BVPE preparation method based on solid acid catalysis and continuous flow reaction

Abstract

The invention provides a BVPE preparation method based on solid acid catalysis and continuous flow reaction, and relates to the technical field of disubstituted ethane preparation, and the method comprises the following steps: mixing a compound 1, a polymerization inhibitor, a solid acid catalyst and a solvent to form a reaction liquid; enabling the reaction liquid to pass through a fixed bed continuous flow reactor, and reacting at 20-180 DEG C for 1-45 minutes to obtain a compound 2; post-treating, separating and purifying a product; wherein the solid acid catalyst is an HZSM-5 type molecular sieve or acidic resin, the product purity and yield are high, the HZSM-5 type molecular sieve or acidic resin is adopted as the solid acid catalyst, residual pollution of traditional protonic acid (such as p-toluenesulfonic acid) is avoided, in embodiments 1-3, the product GC purity reaches 98.6%-99.1%, the yield reaches 88.8%-93.8%, and the product GC purity and the yield are remarkably higher than those of a contrast (the purity is 96.1%, and the yield is 74.2%).

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of disubstituted ethane, and more specifically, particularly relates to a method for preparing BVPE based on solid acid catalysis and continuous flow reaction. Background Art

[0002] As a key functional monomer, 1,2-bis(4-vinylphenyl)ethane has broad application prospects in the resin field. It can be used in crosslinked polypropylene resins for 3D printing (CN103980402); it can be used as a crosslinking agent to chemically react with other resin components to form a crosslinked structure, thereby significantly improving the strength and heat resistance of the resin composition. This improvement in performance is crucial for the manufacture of high-quality and highly reliable electronic products and components (CN113667232).

[0003] In the prior art, p-toluenesulfonic acid (Russian Journal of Applied Chemistry, 2011, vol. 84, #10, p. 1783-1794; CN113372187) or pyridinium p-toluenesulfonate is used as a catalyst (CN115385767A) for the reaction. This method requires strict control of both the concentration of the acid catalyst and the reaction time, and it is difficult to obtain a high-purity monomer.

[0004] In recent years, the rise of continuous flow reaction technology has opened up new paths for the field of organic synthesis. With its highly controllable reaction conditions, efficient mass and heat transfer performance, and the convenience of automated and continuous production, continuous flow reactors have significantly improved reaction efficiency, reduced costs, and alleviated environmental pressure. Applying this technology to the synthesis of 1,2-bis(4-vinylphenyl)ethane is expected to fundamentally solve the problems existing in traditional methods and achieve efficient, environmentally friendly, and continuous industrial production.

[0005] Although the application of continuous flow technology in the synthesis of some organic compounds has been reported, continuous synthesis strategies for 1,2-bis(4-vinylphenyl)ethane are still relatively rare. Therefore, developing a new method for synthesizing 1,2-bis(4-vinylphenyl)ethane based on a continuous flow fixed bed reactor not only makes a significant academic contribution but also has profound practical significance for accelerating its industrialization process and meeting diverse application needs, which is a key step in promoting the development of this field. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a method for preparing BVPE based on solid acid catalysis and continuous flow reaction to solve the above problems.

[0007] A preparation method of 1,2-bis(4-vinylphenyl)ethane, comprising the following steps: (1) Mixing a compound 1, an inhibitor, a solid acid catalyst and a solvent to form a reaction solution; (2) Passing the reaction solution through a fixed-bed continuous flow reactor and reacting at 20-180°C for 1-45 minutes to obtain a compound 2; (3) Post-treating and separating and purifying the product; wherein, the solid acid catalyst is an HZSM-5 type molecular sieve or an acidic resin.

[0008] Preferably, the solid acid catalyst is an HZSM-5 type molecular sieve with a silicon-aluminum ratio (Si / Al) of 30-75, the solid acid catalyst is a 724 type cation exchange resin, the inhibitor is p-tert-butylcatechol or hydroquinone, and the dosage is 0.5% to 2% of the mass of the compound 1.

[0009] Preferably, the solvent is selected from xylene, chlorobenzene or nitrobenzene, the reaction temperature of the fixed-bed continuous flow reactor is 80-150°C, the reaction time is 10-30 minutes, the dosage of the solid acid catalyst is 25% to 100% of the mass of the compound 1, the reaction is carried out under the protection of an inert gas, and the post-treatment includes filtering to remove the catalyst, concentrating the solvent, recrystallizing with methanol and vacuum drying.

[0010] 1,2-bis(4-vinylphenyl)ethane, with a GC purity ≥ 98.6% and a yield ≥ 88.8%.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] High product purity and yield:

[0013] Using an HZSM-5 molecular sieve or an acidic resin as the solid acid catalyst avoids the residual pollution of traditional protonic acids (such as p-toluenesulfonic acid). In Examples 1-3, the GC purity of the product reaches 98.6% - 99.1%, and the yield is 88.8% - 93.8%, which is significantly higher than that of the comparative example (purity 96.1%, yield 74.2%).

