials, as well as methods for producing the same. [Means for solving the problem]

[0007] As a result of intensive investigations into the problems associated with aromatic diamines as described above, the present inventors have produced novel meta-ester aromatic diamines, which are trinuclear or tetranuclear bis(3-aminobenzoyloxy) compounds having 3-aminobenzoyloxy, and pentanuclear meta-ester aromatic diamines, thereby completing the present invention.

[0008] That is, the present invention provides a compound represented by the following formula (1) and a method for producing the same. [ka] In formula (1), X is the following (a), (b), or (c): [ka] [ka] [ka] R1, R2, R3, and R4 in formula (1), and R5 and R in (a), (b), and (c) 6、 R7, R 8、 R9 and R 10are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, provided that R, R 8、 R9 and R 10 At least one of the groups is an alkyl group or an alkoxy group.

[0009] The present invention also provides a compound represented by the following formula (1') and a method for producing the same. [ka] In formula (1'), X is the following (d): [ka] R1, R2, R3, R4, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.

[0010] The present invention further provides a polyimide compound which is a reaction product of the above diamine compound, an acid anhydride, and optionally another diamine compound. [Effects of the Invention]

[0011] The meta-ester aromatic diamine of the present invention has excellent solubility in various solvents. Furthermore, since the meta-ester aromatic diamine of the present invention has three or more aromatic rings, the imide concentration of the resulting polyimide can be reduced, and since it has an ester moiety, the moisture absorption of the resulting polyimide can be reduced. Therefore, it is effective in lowering the dielectric constant of polyimides. Furthermore, since the ester aromatic diamine of the present invention is meta-ester, it can be suitably used as a polyimide raw material with high processability. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a chart of the 1H-NMR spectrum of the compound prepared in Example 2. [Figure 2] FIG. 2 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 2. [Figure 3] FIG. 3 is a chart of the 13C-NMR spectrum of the compound prepared in Example 2. [Figure 4] FIG. 3 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 2. [Figure 5] FIG. 5 is a chart of the 1H-NMR spectrum of the compound prepared in Example 4. [Figure 6] FIG. 6 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 4. [Figure 7] FIG. 7 is a chart of the 13C-NMR spectrum of the compound prepared in Example 4. [Figure 8] FIG. 8 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 4. [Figure 9] FIG. 9 is a chart of the 1H-NMR spectrum of the compound prepared in Example 6. [Figure 10] FIG. 10 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 6. [Figure 11] FIG. 11 is a chart of the 13C-NMR spectrum of the compound prepared in Example 6. [Figure 12] FIG. 12 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 6. [Figure 13] FIG. 13 is a chart of the 1H-NMR spectrum of the compound prepared in Example 8. [Figure 14] FIG. 14 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 8. [Figure 15] FIG. 15 is a chart of the 13C-NMR spectrum of the compound prepared in Example 8. [Figure 16] FIG. 16 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 8. [Figure 17] FIG. 17 is an FT-IR spectrum of the polyamic acid produced in Example 13. [Figure 18] FIG. 18 shows the FT-IR spectrum of the polyimide powder produced in Example 13. [Figure 19] FIG. 19 shows the FT-IR spectrum of the polyimide powder produced in Example 14. [Figure 20] FIG. 20 shows the FT-IR spectrum of the polyimide powder produced in Example 15. [Figure 21] FIG. 21 shows the FT-IR spectrum of the polyimide powder produced in Example 16. [Figure 22] FIG. 22 shows the FT-IR spectrum of the polyimide powder produced in Example 17. [Figure 23] FIG. 23 shows the FT-IR spectrum of the polyimide powder produced in Example 18. [Figure 24] FIG. 24 is a chart of the 1H-NMR spectrum of the compound prepared in Example 9. [Figure 25] FIG. 25 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 9. [Figure 26] FIG. 26 is a chart of the 1H-NMR spectrum of the compound prepared in Example 10. [Figure 27] FIG. 27 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 10. [Figure 28] FIG. 28 is a chart of the 13C-NMR spectrum of the compound prepared in Example 10. [Figure 29] FIG. 29 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 10. [Figure 30] FIG. 30 is a chart of the 1H-NMR spectrum of the compound prepared in Example 11. [Figure 31]FIG. 31 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 11. [Figure 32] FIG. 32 is a chart of the 1H-NMR spectrum of the compound prepared in Example 11. [Figure 33] FIG. 33 is an enlarged chart of the 1H-NMR spectrum of the compound prepared in Example 11. [Figure 34] FIG. 34 is a chart of the 13C-NMR spectrum of the compound prepared in Example 11. [Figure 35] FIG. 35 is an enlarged chart of the 13C-NMR spectrum of the compound prepared in Example 11. DETAILED DESCRIPTION OF THE INVENTION

[0013] One aspect of the present invention relates to a meta-ester aromatic diamine represented by the following formula (1). [ka] In formula (1), X is the following (a), (b), or (c): [ka] [ka] [ka] R1, R2, R3, and R4 in formula (1), and R5, R 6、 R7, R 8、 R9 and R 10 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, provided that R, R 8、 R9 and R 10 At least one of the groups is an alkyl group or an alkoxy group.

[0014] Another aspect of the present invention relates to a meta-ester aromatic diamine represented by the following formula (1'). [ka] In formula (1'), X is the following (d): [ka] R1, R2, R3, R4, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.

