Preparation method of diamine monomer containing acridone unit
Through the novel substitution reaction, condensation reaction and catalytic reduction reaction, methanol solvent and polybasic acid are used as catalysts and solvents, the preparation process of acridone unit diamine monomer is simplified, and the complex process and high cost in the existing technology are solved. Problem, an efficient and low-cost preparation method is realized.
Patent Information
- Application Number
- CN202411524489.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-07
AI Technical Summary
In the prior art, the process of preparing acridone unit diamine monomers is complex and has high cost, and it is difficult to effectively reduce the preparation cost of diamine monomers.
A new method is used to prepare acridone-containing diamine monomers through substitution reactions, condensation reactions and catalytic reduction reactions. Using methanol solvents and polybasic acids as catalysts and solvents, simplifying the preparation process and reducing the use of catalysts and solvents.
The preparation process is simplified, the cost is reduced, the yield and reaction efficiency are improved, and the performance of diamine monomers is improved, making it suitable for industrial production.
Smart Images
Figure CN119390650A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of organic synthesis, and in particular to a method for preparing a diamine monomer containing an acridone unit. Background Art
[0002] Among industrial engineering plastics, polyimide (PI) has good mechanical properties, high and low temperature resistance, dielectric properties and structural designability, and has made great progress in the fields of organic electrical storage, nonlinear optical materials, and liquid crystal display alignment film materials. However, with the development of flexible electronics and display fields, the demand for PI materials is increasing, which has led to a sharp increase in the price of diamine raw materials required for the preparation of PI materials. In order to find better diamine monomer raw materials, researchers are committed to developing new diamine monomers and optimizing the preparation cost of known diamine monomers. For example, some scholars introduce rigid structures containing cross-linkable groups into diamine monomers, which can improve the rigidity of the main chain of the subsequently synthesized polyimide molecule, thereby improving its mechanical properties and thermal stability. In addition, optimizing the use of solvents and catalysts in the preparation of diamine monomers and making post-processing simple to operate is also one of the effective ways to reduce the market price of diamines. As we all know, acridone-unit diamine monomers are a typical rigid aromatic heterocyclic structure monomer. This organic compound and its derivatives have been extensively studied in antioxidant, antibacterial, anticancer, sunscreen, thermally activated delayed fluorescence and other materials. However, the preparation process of acridone-unit diamine monomers is relatively complicated and costly, and it is not realistic to introduce them into the PI molecular chain to improve the thermal properties of the polymer.
[0003] Therefore, it is particularly important to develop a method for preparing a diamine monomer containing an acridone unit with a simple synthesis method, low production cost, high reaction efficiency and yield. Summary of the invention
[0004] In view of this, the object of the present invention is to provide a method for preparing a diamine monomer containing an acridone unit, so as to solve the problems that the diamine monomer process for preparing an acridone unit in the prior art is relatively complicated and the cost is high. The diamine monomer containing an acridone unit prepared by the present invention adopts a novel method, and the introduction of the acridone ring makes the diamine monomer present a coplanar structure. The existence of the coplanar structure is not conducive to the twisting of the monomer side group. At the same time, the carbonyl group is also accompanied by the introduction of the acridone ring to promote the monomer to have a strong electrophilicity, which can bring more excellent performance to the diamine monomer. The preparation process of the diamine monomer provided by the present invention is relatively simple, the raw materials are easy to obtain, the post-processing operation is simple, and it is easy to industrialize, which greatly simplifies the preparation process of the acridone diamine monomer. The first step of the novel preparation method only needs to regulate the solvent and temperature used, successfully synthesize and improve the yield of the acridone ring precursor, and reduce the use of catalysts and solvents. The acridone precursor forms an acridone ring through a condensation reaction, and only one polyacid is used, which plays the role of both solvent and catalyst, greatly improving the complexity of the preparation process. The invention of this new preparation method successfully reduces the preparation cost of diamine monomers containing acridone units and introduces it into the PI molecular chain to improve the high temperature resistance and mechanical properties of new polymer materials, bringing new hope.
