Synthesis method of 1, 2-bis (4-vinyl phenyl) ethane

Abstract

The invention relates to a synthesis method of 1, 2-bis (4-vinyl phenyl) ethane, which comprises the following steps: 1) under the action of magnesium or zinc, carrying out self-coupling reaction on benzyl halide at a benzyl position to obtain 1, 2-bis (4-halogen phenyl) ethane, and 2) preparing the 1, 2-bis (4-vinyl phenyl) ethane from the 1, 2-bis (4-halogen phenyl) ethane, which is selected from any one of the following schemes: 2i: carrying out self-coupling reaction on the 1, 2-bis (4-vinyl phenyl) ethane obtained in the step 1) to obtain the 1, 2-bis (4-vinyl phenyl) ethane. The preparation method comprises the following steps: preparing a Grignard reagent from 1, 2-bis (4-halogen phenyl) ethane, and coupling the Grignard reagent with vinyl chloride to prepare 1, 2-bis (4-vinyl phenyl) ethane; and (2iii) coupling the 1, 2-bis (4-halogen phenyl) ethane obtained in the step (1) with vinyl magnesium chloride to prepare the 1, 2-bis (4-vinyl phenyl) ethane. According to the invention, the 1, 2-bis (4-vinyl phenyl) ethane is prepared from p-benzyl halide through two-step reaction at a relatively high yield, and the yield of the two-step reaction can reach 86.9%.

Description

Technical Field

[0001] The invention relates to the field of organic chemistry, and in particular to a method for synthesizing 1,2-bis(4-vinylphenyl)ethane (BVPE). Background Art

[0002] 1,2-Bis(4-vinylphenyl)ethane (BVPE) is a bifunctional styrene monomer with excellent performance. It can be cured at a relatively low temperature. The synthesized polymer material has excellent mechanical properties, a wide range of uses, and high economic benefits. At present, BVPE has great application prospects in chromatographic separation, photoresist resins, electronic packaging materials, and signal transmission materials for high-end electronic products.

[0003]

[0004] The optional synthesis method of 1,2-bis(4-vinylphenyl)ethane can be obtained by coupling reaction with p-chloromethylstyrene as raw material, but the conventional method for synthesizing p-chloromethylstyrene generates ortho-meta impurities, resulting in a low yield of p-chloromethylstyrene, which leads to high cost of p-chloromethylstyrene (Synthetic Communications, 1974, 4 (4), 193-197), and the cost of producing BVPE is very high. Alternatively, 1,2-diphenylethane can be used as raw material to obtain the product through Friedel-Crafts acylation, hydrogenation and dehydration reaction (Russian Journal of Applied Chemistry, 2011, 84 (10), 1783-1794). This route requires high-pressure hydrogenation, and finally uses p-toluenesulfonic acid for dehydration reaction, which easily causes the product to polymerize. The three-step yield is 44.4%, which is not suitable for large-scale production. In addition, there is also a Chinese patent CN113372187B that uses 1,2-diphenylethane as a raw material, first obtains 4,4'-diacetyldiphenylethane under the action of aluminum chloride and acetyl chloride, and then obtains BVPE through sodium borohydride reduction and p-toluenesulfonic acid dehydration reaction. This route requires three steps of reaction, and the three-step yield is 76.5%. The reaction requires sodium borohydride, which has a high risk factor. Finally, the p-toluenesulfonic acid dehydration reaction is not avoided, and the product needs to be purified by column, so the economic benefit is not high. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a simple and efficient synthesis method of 1,2-bis(4-vinylphenyl)ethane to solve the problems in the prior art.