[0015] R1, R2, R3, R4, R5, R 6、 R7, R 8、 R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 Examples of the optionally substituted alkyl group having 1 to 6 carbon atoms and represented by the formula (I) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, neopentyl, cyclopentyl, hexyl, and cyclohexyl groups. Examples of the alkoxy group having 1 to 3 carbon atoms include methoxy, ethoxy, and propoxy groups. R1, R2, R3, R4, R5, and R 6、 R7, R 8、 R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R18 , R 19 and R 20 may be different or the same. They are preferably hydrogen atoms or alkyl groups having 1 to 6 carbon atoms. More preferably, in the above (a), (b), and (d), R1, R2, R3, R4, R5, R6, and R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 In the above (c), R1, R2, R3, and R4 are preferably hydrogen atoms, and R7 and R 8、 R9 and R 10 At least one of these is preferably a methyl group.

[0016] Preferably, it is a tetranuclear compound represented by the following formula (1a) or (1b), or a trinuclear compound represented by the following formula (1c). [ka] [ka] In formulae (1a) and (1b), R1, R2, R3, R4, R5 and R6 are as defined above and are preferably hydrogen atoms. [ka] In formula (1c), R1, R2, R3, and R4 are as defined above and are preferably hydrogen atoms; R7, R 8、 R9 and R 10 are as above, at least one of which is a methyl group.

[0017] Moreover, the above formula (d) is preferably represented by the following formula (1d). [ka] (1d) In formula (1d), R1, R2, R3, R4, R11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 is as defined above, and is preferably a hydrogen atom. 19 and R 20 is as defined above, and is preferably a methyl group.

[0018] In the formula (d), the bonding positions of the substituents and aromatic rings are not particularly limited. Preferred are compounds in which X has the following structure: [ka] [ka] R1, R2, R3, R4, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 is as defined above, and is preferably a hydrogen atom. 19 and R 20 is as defined above, and is preferably a methyl group. In the formula, the position indicated by * indicates a bond to an oxygen atom.

[0019] The compound of the present invention is particularly preferably the following compound: [ka] [ka] [ka] [ka] [ka] [ka]

[0020] The compound represented by the above formula (1) can be easily obtained by reducing the two nitro groups of the compound represented by the following formula (3). [ka] (In the formula, R 1 , R 2 , R 3 , R 4 and X are as above)

[0021] The manufacturing method will be described in more detail below.

[0022] The reduction reaction of the nitro group is not particularly limited, and any known method for reducing a nitro group to an amino group can be used. For example, methods for reducing aromatic dinitro compounds include catalytic reduction, Bechamp reduction, zinc dust reduction, tin chloride reduction, and hydrazine reduction.

[0023] Examples of solvents used in the reduction reaction include alcohol solvents such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-methoxyethanol, and 2-ethoxyethanol, amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and N,N'-dimethylimidazolidinone, and ether solvents such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol, but are not limited to these as long as the solvent dissolves the aromatic dinitro compound. The amount of solvent may be adjusted appropriately.

[0024] The catalyst used in the reduction reaction may be any known catalyst for the above-mentioned reduction reactions. For example, catalysts used in catalytic reduction or hydrazine reduction include noble metal catalysts such as palladium, platinum, and rhodium supported on activated carbon, carbon black, graphite, and alumina, Raney nickel catalysts, and sponge nickel catalysts. The amount of catalyst is not particularly limited, but is usually 0.1 to 10 wt% based on the aromatic dinitro compound.

[0025] The reaction temperature and time for the reduction reaction may be selected as appropriate. For example, the reaction may be carried out at a temperature in the range of 50 to 150°C, preferably 60 to 130°C, for 1 to 35 hours, preferably 3 to 10 hours. The method for treating the reaction product is not particularly limited. For example, after removing the catalyst and cooling, the resulting solid can be filtered, washed with water, and dried to obtain the compound represented by the general formula (1). Furthermore, if necessary, the product can be further purified by methods such as crystallization filtration and column separation to obtain a highly pure product.

[0026] The compound represented by the above formula (3) is particularly preferably represented by the following formula: [ka] [ka] [ka] [ka] [ka] [ka]

[0027] The compounds represented by the formula (3) can be produced by known methods, for example, by condensing the corresponding diol compound with m-nitrobenzoic acid chloride.

[0028] The meta-ester aromatic diamine represented by the formula (1) has excellent solubility in various solvents and is useful as a raw material for polyimides. For example, a polyimide compound can be obtained by reacting the meta-ester aromatic diamine represented by the formula (1) with an acid anhydride.

[0029] The acid anhydride may be any known acid anhydride used as a raw material for polyimide, such as at least one acid dianhydride selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, benzophenone-3,4,3',4'-tetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and oxy-4,4'-diphthalic dianhydride.

[0030] The reaction conditions and reaction ratio of the diamine compound and acid anhydride are not particularly limited and may be appropriately selected according to conventional methods. For example, the reaction may be carried out at a temperature in the range of 25 to 30°C for 0.5 to 24 hours. The reaction ratio may be 1.00. The resulting polyimide compound preferably has a number average molecular weight of 2,000 to 200,000, and more preferably 10,000 to 50,000. The number average molecular weight is measured, for example, by GPC (gel permeation chromatography, THF).