[0005] To achieve the above object, the present invention provides a method for preparing a diamine monomer containing an acridone unit, which comprises the following steps:
[0006] (1) 2-Fluoro-5-nitrobenzoic acid and a diamine monomer (p-phenylenediamine or m-phenylenediamine) undergo a substitution reaction in the presence of a methanol reagent to obtain intermediate compounds A having structures represented by formula (1a) and formula (1b), respectively.
[0007] The structural formula of 2-fluoro-5-nitrobenzoic acid, p-phenylenediamine, m-phenylenediamine and the intermediate compound A is as follows:
[0008]
[0009] (2) The intermediate compound A having the structure represented by formula (1a) and formula (1b) is subjected to condensation reaction in the presence of an acidic reagent to obtain the intermediate compound B having the structure represented by formula (2a) and formula (2b), respectively.
[0010] The structural formula of intermediate compound B is as follows:
[0011]
[0012] (3) subjecting the intermediate compound B having the structure represented by formula (2a) and formula (2b) to a catalytic reduction reaction in the presence of a catalyst to obtain acridone unit-containing diamine monomers having the structure represented by formula (3a) and formula (3b), respectively, wherein the catalyst is one or more of palladium carbon, activated nickel, and rhodium carbon.
[0013] The synthetic route of the novel preparation method of the present invention for preparing diamine monomer containing acridone unit is as follows:
[0014]
[0015] In the substitution reaction, methanol solvent is used, which plays a role of both solvent and catalyst, reduces the generation of residue, and improves the production efficiency and final yield of this step. The temperature of the substitution reaction is 40-60°C, more preferably 50-55°C, and the reaction time is 18-24h, more preferably 20h.
[0016] In the substitution reaction, the molar ratio of 2-fluoro-5-nitrobenzoic acid to the diamine monomer is preferably 1:1 to 1.4, more preferably 1:1.2.
[0017] As a further preferred technical solution of the present invention, after the substitution reaction is completed, the obtained product liquid is preferably subjected to post-treatment, and the post-treatment preferably includes the following steps:
[0018] The product liquid obtained by the substitution reaction is cooled and then vacuum filtered to obtain a crude product; the crude product is recrystallized with ethanol, and then solid-liquid separation and vacuum drying are performed in sequence to obtain an intermediate compound A.
[0019] In the condensation reaction, the acidic reagent is one or more of polyphosphoric acid, acetic acid, hydrochloric acid, and sulfuric acid. Further preferably, due to the different properties of the intermediate compound A of formula (1a) and formula (1b), polyphosphoric acid and concentrated sulfuric acid are selected respectively, which can reduce the risk factor of the test and also play a certain catalytic effect, avoiding the formation of by-products caused by different acidity and affecting the final yield. The dosage ratio of the intermediate compound A of formula (1a) to polyphosphoric acid is preferably 1g:10-15g, and the dosage ratio of the intermediate compound A of formula (1b) to polyphosphoric acid is preferably 1g:5-15ml, and more preferably 1g:10g and 1g:7ml, respectively.
[0020] The temperature of the condensation reaction is preferably 100 to 150° C., more preferably 100 to 120° C., and the completion of the reaction is preferably detected using TLC.
[0021] In the condensation reaction, the acidic reagent is first heated and melted, and when the temperature rises to the reaction temperature, the intermediate compound A is added thereto for reaction.
[0022] As a further preferred technical solution of the present invention, after the condensation reaction is completed, the obtained product liquid is preferably subjected to post-treatment, and the post-treatment preferably includes the following steps:
[0023] The product liquid obtained from the condensation reaction is poured into ice water while hot to cool, stirred overnight, and then slowly added with ammonia water to adjust the pH value to 7, fully stirred and vacuum filtered to obtain a crude product; the crude product is recrystallized with ammonia water, and then solid-liquid separation and vacuum drying are carried out in sequence to obtain intermediate compound B.
[0024] In the catalytic reduction reaction, the mass ratio of the catalyst to the intermediate compound B is preferably 0.05 to 0.15:1, more preferably 0.1:1.
