Preparation method of octocrylene
Through the design of a one-pot cascade reaction and a fluorotriptycene trialdehyde catalyst, the problems of lengthy processes and numerous side reactions in the preparation of octocrylene were solved, efficient and environmentally friendly esterification and condensation reactions were achieved, and the yield and purity of the product were improved.
Patent Information
- Application Number
- CN202510699127.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-28
- Publication Date
- 2025-09-05
AI Technical Summary
Existing methods for preparing octocrylene have problems such as lengthy process flow, high solvent consumption, numerous side reactions, and equipment corrosion. In particular, the catalyst selectivity and conversion rate are insufficient in the esterification and condensation reactions.
A one-pot cascade reaction was adopted, fluorotriptycene trialdehyde was used as the porous catalyst skeleton, and the metal active center was modified with amine compounds to construct a multifunctional catalytic system with both acid and base catalytic sites, achieving efficient synthesis of esterification and condensation reactions.
The reaction conversion rate and selectivity are improved, solvent consumption and side reactions are reduced, the process flow is simplified, the risk of equipment corrosion is reduced, and the yield and purity of the product are improved.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of organic synthesis, and more particularly to a method for preparing octocrylene. Background Art
[0002] Octocrylene, whose chemical name is 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, is a third-generation ultraviolet absorber. It is widely used in sunscreen cosmetics and plastic anti-aging fields because of its broad-spectrum and efficient absorption capacity in the UVB band, good chemical stability and strong compatibility.
[0003] Currently, the industrial production of octocrylene typically utilizes a cyanoacetic acid esterification reaction followed by a Knoevenagel condensation reaction with benzophenone. However, the separate steps of esterification and condensation reactions result in a lengthy process flow, requiring repeated purification of intermediate products, resulting in increased solvent consumption and product loss. The esterification stage often utilizes strong acidic catalysts such as concentrated sulfuric acid and p-toluenesulfonic acid, which can easily lead to side reactions such as the dehydration of isooctyl alcohol to olefins and darken the product color. The Knoevenagel condensation stage relies on alkaline catalysts such as ammonium acetate and sodium hydroxide, which can cause equipment corrosion, catalyst residue, and solid waste pollution. Therefore, the present invention provides a method for preparing octocrylene to address the aforementioned technical problems. Summary of the Invention
[0004] The present invention aims to provide a method for preparing octocrylene, which adopts a one-pot process to achieve efficient synthesis through a series reaction of esterification and condensation. The bifunctional catalyst used therein adopts fluorotriptycene trialdehyde as an organic framework porous structure, which is prepared by multi-step modification to load metal active centers. The catalyst has high catalytic activity and stability, and improves the conversion rate and selectivity of the reaction.
[0005] The present invention provides a method for preparing octocrylene, comprising the following steps:
[0006] (1) Under inert gas protection, add cyanoacetic acid, isooctyl alcohol, toluene, 1-butyl-3-methylimidazolium tetrafluoroborate and a bifunctional catalyst to a dry reaction vessel in sequence, install a water separator and a condenser reflux device, raise the temperature to 80-85°C, control the stirring rate to 400-500 rpm, continue to remove water for 3-6 hours, and monitor the reaction endpoint by TLC;
[0007] (2) Benzophenone and ammonium carbonate are added to the reaction system of step (1), the temperature is raised to 100-105°C, and the condensation reaction is carried out under the protection of inert gas for 2-4 hours. After the reaction is completed, the upper layer crude product is obtained by phase separation, and the lower layer liquid phase is treated with solvent recovery and ionic liquid regeneration, and then purified by molecular distillation to obtain octocrylene.
[0008] Preferably, the preparation steps of the bifunctional catalyst in step (1) are:
[0009] S1. Dissolve fluorotriptycene trialdehyde, p-phenylenediamine, p-sulfonic acid aniline, and hexamethylenediamine in dichloromethane, add acetic acid, and react at 40-50°C for 12-16 hours. Add chlorosulfonic acid-pyridine complex, and react at -5-5°C for 2-4 hours. Then add sodium cyanoborohydride and carry out reduction reaction at the same temperature for 1-3 hours. After precipitation, filtration, washing, and drying, obtain an intermediate.