[0031] The polyimide compound may be further reacted with any diamine compound other than the diamine compound of the present invention. In the polyimide compound, the ratio of the units derived from the diamine compound of the present invention to the total moles of units derived from all diamine compounds is preferably 10 mol% to 100 mol%. Examples of the optional diamine compound other than the diamine compound of the present invention include 1,4-phenylenediamine, 1,3-phenylenediamine, 1,2-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, m-xylylenediamine, p-xylylenediamine, 2,2'-dimethylbenzidine, 3,3'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl and 9,9'-bis[4-(4-aminophenoxy)phenyl]fluorene.

[0032] Molded articles made of the polyimide compound of the present invention include, for example, materials for high-speed, large-capacity communication. [Example]

[0033] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The measurement methods and devices used in the following examples are as follows. For HPLC measurement, SPD-20A manufactured by SHIMADZU was used, and for melting point measurement, MP-21 manufactured by YAMATO was used. 1 For 1 H nuclear magnetic resonance spectroscopy, Avance iii HD 400 (Bruker Biospin) was used, and deuterated DMSO was used as the measurement solvent. 13 For C nuclear magnetic resonance spectroscopy, Avance iii HD 400 (Bruker Biospin) was used, and deuterated DMSO was used as the measurement solvent. Infrared spectroscopy was performed using FT / IR-4700 manufactured by JASCO Corporation, using the ATR method. For accurate mass analysis, a Xevo g2-XS QTof manufactured by Waters was used.

[0034] [Example 1] Synthesis of 2,2'-bis[4-(3-nitrobenzoyloxy)phenyl]hexafluoropropane [ka] A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 25.2 g (75 mmol) of bisphenol AF, 200 mL of tetrahydrofuran (THF), and 16.0 g (158 mmol) of triethylamine and dissolved at room temperature (a pale yellow, transparent solution). 25.0 g (158 mmol) of m-nitrobenzoic acid chloride (MNBC) was added, and a white precipitate immediately formed. The internal temperature rose from 25°C to 55°C and then cooled shortly thereafter. The mixture was stirred at room temperature for 1 hour, and the disappearance of MNBC was confirmed by HPLC. The triethylamine hydrochloride was filtered off at room temperature, and the solvent was removed by evaporation. The resulting white solid was slurry-washed with 300 mL of ion-exchanged water and filtered, and the cake was dissolved in 260 mL of acetonitrile with heating. The mixture was cooled to 5°C, filtered, and dried to obtain 36.0 g of white needles (yield 76%), with an mp of 195.2-196.5°C and an HPLC purity of 98.7%. The product was 2,2'-bis[4-(3-nitrobenzoyloxy)phenyl]hexafluoropropane (hereinafter referred to as dinitro compound 1) represented by the above formula (a). TOF-MS (ESI): 633.073 (M) -

[0035] [Example 2] Synthesis of 2,2'-bis[4-(3-aminobenzoyloxy)phenyl]hexafluoropropane [ka] A 300 mL SUS autoclave was charged with 22.5 g (35 mmol / purity equivalent) of the dinitro compound 1 obtained in Example 1, 0.261 g (0.113 g as dry) of 5% Pd / C, and 150 mL of THF and sealed. The atmosphere was repeatedly purged with nitrogen and hydrogen four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 50 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. While maintaining the internal temperature at 60-65 °C, the theoretical amount of hydrogen was absorbed over 38 minutes, and the autoclave was further aged for 10 minutes to confirm that the internal pressure did not decrease. After purging with nitrogen, the autoclave was opened, and the spent catalyst was filtered while hot. The solvent was removed from the hydrogenation mother liquor using an evaporator, and the resulting white solid was dissolved in 150 mL of isopropanol with heating. 0.4 g of activated carbon was added, and the mixture was stirred under reflux for 30 minutes. The activated carbon was filtered off, and 90 mL of ion-exchanged water was added. The resulting precipitate was heated to dissolve, slowly cooled to 5°C, filtered, and dried to obtain 18.5 g of pale yellow needles (yield 92%), with an mp of 159.6-160.5°C and an HPLC purity of 99.6%. 1 H-NMR and 13 The structure was analyzed by C-NMR. The results are shown in Figures 1 to 4. The product was 2,2'-bis[4-(3-aminobenzoyloxy)phenyl]hexafluoropropane represented by the above formula (b). TOF-MS (ESI): 575.1414 (M+H) +

[0036] [Example 3] Synthesis of bis[4-(3-nitrobenzoyloxy)phenyl]sulfone [ka] A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 12.8 g (51 mmol) of bisphenol S, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine and heated to 50 °C (white slurry). Upon addition of 25.0 g (158 mmol) of MNBC (m-nitrobenzoic acid chloride), the internal temperature immediately rose from 50 to 70 °C and then cooled shortly thereafter. The mixture was stirred for 1 hour while maintaining the temperature at 60 °C. The white precipitate was collected by filtration at 50 °C, and the cake was washed with methanol. The product was air-dried to obtain 27.3 g of a white powder (yield: 95%), with an MP of 252-253 °C and an HPLC purity of 98%. This product was bis[4-(3-nitrobenzoyloxy)phenyl]sulfone (hereinafter referred to as dinitro product 2) represented by the above formula (c).

