Preparation method of triazine ultraviolet light absorber
By performing pre-desolvation and controlling the reaction temperature during the preparation process of the ultraviolet absorber, the yield and purity of the product are improved, the problems of low yield and purity in the existing technology are solved, and efficient and pure products are achieved. preparation effect.
Patent Information
- Application Number
- CN202310882061.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-18
- Publication Date
- 2025-01-21
AI Technical Summary
The ultraviolet absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5,-triazine in the prior art The yield and purity are low, and there are problems such as poor selectivity, large reagent consumption and complex operation process.
Pre-desolubilization is carried out before the reaction, the moisture content is controlled below 500 ppm, and the reaction is carried out at a reaction temperature of 130 to 150°C to ensure that 1-chloron-octane is fully reacted, thereby improving the yield and purity of the product.
Through this method, the yield of the ultraviolet absorber is increased to more than or equal to 80%, and the purity reaches more than 99.6%, which solves the problem of low product yield and purity in the existing technology.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of ultraviolet absorbers, and in particular to a method for preparing a triazine ultraviolet absorber, 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine. Background Art
[0002] A triazine ultraviolet absorber, whose chemical name is 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, is a high-efficiency anti-aging agent with excellent performance. 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine has strong absorption of UVA and UVB, with an absorption range of 200-400 nanometers, and has the characteristics of light color, non-toxicity, good compatibility, low migration, easy processing, etc. It also has low volatility and strong light and heat stability. It has the greatest protective effect on polymers, helps to reduce color, delays yellowing and blocks physical property loss, and is widely used in polymers such as PE, PET, PA, POM, PC, ABS, PMMA, etc., providing them with good light stabilization effect.
[0003] At present, the synthesis of the ultraviolet absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine mainly includes direct alkylation, cyclization and grignard coupling. However, most of the synthesis methods in the prior art have the defects of poor selectivity, large reagent consumption and complicated operation process, resulting in low product yield and low purity. Summary of the invention
[0004] The invention provides a method for preparing a triazine ultraviolet absorber, which is used to solve the defects of low yield and purity in the prior art, thereby preparing 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine with good appearance color, high purity and high yield.
[0005] The present invention provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, comprising:
[0006] The reaction is prepared by using 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine and 1-chlorooctane as raw materials, wherein the reaction system is pre-desolventized before the reaction to control the water content below 500 ppm. Too high a water content in the reaction system will cause the loss of 1-chlorooctane and make it unable to be fully utilized.
[0007] In the prior art, 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine (hereinafter referred to as intermediate) is generally directly mixed with 1-chlorooctane to react to prepare 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine. However, the present invention has found that the water content in the reaction system has a great influence on the yield of the final product. Therefore, the present invention proposes pre-desolventization to remove the water content in the system and control the water content below 500ppm, thereby improving the yield of the ultraviolet absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine.
[0008] (I) Pre-desolventization
[0009] In some embodiments of the present invention, the pre-desolventizing step comprises:
[0010] Mix 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, a catalyst, PEG-400 and xylene in a reactor, control the vacuum degree to -0.08 to 0 MPa, raise the internal temperature to 100 to 120° C. to distill out part of the solvent, and stop when the moisture content is controlled below 500 ppm.
[0011] It should be noted that the term "internal temperature" used in the present invention refers to the actual temperature of the reaction system (a mixture of various reaction raw materials or products in the reactor), rather than the displayed temperature of the heating equipment.
[0012] In the above technical solution, PEG-400 and xylene are both solvents, the mass ratio of PEG-400 to the intermediate is 1:2 to 1:2.4, and the mass ratio of xylene to the intermediate is 5:2 to 6:2.
[0013] The catalyst can be potassium carbonate or potassium bromide, and the molar ratio of the intermediate to the catalyst is 1:1.1.
[0014] (II) Reaction stage
[0015] The preparation of 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine by reacting the intermediate with 1-chlorooctane is already disclosed in the prior art, and the reaction formula is as follows:
[0016]
[0017] However, the reaction conditions in the prior art are not necessarily optimal.
