A method for synthesizing carboxyl-containing adamantyl methacrylate-based resin monomers
The improved synthesis method solves the problems of low conversion rate and use of highly toxic raw materials for carboxyl-containing adamantane methacrylate resin monomers, achieving high-purity, high-yield green synthesis suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN MANARECO NEW MATERIALS CO LTD
- Filing Date
- 2023-12-28
- Publication Date
- 2026-06-02
AI Technical Summary
The synthesis of carboxyl-containing adamantane methacrylate resin monomers in the existing technology suffers from problems such as low conversion rate, large amount of raw material residue, and use of highly toxic raw materials.
A method for synthesizing a carboxyl-containing adamantane methacrylate resin monomer includes the following steps: S1: preparing methyl 3-hydroxyadamantane-1-carboxylate under the conditions of concentrated sulfuric acid and a primary alcohol; S2: esterifying methyl 3-methacrylate-adamantane-1-carboxylate in a dichloromethane solution of methacryloyl chloride and triethylamine; and S3: preparing the carboxyl-containing adamantane methacrylate resin monomer by alkaline hydrolysis in an aqueous solution of an alkali and a secondary alcohol. This method avoids the use of highly toxic substances and employs a protective reaction to improve the conversion rate.
This process achieves a green and environmentally friendly synthesis, improves the quality and yield of the target product, ensures high product purity, facilitates large-scale production, and avoids the use of highly toxic raw materials.
Smart Images
Figure CN117800842B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for synthesizing adamantane methacrylate resin monomer containing a carboxyl group. Background Technology
[0002] Methacrylate resin monomers have research value and application prospects in fields such as information display and photosensitive adhesive materials. Among them, carboxyl-containing adamantane methacrylate resin monomers are an important class of functional resin raw materials. Bridgehead alicyclic resin compounds containing adamantane skeletons have advantages such as rigid structure, high surface hardness, high heat resistance, and excellent optical properties.
[0003] To date, numerous studies have reported on the synthesis of carboxyl-containing adamantane methacrylate resin monomers. The two main conventional synthetic methods are as follows:
[0004] Method 1 (CN112794834A):
[0005]
[0006] Method 2 (JP2016-84315A):
[0007]
[0008] In Method 1, when carboxyl groups are present in the raw materials and products, the conversion rate of the esterification reaction is low and the raw material residue is large, making it difficult to achieve industrial-scale production. In Method 2, the first step uses chloromethyl ether, a highly toxic substance, which is volatile and difficult to store, making it unsuitable for large-scale production. In the third step of Method 2, when hydrochloric acid is used to remove the MOM protecting group, the conditions are strong and the ester bond on the methacrylate side will break, resulting in low selectivity of the main product. Summary of the Invention
[0009] The purpose of this invention is to solve the technical problems in the synthesis of carboxyl-containing adamantane methacrylate resin monomers, such as low conversion rate, large amount of raw material residue, use of highly toxic raw materials, and low selectivity of main product.
[0010] To address the above objective, this application provides a method for synthesizing a carboxyl-containing adamantane methacrylate resin monomer to meet this need in the field.
[0011] On one hand, the present invention relates to 1. a method for synthesizing a carboxyl-containing adamantane methacrylate resin monomer, comprising the following reaction steps:
[0012]
[0013] Furthermore, the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention includes the following steps:
[0014] S1: 3-Hydroxyadamantane-1-carboxylic acid is prepared as methyl 3-hydroxyadamantane-1-carboxylic acid under reaction conditions containing concentrated sulfuric acid and a primary alcohol;
[0015] S2: Methyl 3-hydroxyadamantane-1-carboxylate is esterified in reaction conditions containing methacryloyl chloride, triethylamine, and dichloromethane to produce methyl 3-methacrylate-adamantane-1-carboxylate.
[0016] S3: 3-Methacrylate-adamantane-1-carboxylic acid methyl ester is prepared by alkaline hydrolysis of methacryloyl chloride in the presence of alkali, water, and a second alcohol to obtain a carboxyl-containing adamantane methacrylate resin monomer.
[0017] The structural formula of the carboxyl-containing adamantane methacrylate resin monomer is shown in formula (1).
