Chloromethylation catalyst, preparation method and method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene by using chloromethylation catalyst

Abstract

The invention relates to the technical field of catalytic synthesis, in particular to a chloromethylation catalyst, a preparation method of the chloromethylation catalyst and a method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene through the chloromethylation catalyst, and the chloromethylation catalyst is prepared by loading sulfonic acid compounds and (or) pyridine compounds and (or) copper salt on a molecular sieve. The method can improve the localization selectivity of chloromethylation. The method for preparing high-purity ortho-position, meta-position and para-position chloromethyl styrene comprises the following steps of: reacting beta-bromophenylethane, paraformaldehyde and lewis acid in the presence of the chloromethylation catalyst to generate chloromethyl beta-bromophenylethane, and then performing elimination reaction under an alkaline condition to generate a chloromethyl styrene crude product; the high-purity ortho-position, meta-position and para-position chloromethyl styrene is obtained after the crude product is rectified, the brand-new catalyst is adopted in the method, the reaction selectivity is enhanced, the process is simple, and industrial production is facilitated.

Description

Technical Field

[0001] This invention relates to the field of catalytic synthesis technology, specifically to a chloromethylation catalyst, its preparation method, and a method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene. Background Technology

[0002] The Blanc chloromethylation reaction is an important organic synthesis method that introduces chloromethyl functional groups into the structure of aromatic compounds. Chloromethyl groups have important chemical properties and can be converted into aminomethyl, hydroxymethyl, aldehyde, acetonitrile, etc. The resulting chemical intermediates can be applied in the fields of medicine, pesticides, and materials.

[0003] Currently, the catalysts for the Blanc chloromethylation reaction are mainly protic acids and Lewis acids, as reported in numerous patent-related articles. For example: (1) WO2007016525, using o-hydroxyacetophenone and paraformaldehyde as raw materials, undergoes chloromethylation at the meta-carbonyl and para-hydroxyl positions catalyzed by hydrochloric acid: (2) IN201623016318, using acetophenone and paraformaldehyde as raw materials, undergoes a chloromethylation reaction at the meta-carbonyl group catalyzed by aluminum trichloride: (3) US3948904, using phenylacetic acid and paraformaldehyde as raw materials, and zinc chloride as a catalyst, a chloromethylation reaction occurs at the para-carboxyl group: (4) US6160175, using 1-benzylnaphthalene and formaldehyde as raw materials, chloromethylation reaction occurs at the benzyl ortho position catalyzed by acetic acid, hydrochloric acid and phosphoric acid; (5) US3931205, using 5,10-dihydrobenzo[g]quinoline and paraformaldehyde as raw materials, the chloromethylation reaction occurs at the 8-position of the main raw materials catalyzed by sulfuric acid and hydrochloric acid; The catalysts used in the above chloromethylation reactions are mainly aluminum trichloride, zinc chloride, hydrochloric acid, sulfuric acid, and phosphoric acid. Under the orientation of aromatic hydrocarbon substituents, the chloromethylation products are obtained by catalysis. These catalysts still have some shortcomings, such as: (1) they are mainly protic acid and Lewis acid catalysts, and there are no supported catalysts; (2) protic acid and Lewis acid catalysts are not easy to recover; (3) the catalytic selectivity is greatly affected by substituents.

[0004] Chloromethylstyrene (CMS) is a compound containing vinyl and chloromethyl groups, and therefore possesses certain reactivity. It can undergo typical reactions such as addition, substitution, and polymerization, and has a wide range of applications.

[0005] Chloromethylstyrene can participate in polymerization reactions as a monomer to prepare various functional polymer materials. For example, it can polymerize into polymers with allyl side chains, thereby endowing materials with special properties and functions. Chloromethylstyrene can be used as a raw material for surfactants and surface modifiers. By introducing allyl or chloro groups, the hydrophilicity, wettability, and adhesion of materials can be modified, thereby improving the performance of materials in applications such as coatings, adhesives, and inks. Chloromethylstyrene is often used as an important intermediate in organic synthesis. It can undergo various substitution reactions, such as amino substitution, alkyl substitution, and alcohol substitution, to synthesize compounds with specific functional groups.