[0006] To achieve the above object and other related objects, the present invention provides a method for synthesizing 1,2-bis(4-vinylphenyl)ethane, comprising:

[0007] 1) Under the action of magnesium or zinc, the p-halobenzyl halide undergoes a self-coupling reaction at the benzyl position to obtain 1,2-bis(4-halophenyl)ethane. The reaction equation is as follows:

[0008]

[0009] Wherein, X is Cl and / or Br;

[0010] 2) The step of preparing 1,2-bis(4-vinylphenyl)ethane from 1,2-bis(4-halophenyl)ethane obtained in step 1) is selected from any one of the following schemes:

[0011] 2i: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is prepared into a Grignard reagent, and then coupled with vinyl chloride to prepare 1,2-bis(4-vinylphenyl)ethane. The reaction equation is as follows:

[0012]

[0013] Wherein, X is Cl or Br;

[0014] 2ii: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is coupled with vinylmagnesium chloride or vinylmagnesium bromide to prepare 1,2-bis(4-vinylphenyl)ethane. The reaction equation is as follows:

[0015]

[0016] Wherein, X is Cl or Br.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The synthesis method of 1,2-bis(4-vinylphenyl)ethane provided by the present invention starts from a benzyl halide and undergoes two-step reactions to prepare 1,2-bis(4-vinylphenyl)ethane with a relatively high yield, and the two-step reaction yield can reach 86.9%. The synthesis method of 1,2-bis(4-vinylphenyl)ethane provided by the present invention has the advantages of no isomerization, high yield, less three wastes, easy purification, short steps, etc., does not require the selection of special reaction equipment, has mild reaction conditions, and all operations are conventional operations, is particularly suitable for industrial production, and has good industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shown is the hydrogen spectrum of 1,2-bis(4-chlorophenyl)ethane prepared in Example 1 of the present invention;

[0020] Figure 2 Shown is the hydrogen spectrum of 1,2-bis(4-vinylphenyl)ethane prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The inventors of the present invention have provided a novel method for synthesizing 1,2-bis(4-vinylphenyl)ethane after extensive research. The method has the characteristics of high yield, fewer steps, mild conditions, etc., and is a method for synthesizing 1,2-bis(4-vinylphenyl)ethane that is more suitable for industrial scale-up production. The present invention was completed on this basis.

[0022] The present invention provides a method for synthesizing 1,2-bis(4-vinylphenyl)ethane, comprising:

[0023] 1) Under the action of magnesium or zinc, the p-halobenzyl halide undergoes a self-coupling reaction at the benzyl position to obtain the intermediate compound 1,2-bis(4-halophenyl)ethane;

[0024] 2) The step of preparing 1,2-bis(4-vinylphenyl)ethane from 1,2-bis(4-halophenyl)ethane obtained in step 1) is selected from any one of the following schemes:

[0025] 2i: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is prepared into a Grignard reagent, and then coupled with vinyl chloride to prepare 1,2-bis(4-vinylphenyl)ethane. The reaction equation is as follows:

[0026] 2ii: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is coupled with vinylmagnesium chloride or vinylmagnesium bromide to prepare 1,2-bis(4-vinylphenyl)ethane.

[0027] The method for synthesizing 1,2-bis(4-vinylphenyl)ethane provided by the present invention may include a benzyl chloride or benzyl bromide coupling reaction in step 1), and the coupling reaction may specifically include: under the action of magnesium or zinc, a self-coupling reaction of the para-halobenzyl halide occurs at the benzyl position to obtain 1,2-bis(4-halophenyl)ethane. The reaction equation is as follows:

[0028]

[0029] In the formula, X is Cl and / or Br.

[0030] In step 1) of the present invention, the para-halobenzyl halide is selected from one of para-chlorobenzyl chloride, para-bromobenzyl bromide, para-bromobenzyl chloride and para-chlorobenzyl bromide. In step 1), 1,2-bis(4-halophenyl)ethane is 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane. Para-chlorobenzyl chloride, para-bromobenzyl bromide, para-bromobenzyl chloride and para-chlorobenzyl bromide can be used to undergo a self-coupling reaction at the benzyl position to obtain an intermediate compound 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane.

[0031] In step 1) of the present invention, in the coupling reaction of benzyl chloride or benzyl bromide, the reaction is usually carried out in the presence of a first solvent, which is usually a good solvent for the reaction system. Those skilled in the art can select a suitable type and amount of the first solvent for the coupling reaction. For example, the first solvent used in the coupling reaction can be selected from an organic solvent, and specifically can be selected from a combination of one or more of ether solvents, alkane solvents, aromatic hydrocarbon solvents, etc. In a specific embodiment of the present invention, the first solvent used in the coupling reaction can be selected from a combination of one or more of diethyl ether, propyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, methyltetrahydrofuran, methylcyclopentyl ether, methylcyclohexyl ether, hexane, cyclohexane, heptane, benzene, toluene, xylene, trimethylbenzene, ethylbenzene, isopropylbenzene, etc., and preferably can be selected from a combination of one or more of tetrahydrofuran, methyltetrahydrofuran, toluene, xylene, etc. For another example, in the coupling reaction, the mass of the solvent used can be 1 to 10 times, 1 to 2 times, 2 to 4 times, 4 to 6 times, 6 to 8 times, or 8 to 10 times the mass of the benzyl halide, preferably 2 to 4 times.