[0010] S2. Disperse the intermediate in methanol, add a metal salt mixture, adjust the pH to 8-9 with ammonia water, continue the reaction at 100-105° C. for 18-24 hours, centrifuge, wash, and dry to obtain a bifunctional catalyst.
[0011] Preferably, the preparation steps of fluorotriptycene trialdehyde in step S1 are:
[0012] A1. Dissolve triptycene, N-fluorobisbenzenesulfonamide, triethylamine, and aluminum trichloride in anhydrous dichloromethane in an ice-water bath under nitrogen protection. React at 0-5°C for 1.5-3 hours. Quench the reaction with ice water. Extract, dry, and distill under reduced pressure to obtain the fluorinated product.
[0013] A2. Dissolve the fluorinated product in dichloromethane, add Dess-Martin oxidant, react at 25-30°C for 12-18 hours, extract, and purify by column chromatography to obtain fluorinated triptycene trialdehyde.
[0014] Preferably, in step (1), the components by weight include 5-8 parts of cyanoacetic acid, 8-12 parts of isooctyl alcohol, 16-20 parts of toluene, 1-3 parts of 1-butyl-3-methylimidazolium tetrafluoroborate and 0.6-0.9 parts of a bifunctional catalyst.
[0015] Preferably, in step (2), 6-10 parts of benzophenone and 1-3 parts of ammonium carbonate are used in parts by weight.
[0016] Preferably, in step S1, the ingredients in parts by weight include 12-15 parts of fluorotriptycene trialdehyde, 3-5 parts of p-phenylenediamine, 6-8 parts of p-sulfoaniline, 3-5 parts of hexamethylenediamine, 90-100 parts of dichloromethane, 2-4 parts of acetic acid, 8-12 parts of chlorosulfonic acid-pyridine complex and 3-6 parts of sodium cyanoborohydride.
[0017] Preferably, in step S2, the components include 10-15 parts of the intermediate, 90-100 parts of methanol and 8-12 parts of a metal salt mixture in parts by weight, wherein the metal salt mixture consists of zirconium nitrate, aluminum nitrate and cerium nitrate in a mass ratio of 3-5:0.6-0.8:0.1-0.3.
[0018] Preferably, in step A1, the components by weight include 15-18 parts of trisolene, 20-25 parts of N-fluorobisbenzenesulfonamide, 10-13 parts of triethylamine, 4-6 parts of aluminum chloride, and 90-100 parts of dichloromethane.
[0019] Preferably, in step A2, the components comprise, by weight, 4-6 parts of fluorinated product, 20-25 parts of dichloromethane, and 3-5 parts of Dess-Martin oxidant.
[0020] In summary, the present invention has the following beneficial effects:
[0021] 1. The present invention achieves tandem esterification and condensation reactions through a one-pot process, effectively overcoming the solvent waste and product loss caused by intermediate separation and purification in traditional step-by-step processes. The reaction system completes the multi-step transformation under the protection of an inert atmosphere. Utilizing the synergistic effect of the ionic liquid medium and the heterogeneous catalytic system, the esterification reaction equilibrium is shifted through physical azeotropic water removal. Simultaneously, an alkaline environment is created in situ during the condensation stage to promote the Knoevenagel reaction process, achieving an integrated and efficient reaction process.
[0022] 2. The bifunctional catalyst designed in the present invention uses fluorotriptycene trialdehyde as a rigid porous framework. Through modification with amine compounds and loading of metal active centers, a multifunctional catalytic system with both acid-base catalytic sites and metal synergy is constructed, thereby improving the reaction selectivity and conversion rate. The rigid pore structure of the fluorotriptycene skeleton provides a rich specific surface area and a regular spatially confined environment, allowing the acidic sulfonic acid groups and the basic amino groups to form a spatially isolated active site distribution in the pores, avoiding the risk of inactivation caused by direct contact between the acid-base sites. In the acidic environment of the esterification reaction, it can selectively activate the carboxyl group of cyanoacetic acid and the hydroxyl group of isooctyl alcohol, promoting ester bond formation through a nucleophilic addition-elimination mechanism while inhibiting side reactions such as isooctyl alcohol dehydration. The hydrophobic channels of the porous framework form a physical barrier to the alkaline sites, and the electron-withdrawing effect of the fluorinated group enhances the coordination stability of the metal active center. In the alkaline environment of the condensation reaction, the sulfonic acid acidic sites rely on the steric hindrance effect of the channels to avoid direct interaction with the alkaline medium. The metal active center and the alkaline sites work synergistically to catalyze the formation of octocrylene through the Knoevenagel condensation reaction mechanism. DETAILED DESCRIPTION
[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.