[0018]
[0019] The first alcohol or the second alcohol is an alcohol with 1 to 3 carbon atoms.
[0020] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, the first alcohol is methanol, the second alcohol is ethanol, and the base is sodium hydroxide.
[0021] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, the mass ratio of sulfuric acid to 3-hydroxyadamantane-1-carboxylic acid is 1:0.1 to 0.5;
[0022] The molar ratio of methyl 3-hydroxyadamantane-1-carboxylic acid to triethylamine is 1:1.5 to 4.5;
[0023] The molar ratio of methyl 3-hydroxyadamantane-1-carboxylate to methacryloyl chloride is 1:1.0 to 2.5;
[0024] The mass ratio of methyl 3-methacrylate-adamantane-1-carboxylic acid ester to the base is 1:1.0 to 1.8.
[0025] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, S1 includes: under nitrogen protection, stirring and adding concentrated sulfuric acid dropwise to a mixture of 3-hydroxyadamantane-1-carboxylic acid and a first alcohol, followed by heating to reflux at 55°C to 65°C to obtain a first reaction solution containing methyl 3-hydroxyadamantane-1-carboxylic acid.
[0026] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, when concentrated sulfuric acid is added dropwise to the mixture of 3-hydroxyadamantane-1-carboxylic acid and the first alcohol, the reaction temperature is 20℃~65℃.
[0027] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, S2 includes: under nitrogen protection, adding methyl 3-hydroxyadamantane-1-carboxylate and triethylamine sequentially to dichloromethane, stirring, cooling and adding methacryloyl chloride dropwise, and then maintaining the temperature to react after the addition is complete, to obtain a second reaction solution containing methyl 3-methacrylate adamantane-1-carboxylate.
[0028] Furthermore, in the synthesis method of carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, methacryloyl chloride is added dropwise while the temperature is lowered to -20℃ to 10℃.
[0029] Furthermore, in the method for synthesizing carboxyl-containing adamantane methacrylate resin monomers provided by the present invention, step S3 includes: under nitrogen protection, adding a second alcohol and methyl 3-methacrylate adamantane-1-carboxylic acid to the aqueous solution of the alkali, and heating to reflux at 55°C to 65°C to react, thereby obtaining a third reaction solution containing the carboxyl-containing adamantane methacrylate resin monomer.
[0030] Compared with the prior art, the present invention has the following beneficial effects or advantages:
[0031] This invention provides a method for synthesizing carboxyl-containing adamantane methacrylate resin monomers. The raw materials used in the preparation are non-toxic, green, environmentally friendly, and environmentally friendly. The process of protecting the raw materials before esterification avoids affecting the conversion rate of the esterification reaction in the presence of carboxyl groups. The reaction type is simple, easy to implement, and easy to scale up for production. The target product obtained has stable quality, high content (99.40% main content in GC chromatography), and small polymer size. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 The image shows the GC chromatogram of the carboxyl-containing adamantane methacrylate resin monomer prepared in Example 2.
[0034] Figure 2The 1H-NMR spectrum of the carboxyl-containing adamantane methacrylate resin monomer prepared in Example 2 is shown. Detailed Implementation
[0035] The technical solution of the present invention will be described below with reference to the embodiments. However, the present invention is not limited to the following embodiments.
[0036] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.
[0037] Unless otherwise specified, the experimental and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.
[0038] This invention provides a method for synthesizing carboxyl-containing adamantane methacrylate resin monomers, the synthetic route of which is as follows:
[0039]
[0040] Specifically, it includes the following steps:
[0041] S1: Under nitrogen protection, concentrated sulfuric acid was added dropwise to a mixture of 3-hydroxyadamantane-1-carboxylic acid and methanol at 20℃~65℃ with stirring. The mixture was then heated to reflux (55℃~65℃) and reacted for 1~8 hours to obtain the first reaction solution. The first reaction solution was concentrated, washed with alkali, extracted, washed with water, and concentrated to obtain methyl 3-hydroxyadamantane-1-carboxylic acid. The mass ratio of sulfuric acid to 3-hydroxyadamantane-1-carboxylic acid was 1:0.1~0.5.