[0006] Currently, the main synthetic method for chloromethylstyrene involves the Blanc chloromethylation reaction of halophenylethanes with formaldehyde, followed by the elimination of hydrogen halides under alkaline conditions. This method has been reported in numerous publications. For example: (1) CN112723986, using 2-phenylethanol as raw material, through hydrochloric acid p-hydroxy chlorination, chloromethylation of paraformaldehyde and hydrogen chloride gas under zinc chloride catalysis, and elimination reaction with tert-butanol as base, p-chloromethylstyrene is synthesized: (2) Croatica Chemica Acta, 1976, 48: 59-64, using β-bromophenylethane and chloromethyl methyl ether as raw materials, carbon disulfide as solvent, and tin tetrachloride as catalyst to synthesize chloromethyl β-bromophenylethane, and using isobutanol as solvent and potassium hydroxide as base to eliminate and synthesize chloromethyl styrene: (3) Yuki Gosei Kagaku Kyokaishi, 1969, 27: 858-862, using β-bromophenylethane and chloromethyl methyl ether as raw materials, 1,1,2,2-tetrachloroethane as solvent, and aluminum trichloride as catalyst to synthesize chloromethyl β-bromophenylethane, and using tert-butanol as solvent and sodium tert-butoxide as base to eliminate and synthesize chloromethyl styrene: (4) Yuki Gosei Kagaku Kyokaishi, 1973, 31:1050, Synthetic Communications, 1974, 4:193-197, using β-bromophenylethane and chloromethyl methyl ether as raw materials, 1,1,2,2-tetrachloroethane as solvent, and aluminum trichloride as catalyst to synthesize chloromethyl β-bromophenylethane, and using diethyl ether and tert-butanol as solvent, and potassium tert-butoxide as base to eliminate and synthesize chloromethyl styrene: The above synthesis process has the following shortcomings: (1) The use of hydrogen chloride gas or chloromethyl ether will cause a large amount of hazardous waste, resulting in high costs and pollution; (2) Chloromethyl ether is a toxic reagent that will harm the human body; (3) Chloromethylation has poor selectivity, and the isomers are not easy to separate and purify. The proportion of each isomer in the chloromethyl styrene product is approximately: o-chloromethyl styrene 10~20%, m-chloromethyl styrene 5~10%, and p-chloromethyl styrene 70~75%. The low purity limits its application field. Summary of the Invention

[0007] The primary objective of this invention is to provide a chloromethylation catalyst and a preparation method thereof, which can enhance or alter the directing effect of aromatic hydrocarbon substituents and improve the yield of the target product.

[0008] The second objective of this invention is to provide a method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene using the above-mentioned chloromethylation catalyst, wherein the selectivity of chloromethylation is improved by co-catalyzing the chloromethylation catalyst with a Lewis acid.

[0009] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a chloromethylation catalyst involves loading a sulfonic acid compound and / or a pyridine compound and / or a copper salt onto a molecular sieve, specifically using any of the following preparation methods: The first method involves mixing sulfonic acid compounds with molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, controlling the temperature at 25 to 85°C, and maintaining the reaction temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C and dried in a forced-air oven for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-A. The second method involves mixing sulfonic acid compounds and molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, adding pyridine compounds, and mixing the pyridine compounds and sulfonic acid compounds in a molar ratio of 1:1 to 1:50. The temperature is controlled at 25 to 85°C, and the reaction is maintained at this temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C, and the mixture is dried in a forced-air oven for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-B. The third method involves mixing sulfonic acid compounds and molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, adding copper salt, and mixing the copper salt and sulfonic acid compounds in a molar ratio of 1:1 to 1:50. The temperature is controlled at 25 to 85°C, and the reaction is maintained at this temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C, and the mixture is dried in a forced-air oven for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-C.

[0010] Furthermore, the solvent is at least one selected from dichloromethane, trichloromethane, tetrahydrofuran, methanol, ethanol, toluene, and xylene.

[0011] Furthermore, the molecular sieve is at least one of the following varieties: 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve, 13X molecular sieve, SBA-15 molecular sieve, SAPO-34 molecular sieve, NKF-7 molecular sieve, titanium silicate molecular sieve TS-1, SSZ-13 molecular sieve, MCM-22 molecular sieve, NHY molecular sieve, HZSM-5 molecular sieve, ZSM-5 molecular sieve, N-1ZSM-5 molecular sieve, ZSM-23 molecular sieve, N-1β molecular sieve, SSM-13 molecular sieve, FX-I type molecular sieve, molecular sieve SAPO-34, TS-1 molecular sieve, HZSM-12 molecular sieve, HZSM-12 Hbeta type molecular sieve, 3A type hollow glass molecular sieve, USY molecular sieve, carbon molecular sieve, Y type molecular sieve, Beta molecular sieve, KIT-6 cubic structure mesoporous molecular sieve.

[0012] Furthermore, the sulfonic acid compound is at least one of methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid.