[0014] In the fixed-bed continuous flow examples (Examples 4-6), the product purity is further increased to 99.1% - 99.87%.

[0015] Efficient continuous production:

[0016] Through the fixed-bed continuous flow reactor, the reaction time is shortened to 5-45 minutes (preferably 10-30 minutes), continuous production is realized, there is no need for batch intervals, and the production efficiency is increased by more than 50%.

[0017] The reaction conditions are precisely controllable (temperature 20-180°C, pressure 0.2 MPa), with a high degree of automation, reducing manual operation errors.

[0018] Environmental friendliness and cost reduction:

[0019] The solid acid catalyst can be reused, reducing waste emissions and avoiding the corrosion of equipment by traditional proton acids and the cost of treating the three wastes.

[0020] The continuous flow system has a high material utilization rate, and solvents (such as xylene and chlorobenzene) can be recycled, reducing the comprehensive production cost by more than 30%.

[0021] Process safety and scalability:

[0022] The fixed-bed reactor has an explosion-proof design and an online monitoring function, reducing the risk of reaction runaway (in the comparative example, high-temperature and high-pressure operations are required, with relatively high safety hazards).

[0023] Process parameters (such as catalyst loading and flow rate) can be flexibly adjusted, suitable for multi-scale production from laboratory to industrialization. Description of the drawings

[0024] Figure 1 is the GC chromatogram of 1,2-bis(4-vinylphenyl)ethane of the present invention;

[0025] Figure 2 is the data schematic diagram of 1,2-bis(4-vinylphenyl)ethane of the present invention;

[0026] Figure 3 is the schematic diagram of the continuous flow fixed bed of the present invention. Detailed implementation manners

[0027] The following further describes in detail the implementation manners of the present invention in conjunction with the drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0028] Please refer to Figures 1-3 , the present invention provides an efficient preparation method of 1,2-bis(4-vinylphenyl)ethane, and modifies it with a fixed bed to achieve the efficient continuous synthesis of 1,2-bis(4-vinylphenyl)ethane (2);

[0029]

[0030] A preparation method of 1,2-bis(4-vinylphenyl)ethane, comprising the following steps: (1) Mixing compound 1, a polymerization inhibitor, a solid acid catalyst and a solvent to form a reaction solution; (2) Passing the reaction solution through a fixed-bed continuous flow reactor and reacting at 20-180 °C for 1-45 minutes to obtain compound 2; (3) Post-treating and separating and purifying the product; wherein, the solid acid catalyst is HZSM-5 type molecular sieve or acidic resin.

[0031] The solid acid catalyst is HZSM-5 molecular sieve with a silicon-aluminum ratio (Si / Al) of 30 - 75. The solid acid catalyst is 724 type cation exchange resin. The inhibitor is p-tert-butylcatechol or hydroquinone, and the dosage is 0.5% - 2% of the mass of Compound 1.

[0032] The solvent is selected from xylene, chlorobenzene or nitrobenzene. The reaction temperature of the fixed bed continuous flow reactor is 80 - 150 °C, the reaction time is 10 - 30 minutes, the dosage of the solid acid catalyst is 25% - 100% of the mass of Compound 1, the reaction is carried out under the protection of inert gas, and the post-treatment includes filtering to remove the catalyst, concentrating the solvent, recrystallizing with methanol and vacuum drying.

[0033] 1,2-bis(4-vinylphenyl)ethane, with a GC purity ≥ 98.6% and a yield ≥ 88.8%.

[0034] A method for synthesizing 1,2-bis(4-vinylphenyl)ethane (2) using a continuous flow fixed bed reactor.

[0035] The reaction temperature of the continuous flow fixed bed reaction is 20 - 180 °C, preferably 80 - 150 °C. For example, the specific reaction temperatures that can be listed are 70 °C, 80 °C, 100 °C, 120 °C, 140 °C, 150 °C, etc.

[0036] The reaction time of the reaction solution in the continuous flow reactor is 1 - 45 min, preferably 10 - 30 min. For example, the reaction times that can be listed are 10 min, 15 min, 20 min, 25 min, 30 min, etc.

[0037] In the following examples, HZSM-5 molecular sieve (Si / Al = 75, 50, 30) is produced by China Catalyst Holdings Co., Ltd.; the acidic resin is produced by Shanghai Quanyi Electronic Technology Co., Ltd., product name: 724 type cation exchange resin.

[0038] In the following examples, Compound 1 is self-made.

[0039] In the following examples, the xylene is a commercially available xylene isomer mixture, cas number 1330 - 20 - 7.

[0040] Comparative Example: Under nitrogen protection, 100 g (0.37 mol, 1.0 eq) of Compound 1 was dissolved in 500 g of xylene, 2 g of p-tert-butylcatechol (2% wt) was added, and then p-toluenesulfonic acid (1.2 g, 0.02 eq) was added. Under nitrogen protection, the temperature was raised to 140 °C and the reaction was kept for 2 h. The reaction system was cooled to 20 °C, filtered, the xylene was concentrated, 10V of methanol was added, the internal temperature was raised to 70 °C and stirred for 1 h until clear, the internal temperature was lowered to 50 °C and solids gradually precipitated out, the temperature was gradually lowered to 10 °C and stirred for 1 h and then filtered, and dried in vacuo at 60 °C to obtain 64.2 g of Compound 2 with a yield of 74.2% and a GC purity of 96.1%.

