Di(propyl-2-enyl)furan-2,5-dicarboxylate and a method for its preparation

Abstract

The application discloses a kind of di (propyl-2-alkenyl) furan-2, 5-dicarboxylic acid ester and preparation method thereof, it is related to biomass-based organic synthesis method technical field.The method with 2, 5-furan dicarboxylic acid as base material, by esterification reaction under the action of inorganic metal catalyst, will be grafted in 2, 5-furan dicarboxylic acid on allyl, obtains di (propyl-2-alkenyl) furan-2, 5-dicarboxylic acid ester.Compared with traditional synthesis method, the required reaction condition is relatively mild, without high temperature and high pressure environment, not only reduce energy consumption, also reduce operating risk and equipment cost.Mild reaction condition is also more conducive to keeping the activity and selectivity of catalyst, improves reaction efficiency.The obtained product is high in purity, without complex post-processing step can be directly used in subsequent application or further chemical conversion, improves overall production efficiency.The application provides a new idea for 2, 5-furan dicarboxylic acid and other biomass materials to realize high value-added utilization.

Description

Technical Field

[0001] This invention belongs to the technical field of biomass-based organic synthesis methods, specifically relating to a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester and its preparation method. Background Technology

[0002] To protect the natural environment and promote sustainable economic development, developing renewable resources to replace traditional fossil fuels is becoming increasingly important. Biomass resources are a special type of renewable resource, generated by green plants through photosynthesis, converting solar energy into chemical energy and storing it in biomass. Biomass resources are widely distributed, abundant, and renewable, and are considered carbon-neutral resources. The carbon dioxide produced during the consumption of biomass resources is fixed back into the biomass through plant photosynthesis, achieving zero carbon dioxide emissions and reducing air pollution. Therefore, it is essential to find natural, renewable, biodegradable, and pollution-free biomass materials to replace traditional fossil fuels. The twelve high-value bio-based platform compounds derived from carbohydrates through biological or chemical conversion include: 1,4-dicarboxylic acid, 2,5-furandicarboxylic acid, 3-hydroxypropionic acid, aspartic acid, gluconic acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol. Among these, 2,5-furandicarboxylic acid is a high-value biochemical substance and the only aromatic bio-based platform compound. In recent years, it has been used as a substitute for terephthalic acid, a petrochemical derivative, to synthesize high-value polymers, and has great market potential.

[0003] Di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, as a biomass-based compound, can be used to synthesize polyesters. As a polyester monomer, the presence of furanyldicarboxylic acid in the aromatic ring of the di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester structure can improve the polymer's mechanical properties, melting point, and creep resistance. Polyesters synthesized from di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester possess unique chemical structures and excellent mechanical properties, and are non-toxic and harmless, perfectly meeting the requirements of "green chemistry." Existing processes for synthesizing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, such as patent CN113185694 A, involve long reaction times, high reaction temperatures, and the use of large amounts of organic reagents, resulting in high production costs and environmental unfriendliness.

[0004] To address the problems of high preparation cost, long reaction time, and environmental pollution caused by toxic and harmful reagents in the existing synthesis process of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, there is an urgent need to find a new method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester to reduce the reaction conditions, simplify the preparation process, and lower the preparation cost. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester and its preparation method, so as to solve the problems of high cost, long reaction time and environmental pollution caused by toxic and harmful reagents in traditional methods.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, comprising:

[0008] First, under an inert atmosphere, the hydroxide, 2,5-furandicarboxylic acid, and solvent were mixed and reacted once with stirring. After cooling, the catalyst was added and stirred until homogeneous. Then, the allyl compound was slowly added and reacted twice with stirring. After cooling to room temperature, the mixture was filtered to obtain a white solid suspended in the upper layer of the reaction solution. Finally, after washing, rotary evaporation, recrystallization, filtration, and vacuum drying, di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester was obtained.

[0009] Preferably, the mass ratio of hydroxide, 2,5-furandicarboxylic acid, solvent, catalyst and allyl compound is (5~10):(10~20):(50~100):(0.4~0.8):(10~30).

[0010] More preferably, the mass ratio of solvent to hydroxide is 20:(1~2); the mass ratio of 2,5-furandicarboxylic acid to hydroxide is 2:(1~1.5); the mass ratio of catalyst to 2,5-furandicarboxylic acid is 1:(12.5~25); and the mass ratio of allyl compound to 2,5-furandicarboxylic acid is (1.2~2.4):1.

[0011] Preferably, the inert atmosphere is N2; the temperature of the first stirring reaction is 60~80℃, and the time of the first stirring reaction is 3~6h; after cooling to 40~70℃, the catalyst is added.