[0013] Furthermore, the pyridine compound is at least one selected from pyridine, 2-methylpyridine, 2,6-dimethylpyridine, 2,4-dimethylpyridine, 2,2'-bipyridine, and 4,4'-bipyridine.

[0014] Furthermore, the copper salt is at least one of copper acetate, copper bromide, and copper chloride.

[0015] The method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene using the chloromethylation catalyst described above in this invention involves reacting β-bromophenylethane, paraformaldehyde, and a Lewis acid under chloromethylation catalyst conditions to generate chloromethyl β-bromophenylethane. Then, an elimination reaction occurs under alkaline conditions to generate crude chloromethylstyrene. The crude product is then purified by distillation to obtain the final product, chloromethylstyrene. The specific steps include: (1) Chloromethylation reaction In the presence of a solvent, β-bromophenylethane and Lewis acid are mixed at a molar ratio of 1:2 to 1:5, and a chloromethylation catalyst is added, wherein the mass ratio of β-bromophenylethane to the chloromethylation catalyst is 1:0.001 to 1:0.5. Paraformaldehyde is added in batches, wherein the molar ratio of β-bromophenylethane to paraformaldehyde is 1:1 to 1:10. The reaction is carried out at a controlled temperature of 35 to 80°C for 5 to 25 hours. After the reaction is completed, the temperature is controlled at 10 to 20°C, and the mixture is added dropwise to 2N hydrochloric acid. The mixture is separated into liquid and liquid phases, and the aqueous phase is extracted with 1,2-dichloroethane. The liquid and liquid phases are then separated, and the combined organic phases are concentrated. After the solvent is evaporated, the residue is purified to obtain chloromethyl β-bromophenylethane with high purity; the yield is 60 to 95%.

[0016] (2) Elimination reaction In the presence of a solvent, chloromethyl β-bromophenylethane and a base are mixed at a molar ratio of 1:1 to 1:30. A polymerization inhibitor is added, with a mass ratio of chloromethyl β-bromophenylethane to the polymerization inhibitor of 1:0.01 to 1:0.3. A phase transfer catalyst is added, with a mass ratio of chloromethyl β-bromophenylethane to the phase transfer catalyst of 1:0.01 to 1:0.5. The temperature is controlled at 10 to 45°C, and the reaction is maintained at this temperature for 5 to 25 hours. After the reaction is completed, water is added, and the mixture is extracted with toluene. The liquid is separated, the organic phase is concentrated, and after the toluene is removed by evaporation, the residue is purified by distillation to obtain chloromethylstyrene with high purity; the yield is 65% to 95%.

[0017] Furthermore, in step (1), the solvent includes at least one of dichloromethane, trichloromethane, carbon tetrachloride, and 1,2-dichloroethane.

[0018] Furthermore, the Lewis acid includes at least one of aluminum trichloride, ferric trichloride, zinc chloride, tin tetrachloride, boron trifluoride, titanium tetrachloride, indium chloride, zirconium tetrachloride, aluminum tribromide, copper chloride, ferric tribromide, niobium chloride, and antimony chloride.

[0019] Furthermore, the Lewis acid can be one of the following combinations, including but not limited to aluminum trichloride + ferric trichloride, aluminum trichloride + zinc chloride, ferric trichloride + zinc chloride, aluminum trichloride + tin tetrachloride, aluminum trichloride + titanium tetrachloride, aluminum trichloride + indium chloride, aluminum trichloride + zirconium tetrachloride, aluminum trichloride + copper chloride, aluminum trichloride + ferric tribromide, aluminum trichloride + niobium chloride, and aluminum trichloride + antimony chloride.

[0020] When using a combination of two Lewis acids, the ratio of the two acids is (1~10):(99~90), (11~20):(89~80), (21~30):(79~70), (31~40):(69~60), (41~50):(59~50), (51~60):(49~40), (61~70):(39~30), (71~80):(29~20), (81~90):(19~10) or (91~99):(9~1).

[0021] Furthermore, in step (2), the solvent includes at least one of toluene, xylene, tetrahydrofuran, methyltetrahydrofuran, and dioxane.

[0022] Furthermore, in step (2), the alkali includes at least one of potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, and sodium hydroxide.

[0023] The phase transfer catalyst includes at least one of p-tert-butylcatechol, o-nitroethylbenzene, o-nitrophenol, and o-nitro-p-cresol.

[0024] Furthermore, the polymerization inhibitor includes at least one of 18-crown-6, tetrabutylammonium bromide, tetrabutylammonium chloride, and polyethylene glycol.

