Fluorine-containing bismaleimide compound as well as preparation method and application thereof, precursor fluorine-containing bismaleimide acid compound as well as preparation method and application thereof

Abstract

The invention relates to a fluorine-containing bismaleimide compound as well as a preparation method and application thereof, a precursor fluorine-containing bismaleimide acid compound as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. The preparation method of the fluorine-containing bismaleimide compound comprises the following steps: adding a fluoroalkyl substituted 4, 4 '-diaminodiphenylmethane compound and a maleic anhydride compound into a ball-milling tank, and carrying out mechanical ball-milling reaction under the action of a trace ionic liquid solvent and a ball-milling medium to obtain the fluorine-containing bismaleimide compound. And after the reaction is finished, sequentially pulping, filtering and drying the ball-milled product by using absolute ethyl alcohol to obtain the fluorine-containing bismaleimide compound. The preparation method has the advantages of mild conditions, simple operation, high reaction efficiency, cheap and easily available raw materials, good atom economy, low cost, safety improvement, facilitation of efficient green industrial production, reduction of three-waste emission, good yield, short reaction time, small environmental pollution and the like, and is suitable for industrial popularization and application.

Description

Technical Field

[0001] This application relates to the field of organic synthesis technology, and in particular to a fluorinated bismaleimide compound, its preparation method, its application, its precursor fluorinated bismaleimide acid compound, its preparation method, and its application. Background Technology

[0002] Bismaleimide (BMI) is an important organic synthesis intermediate. Its molecular structure features rigid benzene and maleimide rings and a high crosslinking density, making it suitable for manufacturing high-performance polymer materials. BMI possesses numerous excellent properties, including high temperature resistance, resistance to damp heat, radiation resistance, wear resistance, high dielectric constant, and high strength, and is widely used in aerospace, military, automotive, railway, and electronics industries. However, it also has drawbacks such as high melting point, poor solubility, high molding temperature, and brittleness of the cured product. Poor toughness is a key factor hindering its further development.

[0003] Introducing fluorine-containing substituents into the molecular structure of bismaleimide can effectively compensate for these deficiencies, reduce optical loss, dielectric constant, and hygroscopicity, while improving solubility and transparency, giving it unique advantages and broad development prospects in optoelectronics, aerospace, and other fields. Currently, the industrial production of bismaleimide mainly includes: (I) Acetic anhydride dehydration method (e.g., US3127414). This method generates a large amount of acidic organic wastewater, which is difficult to treat and greatly increases costs and environmental pressure. (II) Azeotropic distillation method (e.g., *Journal of East China University of Science and Technology (Natural Science Edition)*, 2006, 217-220). This method involves high reaction temperatures and easily produces a brown, resinous viscous substance.

[0004] In summary, the current method for synthesizing fluorinated bismaleimides, fluorinated bismaleamic acids, and their analogues using fluoroalkyl-substituted 4,4'-diaminodiphenylmethane faces numerous challenges, including difficulty in obtaining raw materials, dangerous and cumbersome operation, and high post-processing costs. Therefore, developing a simple, safe, low-cost, and environmentally friendly synthetic method for synthesizing fluorinated bismaleimides, fluorinated bismaleamic acids, and their analogues is of paramount importance. Summary of the Invention

[0005] In view of this, this application provides a fluorinated bismaleimide compound, its preparation method, its application, its precursor fluorinated bismaleimide acid compound, its preparation method and application. The method has readily available raw materials, simple operation, mild reaction conditions, high safety and high reaction yield, good atom economy, and has the prospect of large-scale application. It can effectively overcome the defects of the above-mentioned prior art.

[0006] The first aspect of this application provides a fluorinated bismaleimide compound, the general structural formula of which is shown in Formula [1] or as shown:

[0007]

[0008] In equation [1], n1 and n2 are independently selected from integers between 0 and 4; R 1 Selected from at least one of hydrogen, alkyl, alkoxy, cycloalkyl, aryl, propenyl, halogen, hydroxyl, benzyl, thioalkyl, and ester; R f It is selected from at least one of difluoromethyl, trifluoromethyl, trifluoroethyl, tetrafluoroethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, and bis(trifluoromethyl).

[0009] Preferably, the fluorinated bismaleimide compound is selected from any of the compounds represented by the following formulas [2], [3], [4], and [5]:

[0010] , , , .

[0011] The second aspect of this application also provides a fluorinated bismaleimide precursor fluorinated bismaleimide acid compound, the general structural formula of which is shown in Formula [6]:

[0012]

[0013] In equation [6], n1 and n2 are independently selected from integers between 0 and 4; R 1 Selected from at least one of hydrogen, alkyl, alkoxy, cycloalkyl, aryl, propenyl, halogen, hydroxyl, benzyl, thioalkyl, and ester; R f It is selected from at least one of difluoromethyl, trifluoromethyl, trifluoroethyl, tetrafluoroethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, and bis(trifluoromethyl).