[0012] Preferably, the conditions for the secondary stirring reaction are: stirring reaction for 3 to 6 hours under reflux condensation conditions.

[0013] Preferably, the hydroxide is sodium hydroxide or potassium hydroxide; the solvent is at least one of water, methanol, ethanol and N,N-dimethylformamide; and the catalyst is at least one of ferric chloride, ferrous chloride, aluminum chloride, cupric chloride, cuprous chloride, potassium chloride and cuprous bromide.

[0014] Preferably, the allyl compound is at least one of allyl chloride and allyl bromide.

[0015] Preferably, the allyl compound is slowly added dropwise over a period of 30 to 60 minutes.

[0016] Preferably, the organic solvent for recrystallization is at least one selected from methanol, ethanol, n-hexane, cyclohexane, toluene, chloroform, and tetrahydrofuran.

[0017] This invention also discloses a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, prepared by the above method, with the following structural formula:

[0018] .

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses a method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester. The method uses 2,5-furandicarboxylic acid as the base material, and obtains di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester by grafting allyl groups onto 2,5-furandicarboxylic acid via an esterification reaction under the action of an inorganic metal catalyst. The reaction conditions are relatively low, requiring no high temperature or high pressure. The preparation process is simple and convenient, with no side reactions, and the product has high purity, significantly reducing preparation costs. Compared with traditional organic synthesis reactions, the reaction conditions required by this invention are milder, eliminating the need for a high-temperature and high-pressure environment. This not only reduces energy consumption but also minimizes operational risks and equipment costs. The milder reaction conditions also better maintain the activity and selectivity of the catalyst, improving reaction efficiency. The use of an inorganic metal catalyst promotes the esterification reaction while exhibiting good stability and recyclability, reducing catalyst usage costs and waste disposal burden. Furthermore, inorganic metal catalysts are generally less toxic and environmentally friendly. The reaction process is simple and precisely controlled, with almost no byproducts. The resulting di(propyl-2-enyl)furan-2,5-dicarboxylic ester product has high purity and can be directly used for subsequent applications or further chemical conversions without complex post-processing steps, thus improving overall production efficiency. While ensuring product quality, it significantly reduces costs in raw materials, energy consumption, equipment investment, and waste disposal, making the production of di(propyl-2-enyl)furan-2,5-dicarboxylic ester more economical and feasible. Attached Figure Description

[0021] Figure 1 This is a flowchart of the preparation process of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) disclosed in this invention;

[0022] Figure 2 The FT-IR spectrum of the di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester disclosed in Example 1 of this invention;

[0023] Figure 3 The bis(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) disclosed in Example 1 of this invention is an example of this invention. 1 H NMR spectrum. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings:

[0027] This invention discloses a method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE), belonging to the technical field of biomass-based organic synthesis methods. The method uses 2,5-furandicarboxylic acid as a base material, and obtains di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) through an esterification reaction under the action of an inorganic metal catalyst by grafting allyl groups onto 2,5-furandicarboxylic acid. This invention provides a new approach for realizing high-value-added utilization of biomass materials such as 2,5-furandicarboxylic acid (FDCA).

[0028] This invention discloses a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE), the structural formula of which is as follows:

[0029] .

[0030] This invention also discloses a method for preparing the above-mentioned di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE), specifically including the following steps:

[0031] Step 1: By mass, under N2 protection, take 5-10 parts of sodium hydroxide or potassium hydroxide, 10-20 parts of 2,5-furandicarboxylic acid, and 50-100 parts of solvent. Slowly heat to 60-80℃ and stir to dissolve. React at 60-80℃ for 3-6 hours.

[0032] Step 2: After the reaction temperature from Step 1 has cooled to 40-70°C, add 0.4-0.8 parts of catalyst by mass and stir until homogeneous. Take 10-30 parts of allyl compound and slowly add it dropwise under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 3-6 hours.

[0033] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash with a large amount of water, evaporate by rotary evaporation to remove impurities, and obtain a white solid. Recrystallize the white solid in an organic solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE).

[0034] Preferably, in step one, the solvent is at least one selected from water, methanol, ethanol, and N,N-dimethylformamide. The mass ratio of the solvent to the hydroxide is 20:(1~2).

[0035] The mass ratio of 2,5-furandicarboxylic acid to hydroxide is 2:(1~1.5).

[0036] In step two, the catalyst is at least one of ferric chloride, ferrous chloride, aluminum chloride, cupric chloride, cuprous chloride, potassium chloride, and cuprous bromide.

[0037] The mass ratio of catalyst to 2,5-furandicarboxylic acid is 1:(12.5~25).