[0025] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention prepares a new supported catalyst that can catalyze the chloromethylation reaction of Blanc.

[0026] (2) The method for preparing the chloromethylation catalyst of the present invention is simple, and the catalyst can be recovered, which can improve or change the positioning effect of the substituent and improve the yield of the target product.

[0027] (3) In the method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene of the present invention, the mass ratio of chloromethylstyrene isomers can be controlled, avoiding the use of highly polluting and highly toxic reagents; there are few by-products in the reaction, which are easy to purify by distillation and are conducive to industrial production. Attached Figure Description

[0028] Figure 1 The NMR spectrum of the product in Example 4 is shown.

[0029] Figure 2 The NMR spectrum of the product from Example 5 is shown below.

[0030] Figure 3 The NMR spectrum of the product from Example 6 is shown below. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0032] Example 1 Add 50g of 4A molecular sieve and 300g of dichloromethane to a reaction flask, start stirring, add 5g of methanesulfonic acid, keep the reaction at 25~35℃ for 11 hours, filter, and dry the solid at 85℃ for 6 hours to obtain an off-white powder weighing 43.1g. The catalyst code is MR-A-02.

[0033] The catalyst was prepared using the same process parameters as catalyst MR-A-02, only the molecular sieve type and sulfonic acid compound were changed. Details are shown in the table below.

[0034] Molecular sieve type Sulfonic acid compound Catalyst code 3A Methanesulfonic acid MR-A-01 4A Methanesulfonic acid MR-A-02 5A Methanesulfonic acid MR-A-03 10X Methanesulfonic acid MR-A-04 13X Methanesulfonic acid MR-A-05 ZSM-5 p-Toluenesulfonic acid MR-A-06 HZSM-5 p-Toluenesulfonic acid MR-A-07 HZSM-12 p-Toluenesulfonic acid MR-A-08 ZSM-5 Methanesulfonic acid MR-A-09 HZSM-5 Methanesulfonic acid MR-A-10 HZSM-12 Methanesulfonic acid MR-A-11 Example 2 Add 50g of 4A molecular sieve and 250g of ethanol to the reaction flask, start stirring, add 6g of p-toluenesulfonic acid and 3.3g of pyridine, keep the reaction at 55~65℃ for 8 hours, cool to 20~30℃, filter, and dry the solid at 85℃ for 6 hours to obtain an off-white powder weighing 39.8g. The catalyst code is MR-B-14.

[0035] The catalyst was prepared using the same process parameters as catalyst MR-B-14, only changing the molecular sieve type, sulfonic acid compound, and pyridine compound. Details are shown in the table below.

[0036] Molecular sieve type Sulfonic acid compound Pyridine compound Catalyst code 3A Methanesulfonic acid Pyridine MR-B-01 4A Methanesulfonic acid Pyridine MR-B-02 5A Methanesulfonic acid Pyridine MR-B-03 10X Methanesulfonic acid 2, 6-Dimethylpyridine MR-B-04 13X Methanesulfonic acid 2, 6-Dimethylpyridine MR-B-05 ZSM-5 p-Toluenesulfonic acid 2, 6-Dimethylpyridine MR-B-06 HZSM-5 p-Toluenesulfonic acid 2, 6-Dimethylpyridine MR-B-07 HZSM-12 Methanesulfonic acid 2, 6-Dimethylpyridine MR-B-08 ZSM-5 Methanesulfonic acid 2, 6-Dimethylpyridine MR-B-09 HZSM-5 Methanesulfonic acid 2, 6-Dimethylpyridine MR-B-10 ZSM-5 p-Toluenesulfonic acid Pyridine MR-B-11 HZSM-5 p-Toluenesulfonic acid Pyridine MR-B-12 HZSM-12 Methanesulfonic acid Pyridine MR-B-13 4A p-Toluenesulfonic acid Pyridine MR-B-14 Example 3 Add 50g of 4A molecular sieve and 300g of tetrahydrofuran to a reaction flask, start stirring, add 6.5g of p-toluenesulfonic acid and 13.7g of copper acetate, keep the temperature at 50~60℃ for 11 hours, cool to 20~30℃, filter, and dry the solid at 85℃ for 8 hours to obtain an off-white powder weighing 40.2g. The catalyst code is MR-C-16.

[0037] The catalyst was prepared using the same process parameters as catalyst MR-C-16, only the molecular sieve type, sulfonic acid compound, and copper salt were changed. Details are shown in the table below.