[0014] Preferably, the precursor fluorinated bismaleimide is a fluorinated bismaleimide acid compound selected from any of the compounds represented by the following formulas [7], [8], [9], and

[10] :

[0015] , , , .

[0016] A third aspect of this application also provides a method for preparing the above-mentioned fluorinated bismaleimide compound, comprising the following steps:

[0017] Fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds and maleic anhydride compounds were added to a ball mill jar and mechanically ball-milled under the action of a trace amount of ionic liquid solvent and ball milling media. After the reaction, the ball-milled products were successively slurried with anhydrous ethanol, filtered, and dried to obtain fluorinated bismaleimide compounds.

[0018] Preferably, the molar ratio of the fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compound and the maleic anhydride compound is 1:(1.0-2.0); the trace ionic liquid solvent is the ionic liquid [Bmim] [PF6], and the ratio of the trace ionic liquid solvent to the total amount of the fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compound and the maleic anhydride compound is (0.15-0.5) μL:1 mg; the ball milling media are stainless steel ball milling beads or polytetrafluoroethylene ball milling beads, and the diameter of the ball milling media is selected from at least one of 7 mm, 10 mm, 12 mm, and 14 mm; the mechanical ball milling reaction time is 20-60 min, and the ball milling frequency is 30 Hz.

[0019] The fourth aspect of this application also provides a method for preparing the above-mentioned precursor fluorinated bismaleimide, a fluorinated bismaleimide acid compound, comprising the following steps:

[0020] Fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds and maleic anhydride compounds were added to a ball mill jar and mechanically ball-milled under the action of a trace amount of nonionic liquid reaction solvent and ball milling media. After the reaction, the ball-milled products were successively slurried with anhydrous ethanol, filtered, and dried to obtain fluorinated bismaleimide precursors, fluorinated bismaleimide acid compounds.

[0021] Preferably, the nonionic liquid reaction solvent is selected from at least one of tetrahydrofuran, acetonitrile, and acetone; the milling media is stainless steel milling beads or polytetrafluoroethylene milling beads, and the diameter of the milling media is selected from at least one of 7 mm, 10 mm, 12 mm, and 14 mm; the mechanical milling reaction time is 20 to 60 minutes, and the milling frequency is 30 Hz.

[0022] The fifth aspect of this application also provides the application of the aforementioned fluorinated bismaleimide compounds in the fields of aviation, aerospace, military, automotive, railway and electronics.

[0023] The sixth aspect of this application also provides the application of the aforementioned fluorinated bismaleimide precursor fluorinated bismaleimide acid compounds in the fields of aviation, aerospace, military, automotive, railway and electronics.

[0024] Compared with the prior art, this application has the following advantages:

[0025] This application provides a novel method for synthesizing fluorinated maleimide and its precursor fluorinated maleamide acid compounds. The reaction conditions are mild, the operation is simple, the reaction efficiency is high, the raw materials are inexpensive and readily available, the atom economy is good, the cost is low, and the process safety is improved. This method is conducive to efficient and green industrial production, reduces the emission of waste, and has the advantages of good yield, short reaction time, and less environmental pollution. It is suitable for industrial application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.

[0028] In the following examples, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.

[0029] It should be noted that the fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds are prepared according to the method disclosed in the applicant's publication number CN 119874465 A, entitled "A new method for synthesizing fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds".

[0030] Example 1

[0031]

[0032] Trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), maleic anhydride (0.98 g, 10 mmol), and 0.39 mL of ionic liquid [Bmim][PF6] were added to a 50 mL stainless steel ball milling jar. Two stainless steel ball milling beads with a diameter of 14 mm were then added. The jar was sealed, and the milling frequency was set to 30 Hz for 35 min. The milled product was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 77%.

[0033] 1 H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 8.4 Hz, 4H), 7.38 (d, J = 8.5Hz, 4H), 6.85 (s, 4H), 4.76 (q, J = 9.6 Hz, 1H);19 F NMR (376 MHz, CDCl3) δ -65.76 (d, J = 9.7 Hz, 3F); 13 C NMR (100 MHz, CDCl3) δ 169.2, 134.4, 134.3,131.1, 129.9, 126.0, 125.8 (d, 1 J C-F = 278.9 Hz), 54.7 (q, 2 J C-F = 28.0 Hz);HRMS (ESI) m / z: [MH] - Calculated value C 22 H 12 F3N2O4: 425.0755, Measured value: 425.0749.