[0024] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used are purchased from conventional biochemical reagent stores unless otherwise specified. The quantitative experiments in the following examples were all repeated three times, and the data are the average or mean ± standard deviation of the three repeated experiments.
[0025] 1-Butyl-3-methylimidazolium tetrafluoroborate was purchased from Shanghai Yuanye Biotechnology Co., Ltd. with the product number S43663;
[0026] Dess-Martin oxidant was purchased from Shanghai Yuanye Biotechnology Co., Ltd., product number S51421.
[0027] Example 1
[0028] A method for preparing octocrylene, comprising the following steps:
[0029] (1) In a dry three-necked flask equipped with a water separator, a condensing reflux device, a mechanical stirrer, and a thermometer, 5 parts of cyanoacetic acid, 8 parts of isooctyl alcohol, 16 parts of toluene, 1 part of 1-butyl-3-methylimidazolium tetrafluoroborate, and 0.6 parts of a bifunctional catalyst were added in sequence. Dry nitrogen was introduced to replace the air in the reaction vessel to ensure that the entire reaction process was carried out under the protection of an inert gas. Stirring was started and the stirring speed was set to 400 rpm. The temperature was raised to 80°C and the esterification reaction was carried out for 6 hours. At the same time, water was continuously removed through the water separator. The reaction progress was monitored by TLC.
[0030] (2) Add 6 parts of benzophenone and 1 part of ammonium carbonate to the reaction system of step (1), raise the temperature to 100°C under the condition of stirring at a speed of 400 rpm, and continue the condensation reaction under nitrogen protection for 4 hours. After the reaction is completed, the upper layer of crude product is obtained by phase separation. The lower layer of liquid phase is treated with solvent recovery and ionic liquid regeneration, and then purified by molecular distillation to obtain octocrylene.
[0031] The preparation steps of the bifunctional catalyst are as follows:
[0032] S1. Dissolve 12 parts of fluorotriptycene trialdehyde, 3 parts of p-phenylenediamine, 6 parts of p-sulfoaniline and 3 parts of hexamethylenediamine in 90 parts of dichloromethane, add 2 parts of acetic acid, and continue stirring at 40°C at a speed of 300 rpm for 16 hours. Then, add 8 parts of chlorosulfonic acid-pyridine complex to the reaction system, wherein the molar ratio of chlorosulfonic acid to pyridine is 1:1, continue stirring at 5°C at a speed of 200 rpm for 4 hours, and finally add 3 parts of sodium cyanoborohydride. Reduce the mixture at the same temperature for 3 hours, and obtain an intermediate after precipitation, filtration, washing and drying.
[0033] S2. Disperse 10 parts of the intermediate in 90 parts of methanol in a reactor, add 8 parts of a metal salt mixture, adjust the pH of the system to 8 with ammonia water, and reflux the reaction at 100°C and a speed of 300 pm for 24 hours. After the reaction is completed, centrifuge, wash, and dry to obtain a bifunctional catalyst.
[0034] The preparation steps of fluorotriptycene trialdehyde are as follows:
[0035] A1. In a three-necked flask, dissolve 15 parts of triptycene, 20 parts of N-fluorobisbenzenesulfonamide, 10 parts of triethylamine, and 4 parts of aluminum trichloride in 90 parts of anhydrous dichloromethane. Stir in an ice-water bath at 5°C under nitrogen protection at a stirring speed of 300 rpm for 3 h. Quench the reaction with ice water, extract, dry, and distill under reduced pressure to obtain the fluorinated product.
[0036] A2. Dissolve 4 parts of the fluorinated product in 20 parts of dichloromethane, add 3 parts of Dess-Martin oxidant, react at 25°C and a stirring speed of 350 rpm for 18 hours, extract, and purify by column chromatography to obtain fluorinated triptycene trialdehyde.