[0037] [Example 4] Synthesis of bis[4-(3-aminobenzoyloxy)phenyl]sulfone [ka] A 300 mL SUS autoclave was charged with 22.5 g (35 mmol / purity equivalent) of the dinitro compound 2 obtained in Example 3, 0.261 g (0.113 g as dry) of 5% Pd / C, and 150 mL of THF and sealed. The atmosphere was repeatedly purged with nitrogen and hydrogen four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 50 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. The theoretical amount of hydrogen was absorbed over 85 minutes while maintaining the internal temperature at 60-65 °C, and the autoclave was aged for an additional 20 minutes to confirm that the internal pressure did not decrease. After purging with nitrogen, the autoclave was opened. Since the diamine had precipitated, the solvent was removed from the hydrogenated mother liquor using an evaporator and the mixture was dissolved in 350 mL of acetonitrile with heating. 0.4 g of activated carbon was added, and the mixture was stirred under reflux for 30 minutes. The activated carbon was filtered off, and 40 mL of ion-exchanged water was added. The resulting precipitate was dissolved by heating, slowly cooled to 5°C, filtered, and dried to obtain 14.5 g of a pale yellow crystalline powder (yield 74%), with an mp of 235-236°C and an HPLC purity of 94%. 1 H-NMR and 13The structure was analyzed by C-NMR, and the results are shown in Figures 5 to 8. The product was bis[4-(3-aminobenzoyloxy)phenyl]sulfone represented by the above formula (d). TOF-MS(ESI):489.1106(M+H) +

[0038] [Example 5] Synthesis of 1-methyl-2,5-bis(3-nitrobenzoyloxy)benzene [ka] A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 9.3 g (75 mmol) of methylhydroquinone, 200 mL of THF, and 16.0 g (158 mmol) of triethylamine and dissolved at room temperature (a colorless, transparent solution). Upon addition of 25.0 g (158 mmol) of MNBC (m-nitrobenzoic acid chloride), a white precipitate immediately formed. The internal temperature rose from 25 °C to 58 °C and then cooled shortly thereafter. The mixture was stirred at room temperature for 1 hour, and the disappearance of MNBC was confirmed by HPLC. The white precipitate was collected by filtration at room temperature, washed with THF, and then subjected to slurry washing with 400 mL of ion-exchanged water at 60 °C for 30 minutes. The precipitate was filtered at 60 °C, and the cake was washed with methanol. The product was air-dried to give 24.6 g of a white powder (78% yield), with an MP of 198.0-199.2 °C and an HPLC purity of 99.3%. The product was 1-methyl-2,5-bis(3-nitrobenzoyloxy)benzene (hereinafter referred to as dinitro product 3) represented by the above formula (e).

[0039] [Example 6] Synthesis of 1-methyl-2,5-bis(3-aminobenzoyloxy)benzene [ka] A 300 mL SUS autoclave was charged with 22.5 g (35 mmol / purity equivalent) of the dinitro compound 3 obtained in Example 5, 0.261 g (0.113 g as dry) of 5% Pd / C, and 150 mL of THF and sealed. The atmosphere was repeatedly purged with nitrogen and hydrogen four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 50 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. The theoretical amount of hydrogen was absorbed over 30 minutes while maintaining the internal temperature at 60-65 °C, and the autoclave was aged for an additional 10 minutes to confirm that the internal pressure did not decrease. After purging with nitrogen, the autoclave was opened, and the spent catalyst was filtered while hot. The solvent was removed from the hydrogenation mother liquor using an evaporator, and the resulting white solid was dissolved in 500 mL of isopropanol with heating. 0.4 g of activated carbon was added, and the mixture was stirred under reflux for 30 minutes. The activated carbon was filtered off, and 500 mL of ion-exchanged water was added. The resulting precipitate was dissolved by heating, gradually cooled to 5°C, filtered, and dried to obtain 11.7 g of a pale yellow crystalline powder (yield 61%), with an mp of 148-150°C and an HPLC purity of 96%. 1 H-NMR and 13 The structure was analyzed by C-NMR, and the results are shown in Figures 9 to 12. The product was 1-methyl-2,5-bis(3-aminobenzoyloxy)benzene represented by the above formula (f). TOF-MS(ESI):363.1336(M+H) +

[0040] [Example 7] Synthesis of 1,2,4-trimethyl-3,6-bis(3-nitrobenzoyloxy)benzene [ka] A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 11.4 g (75 mmol) of trimethylhydroquinone, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine and dissolved at room temperature (a colorless, clear solution). Upon addition of 25.0 g (158 mmol) of MNBC (m-nitrobenzoic acid chloride), a pale yellow precipitate immediately formed. The internal temperature rose from 18 to 57 °C, and the viscosity also increased. Upon heating to 70 °C, the viscosity gradually decreased. After 2 h, the mixture was cooled to 25 °C, and the white precipitate was collected by filtration. The cake was washed with methanol. The product was air-dried to yield 27.3 g of a white powder (81% yield), with an mp of 226.0-226.8 °C and an HPLC purity of 99.9%. The product was 1,2,4-trimethyl-3,6-bis(3-nitrobenzoyloxy)benzene (hereinafter referred to as dinitro product 4) represented by the above formula (g).