[0042] S2: Under nitrogen protection, methyl 3-hydroxyadamantane-1-carboxylate and triethylamine were added sequentially to dichloromethane, stirred, and cooled to -20℃~10℃ before adding methacryloyl chloride dropwise. After the addition was complete, the reaction was kept at this temperature for 2 hours to obtain a second reaction solution. The second reaction solution was filtered, extracted with organic phase, washed with water, and concentrated to obtain methyl 3-methacrylate adamantane-1-carboxylate.
[0043] S3: Under nitrogen protection, a second alcohol and methyl 3-methacrylate adamantane-1-carboxylic acid were added to an aqueous solution of sodium hydroxide. The mixture was heated to reflux at 55℃~65℃ and reacted for 1h~5h to obtain a third reaction solution. The third reaction solution was concentrated, back-extracted, separated, acidified, extracted, washed with water, concentrated, and recrystallized to obtain adamantane methacrylate resin monomer compounds containing carboxyl groups.
[0044] The structural formula of the carboxyl-containing adamantane methacrylate resin monomer is shown in formula (1).
[0045]
[0046] The first alcohol or the second alcohol is an alcohol with 1 to 3 carbon atoms.
[0047] Example 1
[0048] This embodiment provides a preparation experiment of adamantane methacrylate resin monomer containing a carboxyl group.
[0049] Under S1 and N2 protection, 2400 mL of methanol and 400 g of 3-hydroxyadamantane-1-carboxylic acid were added to a 5 L three-necked flask. Stirring was started, and 40 g of sulfuric acid was added dropwise at room temperature, maintaining the temperature below 65 °C during the addition. After the addition was complete, the mixture was kept at 55 °C–65 °C for 2 hours, then cooled to below 40 °C, and the methanol was concentrated. The methanol was extracted with dichloromethane, and the pH was adjusted to 7–8 with sodium bicarbonate aqueous solution. The solution was concentrated to dryness to obtain 422.2 g of a brown liquid (yield after dissolution was 97.22%, GC = 98.6934%).
[0050] Under S2 and N2 protection, 1000 mL of dichloromethane, 200 g of methyl 3-hydroxyadamantane-1-carboxylate (theoretical amount), and 144.38 g of triethylamine were added to a 3 L three-necked flask. The temperature was lowered to -10℃ to 0℃, and 99.43 g of methacryloyl chloride was added dropwise while maintaining the temperature at -10℃ to 0℃ during the dropwise addition. After the addition was complete, the temperature was kept at -10℃ to 0℃ for 2 h. The reaction solution was filtered, the filter cake was washed with dichloromethane, and the solution was dried under vacuum. The filtrate was washed twice with an approximately 10% sodium chloride aqueous solution. The organic phase was concentrated to obtain a yellow liquid: 296.4 g (theoretical amount: 251.51 g, yield: 95%, GC = 84.3159%, methacrylic anhydride GC = 11.8358%).
[0051] S3. Add 794 mL of water and 38.04 g of sodium hydroxide to a 3 L three-necked flask, stir for 10 min to dissolve, then add 794 mL of ethanol and 264.75 g (theoretical amount) of methyl 3-methacrylate-adamantane-1-carboxylic acid. Heat to 50℃~60℃ and maintain the temperature at 50℃~60℃ for 2 h, then cool to below 40℃. Concentrate the reaction solution, extract with methylcyclohexane under stirring, separate the layers, add methylcyclohexane to the aqueous phase under stirring, adjust the pH to 2~3 with hydrochloric acid, separate the layers, wash the organic phase with water until neutral, concentrate, recrystallize the methylcyclohexane / ethanol system once, and dry to obtain 100 g of off-white solid (yield 55.5%, GC=99.39%). (Control) Figure 1 GC chromatographic principal content (x-axis at 8.943 min); control Figure 2 H-NMR qualitative analysis of product structure The target product.
[0052] Example 2
[0053] This embodiment provides a preparation experiment of adamantane methacrylate resin monomer containing a carboxyl group.