[0025] In the catalytic reduction reaction, the solvent for the catalytic reduction reaction includes one or more of tetrahydrofuran, ethanol, methanol, isopropanol, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 1,4-dioxane and xylene. The present invention has no special requirements for the amount of the solvent, as long as the catalytic reduction can be carried out smoothly. The catalytic reduction reaction temperature is preferably 40 to 110°C, more preferably 40 to 100°C, and the reaction time is preferably 4 to 8h, more preferably 5 to 6h. In a specific embodiment of the present invention, it is preferred to use TLC to detect the end of the reaction.
[0026] In the catalytic reduction reaction, it is further preferred to use Pd / C reagent for catalytic reduction, avoiding the use of dangerous reagents such as hydrochloric acid. The solvent is ethanol, which makes the post-treatment simpler, easy to crystallize and purify, and improves performance.
[0027] As a further preferred technical solution of the present invention, after the catalytic reduction reaction is completed, the present invention preferably performs post-treatment on the obtained product liquid, and the post-treatment preferably comprises the following steps:
[0028] The feed liquid obtained by the catalytic reduction reaction is filtered while hot and the catalyst is removed. The obtained solution is suspended and evaporated and water is added to precipitate solids. The precipitate is poured into a small amount of DMF to dissolve and filter. The filtered solution is suspended and evaporated and water is added again to precipitate a large amount of solids (the filter residue is repeated at least three times). The solution is vacuum filtered and dried to obtain a diamine monomer containing an acridone unit.
[0029] The invention adopts a novel method to prepare a diamine monomer containing an acridone unit. The introduction of an acridone ring enables the diamine monomer to present a coplanar structure. The existence of the coplanar structure is not conducive to the twisting of the side group of the monomer. At the same time, the introduction of the carbonyl group along with the acridone ring enables the monomer to have a stronger electrophilicity, which can bring more excellent performance to the diamine monomer.
[0030] The diamine monomer preparation process provided by the present invention is relatively simple, the raw materials are easy to obtain, the post-processing operation is simple, and it is easy to industrialize, which greatly simplifies the preparation process of the acridone diamine monomer.
[0031] In the preparation method of the present invention, the first step only requires regulating the solvent and temperature used, successfully synthesizing and improving the yield of the acridone ring precursor, and reducing the use of catalysts and solvents; the acridone precursor forms the acridone ring through a condensation reaction, and only one polyacid is used, which plays the role of both solvent and catalyst, greatly improving the complexity of the preparation process.
[0032] This preparation method successfully reduces the preparation cost of diamine monomers containing acridone units and brings new hope for improving the high temperature resistance and mechanical properties of new polymer materials by introducing them into the PI molecular chain.
[0033] The novel preparation method of the diamine monomer containing acridone units provided by the present invention has the following advantages compared with the traditional preparation method:
[0034] 1) The raw materials used are more environmentally friendly, reducing the discharge of organic wastewater, waste gas and waste residue, and reducing major pollution to the environment;
[0035] 2) Reduce energy consumption at the source, and minimize reaction temperature, pressure, solvents, catalysts and other reaction agents as much as possible, which fully meets the requirements of sustainable development;
[0036] 3) Improve the reaction efficiency and yield. The methanol solvent used accelerates the reaction process to a certain extent. Ammonia water is used in the post-treatment to control the pH value, which greatly improves the avoidance of side reactions and the improvement of purity.
[0037] In summary, the preparation method provided by the present invention uses 2-fluoro-5-nitrobenzoic acid and a diamine monomer (p-phenylenediamine or m-phenylenediamine) as starting materials, and the final product, acridone unit-containing diamine monomer, can be obtained through substitution reaction, condensation reaction and catalytic hydrogenation reaction. The preparation method provided by the present invention has cheap and readily available raw materials, high process safety, simple operation, low production cost, high reaction yield, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0039] Figure 1 This is the H NMR spectrum of 2,7-diaminoacridine-9-one prepared in Example 1.