[0041] [Example 8] Synthesis of 1,2,4-trimethyl-3,6-bis(3-aminobenzoyloxy)benzene [ka] A 300 mL SUS autoclave was charged with 22.5 g (35 mmol / purity equivalent) of the dinitro compound 4 obtained in Example 7, 0.261 g (0.113 g as dry) of 5% Pd / C, and 150 mL of THF and sealed. The atmosphere was repeatedly purged with nitrogen and hydrogen four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 50 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. The theoretical amount of hydrogen was absorbed over 50 minutes while maintaining the internal temperature at 60-65 °C. The mixture was then aged for an additional 10 minutes to confirm that the internal pressure was not decreasing. After purging with nitrogen, the autoclave was opened, and the spent catalyst was filtered while hot. The solvent was removed from the hydrogenation mother liquor using an evaporator, and the resulting white solid was dissolved in 500 mL of isopropanol with heating. 0.4 g of activated carbon was added, and the mixture was stirred under reflux for 30 minutes. The activated carbon was filtered off, and 500 mL of ion-exchanged water was added. The resulting precipitate was heated and dissolved, then slowly cooled to 5°C, and the primary crystals were filtered. The filtrate was concentrated to 2 / 3, and the resulting secondary crystals were filtered and combined with the primary crystals and dried. A pale yellow crystalline powder (18.9 g, yield 94%) was obtained, with an mp of 187-189°C and an HPLC purity of 97%. 1 H-NMR and 13 The structure was analyzed by C-NMR, and the results are shown in Figures 13 to 16. The product was 1,2,4-trimethyl-3,6-bis(3-aminobenzoyloxy)benzene represented by the above formula (h). TOF-MS(ESI):391.1643(M+H) +

[0042] [Example 9] [1,4-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene) Synthesis of bis(3-nitrobenzoate) [ka] A 500 mL four-neck flask equipped with a stirrer, thermometer, Dane stack, and Dimroth condenser was charged with 26.0 g (72 mmol) of bis(4-hydroxyphenyl)-1,4-diisopropylbenzene, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine, and stirred at 300 rpm (white slurry). Then, 25.0 g (158 mmol) of m-nitrobenzoyl chloride (MNCB) was added and stirred at 75 °C for 3 hours (the internal temperature rose to 50 °C upon the addition of MNCB). The mixture was cooled to 25°C, and the white precipitate was filtered through a 110mm diameter Kiriyama funnel with No. 5C filter paper. The white precipitate was washed by immersion with 100mL of methanol and 200mL of ion-exchanged water, and then dried under reduced pressure at 90°C and -0.1MPa for 16 hours to obtain 40.6g of the nitro compound as a white powder. The yield was 88%, the LC purity (area%) was 98.8%, and the melting point (visual) was 208-209°C. The product was [1,4-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene)bis(3-nitrobenzoate) (hereafter referred to as dinitro compound 5) as shown in formula (i) above. TOF-MS (ESI): 643.209(MH). -

[0043] [Example 10] [1,4-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene) Synthesis of bis(3-aminobenzoate) [ka] A 300 mL autoclave was charged with 15.0 g (23 mmol) of dinitro 5, 100 mL of DMF, and 1.0 g of Raney Ni and sealed. The autoclave was repeatedly purged with nitrogen and hydrogen four times, and the internal pressure of the autoclave was adjusted to 0.8 MPa. A leak check was performed to confirm no hydrogen leaks. After confirming no hydrogen leaks, the hydrogen inlet valve was closed and the autoclave was sealed. The mixture was heated with a preheated mantle heater while stirring at 200 rpm. When the temperature reached 90 °C, the stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened to initiate the hydrogenation reaction (this point was designated as 0 min after the start of the reaction). The reaction was carried out at 90 ± 1 °C under a constant pressure of 0.80 MPa. The reaction was continued until instantaneous hydrogen absorption ceased as measured by a large flow meter. The hydrogenation time was 50 min. The hydrogen inlet valve was closed and the mixture was stirred for 60 min. After confirming that the internal pressure was not decreasing, the stirring was stopped. The hydrogen inlet valve was evacuated and the autoclave was purged with nitrogen (gauge pressure 0–0.3 MPa) three times. After opening the autoclave, the diamine precipitated. The solvent was removed using an evaporator, 200 mL of acetonitrile was added, and the mixture was heated to dissolve. The catalyst was then filtered. The filtrate was cooled to 5°C (a pale gray-white powder precipitated at approximately 20°C). The powder was filtered through a 110 mm diameter Kiriyama funnel with No. 5C filter paper, immersion washed with 30 mL of methanol and 30 mL of ion-exchanged water, and dried under reduced pressure at 90°C and -0.1 MPa for 16 hours to obtain 7.9 g of a pale gray-white powder with a yield of 97%, LC purity of 98.6%, and a melting point (visual) of 284-285°C. The product was [1,4-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene)bis(3-aminobenzoate), as shown in formula (j) above. TOF-MS(ESI):585.276(M+H) +

[0044] [Example 11] [1,3-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene) Synthesis of bis(3-nitrobenzoate) [ka] A 500 mL four-neck flask equipped with a stirrer, thermometer, Dane stack, and Dimroth condenser was charged with 26.0 g (75 mmol) of bisphenol M, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine and stirred at 300 rpm (colorless, transparent). Then, 25.0 g (158 mmol) of m-nitrobenzoic acid chloride (MNCB) was added and stirred at 60 °C for 2 h (the internal temperature rose to 42 °C upon addition of MNCB). After cooling to 30 °C, the white precipitate was filtered through a 110 mm diameter Kiriyama funnel with No. 5C filter paper, immersion-washed with 100 mL of methanol and 200 mL of ion-exchanged water, and dried at 90 °C and -0.1 MPa for 16 h under reduced pressure to obtain a white powder (yield 82% (weight 18.6 g)), with an LC purity of 99.1% and a melting point (visual) of 160-161 °C. The product was [1,3-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene)bis(3-nitrobenzoate) (hereinafter referred to as dinitro compound 6) represented by the above formula (k). TOF-MS (ESI): 643.209 (MH). -