[0034] The preparation method of the trifluoromethyl-substituted 4,4'-diaminodiphenylmethane involved is as follows:

[0035] Aniline (7.6 mol, 2 equiv), trifluoroacetaldehyde hydrate (441 g, 3.8 mol), trifluoroethanol (6.4 L), and phenylboronic acid (0.38 mol) were added sequentially to a 50 L reactor. The reaction was carried out at 45 °C, and the reaction was monitored by TLC. The reaction was completed in 36 h. After the reaction was completed, the solvent was recovered by rotary evaporation, and the crude product was recrystallized from toluene to obtain a white powder of trifluoromethyl-substituted 4,4'-diaminodiphenylmethane.

[0036] Example 2

[0037]

[0038] Trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10 mmol), and 0.39 mL of ionic liquid [Bmim][PF6] were added to a 50 mL stainless steel ball milling jar. The jar was sealed, and the milling frequency was set to 30 Hz for 35 min. The milled product was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 63%.

[0039] 1H NMR (400 MHz, CDCl3) δ 7.47 (d, J = 8.4 Hz, 4H), 7.38 (d, J = 8.5Hz, 4H), 6.85 (s, 4H), 4.76 (q, J = 9.6 Hz, 1H); 19 F NMR (376 MHz, CDCl3) δ -65.76 (d, J = 9.7 Hz, 3F); 13 C NMR (100 MHz, CDCl3) δ 169.2, 134.4, 134.3,131.1, 129.9, 126.0, 125.8 (d, 1 J C-F = 278.9 Hz), 54.7 (q, 2 J C-F = 28.0 Hz);HRMS (ESI) m / z: [MH] - Calculated value C 22 H 12 F3N2O4: 425.0755, Measured value: 425.0749.

[0040] Example 3

[0041]

[0042] Trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), phthalic anhydride (1.48 g, 10 mmol), and 0.39 mL of ionic liquid [Bmim][PF6] were added to a 50 mL stainless steel ball milling jar. Two 12 mm diameter stainless steel ball milling beads were then added. The jar was sealed, and the milling frequency was set to 30 Hz for 55 min. The milled product was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 55%.

[0043] Example 4

[0044]

[0045] Trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), 2,3-naphthalenedicarboxylic anhydride (1.98 g, 10 mmol), and 0.53 mL of ionic liquid [Bmim][PF6] were added to a 50 mL stainless steel ball milling jar. The jar was sealed, and the milling frequency was set to 30 Hz for 45 min. The milled product was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 56%.

[0046] Example 5

[0047]

[0048] In a 50 mL stainless steel ball mill jar, trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), maleic anhydride (0.98 g, 10 mmol), 0.4 mL tetrahydrofuran, and 12 mm × 2 stainless steel ball milling beads were added sequentially. The ball mill jar was sealed, and the ball milling frequency was set to 30 Hz for 25 min. The product after ball milling was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 90%.

[0049] 1 H NMR (400 MHz, DMSO) δ 10.45 (s, 2H), 7.62 (d, J = 8.6 Hz, 4H), 7.40 (d, J = 8.3 Hz, 4H), 6.46 (d, J = 12.1 Hz, 2H), 6.30 (d, J = 12.0 Hz, 2H), 5.15 (q, J = 10.4 Hz, 1H); 19 F NMR (376 MHz, DMSO) δ -65.09 (d, J = 10.6Hz, 3F); 13 C NMR (100 MHz, DMSO) δ 166.9, 163.3, 138.2, 131.6, 130.7, 130.4,129.4, 126.53 (d, J=280.2 Hz), 119.7, 52.2 (q, J=26.9 Hz); HRMS (ESI) m / z: [MH] - Calculated value C 22 H 17 F3N2O6: 461.0966, Measured value: 461.0964.

[0050] Example 6

[0051]

[0052] In a 50 mL stainless steel ball mill jar, trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10 mmol), 0.4 mL tetrahydrofuran, and 14 mm × 2 stainless steel ball milling beads were added sequentially. The ball mill jar was sealed, and the ball milling frequency was set to 30 Hz for 35 min. The product after ball milling was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 89%.

[0053] Example 7

[0054]

[0055] In a 50 mL stainless steel ball mill jar, trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), phthalic anhydride (1.48 g, 10 mmol), 0.4 mL tetrahydrofuran, and 14 mm × 2 stainless steel grinding beads were added sequentially. The ball mill jar was sealed, and the ball milling frequency was set to 30 Hz for 40 min. The product after ball milling was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 87%.