[0037] Example 2
[0038] A method for preparing octocrylene, comprising the following steps:
[0039] (1) In a dry three-necked flask equipped with a water separator, a condensing reflux device, a mechanical stirrer, and a thermometer, 6 parts of cyanoacetic acid, 9 parts of isooctyl alcohol, 17 parts of toluene, 2 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, and 0.7 parts of a bifunctional catalyst were added in sequence. Dry nitrogen was introduced to replace the air in the reaction vessel to ensure that the entire reaction process was carried out under the protection of an inert gas. Stirring was started and the stirring speed was set to 410 rpm. The temperature was raised to 82°C and the esterification reaction was carried out for 5.8 hours. At the same time, water was continuously removed through the water separator. The reaction progress was monitored by TLC.
[0040] (2) 7 parts of benzophenone and 2 parts of ammonium carbonate were added to the reaction system of step (1). The temperature was raised to 102°C with a stirring speed of 420 rpm. The condensation reaction was continued under nitrogen protection for 3.9 hours. After the reaction was completed, the upper layer of crude product was obtained by phase separation. The lower layer of liquid phase was recovered by solvent and regenerated by ionic liquid, and then purified by molecular distillation to obtain octocrylene.
[0041] The preparation steps of the bifunctional catalyst are as follows:
[0042] S1. Dissolve 13 parts of fluorotriptycene trialdehyde, 4 parts of p-phenylenediamine, 7 parts of p-sulfoaniline and 4 parts of hexamethylenediamine in 92 parts of dichloromethane, add 3 parts of acetic acid, and continue stirring at 42°C at a speed of 320 rpm for 15.8 hours. Then, add 9 parts of chlorosulfonic acid-pyridine complex to the reaction system, wherein the molar ratio of chlorosulfonic acid to pyridine is 2:1, and continue stirring at 3°C at a speed of 210 rpm for 3.8 hours. Finally, add 4 parts of sodium cyanoborohydride, and reverse-reduction reaction at the same temperature for 2.8 hours. After precipitation, filtration, washing and drying, an intermediate is obtained;
[0043] S2. Disperse 11 parts of the intermediate in 92 parts of methanol in a reactor, add 9 parts of a metal salt mixture, adjust the pH of the system to 8.2 with ammonia water, and reflux the reaction at 101°C and 320 rpm for 23.8 hours. After the reaction is completed, centrifuge, wash, and dry to obtain a bifunctional catalyst.
[0044] The preparation steps of fluorotriptycene trialdehyde are as follows:
[0045] A1. In a three-necked flask, dissolve 16 parts of triptycene, 21 parts of N-fluorobisbenzenesulfonamide, 11 parts of triethylamine, and 5 parts of aluminum trichloride in 92 parts of anhydrous dichloromethane. Stir in an ice-water bath at 3°C under nitrogen protection at a speed of 320 rpm for 2.8 hours. Quench the reaction with ice water, extract, dry, and distill under reduced pressure to obtain the fluorinated product.
[0046] A2. Dissolve 5 parts of the fluorinated product in 21 parts of dichloromethane, add 4 parts of Dess-Martin oxidant, react at 26°C and a stirring speed of 360 rpm for 17 hours, extract, and purify by column chromatography to obtain fluorinated triptycene trialdehyde.
[0047] Example 3
[0048] A method for preparing octocrylene, comprising the following steps:
[0049] (1) In a dry three-necked flask equipped with a water separator, a condensing reflux device, a mechanical stirrer, and a thermometer, 8 parts of cyanoacetic acid, 12 parts of isooctyl alcohol, 20 parts of toluene, 3 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, and 0.9 parts of a bifunctional catalyst were added in sequence. Dry nitrogen was introduced to replace the air in the reaction vessel to ensure that the entire reaction process was carried out under the protection of an inert gas. Stirring was started and the stirring speed was set to 500 rpm. The temperature was raised to 85°C and the esterification reaction was carried out for 3 hours. At the same time, water was continuously removed through the water separator. The reaction progress was monitored by TLC.
[0050] (2) 10 parts of benzophenone and 3 parts of ammonium carbonate were added to the reaction system of step (1), and the temperature was raised to 105°C under a stirring speed of 500 rpm. The condensation reaction was continued under nitrogen protection for 2 hours. After the reaction was completed, the upper layer of crude product was obtained by phase separation. The lower layer of liquid phase was recovered by solvent and regenerated by ionic liquid, and then purified by molecular distillation to obtain octocrylene.