[0045] [Example 12] [1,3-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene) Synthesis of bis(3-aminobenzoate) [ka] A 300 mL autoclave was charged with 17.0 g (26 mmol) of dinitro compound 6, 120 mL of THF, and 0.1 g (as dry) of 5% Pd / C and sealed. The autoclave was repeatedly purged with nitrogen and hydrogen four times, and the internal pressure of the autoclave was adjusted to 0.8 MPa. A leak check was performed to confirm no hydrogen leaks. After confirming no hydrogen leaks, the hydrogen inlet valve was closed and the autoclave was sealed. The mixture was heated with a preheated mantle heater while stirring at 200 rpm. When the temperature reached 60 °C, the stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened to initiate the hydrogenation reaction (this point was designated as 0 min after the start of the reaction). The reaction was carried out at 65 ± 1 °C under a constant pressure of 0.80 MPa. The reaction was continued until instantaneous hydrogen absorption ceased as measured by a large flow meter. The hydrogenation time was 28 min. The hydrogen inlet valve was closed and the mixture was stirred for 60 min. After confirming that the internal pressure had not dropped, the stirring was stopped. The hydrogen in the autoclave was evacuated and then replaced with nitrogen (gauge pressure: 0-0.3 MPa) three times. The autoclave was opened and the catalyst was filtered. The filtrate was cooled to 5°C, but no crystals precipitated. Therefore, the solvent was removed using an evaporator (to form a paste). 100 mL of methanol was added and heated to dissolve. The mixture was then cooled to 10°C, whereupon a white powder precipitated. The mixture was filtered using a 110 mm diameter Kiriyama funnel with No. 5C filter paper, immersed and washed with 50 mL of methanol and 100 mL of ion-exchanged water, and dried under reduced pressure at 90°C and -0.1 MPa for 16 h. A white powder was obtained in a 98% yield (15.0 g), with a LC purity of 99.5% and a melting point (visual) of 161-162°C. The product was [1,3-phenylenebis(propane-2,2-diyl)]bis(4,1-phenylene)bis(3-aminobenzoate) represented by the above formula (m). TOF-MS (ESI): 585.276 (M+H) +

[0046] [Comparative Example 1] Synthesis of 1,4-bis(4-aminobenzoyloxy)benzene / hydroquinone-type p-diamine [ka] (n) A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 8.3 g (75 mmol) of hydroquinone, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine, and heated to 45°C to dissolve (a clear, reddish-brown solution). 25.0 g (158 mmol) of PNBC (m-nitrobenzoic acid chloride) was added, and a white precipitate immediately formed. The internal temperature rose from 45°C to 68°C and then cooled shortly thereafter (a thin greenish-white slurry). The mixture was stirred at 45°C for 1 hour, and the disappearance of PNBC was confirmed by HPLC. After cooling to room temperature, the white precipitate was collected by filtration, and the cake was washed with methanol. The product was air-dried to obtain 22.4 g of a white powder (73% yield), with an MP of 263-264.5°C and an HPLC purity of 99.6%. This product is the compound represented by formula (n) above (hereinafter referred to as dinitro compound 5). [ka] A 300 mL SUS autoclave was charged with 22.5 g (53 mmol / purity equivalent), 0.130 g (0.056 g as dry) of the dinitro compound (n), and 150 mL of methyl cellosolve (MC) and sealed. The nitrogen and hydrogen purges were repeated four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 70 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. The theoretical amount of hydrogen was absorbed over 42 minutes while maintaining the internal temperature at 85–90 °C. The autoclave was then aged for an additional 20 minutes to confirm that the internal pressure was not decreasing. After nitrogen purge, the autoclave was opened, and 1 L of DMF was added to the white mousse-like slurry and dissolved at reflux temperature. The spent catalyst was filtered off while hot, and the filtrate was slowly cooled. The resulting precipitate was collected by filtration at 5 °C. 200 mL of γ-butyrolactone was added to the cake and heated to 165°C to dissolve. The mixture was gradually cooled to 30°C, and the resulting precipitate was collected by filtration. The cake was washed with methanol and air-dried to obtain 12.6 g of a peach-white powder (yield: 71%), with an MP of >300°C and an HPLC purity of 96%. The product was 1,4-bis(4-aminobenzoyloxy)benzene, as shown in formula (p) above.