[0018] In some embodiments of the present invention, after the pre-desolventization is completed, the internal temperature is raised to 130-150° C., and 1-chlorooctane is added to react until the content of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine in the reaction system is 0.1-0.8%.
[0019] The present invention has found that controlling the reaction temperature at 130-150° C. is beneficial to accelerating the reaction rate, shortening the reaction time, and further beneficial to the full reaction of 1-chlorooctane, thereby improving the yield of the 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine product.
[0020] In the above technical solution, the molar ratio of the intermediate to 1-chlorooctane is controlled at 1:1.05, which is conducive to sufficient reaction.
[0021] In addition, in order to increase the yield of 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine as much as possible, the reaction degree needs to be monitored during the reaction. When the content of the intermediate is in the range of 0.1 to 0.8%, it is more ideal, and more preferably 0.1 to 0.4%. Specifically, the intermediate content can be monitored by regular sampling and detection.
[0022] (III) Post-processing
[0023] In some embodiments of the present invention, after the reaction is completed, the reaction solution is filtered while hot and the filtrate is taken out for crystallization.
[0024] Furthermore, the step of the crystallization treatment comprises:
[0025] The filtrate is cooled to -10 to 10°C for crystallization to obtain a wet crude product, the wet crude product is mixed with an adsorbent material and a recrystallization solvent, heated to reflux, filtered while hot, and the filtrate is taken out, cooled to 0 to 20°C for recrystallization to obtain a wet fine product;
[0026] The recrystallization solvent is methanol, ethanol, toluene, xylene or acetone;
[0027] Preferably, the recrystallization solvent is acetone.
[0028] Among them, the quality of the wet crude product obtained by crystallization is general, and the indicators such as color and purity do not meet the high requirements. The present invention performs recrystallization, wherein the recrystallization solvent is preferably acetone. Using acetone as the recrystallization solvent has higher selectivity for impurities, can remove more impurities, and is conducive to product purification.
[0029] Furthermore, the adsorption material is activated carbon, diatomaceous earth, primary silica gel or activated white clay.
[0030] In some embodiments of the present invention, the adsorption material is activated carbon with a particle size of 100-200 meshes. The amount of the adsorption material used is 1-10% of the quality of the wet crude product.
[0031] Furthermore, the mass ratio of the recrystallization solvent to the wet crude product is (2-6):1.
[0032] Furthermore, the heating reflux temperature is 50-70° C., preferably 55-60° C., and the time is 1-2 h.
[0033] The wet fine product obtained by the present invention is a light yellow solid. The wet fine product is dried under reduced pressure at 60 to 80° C., and the reduced pressure vacuum degree is -0.095 to -0.1 Mpa, thereby obtaining the target product, ultraviolet absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine.
[0034] By adopting the preparation method of the present invention, the purity of the obtained 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine is above 99.6% (detected by high performance liquid chromatography), and the yield is greater than or equal to 80%.
[0035] (IV) Preparation and purification of 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-S-triazine
[0036] 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine is an important intermediate for the preparation of 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, which is usually obtained by reacting cyanuric chloride, m-xylene and resorcinol as main raw materials.
[0037] In some embodiments of the present invention, the preparation method of 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-S-triazine comprises:
[0038] Using cyanuric chloride and m-xylene as raw materials, adding a reaction solvent to react under the catalytic action of aluminum chloride to generate an intermediate, and the intermediate reacts with resorcinol to generate 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine;
[0039] The reaction liquid containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine is decontaminated with a mixed solution of water, ethyl acetate and hydrochloric acid to remove the solvent and water-soluble impurities to obtain a solid base material; the solid base material is crystallized, and the crystallization solvent is xylene, toluene, n-heptane or cyclohexane.
[0040] Furthermore, the crystallization step includes: mixing the solid base material with a crystallization solvent, stirring at a temperature below 140°C for 1-2 hours to dissolve, then cooling to 5-15°C for crystallization, and after the crystallization is completed, filtering the filter cake to obtain a wet crude product.