[0038] The allyl compound is at least one of allyl chloride and allyl bromide.

[0039] The mass ratio of allyl compound to 2,5-furandicarboxylic acid is (1.2~2.4):1.

[0040] The allyl compound should be added slowly over a period of 30 to 60 minutes.

[0041] In step three, the recrystallization purification step uses at least one of methanol, ethanol, n-hexane, cyclohexane, toluene, chloroform, and tetrahydrofuran as the organic solvent.

[0042] Example 1

[0043] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0044] Step 1: By mass, under N2 protection, take 6 parts sodium hydroxide, 10 parts 2,5-furandicarboxylic acid, and 60 parts water. Slowly heat to 80°C and stir to dissolve. React at 80°C for 3 hours.

[0045] Step 2: After the reaction temperature from Step 1 has cooled to 55°C, add 0.4 parts of the catalyst, copper dichloride, and stir until homogeneous. Take 18 parts of bromopropylene and slowly add it dropwise over 30 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 4 hours.

[0046] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, rotary evaporate to remove impurities, and obtain a white solid. Recrystallize the white solid in n-hexane solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 94% yield.

[0047] See Figure 1 This is a flowchart of the preparation process of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) disclosed in this invention. As can be seen from the figure, the preparation process consists of two steps. The first step is the reaction of 2,5-furandicarboxylic acid with sodium hydroxide to generate sodium alkoxide and water. The second step is the reaction of sodium alkoxide with an allyl compound, where an allyl group is grafted to generate di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE). The entire reaction process does not generate any other byproducts, the reaction conditions are relatively mild, and it does not require high temperature or high pressure, making it simple and convenient.

[0048] Figure 2 The image shows the FT-IR spectrum of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester disclosed in Example 1 of this invention; it can be seen from the FT-IR spectrum that, compared with FDCA, FDCE has a higher FT-IR spectrum at 3020 cm⁻¹. -1 The corresponding absorption peak of the olefinic hydrogen (=CH) stretching vibration at 1028 cm⁻¹; -1 and 1288 cm -1 The corresponding ester group (CO) absorption peaks indicate the formation of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE).

[0049] Figure 3 The bis(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) disclosed in Example 1 of this invention is an example of this invention. 1The 1H NMR spectrum shows that the chemical shifts δ of 7.34 ppm (1), 5.99 ppm (2), 5.43 ppm (3), 5.32 ppm (4), and 4.84 ppm (5) are attributed to the hydrogen NMR peaks at various locations in the FDCE, confirming the successful synthesis of di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE). Furthermore, the integrated area indicates that the purity of the product is very high, approximately 97%.

[0050] Example 2

[0051] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0052] Step 1: By mass, under N2 protection, take 10 parts potassium hydroxide, 15 parts 2,5-furandicarboxylic acid, and 100 parts water, slowly heat to 80°C and stir to dissolve, and react at 80°C for 4 hours.

[0053] Step 2: By mass, after the reaction temperature in Step 1 has cooled to 45°C, add 0.5 parts of ferric chloride catalyst and stir until homogeneous. Take 18 parts of allyl chloride and slowly add it dropwise over 30 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 4 hours.

[0054] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, rotary evaporate to remove impurities, and obtain a white solid. Recrystallize the white solid in n-hexane solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 90% yield.

[0055] Example 3

[0056] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0057] Step 1: By mass, under N2 protection, take 10 parts sodium hydroxide, 16 parts 2,5-furandicarboxylic acid, and 80 parts ethanol. Slowly heat to 65°C and stir to dissolve. React at 65°C for 5 hours.

[0058] Step 2: After the reaction temperature from Step 1 has cooled to 55°C, add 0.6 parts of aluminum trichloride catalyst and stir until homogeneous. Take 25 parts of bromopropylene and slowly add it dropwise over 40 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 5 hours.

[0059] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, evaporate by rotary evaporation to remove impurities, and obtain a white solid. Recrystallize the white solid in ethanol solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 92% yield.

[0060] Example 4

[0061] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0062] Step 1: By mass, under N2 protection, take 5 parts sodium hydroxide, 10 parts 2,5-furandicarboxylic acid, and 50 parts methanol. Slowly heat to 60°C and stir to dissolve. React at 60°C for 5 hours.

[0063] Step 2: By mass, after the reaction temperature in Step 1 has cooled to 45°C, add 0.5 parts of ferric chloride catalyst and stir until homogeneous. Take 20 parts of bromopropylene and slowly add it dropwise over 30 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 6 hours.

[0064] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, rotary evaporate to remove impurities, and obtain a white solid. Recrystallize the white solid in cyclohexane solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 90% yield.