[0047] Comparative Example 2 Synthesis of 2,5-bis(4-aminobenzoyloxy)toluene / methylhydroquinone-type p-diamine [ka] (q) A 300 mL four-neck flask equipped with a mechanical stirrer and thermometer was charged with 9.3 g (75 mmol) of methylhydroquinone, 200 mL of acetonitrile, and 16.0 g (158 mmol) of triethylamine and dissolved at room temperature (a pale yellow, transparent solution). 25.0 g (158 mmol) of PNBC (m-nitrobenzoic acid chloride) was added, and a white precipitate immediately formed. The internal temperature rose from 19°C to 39°C and was then heated to 80°C (a white slurry). The mixture was stirred for 1 hour, and the disappearance of PNBC was confirmed by HPLC. After cooling to room temperature, the white precipitate was collected by filtration, and the cake was washed with methanol. The product was air-dried to obtain 24.8 g of a white powder (98% yield), with an MP of 269-270.5°C and an HPLC purity of 98%. This product was the compound represented by formula (q) (hereafter referred to as dinitro compound 6). [ka] A 300 mL SUS autoclave was charged with 10.6 g (25 mmol / purity equivalent), 0.065 g (0.028 g as dry) of the dinitro compound (q), and 180 mL of methyl cellosolve (MC) and sealed. The atmosphere was repeatedly purged with nitrogen and hydrogen four times, and the absence of gas leakage was confirmed with soapy water. The temperature was raised to 70 °C with stirring at 150 rpm under a constant hydrogen pressure of 0.8 MPa. The stirring speed was increased to 1000 rpm, and the hydrogen inlet valve was opened. The theoretical amount of hydrogen was absorbed over 42 minutes while maintaining the internal temperature at 90–95 °C. The autoclave was then aged for an additional 20 minutes to confirm that the internal pressure was not decreasing. After purging with nitrogen, the autoclave was opened, and the spent catalyst was hot filtered. 45 mL of ion-exchanged water was added (white slurry), and the mixture was heated to reflux temperature to dissolve. After cooling to 20°C, the resulting precipitate was filtered and dried to give 7.5g of a pale yellow powder (yield 83%) with an MP of 271.5-273°C and an LC purity of 96%. The product was 2,5-bis(4-aminobenzoyloxy)toluene, as shown in formula (r) above.

[0048] Diamine solubility The melting points and solubilities in various solvents of the diamines obtained in the above Examples and Comparative Examples are shown in Table 1. In Table 1, +++ means soluble at room temperature, ++ means soluble upon heating, + means semi-soluble upon heating, and - means insoluble in the solvent. Among para-type diamines, unsubstituted hydroquinone-type p-diamine (melting point >300°C, Comparative Example 1) was only soluble in DMF (N,N-dimethylformamide) when heated. Methylhydroquinone-type p-diamine (melting point 272-273°C, Comparative Example 2), which has a methyl group on the central benzene ring, was only soluble in highly polar solvents such as MC (methyl cellosolve) and DMSO (dimethyl sulfoxide) when heated. On the other hand, meta-type diamines have relatively low melting points and are highly soluble in various solvents. The bisphenol AF type in particular was easily soluble in various solvents. In this way, the effects of the present invention were confirmed.

[0049] [Table 1]

[0050] [Example 13] Synthesis of polyimide by polymerization of the diamine compound (bisphenol AF type m-diamine, formula (b)) obtained in Example 2 and pyromellitic dianhydride (PMDA) [ka] A 100 mL separable flask equipped with a mechanical stirrer, thermometer, and condenser was charged with 3.78 g (6.58 mmol) of the diamine compound (bisphenol AF m-diamine, formula (b)) obtained in Example 2 and 20 mL of m-cresol, and dissolved at room temperature (golden viscous solution). Under a nitrogen stream, 1.44 g (6.60 mmol) of pyromellitic dianhydride (PMDA) was added, and the mixture was stirred for 2 hours. During this time, as the viscosity increased, the stirring speed was increased from 300 rpm to 400 rpm, and then from 400 rpm to 500 rpm. 0.50 g (3.8 mmol) of isoquinoline was added, and the mixture was stirred for an additional 4 hours. 0.5 g of the polymerization solution was collected and poured into 30 mL of methanol. The resulting white precipitate was filtered and dried, and the formation of polyamic acid was confirmed by FT-IR. The results are shown in Figure 17. To the viscous polymerization solution, 30 mL of m-cresol was added, heated to 190°C, and stirred for 14 hours. After cooling to room temperature, the polymerization solution was poured into 300 mL of methanol. The resulting precipitate was collected by filtration, and the cake was washed with methanol and heated in a vacuum dryer (180°C / 8 hours). 3.8 g of yellow powder was obtained (yield 84%). FT-IR confirmed that polyimide had been synthesized. The results are shown in Figure 18. The obtained polyimide was soluble in N-methylpyrrolidone (NMP) at room temperature.

[0051] [Example 14] The above example 13 The same procedure as in the above example was repeated except that PMDA was replaced with 4,4'-oxydiphthalic anhydride (ODPA). 13 The above procedure was repeated to synthesize polyimide by polymerization of the diamine compound obtained in Example 2 and ODPA. The FT-IR spectrum of the obtained polyimide powder is shown in Figure 19. The obtained polyimide was soluble in NMP at room temperature.

[0052] [Example 15] The above example 13 The same procedure as in the above example was repeated except that PMDA was replaced with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). 13 The above procedure was repeated to synthesize polyimide by polymerization of the diamine compound obtained in Example 2 with 6FDA. The FT-IR spectrum of the obtained polyimide powder is shown in Figure 20. The obtained polyimide was soluble in NMP at room temperature.

[0053] [Example 16] The above example 13 In the above Example, the diamine compound obtained in Example 2 was replaced with the diamine compound obtained in Example 4 (bisphenol S type m-diamine), and PMDA was replaced with 4,4'-oxydiphthalic anhydride (ODPA). 13 The above procedure was repeated to synthesize polyimide by polymerization of the diamine compound obtained in Example 4 and ODPA. The FT-IR spectrum of the obtained polyimide powder is shown in Figure 21. The obtained polyimide was soluble in NMP at room temperature.