[0041] The amount of the crystallization solvent used is based on the amount that can completely dissolve the solid base material, but it should not be too much, otherwise it will affect the yield.
[0042] In addition, the crystallization temperature needs to be controlled at 5-15°C, which is conducive to the precipitation of the crystallized product and improves the yield of the crystallized product.
[0043] Furthermore, the preparation method further comprises: crystallizing the solid base material to obtain a crude product, and then crystallizing it again to obtain a yellow wet fine product, the purity of which is greater than or equal to 99.5%;
[0044] The solvent for recrystallization is ethyl acetate, methanol, ethanol or methyl isobutyl ketone; preferably, the solvent for recrystallization is ethyl acetate. The amount of the solvent for recrystallization is based on the amount of the crude wet product that is completely dissolved.
[0045] Preferably, the step of recrystallization comprises: mixing the crude product obtained by crystallization with a mixed solution of a recrystallization solvent and an adsorbent material, stirring at a temperature of 1-2 hours, filtering the filtrate, cooling the filtrate to -10-10°C for recrystallization, and after the crystallization is completed, filtering the filter cake to obtain a yellow wet fine product.
[0046] Preferably, when the re-crystallization solvent is ethyl acetate, the temperature of the heat preservation and stirring is 70-90° C., more preferably 75-80° C. The amount of the re-crystallization solvent used is based on the amount of the wet crude product that is completely dissolved.
[0047] Furthermore, the adsorption material is activated carbon, diatomaceous earth, primary silica gel or activated white clay.
[0048] Preferably, the adsorption material is activated carbon with a particle size of 100-200 mesh, which is 5%-10% of the crude wet mass quality.
[0049] Furthermore, after obtaining the yellow wet fine product, it is dried at 100-150° C. to obtain the 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine fine product.
[0050] In some specific embodiments of the present invention, the step of obtaining a solid base material comprises:
[0051] Using cyanuric chloride and m-xylene as raw materials, adding a reaction solvent to react under the catalytic action of aluminum chloride to generate an intermediate, and the intermediate reacts with resorcinol to generate 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine;
[0052] The reaction solution containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine is extracted with a mixed solution of water, ethyl acetate and hydrochloric acid at an extraction temperature of 70-90° C., the aqueous phase is removed, the organic phase is retained and desolventized under reduced pressure to obtain the solid base material.
[0053] The reaction process is specifically divided into the following two steps:
[0054]
[0055] (1) Add appropriate amounts of cyanuric chloride, o-dichlorobenzene and aluminum chloride to a reaction container to prepare a mixed solution, wherein o-dichlorobenzene is a solvent and aluminum chloride is a catalyst, heat and stir the mixed solution, and continue to keep the temperature and stir until the internal temperature is heated to 80-100° C. to fully dissolve the cyanuric chloride; take a certain amount of m-xylene, slowly drop it into the mixed solution, and keep the temperature to react until the reaction is complete; then slowly cool the reaction solution to 30-40° C.; add a certain amount of m-xylene again, and continue to keep the temperature to react until the reaction is complete after the drop is complete, to obtain a first reaction solution.
[0056] In the above scheme, the solvent o-dichlorobenzene can also be selected from solvents such as DMF, PEG-400, toluene, xylene, chlorobenzene, dichloroethane, etc. that can dissolve cyanuric chloride.
[0057] (2) After the first step of the reaction is completed, the first reaction liquid is cooled to 10-20°C. Too high a temperature will cause a large number of bubbles to form in the reaction liquid. An appropriate amount of resorcinol is added to the first reaction liquid to react for about 1 hour; then the temperature is slowly raised to 75-85°C and reacted for about 2 hours to obtain a second reaction liquid, which is a reaction liquid containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine.
[0058] The reaction solution containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine is a mixture. The research of the present invention finds that for the reaction solution containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, a mixed solution of water, ethyl acetate and hydrochloric acid is used to extract the target compound, the extraction temperature is 70-90°C, and the impurity removal effect is good.