[0032] In step 1) of the present invention, in the coupling reaction of benzyl chloride or benzyl bromide, the reaction can usually be carried out at a certain temperature, for example, the reaction temperature of the coupling reaction can be, for example, -10 to 40°C. The reaction temperature of the coupling reaction can be -10 to -0°C, 0 to 10°C, 10 to 15°C, 15 to 25°C, 25 to 40°C, 10 to 20°C, 20 to 30°C, or 30 to 40°C, preferably 15 to 25°C. Those skilled in the art can adjust the reaction time of the coupling reaction according to the progress of the reaction, for example, the reaction progress of the coupling reaction can be judged by methods such as TLC and chromatography, and for another example, the reaction time of the coupling reaction can be 1 to 24 hours, 1 to 2 hours, 2 to 4 hours, 4 to 6 hours, 6 to 8 hours, 8 to 12 hours, or 12 to 24 hours.

[0033] In step 1) of the present invention, the coupling reaction of benzyl chloride or benzyl bromide requires metal magnesium or zinc, and the amount of the metal magnesium or zinc is generally 0.5-0.65 equivalents to the amount of the halobenzyl halogen substance, so as to ensure sufficient reaction of the reaction substrate, and can be selected from 0.5-0.55 equivalents or 0.55-0.65 equivalents, etc. Preferably, it can be 0.55 equivalents.

[0034] Those skilled in the art may select a suitable method to post-treat the product of the coupling reaction of step 1). For example, the coupling reaction may also include extraction, separation, concentration, and purification. In a specific embodiment of the present invention, after the reaction is completed, the reaction system may be quenched with water, extracted and washed, the solvent may be concentrated, and a poor solvent may be added for crystallization to prepare a crude product of 1,2-bis(4-halophenyl)ethane (e.g., 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane), which may be used in the next reaction without further purification.

[0035] The method for synthesizing 1,2-bis(4-vinylphenyl)ethane provided by the present invention comprises the following steps: step 2i: preparing the 1,2-bis(4-halophenyl)ethane obtained in step 1) into a Grignard reagent, and then coupling the reagent with vinyl chloride to obtain 1,2-bis(4-vinylphenyl)ethane.

[0036] Specifically, the above reaction is a Kumada cross-coupling reaction. Further, the Kumada cross-coupling reaction specifically includes: preparing 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane as a Grignard reagent, and then Kumada cross-coupling with vinyl chloride under the action of a catalyst to obtain the target product BVPE.

[0037] The reaction equation is as follows:

[0038]

[0039] In the formula, X is Cl or Br. X is preferably Br.

[0040] In step 2i) of the present invention, the molar ratio of 1,2-bis(4-halophenyl)ethane to Mg is 1:2-4, and can be 1:2-3 or 1:3-4.

[0041] In step 2i) of the present invention, the molar ratio of 1,2-bis(4-halophenyl)ethane to vinyl chloride is 1:2-5, and can be 1:2-3, 1:3-4 or 1:4-5.

[0042] The method for synthesizing 1,2-bis(4-vinylphenyl)ethane provided by the present invention comprises step 2i: coupling the 1,2-bis(4-halophenyl)ethane obtained in step 1) with vinylmagnesium chloride or vinylmagnesium bromide to prepare 1,2-bis(4-vinylphenyl)ethane, and the reaction equation is as follows:

[0043] Specifically, for example, in the presence of a catalyst, 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane undergoes a Kumada cross-coupling reaction with vinylmagnesium chloride or vinylmagnesium bromide to prepare 1,2-bis(4-vinylphenyl)ethane (BVPE).