[0040] Figure 2 This is the H NMR spectrum of 2,6-diaminoacridine-9-one prepared in Example 2.
[0041] Figure 3 This is the infrared hydrogen spectrum of 2,7-diaminoacridine-9-one prepared in Example 1.
[0042] Figure 4This is the infrared hydrogen spectrum of 2,6-diaminoacridine-9-one prepared in Example 2.
[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION
[0044] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.
[0045] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.
[0046] Example 1
[0047] The Chinese name of the diamine monomer containing acridone units in this embodiment is 2,7-diaminoacridine-9-one, and the structural formula is as follows:
[0048]
[0049] The preparation method of the above 2,7-diaminoacridine-9-one is as follows:
[0050] (1) Add 5.00 g of 2-fluoro-5-nitrobenzoic acid and 50 ml of methanol reagent to a three-necked flask, raise the temperature to 55° C., slowly add 8.40 g of p-phenylenediamine raw material, start stirring and react for 20 hours, TLC confirms that the reaction is complete, vacuum filter while hot, add a certain amount of ethanol and stir thoroughly, vacuum filter and dry to obtain a yellow solid 2-((4-aminophenyl)amino)-5-nitrobenzoic acid, yield: 85.20%;
[0051] (2) Before the reaction, heat the polyphosphoric acid with hot water to melt it, take out 100.00g of polyphosphoric acid and 10.00g of 2-((4-aminophenyl)amino)-5-nitrobenzoic acid and put them into a 250ml three-necked flask with a mechanical stirrer. When the temperature reaches 120°C and the polyphosphoric acid becomes a flowing liquid, start stirring and react for 18 hours. TLC confirms that the reaction is over. Pour 400ml of ice water into the reaction system, cool for 12h, and then add ammonia water to adjust the pH value to 7. A large amount of precipitate appears and is filtered. Then, the obtained solid is washed with ammonia water, vacuum filtered and dried to finally obtain black solid 2-amino-7-nitroacridine-9-one with a yield of 80.33%.
[0052] (3) 11.12 g of 2-amino-7-nitroacridine-9-one, 1.67 g of Pd / C, and 133.44 ml of anhydrous ethanol were added to a 250 mL flask equipped with a reflux condenser. When the temperature reached 80 °C, 17.85 g of N2H4·H2O was slowly dripped for 40 minutes, and then the mixture was refluxed for 2.5 hours. The progress of the reaction was observed by TLC. When the reaction was complete, the mixture was filtered while hot and Pd / C was removed. The resulting solution was suspended and evaporated and water was added to precipitate solids. The precipitate was poured into a small amount of DMF to dissolve and filter. The filtered solution was suspended and evaporated and water was added again. A large amount of solids precipitated (the filter residue was repeated three times). The solution was vacuum filtered and dried to obtain a yellow-brown solid 2,7-diaminoacridine-9-one with a yield of 83.25%. The structure of the product was confirmed by NMR and IR spectroscopy. The NMR hydrogen spectrum was as follows: Figure 1 As shown, the infrared spectrum is Figure 3 shown.
[0053] Example 2
[0054] The Chinese name of the diamine monomer containing acridone units in this embodiment is 2,6-diaminoacridine-9-one, and the structure is as follows:
[0055]
[0056] The preparation method of the above 2,6-diaminoacridine-9-one is as follows:
[0057] (1) Add 5.00 g of 2-fluoro-5-nitrobenzoic acid and 50 ml of methanol reagent into a three-necked flask, raise the temperature to 55°C, slowly add 8.40 g of m-phenylenediamine raw material, start stirring and react for 15 hours, TLC confirms that the reaction is complete, vacuum filter while hot, add a certain amount of ethanol and stir thoroughly, vacuum filter and dry to obtain orange solid 2-((3-aminophenyl)amino)-5-nitrobenzoic acid, yield: 88.08%.