[0059] Further, the amount of water used is calculated to be 100g / 0.1mol-150g / 0.1mol cyanuric chloride relative to the molar amount of cyanuric chloride;
[0060] The amount of ethyl acetate used is calculated to be 80 g / 0.1 mol-150 g / 0.1 mol cyanuric chloride relative to the molar amount of cyanuric chloride;
[0061] The hydrochloric acid is concentrated hydrochloric acid, and its usage is calculated as 2g / 0.1mol-8g / 0.1mol cyanuric chloride relative to the molar amount of cyanuric chloride.
[0062] In a preferred embodiment of the present invention, the extraction solution consists of 150 g of water, 100 g of ethyl acetate and 5 g of concentrated hydrochloric acid relative to 0.1 mol of cyanuric chloride.
[0063] Furthermore, the extraction step includes: fully stirring at a temperature of 70-90°C, standing for stratification, separating the aqueous phase and the organic phase, and washing the organic phase twice at a temperature of 70-90°C.
[0064] Furthermore, the step of desolventizing under reduced pressure includes: desolventizing the organic phase under reduced pressure, controlling the vacuum degree to be greater than or equal to 0.090 MPa, and gradually raising the distillation temperature to above 150° C. until there is no obvious fraction to obtain a solid bottom material. The desolventizing under reduced pressure can remove residual o-dichlorobenzene and improve the yield of the intermediate.
[0065] The invention provides a method for preparing a triazine ultraviolet absorber. Before 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-S-triazine and 1-chloro-n-octane are mixed and reacted, pre-desolventizing is performed to control the moisture content below 500 ppm, thereby avoiding unnecessary loss of 1-chloro-n-octane, making full use of 1-chloro-n-octane and completely reacting, thereby improving the yield of the ultraviolet absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine.
[0066] Furthermore, the present invention improves the final yield of 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine to more than 80%, and the purity can reach more than 99.6% by combining the improvement of some reaction conditions in the reaction stage and the post-treatment stage. BRIEF DESCRIPTION OF THE DRAWINGS
[0067] Figure 1 It is the liquid chromatogram of the product of Example 1;
[0068] Figure 2 It is the liquid chromatogram of the product of Example 3;
[0069] Figure 3 This is a physical picture of the product of Example 3. DETAILED DESCRIPTION
[0070] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.
[0071] Unless otherwise specified, the technical means used in the embodiments of the present invention are conventional means well known to those skilled in the art. Unless otherwise specified, the materials and reagents used in the embodiments of the present invention can be obtained through regular commercial channels.
[0072] The preparation method of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine in the following examples is as follows:
[0073] Add 32.67 g (0.245 mol) of aluminum chloride, 18.45 g (0.10 mol) of cyanuric chloride and 60.00 g of o-dichlorobenzene into a reaction container, mix, heat and stir, and wait until the internal temperature is heated to 84°C-86°C. Continue to keep warm and stir, take 9.76 g (0.092 mol) of m-xylene, add it dropwise slowly, and control the reaction time to 4 hours. Then slowly cool the reaction solution to 34°C-36°C, continue to add 14.12 g (0.133 mol) of m-xylene dropwise, and continue to keep warm and react after the addition is completed. Control the reaction time for the second addition to be 4 hours to obtain the first reaction solution.
[0074] After the first step of the reaction was completed, the temperature was lowered to 13°C-17°C, 9.91 g (0.09 mol) of resorcinol was added to the first reaction solution, and the mixture was kept warm for 1 hour. The temperature was then slowly raised to 75°C-80°C, and the mixture was kept warm for 2 hours to obtain a second reaction solution.