[0038] Molecular sieve type Sulfonic acid compound Copper salt Catalyst code 3A Methanesulfonic acid Copper chloride MR-C-01 4A Methanesulfonic acid Copper chloride MR-C-02 5A Methanesulfonic acid Copper bromide MR-C-03 10X Methanesulfonic acid Copper bromide MR-C-04 13X Methanesulfonic acid Copper acetate MR-C-05 ZSM-5 p-Toluenesulfonic acid Copper acetate MR-C-06 HZSM-5 p-Toluenesulfonic acid Copper acetate MR-C-07 HZSM-12 Methanesulfonic acid Copper acetate MR-C-08 5A Methanesulfonic acid Copper acetate MR-C-09 5A p-Toluenesulfonic acid Copper acetate MR-C-10 ZSM-5 Methanesulfonic acid Copper acetate MR-C-11 HZSM-5 Methanesulfonic acid Copper acetate MR-C-12 ZSM-5 Methanesulfonic acid Copper bromide MR-C-13 HZSM-5 Methanesulfonic acid Copper bromide MR-C-14 10X Methanesulfonic acid Copper acetate MR-C-15 4A p-Toluenesulfonic acid Copper acetate MR-C-16 Comparative Example (1) Add 150g of 1,2-dichloroethane and 64.8g of aluminum trichloride to the reaction flask, start stirring, control the temperature at 0~5℃, add 30g of β-bromophenylethane dropwise, after the addition is complete, control the temperature at 15~25℃, add 12.1g of paraformaldehyde in batches, start heating, keep the temperature at 40~45℃ for 6 hours, and detect the reaction by TLC (n-heptane: ethyl acetate = 3:1) and HPLC. After the reaction is complete, cool down to 15~25℃ and add dropwise to 1N hydrochloric acid. During the dropwise addition, control the temperature at 5~15℃. After quenching, separate the liquid and add 50g of β-bromophenylethane to the aqueous phase. Extracted with 1,2-dichloroethane, separated, and the organic phases were combined. The solvent was concentrated under reduced pressure to give a white solid mixture of chloromethyl β-bromophenylethane, weighing 26.2 g, with a yield of 69.2%. GC purity: o-chloromethyl β-bromophenylethane 16.3%, m-chloromethyl β-bromophenylethane 5.6%, and p-chloromethyl β-bromophenylethane 76.5%.

[0039] (2) Add 26g of chloromethyl β-bromophenylethane and 200g of toluene to the reaction flask, start stirring, add 7.5g of potassium hydroxide, 2.6g of polyethylene glycol 600 and 0.26g of p-tert-butylcatechol, keep warm at 35~45℃ for 11 hours, and detect the reaction by TLC (n-heptane: ethyl acetate = 3:1) and HPLC. After the reaction is completed, add 100g of water, extract, separate the liquid, concentrate the organic solvent under reduced pressure, and purify the residue by reduced pressure distillation to obtain colorless transparent liquid chloromethyl styrene, weighing 15.2g, yield 89.4%, GC purity: o-chloromethyl β-bromostyrene 16.5%, m-chloromethyl β-bromostyrene 5.7%, p-chloromethyl β-bromostyrene 76.8%.

[0040] Example 4 (1) Add 150g of 1,2-dichloroethane and 54.0g of aluminum trichloride to the reaction flask, start stirring, add 0.3g of catalyst MR-A-10, control the temperature at 0~5℃, add 30g of β-bromophenylethane dropwise, after the addition is complete, control the temperature at 15~25℃, add 14.6g of paraformaldehyde in batches, start heating, keep the temperature at 40~45℃ for 5.5 hours, and detect the reaction by TLC (n-heptane: ethyl acetate = 3:1) and HPLC. After the reaction is complete, cool down to 15~25℃ and add dropwise to 1N hydrochloric acid. During the dropwise addition, control the temperature at 5~15℃. After quenching, separate the liquid and add 50g of β-bromophenylethane to the aqueous phase. Extracted with 1,2-dichloroethane, separated, and the organic phases were combined. The solvent was concentrated under reduced pressure. The crude product had the following GC purity: o-chloromethylβ-bromophenylethane 7.3%, m-chloromethylβ-bromophenylethane 0.3%, and p-chloromethylβ-bromophenylethane 90.6%. It was crystallized from toluene to obtain a white solid p-chloromethylβ-bromophenylethane, weighing 30.5 g, with a yield of 80.5% and a GC purity of 99.6%.