[0044] The reaction equation is as follows:

[0045]

[0046] In the formula, X is Cl or Br. X is preferably Br.

[0047] In step 2ii) of the present invention, the molar ratio of 1,2-bis(4-halophenyl)ethane to vinylmagnesium chloride is 1:2-5, and can be 1:2-3, 1:3-4 or 1:4-5.

[0048] In step 2i) and step 2ii) of the present invention, the Kumada cross-coupling reaction requires a metal catalyst. Those skilled in the art can usually select a metal catalyst, such as palladium chloride, nickel chloride, ferric chloride, palladium acetate, tetrakistriphenylphosphine palladium, bistriphenylphosphine palladium dichloride, tris(dibenzylideneacetone)dipalladium, acetylacetonate palladium, acetylacetonate nickel, etc. One or more combinations thereof, the amount of the metal catalyst is usually 0.1% to 5% mol of the amount of 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane, so as to ensure sufficient reaction of the reaction substrate, preferably 0.5% to 2% mol.

[0049] In step 2i) and step 2ii) of the present invention, in the Kumada cross-coupling reaction, the reaction is usually carried out in the presence of a base, and those skilled in the art can select a base of suitable type and amount for the Kumada cross-coupling reaction. For example, the base may be selected from a combination of one or more of tetramethylethylenediamine (TMEDA), triethylamine (NEt3), diisopropylamine, pyridine, etc., preferably tetramethylethylenediamine and / or diisopropylamine. The amount of the base may be 1 to 10 times the amount of 1,2-bis(4-halophenyl)ethane. Alternatively, the amount of the base may be 1 to 2 times, 2 to 4 times, 4 to 6 times, 6 to 8 times, 8 to 10 times the amount of 1,2-bis(4-halophenyl)ethane, preferably 6 to 8 times.

[0050] In step 2i) and step 2ii) of the present invention, in the Kumada cross-coupling reaction, the reaction is usually carried out in the presence of a second solvent, and the second solvent is usually a good solvent for the reaction system. Those skilled in the art can select a suitable type and amount of solvent for the Kumada cross-coupling reaction. For example, the second solvent used in the Kumada cross-coupling reaction can be selected from an organic solvent, and specifically can be selected from a combination of one or more of ether solvents, alkane solvents, aromatic hydrocarbon solvents, etc. In a specific embodiment of the present invention, the second solvent used in the Kumada cross-coupling reaction can be selected from a combination of one or more of diethyl ether, propyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, methyltetrahydrofuran, methylcyclopentyl ether, methylcyclohexyl ether, hexane, cyclohexane, heptane, benzene, toluene, xylene, trimethylbenzene, ethylbenzene, isopropylbenzene, etc., and preferably can be selected from a combination of one or more of tetrahydrofuran, methyltetrahydrofuran, toluene, xylene, etc. For another example, in the coupling reaction, the mass of the solvent used can be 1 to 10 times, 1 to 2 times, 2 to 4 times, 4 to 6 times, 6 to 8 times, or 8 to 10 times the mass of 1,2-bis(4-halophenyl)ethane, and preferably can be 2 to 4 times.

[0051] In step 2i) and step 2ii) of the present invention, in the Kumada cross-coupling reaction, the reaction can usually be carried out at a certain temperature, and the reaction temperature of the coupling reaction can be -10 to 60°C. For example, the reaction temperature of the coupling reaction can be -10 to -0°C, 0 to 10°C, 10 to 20°C, 20 to 30°C, 30 to 40°C or 40 to 60°C, preferably 10 to 20°C. Those skilled in the art can adjust the reaction time of the coupling reaction according to the progress of the reaction. For example, the reaction progress of the coupling reaction can be determined by TLC, chromatography and the like. For another example, the reaction time of the coupling reaction can be 1 to 24 hours, 1 to 2 hours, 2 to 4 hours, 4 to 6 hours, 6 to 8 hours, 8 to 12 hours, or 12 to 24 hours.

[0052] Those skilled in the art can select a suitable method to post-treat the product of the Kumada cross-coupling reaction. For example, the hydrolysis reaction can also include extraction, desolventization, and purification. In a specific embodiment of the present invention, after the reaction is completed, the organic solvent of the reaction solution can be desolventized and then extracted with ethyl acetate. The organic phase can be concentrated and then cooled and crystallized to purify to prepare BVPE.