[0075] 150.00 g of water, 100.00 g of ethyl acetate and 5 g of concentrated hydrochloric acid are stirred at room temperature to obtain a mixed solution, and the above-mentioned second reaction liquid is slowly added to the mixed solution. After the addition is completed, stirring is continued at 70-80°C for sufficient time, and the mixture is allowed to stand for stratification to separate the aqueous phase and the organic phase. 60 g of water is added to the organic phase, and the mixture is kept warm and stirred at 80°C-90°C, and the mixture is allowed to stand for stratification to separate the aqueous phase and the organic phase.
[0076] The organic phase was decompressed and desolventized, and the vacuum degree was controlled to be greater than or equal to 0.090Mpa. The distillation temperature was gradually increased to 150°C until there was no obvious fraction. 150g of xylene was added to the distillation bottom residue, and the mixture was stirred for 1h. Then the reaction solution was cooled to 5°C. After crystallization was completed, the filter cake, i.e., the wet crude product, was obtained by suction filtration.
[0077] The obtained wet crude product was added to a mixture of 1.50g activated carbon and 155.0g ethyl acetate, stirred at 75-80℃ for 1h, filtered, cooled to 0℃ for crystallization, and after the crystallization was completed, a yellow filter cake was obtained by suction filtration, i.e., the wet fine product. The obtained wet fine product was placed in a 100℃ forced air oven for drying to obtain 27.32g of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, with a yield of 68.73% based on cyanuric chloride and a purity of 99.9%.
[0078] It should be noted that in actual operation, the amount of raw materials can be increased or decreased in the same proportion according to the above method, so as to obtain 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine of different weights but almost unchanged purity and yield for standby use.
[0079] Example 1
[0080] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0081] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were put into a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.08MPa, the internal temperature was raised to 100°C, and 9g of solvent (mainly xylene and water, the same below) was distilled out to control the moisture content in the reaction system below 500ppm.
[0082] The internal temperature was raised to 130°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.8%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0083] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 10°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 55°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 20°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 12.5 g of a light yellow solid (molar yield of 81.7%), and its purity was 99.62% as determined by high performance liquid chromatography.
[0084] Example 2
[0085] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0086] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.07MPa, the internal temperature was raised to 105°C, 10g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0087] The internal temperature was raised to 135°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.6%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0088] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 5°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 56°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 10°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 12.8 g of a light yellow solid (molar yield of 83.6%), and its purity was 99.73% as determined by high performance liquid chromatography.
[0089] Example 3
[0090] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0091] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.06MPa, the internal temperature was raised to 110°C, 11g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0092] The internal temperature was raised to 140°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.4%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0093] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 0°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 57°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 5°C and recrystallized for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 13.1 g of a light yellow solid (molar yield of 85.6%), and its purity was 99.9% as determined by high performance liquid chromatography.
[0094] Example 4
[0095] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0096] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.05MPa, the internal temperature was raised to 115°C, 11.5g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0097] The internal temperature was raised to 145°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.6%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0098] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to -5°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 58°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 0°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 13.0 g of a light yellow solid (molar yield of 85.0%), and its purity was 99.84% as determined by high performance liquid chromatography.
[0099] Example 5
[0100] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0101] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.04MPa, the internal temperature was raised to 120°C, 12g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0102] The internal temperature was raised to 150°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.6%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0103] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 5°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 60°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 10°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 12.6 g of a light yellow solid (molar yield of 82.3%), and its purity was 99.73% as determined by high performance liquid chromatography.
[0104] Example 6
[0105] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0106] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.02MPa, the internal temperature was raised to 110°C, 10g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0107] The internal temperature was raised to 130°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.4%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0108] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 8°C under uniform stirring, crystallized for 5-7h, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6g of activated carbon were put into 48g of ethanol, heated to reflux, filtered while hot, and the filtrate was stirred and cooled to 15°C for recrystallization for 5-7h to obtain a light yellow wet solid. It was dried under reduced pressure at 60°C to obtain 12.3g of a light yellow solid (molar yield of 80.4%), and its purity was 99.60% as determined by high performance liquid chromatography.