[0051] The preparation steps of the bifunctional catalyst are as follows:
[0052] S1. Dissolve 15 parts of fluorotriptycene trialdehyde, 5 parts of p-phenylenediamine, 8 parts of p-sulfoaniline and 5 parts of hexamethylenediamine in 100 parts of dichloromethane, add 4 parts of acetic acid, and continue stirring at 450 rpm at 50°C for 12 hours. Then, add 12 parts of chlorosulfonic acid-pyridine complex to the reaction system, wherein the molar ratio of chlorosulfonic acid to pyridine is 3:1. Continue stirring at -5°C at 300 rpm for 2 hours. Finally, add 6 parts of sodium cyanoborohydride, and reverse-reduction reaction at the same temperature for 1 hour. After precipitation, filtration, washing and drying, an intermediate is obtained;
[0053] S2. Disperse 15 parts of the intermediate in 100 parts of methanol in a reactor, add 12 parts of a metal salt mixture, adjust the pH of the system to 9 with ammonia water, and reflux the reaction at 105°C and 400 rpm for 18 hours. After the reaction is completed, centrifuge, wash, and dry to obtain a bifunctional catalyst.
[0054] The preparation steps of fluorotriptycene trialdehyde are as follows:
[0055] A1. In a three-necked flask, 18 parts of triptycene, 25 parts of N-fluorobisbenzenesulfonamide, 13 parts of triethylamine, and 6 parts of aluminum trichloride were dissolved in 100 parts of anhydrous dichloromethane. The mixture was stirred at 400 rpm in an ice-water bath at 0°C under nitrogen protection for 1.5 hours. The reaction was quenched with ice water, and the fluorinated product was obtained by extraction, drying, and vacuum distillation.
[0056] A2. Dissolve 6 parts of the fluorinated product in 25 parts of dichloromethane, add 5 parts of Dess-Martin oxidant, and react at 30°C with a stirring speed of 400 rpm for 12 hours. Extract and purify by column chromatography to obtain fluorinated triptycene trialdehyde.
[0057] Example 4
[0058] A method for preparing octocrylene, comprising the following steps:
[0059] (1) In a dry three-necked flask equipped with a water separator, a condensing reflux device, a mechanical stirrer, and a thermometer, 8 parts of cyanoacetic acid, 12 parts of isooctyl alcohol, 20 parts of toluene, 3 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, and 0.8 parts of a bifunctional catalyst were added in sequence. Dry nitrogen was introduced to replace the air in the reaction vessel to ensure that the entire reaction process was carried out under the protection of an inert gas. Stirring was started and the stirring speed was set to 450 rpm. The temperature was raised to 85°C and the esterification reaction was carried out for 4 hours. At the same time, water was continuously removed through the water separator. The reaction progress was monitored by TLC.
[0060] (2) 10 parts of benzophenone and 3 parts of ammonium carbonate were added to the reaction system of step (1), and the temperature was raised to 105°C under a stirring speed of 450 rpm. The condensation reaction was continued under nitrogen protection for 3 hours. After the reaction was completed, the upper layer of crude product was obtained by phase separation. The lower layer of liquid phase was recovered by solvent and regenerated by ionic liquid, and then purified by molecular distillation to obtain octocrylene.
[0061] The preparation steps of the bifunctional catalyst are as follows:
[0062] S1. Dissolve 15 parts of fluorotriptycene trialdehyde, 5 parts of p-phenylenediamine, 8 parts of p-sulfoaniline and 5 parts of hexamethylenediamine in 100 parts of dichloromethane, add 4 parts of acetic acid, and continue stirring at 450 rpm at 50°C for 14 hours. Then, add 12 parts of chlorosulfonic acid-pyridine complex to the reaction system, wherein the molar ratio of chlorosulfonic acid to pyridine is 3:1, continue stirring at -5°C at 280 rpm for 3 hours, and finally add 5 parts of sodium cyanoborohydride. Reduction reaction is carried out at the same temperature for 2.5 hours. After precipitation, filtration, washing and drying, an intermediate is obtained;
[0063] S2. Disperse 14 parts of the intermediate in 100 parts of methanol in a reactor, add 10 parts of a metal salt mixture, adjust the pH of the system to 8.5 with ammonia water, and reflux the reaction at 100°C and 320 rpm for 20 hours. After the reaction is completed, centrifuge, wash, and dry to obtain a bifunctional catalyst.