[0041] (2) Add 30g of p-chloromethylβ-bromophenylethane and 250g of toluene to the reaction flask, start stirring, add 24.7g of sodium tert-butoxide, 3.0g of 18-crown-6, and 0.3g of o-nitrobenzene, and keep the mixture at 35~45℃ for 11 hours. After the reaction is completed, add 100g of water, extract, separate the contents, concentrate the organic solvent under reduced pressure, and purify the residue by distillation under reduced pressure to obtain a colorless and transparent liquid p-chloromethylstyrene, weighing 15.5g, with a yield of 79.0% and a GC purity of 99.8%. The NMR spectrum is shown below. Figure 1 As shown.

[0042] The catalytic effects of the various catalysts prepared in Example 1 are compared in the table below.

[0043] Catalyst code o-Chloromethyl β-bromostyrene m-Chloromethyl β-bromostyrene p-Chloromethyl β-bromostyrene Yield MR-A-01 28.8 3.8 61.7 50.3 MR-A-02 29.6 3.7 63.6 51.4 MR-A-03 28.5 4.1 64.5 50.2 MR-A-04 27.8 4.3 62.3 53.3 MR-A-05 25.1 4.5 67.2 52.5 MR-A-06 10.1 1.7 85.2 70.5 MR-A-07 10.3 1.5 86.5 70.3 MR-A-08 25.3 2.5 66.5 55.1 MR-A-09 7.0 0.5 90.1 78.5 MR-A-10 7.3 0.3 90.6 80.5 MR-A-11 26.6 2.8 67.6 55.3 Example 5 (1) Add 150g of 1,2-dichloroethane, 43.2g of aluminum trichloride, and 11.0g of zinc chloride to the reaction flask, start stirring, add 0.45g of catalyst MR-B-09, control the temperature at 0~5℃, add 30g of β-bromophenylethane dropwise, after the addition is complete, control the temperature at 15~25℃, add 17.0g of paraformaldehyde in batches, start heating, keep the temperature at 65~75℃ for 10 hours, and detect the reaction by TLC (n-heptane: ethyl acetate = 3:1) and HPLC. After the reaction is complete, cool down to 15~25℃ and add dropwise to 1N hydrochloric acid. During the dropwise addition, control the temperature at 5~15℃. After quenching, separate the liquid and add 50g of β-bromophenylethane to the aqueous phase. Extracted with 1,2-dichloroethane, separated, and the organic phases were combined. The solvent was concentrated under reduced pressure. The crude product had the following GC purity: o-chloromethylβ-bromophenylethane 16.3%, m-chloromethylβ-bromophenylethane 75.6%, and p-chloromethylβ-bromophenylethane 6.5%. Recrystallized from toluene and n-heptane in a 5:1 ratio, a white solid m-m-chloromethylβ-bromophenylethane was obtained, weighing 25.3 g, with a yield of 66.8% and a GC purity of 99.7%.

[0044] (2) Add 25g of m-chloromethyl β-bromophenylethane and 200g of toluene to the reaction flask, start stirring, add 14.4g of potassium tert-butoxide, 2.5g of tetrabutylammonium chloride, and 0.25g of p-tert-butylcatechol, and keep the mixture at 35~45℃ for 11 hours. After the reaction is completed, add 100g of water, extract, separate the contents, concentrate the organic solvent under reduced pressure, and purify the residue by distillation under reduced pressure to obtain a colorless transparent liquid m-chloromethylstyrene, weighing 14.1g, with a yield of 86.3% and a GC purity of 99.7%. The NMR spectrum is shown below. Figure 2 As shown.

[0045] The catalytic effects of the various catalysts prepared in Example 2 are compared in the table below.