[0041] Example 1:

[0042] Under nitrogen protection, 100 g (0.37 mol, 1.0 eq) of Compound 1 was dissolved in 500 g of xylene, 2 g of p-tert-butylcatechol (2% wt) was added, and then HZSM-5 zeolite with Si / Al = 75 (25 g, 25% wt) was added. Under nitrogen protection, the temperature was raised to 140 °C and the reaction was kept for 2 h. The reaction system was cooled to 20 °C, filtered, the xylene was concentrated, 10V of methanol was added, the internal temperature was raised to 70 °C and stirred for 1 h until clear, the internal temperature was lowered to 50 °C and solids gradually precipitated out, the temperature was gradually lowered to 10 °C and stirred for 1 h and then filtered, and dried in vacuo at 60 °C to obtain 77 g of Compound 2 with a yield of 88.8% and a GC purity of 98.8%.

[0043] Example 2:

[0044] On the basis of Example 1, the solid acid catalyst was changed to HZSM-5 zeolite with Si / Al = 30, and other conditions remained unchanged. The reaction was kept for 2 h, and after treatment, 81.2 g of Compound 2 was obtained with a yield of 93.8% and a GC purity of 99.1%.

[0045] Example 3:

[0046] On the basis of Example 1, the solid acid catalyst was changed to 724-type cation exchange resin (25% wt), and other conditions remained unchanged. The reaction was kept for 2 h, and after treatment, 79.6 g of Compound 2 was obtained with a yield of 91.8% and a GC purity of 98.6%.

[0047] Fixed-bed continuous flow example

[0048] Fixed-bed installation: A solid acid, such as HZSM-5 zeolite with Si / Al = 30 or 724-type cation exchange resin, was loaded into a fixed-bed reactor equipped with an electric heater and dispersed with glass beads.

[0049] Ingredients: Add 500 g of xylene to a conical flask equipped with a magnetic stirrer, start stirring, slowly add 100 g (0.37 mol, 1.0 eq) of Compound 1 to dissolve, and then add 2 g of p-tert-butylcatechol (2% wt) until completely dissolved for use.

[0050] Example 4:

[0051] The prepared solution is continuously pumped into a fixed-bed reactor (filled with HZSM-5 molecular sieve with Si / Al = 30) through a plunger pump. The reaction temperature is 140 °C, the flow rate is 30 mL / min, the reaction pressure is 0.2 Mpa, and the reaction is carried out in the reactor for 5 min, with a GC purity of 99.2%.

[0052] Example 5:

[0053] Further, on the basis of Example 4, only the reaction residence time is changed to 10 min, and other conditions remain unchanged, with a GC purity of 99.87%.

[0054] Example 6:

[0055] On the basis of maintaining the same experimental apparatus and operation process as in Example 4, only the packing in the fixed bed is replaced with 724-type cation exchange resin, and other conditions remain unchanged, with a GC purity of 99.1%.

[0056] The embodiments of the present invention are given for purposes of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A preparation method of BVPE based on solid acid catalysis and continuous flow reaction, characterized in that, Comprising the following steps: (1) Mix compound 1, inhibitor, solid acid catalyst and solvent to form a reaction solution; (2) Pass the reaction solution through a fixed-bed continuous flow reactor and react at 20 - 180 °C for 1 - 45 minutes to obtain compound 2; (3) Post-treat and separate and purify the product; Wherein, the solid acid catalyst is HZSM-5 type molecular sieve or acidic resin.

2. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, wherein The solid acid catalyst is HZSM-5 type molecular sieve with a silica-alumina ratio (Si / Al) of 30 - 75.

3. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, characterized in that, The solid acid catalyst is 724 type cation exchange resin.

4. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, characterized in that, The inhibitor is p-tert-butylcatechol or hydroquinone, and the dosage is 0.5% - 2% of the mass of compound 1.

5. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, wherein The solvent is selected from xylene, chlorobenzene or nitrobenzene.

6. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, characterized in that, The reaction temperature of the fixed-bed continuous flow reactor is 80 - 150 °C, and the reaction time is 10 - 30 minutes.

7. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, wherein, The dosage of the solid acid catalyst is 25% - 100% of the mass of compound 1.

8. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, characterized in that, The reaction is carried out under the protection of inert gas.

9. The preparation method of BVPE based on solid acid catalysis and continuous flow reaction according to claim 1, characterized in that, The post-treatment includes filtering to remove the catalyst, concentrating the solvent, recrystallizing with methanol and vacuum drying.

10. 1,2-bis(4-vinylphenyl)ethane prepared by any of the methods according to claims 1-9, characterized in that, Its GC purity ≥ 98.6%, and the yield ≥ 88.8%.

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