[0064] The preparation steps of fluorotriptycene trialdehyde are as follows:
[0065] A1. In a three-necked flask, 18 parts of triptycene, 25 parts of N-fluorobisbenzenesulfonamide, 12 parts of triethylamine, and 5 parts of aluminum trichloride were dissolved in 100 parts of anhydrous dichloromethane. The mixture was stirred at 400 rpm in an ice-water bath at 0°C under nitrogen protection for 2 h. The reaction was quenched with ice water, and the fluorinated product was obtained by extraction, drying, and vacuum distillation.
[0066] A2. Dissolve 5 parts of the fluorinated product in 25 parts of dichloromethane, add 4 parts of Dess-Martin oxidant, react at 30°C and at a stirring speed of 380 rpm for 13 hours, extract, and purify by column chromatography to obtain fluorinated triptycene trialdehyde.
[0067] Comparative Example 1
[0068] A method for preparing octocrylene, which differs from Example 4 in that no bifunctional catalyst is used, and other conditions are the same as Example 4.
[0069] Comparative Example 2
[0070] A method for preparing octocrylene, which differs from Example 4 in that the addition of p-sulfonic acid aniline is omitted during the preparation of the bifunctional catalyst, that is, no sulfonic acid site is introduced in step S1, and only p-phenylenediamine and hexamethylenediamine are retained. Other conditions are the same as in Example 4.
[0071] Comparative Example 3
[0072] A method for preparing octocrylene, which differs from Example 4 in that fluorinated triptycene trialdehyde is not used as the catalyst skeleton, but unfluorinated triptycene trialdehyde is used instead. That is, in step S1, fluorinated triptycene trialdehyde is replaced by an equal weight portion of ordinary triptycene trialdehyde. Other conditions are the same as in Example 4.
[0073] Comparative Example 4
[0074] A method for preparing octocrylene, which differs from Example 4 in that the fluorotriptycene trialdehyde used in the catalyst preparation process is not subjected to Dess-Martin oxidation treatment, that is, the fluorinated product obtained in step A1 is directly used in the subsequent catalyst preparation. Other conditions are the same as in Example 4.
[0075] Comparative Example 5
[0076] A method for preparing octocrylene, which differs from Example 4 in that no sulfonic acid site is introduced, that is, no chlorosulfonic acid-pyridine complex is added in step S1, and other conditions are the same as Example 4.
[0077] Comparative Example 6
[0078] A method for preparing octocrylene differs from Example 4 in that the metal active center loading step of the bifunctional catalyst is omitted. That is, in step S2, only the intermediate is dispersed in methanol without adding a metal salt mixture, and the catalyst is directly centrifuged and dried. Other conditions are the same as in Example 4.
[0079] Performance test 12-16 hours
[0080] Octocrylene was prepared according to the preparation methods in Examples 1-4 and Comparative Examples 1-6. The yield and purity of octocrylene are shown in Table 1.
[0081] Table 1
[0082] Test items Octocrylene yield (%) Octocrylene purity (%) Example 1 89.26 97.56 Example 2 91.69 98.12 Example 3 92.43 99.30 Example 4 91.77 99.62 Comparative Example 1 66.35 89.75 Comparative Example 2 75.53 92.46 Comparative Example 3 82.61 95.22 Comparative Example 4 70.98 90.68 Comparative Example 5 77.85 93.17 Comparative Example 6 79.14 96.05
[0083] As can be seen from the tabular data, the yield of octocrylene in Examples 1-4 is between 89.26% and 92.43%, and the purity is between 97.56% and 99.62%, which is significantly better than that in Comparative Examples 1-4. This shows that the one-pot cascade reaction process adopted by the present invention, combined with the design of a bifunctional catalyst, can effectively improve the reaction efficiency and product selectivity. Comparative Example 1 does not use this catalyst, resulting in low efficiency of esterification and condensation reactions, increased by-products, and a significant reduction in yield and purity; Comparative Examples 2-5, by lacking key components such as sulfonic acid groups, fluorinated groups, or metal active centers, destroy the microenvironment of the isolated acid and base sites in the catalyst and the metal synergistic catalytic ability, resulting in a decrease in reaction selectivity and an increase in side reactions; Comparative Example 3 uses an unfluorinated triptycene skeleton, whose rigid pore structure and hydrophobic effect are weakened, resulting in uneven distribution of active sites, deterioration of catalytic stability and regeneration performance. It can be seen that the embodiment achieves spatial isolation of acidic sites and basic sites through the porous framework constructed by fluorotriptycene trialdehyde, and accurately controls the acid-base microenvironment of the esterification-condensation cascade reaction in a one-pot process.