[0109] Example 7
[0110] This embodiment provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, the steps of which are as follows:
[0111] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to 0MPa, the internal temperature was raised to 100°C, 12g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0112] The internal temperature was raised to 140°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.4%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0113] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to -10°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of xylene, heated to reflux, filtered while hot, and the filtrate was stirred and cooled to 5°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 12.4 g of a light yellow solid (molar yield of 81.0%), and its purity was 99.62% as determined by high performance liquid chromatography.
[0114] Comparative Example 1
[0115] This comparative example provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, and the steps are as follows:
[0116] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.06MPa, the internal temperature was raised to 100°C, 10g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0117] The internal temperature was raised to 120°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was less than 0.6%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0118] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 0°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 57°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 5°C and recrystallized for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 11.5 g of a light yellow solid (molar yield of 75.2%), and its purity was 95.32% as determined by high performance liquid chromatography.
[0119] Comparative Example 2
[0120] This comparative example provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, and the steps are as follows:
[0121] 11.92g (0.03mol) of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) of potassium carbonate, 5g of PEG-400 and 30g of xylene were placed in a flask, a thermometer was inserted, a distillation apparatus was set up, the vacuum degree was reduced to -0.06MPa, the internal temperature was raised to 100°C, 9g of solvent was distilled out, and the water content in the reaction system was controlled below 500ppm.
[0122] The internal temperature was raised to 160°C, 4.7 g (0.0316 mol) of 1-chlorooctane was added, and the mixture was kept warm for reaction. Samples were taken for testing, and when the intermediate content was lower than 0.8%, the post-processing stage could be entered, otherwise, the reaction was continued with the heat preservation until the content reached the standard.
[0123] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 10°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6g of activated carbon were put into 48g of acetone, heated to 58°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 15°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 10.5g of a light yellow solid (molar yield of 68.7%), and its purity was 93.46% as determined by high performance liquid chromatography.
[0124] Comparative Example 3
[0125] This comparative example provides a method for preparing a UV absorber 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine, and the steps are as follows:
[0126] 11.92g (0.03mol) 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-S-triazine, 4.56g (0.033mol) potassium carbonate, 5g PEG-400, 30g xylene and 4.7g (0.0316mol) 1-chlorooctane were added into the flask, and the internal temperature was raised to 130°C for heat preservation and reaction. Samples were taken for testing. When the intermediate content was lower than 0.4%, the post-processing stage could be entered. Otherwise, the heat preservation reaction was continued until the standard was reached.
[0127] The reaction solution was filtered while hot to obtain a brown-black filtrate. The obtained brown-black filtrate was cooled to 5°C under uniform stirring, crystallized for 5 to 7 hours, and filtered to obtain a yellow wet solid. The yellow wet solid and 0.6 g of activated carbon were put into 48 g of acetone, heated to 59°C and refluxed, filtered while hot, and the filtrate was stirred and cooled to 10°C for recrystallization for 5 to 7 hours to obtain a light yellow wet solid, which was dried under reduced pressure at 60°C to obtain 11.0 g of a light yellow solid (molar yield of 71.9%), and its purity was 92.54% as determined by high performance liquid chromatography.
[0128] in addition, Figure 1 and Figure 2 They are respectively the liquid chromatograms of the product of Example 1 and the product of Example 3; Figure 3 This is a physical picture of the product of Example 3.
[0129] From the above results, it can be seen that in Examples 1-7 of the present invention, pre-desolventization is performed before the reaction, and the reaction temperature is controlled at 130-150°C, and a 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine product with a purity of more than 99.6% can be obtained, and the yield is greater than or equal to 80%. Among them, acetone is preferably used as the recrystallization solvent, which can obtain a higher yield and purity. Example 3 can achieve a product yield of 85.6% and a purity of 99.90% under optimal conditions. In Comparative Examples 1 and 2, the reaction temperature is not within the range of 130-150°C, and the results are not ideal if it is too high or too low; in Comparative Example 3, no pre-desolventization is performed, and all materials are directly mixed and reacted. As a result, the yield is significantly low, about 10% lower, and the purity is also reduced, but the above causal relationship has not been discovered before, that is, the present invention has found the key to improving the yield and purity of the product, thereby achieving good technical effects.