[0054] [Example 17] The above example 13 In the above Example, the diamine compound obtained in Example 2 was replaced with the diamine compound obtained in Example 6 (methylhydroquinone type m-diamine), and PMDA was replaced with 4,4'-oxydiphthalic anhydride (ODPA). 13 The above procedure was repeated to synthesize polyimide by polymerization of the diamine compound obtained in Example 6 and ODPA. The FT-IR spectrum of the obtained polyimide powder is shown in Figure 22. The obtained polyimide was soluble in NMP at room temperature.

[0055] [Example 18] The above example 13 In the above Example, the diamine compound obtained in Example 2 was replaced with the diamine compound obtained in Example 8 (trimethylhydroquinone type m-diamine), and PMDA was replaced with 4,4'-oxydiphthalic anhydride (ODPA). 13 The above procedure was repeated to synthesize polyimide by polymerization of the diamine compound obtained in Example 8 and ODPA. The FT-IR spectrum of the obtained polyimide powder is shown in Figure 23. The obtained polyimide was soluble in NMP at room temperature. [Industrial Applicability]

[0056] The meta-ester aromatic diamine of the present invention can be suitably used as a novel polyimide raw material, greatly expanding the possibilities in the field of polyimides derived from said compound, and is expected to be a material having excellent high heat resistance and electrical properties.

Claims

1. A compound represented by the following formula (1): 【Chemical 1】 In formula (1), X is the following (a): 【Chemistry 2】 R in formula (1) １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R in (a) ５ , and R ６ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms.

2. A compound represented by the following formula (1'): 【Chemistry 3】 In formula (1′), X is the following (d): 【Chemistry 4】 (R １ , R ２ , R ３ , R ４ , R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms).

3. A compound represented by the following formula (1): 【Chemistry 5】 In formula (1), X is the following (c): 【Chemistry 6】 In formula (1), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms; in (c) above, R 9 is a hydrogen atom; and R 7 , R 8 , and R 10 are each independently an alkyl group having 1 to 6 carbon atoms.

4. In (a), R ５ and R ６ and each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

5. In (c), R １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R ９ is a hydrogen atom, and R ７ , R ８、 and R １０ The compound according to claim 3, wherein is an alkyl group having 1 to 6 carbon atoms.

6. In (d), R １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ and each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

7. The compound according to claim 2 or 6, wherein in (d), X is any one of the following structures: 【Chemistry 7】 【Chemistry 8】 (R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ is as described above, and the position marked with * in the formula indicates a bond to an oxygen atom).

8. A method for producing a compound represented by the following formula (1): 【Chemistry 9】 In formula (1), X is the following (a): 【Chemistry 10】 (R in formula (1) １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R in (a) ５ , and R ６ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. The following formula (2) 【Chemistry 11】 (In the formula, R １ , R ２ , R ３ , R ４ , and X are as defined above). and reducing two nitro groups of a compound represented by the formula (1) to obtain a compound represented by the formula (1).

9. A method for producing a compound represented by the following formula (1): 【Chemistry 12】 In formula (1), X is the following (c): 【Chemistry 13】 (R 1 , R 2 , R 3 , and R 4 in formula (1) are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms; R 9 in (c) above is a hydrogen atom; and R 7 , R 8 , and R 10 are each independently an alkyl group having 1 to 6 carbon atoms.) The following formula (2) 【Chemistry 14】 (wherein R 1 , R 2 , R 3 , R 4 , and X are as defined above). and reducing two nitro groups of a compound represented by the formula (1) to obtain a compound represented by the formula (1).

10. In (a), R ５ and R ６ and each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

11. In (c), R １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R ９ is a hydrogen atom, and R ７ , R ８、 and R １０ The method according to claim 9, wherein is an alkyl group having 1 to 6 carbon atoms.

12. A method for producing a compound represented by the following formula (1'): 【Chemistry 15】 In formula (1′), X is the following (d): 【Chemistry 16】 (R １ , R ２ , R ３ , R ４ , R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms. The following formula (2) 【Chemistry 17】 (In the formula, R １ , R ２ , R ３ , R ４ , and X are as defined above). The method for producing the compound represented by formula (1') is also characterized by the steps of:

13. R １ , R ２ , R ３ , and R ４ is a hydrogen atom, and R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ and each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

14. The method according to claim 12 or 13, wherein in (d), X is any one of the following structures: 【Chemistry 18】 【Chemistry 19】 (R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ and R ２０ is as described above, and the position marked with * in the formula indicates a bond to an oxygen atom).

15. A polyimide compound which is a reaction product of the compound according to any one of claims 1 to 7 with an acid anhydride.

16. The polyimide compound according to claim 15, wherein the acid anhydride is at least one selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, benzophenone-3,4,3',4'-tetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and oxy-4,4'-diphthalic dianhydride.

17. The polyimide compound according to claim 15 or 16, having a number average molecular weight of 2,000 to 200,000.

18. 18. The polyimide compound according to any one of claims 1 to 7, which is a reaction product of the compound according to any one of claims 1 to 7, an acid anhydride, and a diamine compound other than the compounds according to claims 1 to 7, wherein the ratio of the units derived from the compound according to any one of claims 1 to 7 to the total moles of the units derived from the compound according to any one of claims 1 to 7 and the units derived from the diamine compound other than the compounds according to claims 1 to 7 is 10 mol % to 100 mol %.

19. A molded article made of the polyimide compound according to any one of claims 15 to 18.

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