[0084] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.
Claims
1. A method for preparing octocrylene, characterized in that: The method comprises the following preparation steps: (1) Under the protection of inert gas, add cyanoacetic acid, isooctyl alcohol, toluene, 1-butyl-3-methylimidazolium tetrafluoroborate and a bifunctional catalyst into a dry reaction vessel, install a water separator and a condensing reflux device, heat to carry out the esterification reaction while continuously removing water, and monitor the reaction endpoint by TLC; (2) Benzophenone and ammonia water are added to the reaction system of step (1), and the temperature is raised under the protection of inert gas to carry out a condensation reaction. After the reaction is completed, the upper layer crude product is obtained by phase separation, and the lower layer liquid phase is treated with solvent recovery and ionic liquid regeneration, and then purified by molecular distillation to obtain octocrylene.
2. The method for preparing octocrylene according to claim 1, wherein: The preparation steps of the bifunctional catalyst in step (1) are: S1, dissolving fluorotriptycene trialdehyde, p-phenylenediamine, p-sulfonic acid aniline and hexamethylenediamine in dichloromethane, adding acetic acid to react, then adding chlorosulfonic acid-pyridine complex to continue the reaction, and finally reducing with sodium cyanoborohydride, precipitating, filtering, washing and drying to obtain an intermediate; S2. Dispersing the intermediate in methanol, adding a metal salt mixture, stirring, and adding ammonia water to adjust the pH, continuing the reaction, and then centrifuging, washing, and drying to obtain a bifunctional catalyst.
3. The method for preparing octocrylene according to claim 1, wherein: The preparation steps of fluorotriptycene trialdehyde in step S1 are: A1. Dissolve triptycene, N-fluorobisbenzenesulfonamide, triethylamine, and aluminum chloride in anhydrous dichloromethane in an ice-water bath under nitrogen protection, and react. After quenching and purification, obtain the fluorinated product. A2. The fluorinated product is dissolved in dichloromethane, and a Dess-Martin oxidant is added to react. The product is extracted and purified by column chromatography to obtain fluorinated triptycene trialdehyde.
4. The method for preparing octocrylene according to claim 3, wherein: In step (1), the components by weight include 5-8 parts of cyanoacetic acid, 8-12 parts of isooctyl alcohol, 16-20 parts of toluene, 1-3 parts of 1-butyl-3-methylimidazolium tetrafluoroborate and 0.6-0.9 parts of a bifunctional catalyst.
5. The method for preparing octocrylene according to claim 3, wherein: In step (2), the components are 6-10 parts by weight of benzophenone and 1-3 parts by weight of ammonium carbonate.
6. The method for preparing octocrylene according to claim 1, wherein: In step S1, the following components are included by weight: 12-15 parts of fluorotriptycene trialdehyde, 3-5 parts of p-phenylenediamine, 6-8 parts of p-sulfoaniline, 3-5 parts of hexamethylenediamine, 90-100 parts of dichloromethane, 2-4 parts of acetic acid, 8-12 parts of chlorosulfonic acid-pyridine complex and 3-6 parts of sodium cyanoborohydride.
7. The method for preparing octocrylene according to claim 1, wherein: In step S2, the components include 10-15 parts of the intermediate, 90-100 parts of methanol and 8-12 parts of a metal salt mixture in parts by weight, wherein the metal salt mixture consists of zirconium nitrate, aluminum nitrate and cerium nitrate in a mass ratio of 3-5:0.6-0.8:0.1-0.
3.
8. The method for preparing octocrylene according to claim 7, wherein: In step A1, the components by weight include 15-18 parts of trisolene, 20-25 parts of N-fluorobisbenzenesulfonamide, 10-13 parts of triethylamine, 4-6 parts of aluminum chloride and 90-100 parts of dichloromethane.
9. The method for preparing octocrylene according to claim 7, wherein: In step A2, the components are 4-6 parts by weight of the fluorinated product, 20-25 parts by weight of dichloromethane, and 3-5 parts by weight of the Dess-Martin oxidant.