[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a triazine ultraviolet absorber, characterized in that: include: The preparation method is prepared by reaction using 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine and 1-chlorooctane as raw materials, wherein the reaction system is pre-desolventized before the reaction to control the water content below 500 ppm.
2. The method for preparing a triazine ultraviolet absorber according to claim 1, characterized in that: The step of pre-desolventizing comprises: 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine, a catalyst, PEG-400 and xylene are mixed in a reactor, the vacuum degree is controlled at -0.08 to 0 MPa, and the internal temperature is raised to 100 to 120° C. for distillation to perform pre-desolventization.
3. The method for preparing a triazine ultraviolet absorber according to claim 2, characterized in that: After the pre-desolventization is completed, the internal temperature is raised to 130-150° C., and 1-chlorooctane is added to react until the content of 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine in the reaction system is 0.1-0.8%.
4. The method for preparing a triazine ultraviolet absorber according to any one of claims 1 to 3, characterized in that: The method also includes: after the reaction is completed, filtering the reaction solution while hot and taking the filtrate for crystallization.
5. The method for preparing a triazine ultraviolet absorber according to claim 4, characterized in that: The steps of the crystallization treatment include: The filtrate is cooled to -10 to 10°C for crystallization to obtain a wet crude product, the wet crude product is mixed with an adsorbent material and a recrystallization solvent, heated to reflux, filtered while hot, and the filtrate is taken out, cooled to 0 to 20°C for recrystallization to obtain a wet fine product; The recrystallization solvent is methanol, ethanol, toluene, xylene or acetone; Preferably, the recrystallization solvent is acetone.
6. The method for preparing a triazine ultraviolet absorber according to claim 5, characterized in that: The adsorption material is activated carbon, diatomaceous earth, primary silica gel or activated white clay; The adsorption material is preferably activated carbon with a particle size of 100-200 mesh, and the amount of the adsorption material is 5-10% of the quality of the wet crude product; and / or, the mass ratio of the recrystallization solvent to the wet crude product is (2-6):1; And / or, the heating reflux temperature is 50-70° C. and the time is 1-2 h.
7. The method for preparing a triazine ultraviolet absorber according to claim 5, characterized in that: The method also includes drying the wet fine product under reduced pressure at 60 to 80° C., controlling the reduced pressure vacuum degree to be -0.095 to -0.1 MPa, and obtaining 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine product.
8. The method for preparing a triazine ultraviolet absorber according to any one of claims 1 to 7, characterized in that: The preparation of the 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine comprises: Using cyanuric chloride and m-xylene as raw materials, adding a reaction solvent to react under the catalytic action of aluminum chloride to generate an intermediate, and the intermediate reacts with resorcinol to generate 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine; The reaction liquid containing 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine is decontaminated with a mixed solution of water, ethyl acetate and hydrochloric acid to remove the solvent and water-soluble impurities to obtain a solid base material; the solid base material is crystallized, and the crystallization solvent is xylene, toluene, n-heptane or cyclohexane.
9. The method for preparing a triazine ultraviolet absorber according to claim 8, characterized in that: The preparation of the 2-(2,4-dihydroxyphenyl)-4,6-di(2,4-dimethylphenyl)-S-triazine also includes: The crude product obtained by crystallizing the solid base material is crystallized again to obtain a yellow wet fine product with a purity greater than or equal to 99.5%; The solvent for recrystallization is ethyl acetate, methanol, ethanol or methyl isobutyl ketone; preferably, the solvent for recrystallization is ethyl acetate.
10. A triazine ultraviolet absorber product, characterized in that: The 2,4-bis(2,4-xylyl)-6-(2-hydroxy-4-n-octyloxyphenyl)-1,3,5-triazine product is prepared by the method described in any one of claims 1 to 9, and the yield of the product is greater than or equal to 80%, and the purity is greater than or equal to 99.6%.