[0053] The synthesis method of 1,2-bis(4-vinylphenyl)ethane provided by the present invention starts from a benzyl halide and undergoes two-step reactions to prepare 1,2-bis(4-vinylphenyl)ethane with a relatively high yield, and the two-step reaction yield can reach 86.9%. The synthesis method of 1,2-bis(4-vinylphenyl)ethane provided by the present invention has the advantages of no isomerization, high yield, less three wastes, easy purification, short steps, etc., does not require the selection of special reaction equipment, has mild reaction conditions, and all operations are conventional operations, is particularly suitable for industrial production, and has good industrialization prospects.

[0054] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0055] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0056] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0057] Embodiment 1:

[0058] (1) Synthesis of 1,2-bis(4-chlorophenyl)ethane

[0059] First, dissolve 600.0g of p-benzyl chloride in 600.0g of THF solution to prepare 1200.0g of p-benzyl chloride THF solution. Then, add 49.8g of magnesium and 2400.0g of tetrahydrofuran to a 5L dry reaction bottle and start stirring. Add 120.0g of p-benzyl chloride THF solution dropwise under nitrogen protection, and heat to 40°C after the reaction is completed. Then cool to 20°C, add the remaining p-benzyl chloride THF solution dropwise, control the temperature at 20-25°C, and keep warm for 5h after the completion of the addition. After the reaction, 2655.5 g of mother liquor was obtained by filtration, and the solvent was removed under reduced pressure to obtain 948.0 g of crude product. 3.0 kg of DCM and 2.25 kg of 5% hydrochloric acid aqueous solution were added to the crude product for extraction and separation to obtain 3652.0 g of lower organic phase, which was removed under reduced pressure, and then 1260.0 g of methanol was added for pulping, and the product 1,2-bis(4-chlorophenyl)ethane 448.3 g was obtained by filtration and drying, with a GC purity of 98.9% and a yield of 95.8%. Figure 1 , 1 H NMR (400MHz, CCl3D): 7.25 (d, 4H, J = 6.0Hz), 7.05 (d, 4H, J = 8.0Hz), 2.86 (S, 4H).

[0060] (2) Synthesis of 1,2-bis(4-vinylphenyl)ethane (BVPE)

[0061] In a 1L dry reaction bottle, 35.0g magnesium, 200g 1,2-bis(4-chlorophenyl)ethane and 500.0g THF solution were added in sequence, and 10ml isopropyl magnesium chloride solution was added for initiation. The reaction was refluxed at 60°C. After 48h of reaction, GC sampling and Grignard preparation were completed. Prepare another 2L dry reaction bottle, add 250.0g THF, cool to -20°C, pass 150.0g vinyl chloride, add 1.2g ferric chloride and 1.2g tetramethylethylenediamine (TMEDA), heat to 10°C, stir for 0.5h, and drop the prepared Grignard reagent under stirring. The addition was completed after 1h, and the mixture was kept warm and stirred for 4h. After the reaction, the mother liquor was filtered and desolventized to obtain a crude product. 500.0 g of 5% hydrochloric acid aqueous solution and 400.0 g of EA were added to extract the liquid. The organic phase was desolventized to obtain 183.4 g of a crude product. The crude product was dissolved in 366.8 g of DCM, and 1100.4 g of methanol was added to slowly cool to 0°C for crystallization. The product was filtered and dried to obtain 169.2 g of the product, with a GC purity of 98.7% and a yield of 90.7%. Figure 2 , the NMR data are as follows: 1H NMR(400MHz, CDCl3)7.31(d,4H,J=8.0Hz),7.12(d,4H,J=8.0Hz),6.68(m,2H ), 5.70 (d, 2H, J = 17.6Hz), 5.70 (d, 2H), 5.19 (d, 2H, J = 10.8Hz), 2.89 (s, 4H).