[0065] Example 5

[0066] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0067] Step 1: By mass, under N2 protection, take 7 parts sodium hydroxide, 17 parts 2,5-furandicarboxylic acid, and 85 parts N,N-dimethylformamide. Slowly heat to 70°C and stir to dissolve. React at 70°C for 4 hours.

[0068] Step 2: After the reaction temperature from Step 1 has cooled to 40°C, add 0.7 parts of cuprous chloride catalyst and stir until homogeneous. Take 28 parts of bromopropylene and slowly add it dropwise over 40 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 3 hours.

[0069] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, evaporate by rotary evaporation to remove impurities, and obtain a white solid. Recrystallize the white solid in toluene solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 90% yield.

[0070] Example 6

[0071] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0072] Step 1: By mass, under N2 protection, take 9 parts sodium hydroxide, 12 parts 2,5-furandicarboxylic acid, and 90 parts methanol. Slowly heat to 75°C and stir to dissolve. React at 75°C for 5 hours.

[0073] Step 2: After the reaction temperature from Step 1 has cooled to 60°C, add 0.5 parts of potassium chloride catalyst and stir until homogeneous. Take 28 parts of bromopropylene and slowly add it dropwise over 50 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 5 hours.

[0074] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, evaporate by rotary evaporation to remove impurities, and obtain a white solid. Recrystallize the white solid in chloroform solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 92% yield.

[0075] Example 7

[0076] A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) includes the following steps:

[0077] Step 1: By mass, under N2 protection, take 8 parts sodium hydroxide, 20 parts 2,5-furandicarboxylic acid, and 100 parts methanol. Slowly heat to 80°C and stir to dissolve. React at 80°C for 6 hours.

[0078] Step 2: After the reaction temperature from Step 1 has cooled to 70°C, add 0.8 parts of the catalyst cuprous bromide and stir until homogeneous. Take 30 parts of propylene bromide and slowly add it dropwise over 60 minutes under reflux conditions while stirring. After the addition is complete, allow the reaction to proceed for 6 hours.

[0079] Step 3: After the reaction is complete, cool to room temperature and filter to obtain a white solid suspended in the upper layer of the reaction solution. Wash three times with a large amount of water, evaporate by rotary evaporation to remove impurities, and obtain a white solid. Recrystallize the white solid in tetrahydrofuran solvent, filter, dry under vacuum, encapsulate, and seal for storage to obtain di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester (FDCE) in 92% yield.

[0080] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester, characterized in that, include: First, under an inert atmosphere, the hydroxide, 2,5-furandicarboxylic acid, and solvent were mixed and reacted with stirring once. After cooling, the catalyst was added and stirred until homogeneous. Then, the allyl compound was slowly added and reacted with stirring twice. After cooling to room temperature, the mixture was filtered to obtain a white solid suspended in the upper layer of the reaction solution. Finally, after washing, rotary evaporation, recrystallization, filtration, and vacuum drying, di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester was obtained. The hydroxide is sodium hydroxide or potassium hydroxide; the solvent is water; the catalyst is at least one selected from ferric chloride, ferrous chloride, aluminum chloride, cupric chloride, cuprous chloride, potassium chloride, and cuprous bromide. The temperature of the first stirring reaction is 60~80℃, and the time of the first stirring reaction is 3~6h; after cooling to 40~60℃, the catalyst is added.

2. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The mass ratio of the hydroxide, 2,5-furandicarboxylic acid, solvent, catalyst and allyl compound is (5~10):(10~20):(50~100):(0.4~0.8):(10~30).

3. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 2, characterized in that, The mass ratio of the solvent to the hydroxide is 20:(1~2); the mass ratio of 2,5-furandicarboxylic acid to the hydroxide is 2:(1~1.5); the mass ratio of the catalyst to 2,5-furandicarboxylic acid is 1:(12.5~25); and the mass ratio of the allyl compound to 2,5-furandicarboxylic acid is (1.2~2.4):

1.

4. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The inert atmosphere is N2.

5. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The conditions for the secondary stirring reaction are: stirring reaction for 3-6 hours under reflux condensation conditions.

6. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The allyl compound is at least one of allyl chloride and allyl bromide.

7. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The allyl compound was slowly added dropwise over a period of 30 to 60 minutes.

8. The method for preparing di(propyl-2-enyl)furan-2,5-dicarboxylic acid ester according to claim 1, characterized in that, The organic solvent used for recrystallization is at least one selected from methanol, ethanol, n-hexane, cyclohexane, toluene, chloroform, and tetrahydrofuran.

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