[0046] Catalyst code o-Chloromethyl β-bromostyrene m-Chloromethyl β-bromostyrene p-Chloromethyl β-bromostyrene Yield MR-B-01 14.5 52.3 30.8 40.2 MR-B-02 16.3 52.7 28.5 40.5 MR-B-03 12.5 53.7 31.5 41.2 MR-B-04 16.1 52.5 29.7 42.3 MR-B-05 12.7 53.6 30.9 41.5 MR-B-06 15.5 71.5 8.6 60.1 MR-B-07 15.8 72.6 9.3 59.8 MR-B-08 16.6 57.1 23.5 47.2 MR-B-09 16.3 75.6 6.5 66.8 MR-B-10 13.8 73.1 10.1 61.5 MR-B-11 14.3 74.3 9.8 61.8 MR-B-12 13.7 73.8 10.5 60.3 MR-B-13 MR-B-14 13.9 61.1 21.5 50.1 MR-B-14 17.5 57.8 22.3 48.3 Example 6 (1) Add 150g of 1,2-dichloroethane, 32.4g of aluminum trichloride, and 25.0g of indium chloride to the reaction flask, start stirring, add 0.6g of catalyst MR-C-07, control the temperature at 0~5℃, add 30g of β-bromophenylethane dropwise, after the addition is complete, control the temperature at 15~25℃, add 17.0g of paraformaldehyde in batches, start heating, keep the temperature at 45~55℃ for 8 hours, and detect the reaction by TLC (n-heptane: ethyl acetate = 3:1) and HPLC. After the reaction is complete, cool down to 15~25℃ and add dropwise to 1N hydrochloric acid. During the dropwise addition, control the temperature at 5~15℃. After quenching, separate the liquid and add 50g of β-bromophenylethane to the aqueous phase. Extracted with 1,2-dichloroethane, separated, and the organic phases were combined. The solvent was concentrated under reduced pressure. The crude product had the following GC purity: o-chloromethylβ-bromophenylethane 83.8%, m-chloromethylβ-bromophenylethane 5.1%, and p-chloromethylβ-bromophenylethane 9.5%. After purification by distillation, a colorless and transparent liquid mixture of o-chloromethylβ-bromophenylethane was obtained, weighing 27.5 g, with a yield of 72.6% and a GC purity of 99.6%.

[0047] (2) Add 27g of o-chloromethyl β-bromophenylethane and 200g of toluene to the reaction flask, start stirring, add 5.5g of sodium hydroxide, 2.7g of tetrabutylammonium chloride, and 0.27g of p-tert-butylcatechol, and keep the mixture at 35~45℃ for 11 hours. After the reaction is completed, add 100g of water, extract, separate the contents, concentrate the organic solvent under reduced pressure, and purify the residue by distillation under reduced pressure to obtain a colorless and transparent liquid o-chloromethylstyrene, weighing 15.6g, with a yield of 88.4% and a GC purity of 99.7%. The NMR spectrum is shown below. Figure 3 As shown.

[0048] The catalytic effects of the various catalysts prepared in Example 3 are compared in the table below.

[0049] Molecular sieve models o-Chloromethyl β-bromophenylethane % m-Chloromethyl β-bromophenylethane % p-Chloromethyl β-bromophenyl ethane % Yield % MR-C-01 61.7 12.3 22.3 46.2 MR-C-02 58.5 13.4 25.2 41.8 MR-C-03 57.8 12.7 26.1 42.6 MR-C-04 60.2 11.7 24.8 43.3 MR-C-05 59.6 13.3 25.0 41.3 MR-C-06 80.2 5.7 11.8 69.3 MR-C-07 83.8 5.1 9.5 72.6 MR-C-08 58.7 12.7 25.6 44.7 MR-C-09 60.5 11.3 25.3 45.1 MR-C-10 57.2 13.6 26.1 43.2 MR-C-11 79.5 6.1 12.1 68.6 MR-C-12 78.8 6.8 11.2 67.5 MR-C-13 68.1 7.9 20.2 57.1 MR-C-14 67.3 8.3 21.2 55.2 MR-C-15 61.2 8.7 26.5 52.3 MR-C-16 59.5 10.7 27.1 46.2 Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a chloromethylation catalyst, characterized in that, Any of the following preparation methods can be used: The first method involves mixing sulfonic acid compounds with molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, controlling the temperature at 25 to 85°C, and maintaining the reaction temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C and dried for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-A. The second method involves mixing sulfonic acid compounds and molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, adding pyridine compounds, and mixing the pyridine compounds and sulfonic acid compounds in a molar ratio of 1:1 to 1:

50. The temperature is controlled at 25 to 85°C, and the reaction is maintained at this temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C, and the mixture is dried for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-B. The third method involves mixing sulfonic acid compounds and molecular sieves in the presence of a solvent at a mass ratio of 1:1 to 1:100, adding copper salt, and mixing the copper salt and sulfonic acid compounds in a molar ratio of 1:1 to 1:

50. The temperature is controlled at 25 to 85°C, and the reaction is maintained at this temperature for 5 to 25 hours. After concentrating the solvent, the temperature is controlled at 85 to 100°C, and the mixture is dried for 5 to 20 hours to obtain a white powder, which is the chloromethylation catalyst MR-C.

2. The method for preparing the chloromethylation catalyst according to claim 1, characterized in that: The solvent is at least one of dichloromethane, trichloromethane, tetrahydrofuran, methanol, ethanol, toluene, and xylene.