[0062] Embodiment 2:

[0063] (1) Synthesis of 1,2-bis(4-bromophenyl)ethane

[0064] First, dissolve 150.0g of p-bromobenzyl bromide in 150.0g of THF solution to prepare 300.0g of p-bromobenzyl bromide THF solution. Then, add 8.0g of magnesium and 150.0g of tetrahydrofuran to a 2L dry reaction bottle and start stirring. Add 30.0g of p-bromobenzyl bromide THF solution dropwise under nitrogen protection. After the dropwise reaction is completed, the temperature rises to 38°C. Then cool to 10°C, add the remaining p-bromobenzyl bromide THF solution dropwise, control the temperature at 15-20°C, and keep the temperature for 5h after the dropwise reaction. After the reaction, the mother liquor was filtered and desolventized to obtain a crude product. 600.0 g of DCM and 450.0 g of 5% hydrochloric acid aqueous solution were added to the crude product for extraction and separation to obtain a lower organic phase. The solvent was removed under reduced pressure, and then 120.0 g of methanol was added for pulping. The product 1,2-bis(4-bromophenyl)ethane was filtered and dried to obtain 93.6 g of the product with a GC purity of 98.4% and a yield of 91.7%.

[0065] (2) Synthesis of 1,2-bis(4-vinylphenyl)ethane (BVPE)

[0066] First, 22.1g of 1,2-bis(4-bromophenyl)ethane was dissolved in 148.0g of THF solution to prepare 170.1g of 1,2-bis(4-bromophenyl)ethane in THF solution. 3.8g of magnesium and 10.0g of THF solution were added to a 250mL dry reaction bottle in sequence, the temperature was raised to 50°C, and 17.0g of 1,2-bis(4-bromophenyl)ethane in THF solution was added dropwise under stirring to initiate the reaction, the temperature was raised to 60°C, the temperature was lowered to 50°C, and the remaining 1,2-bis(4-bromophenyl)ethane in THF solution was added dropwise, and the temperature was kept and stirred for 1h after the addition was completed. The Grignard preparation was completed after GC sampling. Prepare another 500mL dry reaction bottle, add 62.0g THF, cool to -20°C, pass 12.2g vinyl chloride, add 0.3g ferric chloride and 0.3g tetramethylethylenediamine (TMEDA), warm to 15°C, stir for 0.5h, add the prepared Grignard reagent dropwise under stirring, add dropwise for 1h, and keep stirring for 4h. After the reaction is completed, filter to obtain the mother liquor, desolventize to obtain the crude product, add 100.0g 5% hydrochloric acid aqueous solution and 100.0g EA to extract the liquid, desolventize the organic phase to obtain 16.2g of crude product, dissolve the crude product with 32.4g DCM, add 97.2g methanol and slowly cool to 0°C for crystallization, filter and dry to obtain 13.5g of product, GC purity 97.5%, yield 87.3%.

[0067] Example 3: Synthesis of 1,2-bis(4-vinylphenyl)ethane (BVPE)

[0068] In a 500mL dry reaction bottle, 15.0g of 1,2-bis(4-chlorophenyl)ethane (1,2-bis(4-chlorophenyl)ethane prepared by the method of step 1 of Example 1) and 30.0g of THF solution, 0.15g of ferric chloride and 0.15g of tetramethylethylenediamine (TMEDA) were added in turn, and the temperature was raised to 60°C, stirred for 0.5h, and 150ml of vinyl magnesium chloride reagent (1.0mol / LTHF solution) was added dropwise under stirring, and the addition was completed after 2h, and the mixture was kept warm and stirred for 4h. After the reaction was completed, the mother liquor was filtered to obtain a crude product, and 100.0g of 5% hydrochloric acid aqueous solution and 200.0g of EA were added to extract the liquid, and the organic phase was decompressed to obtain 13.4g of a crude product, which was dissolved with 26.8g of DCM, and 80.4g of methanol was added to slowly cool to 0°C for crystallization, and the product was filtered and dried to obtain 10.3g, with a GC purity of 98.7% and a yield of 73.6%.