[0058] (2) 20.00 g of 2-((3-aminophenyl)amino)-5-nitrobenzoic acid and 140 ml of concentrated sulfuric acid were placed in a 250 mL three-necked round-bottom flask with a magnetic stirrer, stirred and reacted at 100° C. for 3 h. Finally, the mixture was poured into 250 ml of ice water, and ammonia water was added to adjust the pH value to 7. A large number of particles appeared on the surface of the liquid. After vacuum filtration, the filter residue was washed, filtered, and dried with ammonia water and deionized water in turn, and finally a black solid 2-amino-6-nitroacridine-9-one was obtained, with a yield of 82.53%.
[0059] (3) 11.12 g of 2-amino-6-nitroacridine-9-one, 1.67 g of Pd / C, and 133.44 ml of anhydrous ethanol were added to a 250 mL flask equipped with a reflux condenser. When the temperature reached 80 °C, 17.85 g of N2H4·H2O was slowly dripped for 40 minutes, and then the mixture was refluxed for 2.5 hours. The progress of the reaction was observed by TLC. When the reaction was complete, the mixture was filtered while hot and Pd / C was removed. The resulting solution was suspended and evaporated and water was added to precipitate solids. The precipitate was poured into a small amount of DMF to dissolve and filtered. The filtered solution was suspended and evaporated and water was added again. A large amount of solids precipitated (the filter residue was repeated three times). The mixture was vacuum filtered and dried to obtain a dark black solid 2,6-diaminoacridine-9-one with a yield of 83.33%. The structure of the product was confirmed by NMR and IR spectra. The NMR hydrogen spectrum was as follows: Figure 2 As shown, the infrared spectrum is Figure 4 shown.
[0060] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.
Claims
1. A method for preparing a diamine monomer containing an acridone unit, characterized in that: The following steps are involved: S1. Substitution reaction of 2-fluoro-5-nitrobenzoic acid and diamine monomer in the presence of methanol reagent to obtain intermediate compound A, wherein: When the diamine monomer is p-phenylenediamine, the structure of the intermediate compound A is as shown in formula (1a); When the diamine monomer is m-phenylenediamine, the structure of the intermediate compound A is as shown in formula (1b); S2, subjecting the intermediate compound A to a condensation reaction in the presence of an acidic reagent to obtain an intermediate compound B, wherein: When the intermediate compound A is of formula (1a), the structure of the intermediate compound B obtained is as shown in formula (2a); When the intermediate compound A is of formula (1b), the structure of the intermediate compound B is as shown in formula (2b); S3, subjecting the intermediate compound B to a catalytic reduction reaction under the action of a catalyst, and finally obtaining a diamine monomer containing an acridone unit, wherein: The catalyst is one or more of palladium carbon, activated nickel, and rhodium carbon; When the intermediate compound B is of formula (1a), the structure of the obtained acridone unit-containing diamine monomer is as shown in formula (3a); When the intermediate compound B is of the structure of formula (1b), the structure of the obtained acridone unit-containing diamine monomer is as shown in formula (3b); 2. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: In the substitution reaction, the molar ratio of 2-fluoro-5-nitrobenzoic acid to the diamine monomer is 1:1 to 1.
4.
3. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The temperature of the substitution reaction is 40-60° C., and the reaction time is 18-24 hours.
4. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The acidic reagent is one or more of polyphosphoric acid, acetic acid, hydrochloric acid and sulfuric acid.
5. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: When the intermediate compound A is of the structure of formula (1a), the acidic reagent is polyphosphoric acid; when the intermediate compound A is of the structure of formula (1b), the acidic reagent is concentrated sulfuric acid.
6. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The temperature of the condensation reaction is 100-120° C., and the reaction time is 15-20 hours.
7. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The solvent used in the catalytic reduction reaction is one or more of tetrahydrofuran, ethanol, methanol, isopropanol, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 1,4-dioxane, ethyl acetate and benzene.
8. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The catalytic reduction reaction temperature is 40-100° C., and the reaction time is 5-6 hours.
9. The method for preparing acridone unit-containing diamine monomer according to claim 1, characterized in that: The mass ratio of the catalyst to the intermediate compound B is 0.05-0.15:1.