[0054] Under S1 and N2 protection, 2400 mL of methanol and 400 g of 3-hydroxyadamantane-1-carboxylic acid were added to a 5 L three-necked flask. Stirring was started, and 80 g of sulfuric acid was added dropwise at room temperature, maintaining the temperature below 65 °C during the addition. After the addition was complete, the mixture was kept at 55 °C–65 °C for 2 hours, then cooled to below 40 °C, and the methanol was concentrated. The methanol was extracted with dichloromethane, and the pH was adjusted to 7–8 with sodium bicarbonate aqueous solution. The solution was concentrated to dryness to obtain 430.8 g of a brown liquid (yield after dissolution was 99.21%, GC = 98.9710%).
[0055] Under S2 and N2 protection, 1000 mL of dichloromethane, 200 g of methyl 3-hydroxyadamantane-1-carboxylate (theoretical amount), and 385 g of triethylamine were added to a 3 L three-necked flask. The temperature was lowered to -10℃ to 0℃, and 198.85 g of methacryloyl chloride was added dropwise, with the temperature controlled at -10℃ to 0℃ during the dropwise addition. After the addition was completed, the temperature was kept at -10℃ to 0℃ for 2 h. The reaction solution was filtered, the filter cake was washed with dichloromethane, and the solution was dried under vacuum. The filtrate was washed twice with an approximately 10% sodium chloride aqueous solution. The organic phase was concentrated to obtain a yellow liquid: 312 g (theoretical amount: 264.75 g, yield: 100%, GC = 84.9971%, methacrylic anhydride GC = 12.1253%).
[0056] S3. Add 794 mL of water and 57.06 g of sodium hydroxide to a 3 L three-necked flask, stir for 10 min to dissolve, then add 794 mL of ethanol and 264.75 g (theoretical amount) of methyl 3-methacrylate-adamantane-1-carboxylic acid ester. Heat to 50℃~60℃, maintain the temperature at 50℃~60℃ for 2 h, then cool to below 40℃. Concentrate the reaction solution, extract with methylcyclohexane under stirring, separate the layers, add methylcyclohexane to the aqueous phase under stirring, adjust the pH to 2~3 with hydrochloric acid, separate the layers, wash the organic phase with water until neutral, concentrate, recrystallize the methylcyclohexane / ethanol system once, and dry to obtain 117 g of off-white solid (yield 65%, GC = 99.40%). Figure 1 The main content in GC chromatography was 99.40% (at 8.943 min on the x-axis); For example... Figure 2 H-NMR qualitative analysis of product structure The target product.
[0057] Example 3
[0058] This embodiment provides a preparation experiment of adamantane methacrylate resin monomer containing a carboxyl group.
[0059] Under S1 and N2 protection, 2400 mL of methanol and 400 g of 3-hydroxyadamantane-1-carboxylic acid were added to a 5 L three-necked flask. Stirring was started, and 200 g of sulfuric acid was added dropwise at room temperature, maintaining the temperature below 65°C during the addition. After the addition was complete, the mixture was kept at 55°C–65°C for 2 hours, then cooled to below 40°C, and the methanol was concentrated. The methanol was extracted with dichloromethane, and the pH was adjusted to 7–8 with sodium bicarbonate aqueous solution. The solution was concentrated to dryness to obtain 432.1 g of a brown liquid (yield after dissolution was 99.5%, GC = 98.9859%).
[0060] Under S2 and N2 protection, 1000 mL of dichloromethane, 200 g of methyl 3-hydroxyadamantane-1-carboxylate (theoretical amount), and 433.13 g of triethylamine were added to a 3 L three-necked flask. The temperature was lowered to -10℃ to 0℃, and 248.56 g of methacryloyl chloride was added dropwise, with the temperature controlled at -10℃ to 0℃ during the dropwise addition. After the addition was completed, the temperature was kept at -10℃ to 0℃ for 2 h. The reaction solution was filtered, the filter cake was washed with dichloromethane, and the solution was dried under vacuum. The filtrate was washed twice with an approximately 10% sodium chloride aqueous solution. The organic phase was concentrated to obtain a yellow liquid: 327 g (theoretical amount: 264.75 g, yield: 100%, GC = 80.8156%, methacrylic anhydride GC = 16.2597%).