3. The method for preparing the chloromethylation catalyst according to claim 2, characterized in that: The molecular sieve is at least one of the following varieties: 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve, 13X molecular sieve, SBA-15 molecular sieve, SAPO-34 molecular sieve, NKF-7 molecular sieve, titanium silicate molecular sieve TS-1, SSZ-13 molecular sieve, MCM-22 molecular sieve, NHY molecular sieve, HZSM-5 molecular sieve, ZSM-5 molecular sieve, N-1ZSM-5 molecular sieve, ZSM-23 molecular sieve, N-1β molecular sieve, SSM-13 molecular sieve, FX-I type molecular sieve, molecular sieve SAPO-34, TS-1 molecular sieve, HZSM-12 molecular sieve, HZSM-12 Hbeta type molecular sieve, 3A type hollow glass molecular sieve, USY molecular sieve, carbon molecular sieve, Y type molecular sieve, Beta molecular sieve, KIT-6 cubic structure mesoporous molecular sieve.

4. The method for preparing the chloromethylation catalyst according to claim 3, characterized in that: The sulfonic acid compound is at least one of methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid; the pyridine compound is at least one of pyridine, 2-methylpyridine, 2,6-dimethylpyridine, 2,4-dimethylpyridine, 2,2'-bipyridine, and 4,4'-bipyridine; and the copper salt is at least one of copper acetate, copper bromide, and copper chloride.

5. The chloromethylation catalyst prepared by the method according to any one of claims 1-4.

6. A method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene using the chloromethylation catalyst of claim 5, characterized in that, Includes the following steps: (1) Chloromethylation reaction: In the presence of a solvent, β-bromophenylethane and Lewis acid are mixed at a molar ratio of 1:2 to 1:5, and the chloromethylation catalyst described in claim 5 is added, wherein the mass ratio of β-bromophenylethane to the chloromethylation catalyst is 1:0.001 to 1:0.5; paraformaldehyde is added in batches, wherein the molar ratio of β-bromophenylethane to paraformaldehyde is 1:1 to 1:10; the temperature is controlled at 35 to 80°C, and the reaction is kept at this temperature for 5 to 25 hours. After the reaction is completed, the temperature is controlled at 10 to 20°C, and the mixture is added dropwise to 2N hydrochloric acid. The mixture is separated, the aqueous phase is extracted with 1,2-dichloroethane, separated, and the combined organic phases are concentrated. After the solvent is removed by evaporation, the residue is purified to obtain chloromethyl β-bromophenylethane. (2) Elimination reaction: In the presence of a solvent, chloromethyl β-bromophenylethane and a base are mixed at a molar ratio of 1:1 to 1:

30. An inhibitor is added, with a mass ratio of chloromethyl β-bromophenylethane to the inhibitor of 1:0.01 to 1:0.

3. A phase transfer catalyst is added, with a mass ratio of chloromethyl β-bromophenylethane to the phase transfer catalyst of 1:0.01 to 1:0.

5. The temperature is controlled at 10 to 45°C, and the reaction is maintained at this temperature for 5 to 25 hours. After the reaction is completed, water is added, toluene is extracted, the liquid is separated, the organic phase is concentrated, toluene is removed by distillation, and the residue is purified by distillation to obtain chloromethylstyrene.

7. The method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene according to claim 6, characterized in that: In step (1), the solvent includes at least one of dichloromethane, trichloromethane, carbon tetrachloride, and 1,2-dichloroethane; the Lewis acid includes at least one of aluminum trichloride, ferric chloride, zinc chloride, tin tetrachloride, boron trifluoride, titanium tetrachloride, indium chloride, zirconium tetrachloride, aluminum tribromide, copper chloride, ferric tribromide, niobium chloride, and antimony chloride.

8. The method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene according to claim 7, characterized in that: When using a combination of two Lewis acids, the ratio of the two acids is (1~10):(99~90), (11~20):(89~80), (21~30):(79~70), (31~40):(69~60), (41~50):(59~50), (51~60):(49~40), (61~70):(39~30), (71~80):(29~20), (81~90):(19~10) or (91~99):(9~1).

9. The method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene according to claim 6, characterized in that: In step (2), the solvent includes at least one of toluene, xylene, tetrahydrofuran, methyltetrahydrofuran, and dioxane; the base includes at least one of potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, and sodium hydroxide.

10. The method for preparing high-purity ortho-, meta-, and para-chloromethylstyrene according to claim 6, characterized in that: In step (2), the phase transfer catalyst includes at least one of p-tert-butylcatechol, o-nitroethylbenzene, o-nitrophenol, and o-nitro-p-cresol; the polymerization inhibitor includes at least one of 18-crown-6, tetrabutylammonium bromide, tetrabutylammonium chloride, and polyethylene glycol.

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