[0056] Example 8

[0057]

[0058] In a 50 mL stainless steel ball mill jar, trifluoromethyl-substituted 4,4'-diaminodiphenylmethane (5 mmol, 1 equiv), 2,3-naphthalenedicarboxylic anhydride (1.98 g, 10 mmol), 0.42 mL tetrahydrofuran, and 14 mm × 2 stainless steel grinding beads were added sequentially. The ball mill jar was sealed, and the ball milling frequency was set to 30 Hz for 50 min. The product after ball milling was then slurried with 15 mL of anhydrous ethanol, filtered, and dried to obtain the product shown in the above formula, with a yield of 89%.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A fluorinated bismaleimide compound, characterized in that, The general structural formula of the fluorinated bismaleimide compounds is as shown in formula [1] or as illustrated below: ； In equation [1], n1 and n2 are independently selected from integers between 0 and 4; R 1 Selected from at least one of hydrogen, alkyl, alkoxy, cycloalkyl, aryl, propenyl, halogen, hydroxyl, benzyl, thioalkyl, and ester; R f It is selected from at least one of difluoromethyl, trifluoromethyl, trifluoroethyl, tetrafluoroethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, and bis(trifluoromethyl).

2. The fluorinated bismaleimide compound according to claim 1, characterized in that, The fluorinated bismaleimide compounds are selected from any of the compounds represented by the following formulas [2], [3], [4], and [5]: 、 、 、 。 3. A fluorinated bismaleimide precursor compound, characterized in that, The general structural formula of the precursor fluorinated bismaleimide, the fluorinated bismaleimide acid compound, is shown in formula [6]: ； In equation [6], n1 and n2 are independently selected from integers between 0 and 4; R 1 Selected from at least one of hydrogen, alkyl, alkoxy, cycloalkyl, aryl, propenyl, halogen, hydroxyl, benzyl, thioalkyl, and ester; R f It is selected from at least one of difluoromethyl, trifluoromethyl, trifluoroethyl, tetrafluoroethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, and bis(trifluoromethyl).

4. The fluorinated bismaleimide precursor fluorinated bismaleimide acid compound according to claim 3, characterized in that, The precursor fluorinated bismaleimide is a fluorinated bismaleimide acid compound selected from any of the compounds represented by the following formulas [7], [8], [9], and [10]: 、 、 、 。 5. A method for preparing a fluorinated bismaleimide compound as described in claim 1 or 2, characterized in that, Includes the following steps: Fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds and maleic anhydride compounds were added to a ball mill jar and mechanically ball-milled under the action of a trace amount of ionic liquid solvent and ball milling media. After the reaction, the ball-milled products were successively slurried with anhydrous ethanol, filtered, and dried to obtain fluorinated bismaleimide compounds.

6. The method for preparing fluorinated bismaleimide compounds according to claim 5, characterized in that, The molar ratio of the fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compound and the maleic anhydride compound is 1:(1.0-2.0); the trace ionic liquid solvent is the ionic liquid [Bmim] [PF6], and the ratio of the trace ionic liquid solvent to the total amount of the fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compound and the maleic anhydride compound is (0.15-0.5) μL:1 mg; the ball milling media are stainless steel grinding beads or polytetrafluoroethylene grinding beads, and the diameter of the ball milling media is selected from at least one of 7 mm, 10 mm, 12 mm, and 14 mm; the mechanical ball milling reaction time is 20-60 min, and the ball milling frequency is 30 Hz.

7. A method for preparing a fluorinated bismaleimide precursor compound as described in claim 3 or 4, characterized in that, Includes the following steps: Fluoroalkyl-substituted 4,4'-diaminodiphenylmethane compounds and maleic anhydride compounds were added to a ball mill jar and mechanically ball-milled under the action of a trace amount of nonionic liquid reaction solvent and ball milling media. After the reaction, the ball-milled products were successively slurried with anhydrous ethanol, filtered, and dried to obtain fluorinated bismaleimide precursors, fluorinated bismaleimide acid compounds.

8. The method for preparing the precursor fluorinated bismaleimide acid compound according to claim 7, characterized in that, The nonionic liquid reaction solvent is selected from at least one of tetrahydrofuran, acetonitrile, and acetone; the ball milling media are stainless steel ball milling beads or polytetrafluoroethylene ball milling beads, and the diameter of the ball milling media is selected from at least one of 7 mm, 10 mm, 12 mm, and 14 mm; the mechanical ball milling reaction time is 20 to 60 min, and the ball milling frequency is 30 Hz.

9. The use of the fluorinated bismaleimide compounds according to claim 1 or 2 in the fields of aviation, aerospace, military, automotive, railway and electronics.

10. The application of the fluorinated bismaleimide precursor fluorinated bismaleimide acid compound as described in claim 3 or 4 in the fields of aviation, aerospace, military, automotive, railway and electronics.

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