[0061] S3. Add 794 mL of water and 68.47 g of sodium hydroxide to a 3 L three-necked flask, stir for 10 min to dissolve, then add 794 mL of ethanol and 264.75 g (theoretical amount) of methyl 3-methacrylate-adamantane-1-carboxylic acid. Heat to 50℃~60℃ and maintain the temperature at 50℃~60℃ for 2 h, then cool to below 40℃. Concentrate the reaction solution, extract with methylcyclohexane under stirring, separate the layers, add methylcyclohexane to the aqueous phase under stirring, adjust the pH to 2~3 with hydrochloric acid, separate the layers, wash the organic phase with water until neutral, concentrate, recrystallize the methylcyclohexane / ethanol system once, and dry to obtain 114 g of off-white solid (yield 63.33%, GC=99.42%). (Control) Figure 1 GC chromatographic principal content (x-axis at 8.943 min); control Figure 2 H-NMR qualitative analysis of product structure The target product.
[0062] As described above, the present invention can be well implemented. The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, all kinds of changes and improvements made by those skilled in the art to the technical solutions of the present invention should fall within the protection scope defined by the present invention.
Claims
1. A method for synthesizing a carboxyl-containing adamantane methacrylate resin monomer, characterized in that, Includes the following steps: S1: 3-Hydroxyadamantane-1-carboxylic acid is prepared as methyl 3-hydroxyadamantane-1-carboxylic acid under reaction conditions containing concentrated sulfuric acid and a primary alcohol; S2: Methyl 3-hydroxyadamantane-1-carboxylate is esterified in reaction conditions containing methacryloyl chloride, triethylamine, and dichloromethane to produce methyl 3-methacrylate-adamantane-1-carboxylate. S3: 3-Methacrylate-adamantane-1-carboxylic acid methyl ester is prepared by alkaline hydrolysis of methacryloyl chloride in the presence of alkali, water, and a second alcohol to obtain a carboxyl-containing adamantane methacrylate resin monomer. The structural formula of the carboxyl-containing adamantane methacrylate resin monomer is shown in formula (1). The first alcohol or the second alcohol is an alcohol with 1 to 3 carbon atoms.
2. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 1, characterized in that, The first alcohol is methanol, the second alcohol is ethanol, and the base is sodium hydroxide.
3. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 1, characterized in that, The mass ratio of sulfuric acid to 3-hydroxyadamantane-1-carboxylic acid is 1:0.1 to 0.5; The molar ratio of methyl 3-hydroxyadamantane-1-carboxylic acid to triethylamine is 1:1.5 to 4.5; The molar ratio of methyl 3-hydroxyadamantane-1-carboxylate to methacryloyl chloride is 1:1.0 to 2.5; The mass ratio of methyl 3-methacrylate-adamantane-1-carboxylic acid ester to the base is 1:1.0 to 1.
8.
4. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 1, characterized in that, S1 comprises: under nitrogen protection, stirring and adding concentrated sulfuric acid dropwise to a mixture of 3-hydroxyadamantane-1-carboxylic acid and a first alcohol, followed by heating to reflux at 55°C to 65°C to prepare a first reaction solution containing methyl 3-hydroxyadamantane-1-carboxylic acid.
5. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 4, characterized in that, When concentrated sulfuric acid is added dropwise to the mixture of 3-hydroxyadamantane-1-carboxylic acid and the first alcohol, the reaction temperature is 20℃~65℃.
6. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 1, characterized in that, The S2 comprises: under nitrogen protection, adding methyl 3-hydroxyadamantane-1-carboxylate and triethylamine sequentially to dichloromethane, stirring, cooling and adding methacryloyl chloride dropwise, and then maintaining the temperature to react, to obtain a second reaction solution containing methyl 3-methacrylate adamantane-1-carboxylate.
7. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 3, characterized in that, Cool the temperature to -20℃ to 10℃ and add methacryloyl chloride dropwise.
8. The method for synthesizing carboxyl-containing adamantane methacrylate resin monomers according to claim 1, characterized in that, S3 comprises: under nitrogen protection, adding a second alcohol and methyl 3-methacrylate adamantane-1-carboxylic acid to an aqueous solution of the alkali, and heating to reflux at 55°C to 65°C to react, thereby obtaining a third reaction solution containing the carboxyl-containing adamantane methacrylate resin monomer.