[0069] Example 4: Synthesis of 1,2-bis(4-vinylphenyl)ethane (BVPE)

[0070] In a 500mL dry reaction bottle, 20.0g of 1,2-bis(4-bromophenyl)ethane (1,2-bis(4-bromophenyl)ethane prepared by the method of step 1 of Example 2) and 40.0g of THF solution, 0.15g of ferric chloride and 0.15g of tetramethylethylenediamine (TMEDA) were added in turn, and the temperature was raised to 60°C, stirred for 0.5h, and 147ml of vinyl magnesium chloride reagent (1.0mol / L) was added dropwise under stirring, and the addition was completed after 2h, and the mixture was kept warm and stirred for 4h. After the reaction was completed, the mother liquor was filtered to obtain a crude product, and 100.0g of 5% hydrochloric acid aqueous solution and 190.0g of EA were added to extract the liquid, and the organic phase was decompressed to obtain a crude product of 12.6g, which was dissolved with 25.2g of DCM, and 75.6g of methanol was added to slowly cool to 0°C for crystallization, and the product was filtered and dried to obtain 11.0g, with a GC purity of 98.3% and a yield of 79.8%.

[0071] Example 5: Synthesis of 1,2-bis(4-vinylphenyl)ethane (BVPE)

[0072] In a 500 mL dry reaction bottle, 20.0 g of 1,2-bis(4-bromophenyl)ethane (1,2-bis(4-bromophenyl)ethane prepared by the method of step 1 of Example 2) and 40.0 g of THF solution, 0.15 g of ferric chloride and 0.15 g of tetramethylethylenediamine (TMEDA) were added in sequence, the temperature was raised to 60 ° C, stirred for 0.5 h, and 150 ml of vinylmagnesium bromide reagent (1.0 mol / L THF) was added dropwise under stirring.

[0073] Solution), add dropwise for 2h, and stir for 4h. After the reaction, filter to obtain mother liquor, desolventize to obtain crude product, add 100.0g 5% hydrochloric acid aqueous solution and 190.0g EA to extract and separate, desolventize the organic phase to obtain 12.9g crude product, dissolve the crude product in 26g DCM, add 80g methanol and slowly cool to 0℃ for crystallization, filter and dry to obtain 10.9g product, GC purity 98.6%, yield 79.2%.

[0074] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0075] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for synthesizing 1,2-bis(4-vinylphenyl)ethane, characterized in that: The synthesis method comprises: 1) Under the action of magnesium or zinc, the p-halobenzyl halide undergoes a self-coupling reaction at the benzyl position to obtain 1,2-bis(4-halophenyl)ethane. The reaction equation is as follows: Wherein, X is Cl and / or Br; 2) The step of preparing 1,2-bis(4-vinylphenyl)ethane from 1,2-bis(4-halophenyl)ethane obtained in step 1) is selected from any one of the following schemes: 2i: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is prepared into a Grignard reagent, and then coupled with vinyl chloride to prepare 1,2-bis(4-vinylphenyl)ethane. The reaction equation is as follows: Wherein, X is Cl or Br; 2ii: The 1,2-bis(4-halophenyl)ethane obtained in step 1) is coupled with vinylmagnesium chloride or vinylmagnesium bromide to prepare 1,2-bis(4-vinylphenyl)ethane. The reaction equation is as follows: Wherein, X is Cl or Br.

2. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 1, characterized in that: Also includes any one or more of the following features: A1) in step 1), the para-halobenzyl halide is selected from the group consisting of para-chlorobenzyl chloride, para-bromobenzyl bromide, para-bromobenzyl chloride, and para-chlorobenzyl bromide; A2) in step 1), the coupling reaction is carried out in the presence of a first solvent, the first solvent being selected from the group consisting of one or more combinations of ether solvents, alkane solvents, and aromatic hydrocarbon solvents; A3) In step 1), the reaction temperature of the coupling reaction is -10 to 40°C; A4) In step 1), the coupling reaction time is 1 to 24 hours; A5) In step 1), the amount of magnesium or zinc is 0.5-0.65 equivalents to the amount of the halobenzyl halogen substance; A6) Step 1) further comprises post-treatment, wherein the post-treatment comprises extraction, liquid separation, concentration and purification; A7) In step 1), 1,2-bis(4-halophenyl)ethane is 1,2-bis(4-chlorophenyl)ethane or 1,2-bis(4-bromophenyl)ethane.

3. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 2, characterized in that: Also includes any one or more of the following features: A21) in step 1), the first solvent is selected from one or more combinations of diethyl ether, propyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, methyltetrahydrofuran, methyl cyclopentyl ether, methyl cyclohexyl ether, hexane, cyclohexane, heptane, benzene, toluene, xylene, trimethylbenzene, ethylbenzene, and isopropylbenzene; A22) In step 1), the mass of the first solvent used is 1 to 10 times the mass of the para-halobenzyl halide; A31) In step 1), the reaction temperature of the coupling reaction is 15-25°C.

4. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 3, characterized in that: Also includes any one or more of the following features: A211) in step 1), the first solvent is selected from a combination of one or more of tetrahydrofuran, methyltetrahydrofuran, toluene, and xylene; A221) In step 1), the mass of the first solvent used is 2 to 4 times the mass of the para-halobenzyl halide.

5. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 1, characterized in that: Also includes any one or more of the following features: B1) In step 2i), the molar ratio of 1,2-bis(4-halophenyl)ethane to Mg is 1:2-4; B2) In step 2i), the molar ratio of 1,2-bis(4-halophenyl)ethane to vinyl chloride is 1:2-5; B3) In step 2ii), the molar ratio of 1,2-bis(4-halophenyl)ethane to vinylmagnesium chloride is 1:2-5.

6. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 1, characterized in that: Also includes any one or more of the following features: C1) in step 2i) and step 2ii), a metal catalyst is included, wherein the metal catalyst is selected from a combination of one or more of palladium chloride, nickel chloride, ferric chloride, palladium acetate, tetrakistriphenylphosphine palladium, bistriphenylphosphine palladium dichloride, tris(dibenzylideneacetone)dipalladium, acetylacetonate palladium, and acetylacetonate nickel; C2) Step 2i) and step 2ii) further include a base, wherein the base is selected from a combination of one or more of tetramethylethylenediamine, triethylamine, diisopropylamine, pyridine, etc.; C3) In step 2i) and step 2ii), a second solvent is further included, and the second solvent is selected from a combination of one or more of ether solvents, alkane solvents, and aromatic hydrocarbon solvents.

7. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 6, characterized in that: Also includes any one or more of the following features: C11) In step 2i) and step 2ii), the amount of the metal catalyst used is 0.1% to 5% mol of the amount of 1,2-bis(4-halophenyl)ethane; C21) In step 2i) and step 2ii), the amount of the base is 1 to 10 times the amount of 1,2-bis(4-halophenyl)ethane; C22) In step 2i) and step 2ii), the base is tetramethylethylenediamine and / or diisopropylamine; C31) in step 2i) and step 2ii), the second solvent is selected from one or more combinations of diethyl ether, propyl ether, isopropyl ether, methyl tert-butyl ether, tetrahydrofuran, methyltetrahydrofuran, methyl cyclopentyl ether, methyl cyclohexyl ether, hexane, cyclohexane, heptane, benzene, toluene, xylene, trimethylbenzene, ethylbenzene and isopropylbenzene; C32) In step 2i) and step 2ii), the mass of the solvent used is 1 to 10 times the mass of 1,2-bis(4-halophenyl)ethane; 8. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 7, characterized in that: Also includes any one or more of the following features: C111) In step 2i) and step 2ii), the amount of the metal catalyst used is 0.5% to 2% mol of the amount of 1,2-bis(4-halophenyl)ethane; C211) In step 2i) and step 2ii), the amount of the base used is 6 to 8 times the amount of 1,2-bis(4-halophenyl)ethane; C311) In step 2i) and step 2ii), the second solvent is selected from a combination of one or more of tetrahydrofuran, methyltetrahydrofuran, toluene, and xylene; C321) In step 2i) and step 2ii), the mass of the second solvent used is 2 to 4 times the mass of 1,2-bis(4-halophenyl)ethane.

9. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 1, characterized in that: Also includes any one or more of the following features: D1) In step 2i) and step 2ii), the reaction temperature of the coupling reaction is -10 to 60°C; D2) In step 2i) and step 2ii), the coupling reaction time is 1 to 24 hours; D3) Step 2i) and step 2ii) further include post-treatment, which includes extraction, liquid separation, concentration and purification.

10. The method for synthesizing 1,2-bis(4-vinylphenyl)ethane according to claim 9, characterized in that: In step 2i) and step 2ii), the reaction temperature of the coupling reaction is 10-20°C.

Images