Synthesis method of 2, 2 ', 2' '-(1, 3, 5-triazine-2, 4, 6-triyl) tri [5-(hexyloxy)-6-methyl] phenol

Abstract

The invention discloses a synthesis method of 2, 2 ', 2' '-(1, 3, 5-triazine-2, 4, 6-triyl) tri [5-(hexyloxy)-6-methyl] phenol, and belongs to the technical field of chemical preparations. The method for preparing 2, 2 ', 2' '-(1, 3, 5-triazine-2, 4, 6-triyl) tri [5-(hexyloxy)-6-methyl] phenol comprises the following steps: (1) taking 2-methyl resorcinol and halogenated normal hexane as raw materials, and carrying out monoetherification reaction under the action of a first catalyst to obtain an intermediate; and (2) taking the intermediate and trihalogenated s-triazine as raw materials, and carrying out ortho-alkylation reaction under the action of a second catalyst to obtain 2, 2 ', 2' '-(1, 3, 5-triazine-2, 4, 6-triyl) tris [5-(hexyloxy)-6-methyl] phenol, the 2, 2', 2 ''-(1, 3, 5-triazine-2, 4, 6-triyl) tris [5-(hexyloxy)-6-methyl] phenol prepared by the method provided by the invention has the advantages of high yield and few byproducts.

Description

Technical Field

[0001] This invention relates to the field of chemical preparation technology, specifically to a method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol. Background Technology

[0002] Triazine UV absorbers have rapidly developed and become dominant in the field of light stabilizers in recent years due to their excellent comprehensive performance. These compounds possess advantages such as a wide absorption spectrum (especially in the UV-A and UV-B regions), high inherent photostability, strong durability, excellent heat resistance, and good compatibility with various polymer substrates and other additives. They are widely used in plastics, coatings, fibers, cosmetics, and other fields to effectively prevent aging, discoloration, and performance degradation of materials caused by UV radiation. Among them, 2,4,6-tris(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine and 2,4-di(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine are two representative high-efficiency triazine UV absorbers. The alkoxylation modification of multiple phenolic hydroxyl groups in their molecular structure not only enhances their compatibility with polymer matrices but also further improves their photostability.

[0003] Currently, the conventional synthetic route for such triazine UV absorbers typically involves two steps: the first step is to condense a 1,3,5-triazine core with a phenolic compound via Friedel-Crafts alkylation or acylation to generate the key intermediate 2,4,6-tris(2,4-dihydroxy-aryl)-1,3,5-triazine; the second step employs Williamson etherification, where the phenolic hydroxyl group in the intermediate reacts with a haloalkane under alkaline conditions to introduce alkoxy substituents such as hexoxy and butoxy, thereby obtaining the target UV absorber.

[0004] However, this traditional synthetic route has significant technical drawbacks, making it difficult to meet the demands of modern green chemistry and efficient production. First, Friedel-Crafts reactions typically require strong Lewis acids (such as AlCl3 and FeCl3) as catalysts, resulting in harsh reaction conditions and a high risk of side reactions (such as rearrangement and over-alkylation), leading to low purity intermediates. Furthermore, the large amount of catalyst used is difficult to recover, generating substantial amounts of acidic waste liquid and causing severe environmental pollution. Second, the separation and purification of the intermediate 2,4,6-tris(2,4-dihydroxy-aryl)-1,3,5-triazine is complex, with low yields, directly impacting the efficiency of subsequent reactions. Third, in the Williamson etherification step, due to differences in the reactivity of phenolic hydroxyl groups and steric hindrance, the alkylation reaction is often incomplete or has poor selectivity, easily generating monoethers, diethers, and other byproducts, resulting in low purity of the final product. This necessitates multiple recrystallizations or column chromatography purifications, making the process cumbersome, consuming large amounts of solvent and energy.

[0005] To address the aforementioned problems, this invention improves the synthesis method of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol. Summary of the Invention

[0006] The purpose of this invention is to provide a method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, in order to solve the technical problems mentioned in the background section above.

[0007] The technical solution to achieve the objective of this invention is:

[0008] This invention provides a method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, comprising the following preparation steps:

[0009] (1) Using 2-methylresorcinol and halohexane as raw materials, a monoetherification reaction is carried out under the action of a first catalyst to obtain an intermediate;

[0010] (2) Using the intermediate and trihalotriazine as raw materials, an ortho-alkylation reaction was carried out under the action of a second catalyst to obtain 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol;

[0011] The specific reaction pathway is as follows:

[0012]

[0013] In the synthesis of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol of the present invention, 2-methylresorcinol and halohexane are first used as raw materials, and a monoetherification reaction is carried out under the action of a first catalyst to obtain an intermediate. The symmetrical structural properties of 2-methylresorcinol are used for monoetherification, and the reaction conditions are controlled to obtain the intermediate 5-(hexoxy)-6-methylphenol in high yield. Then, the intermediate and trihalomycin are used as raw materials, and an ortho-alkylation reaction is carried out under the action of a second catalyst to obtain 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol. The 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol prepared by the present invention has high yield and high purity.

[0014] Furthermore, the solvent for the etherification reaction is methyl isobutyl ketone, and an acid-binding agent is also added to the etherification reaction; the first catalyst is potassium iodide.

[0015] Further, the molar ratio of 2-methylresorcinol, acid-binding agent, potassium iodide, methyl isobutyl ketone, and halohexane is 1:0.6:(0.18-0.45):(8-12):(1-1.5).

[0016] Furthermore, the acid-binding agent includes carbonates or bicarbonates.

[0017] Furthermore, the etherification reaction temperature is 102–106 °C / h, and the time is 9–11 h.

[0018] Furthermore, the trihalotriazine comprises 2,4,6-triiodo-1,3,5-triazine or 2,4,6-tribromo-1,3,5-triazine.

[0019] Furthermore, the second catalyst is tris(2,2'-bipyridine)ruthenium dichloride.

[0020] Furthermore, the solvent for the ortho-alkylation reaction is a mixed solution of N,N-dimethylformamide and methanol in a volume ratio of 4:1; potassium carbonate and tetrabutylammonium iodide are also added during the ortho-alkylation reaction.

[0021] Further, the molar ratio of the intermediate, trihalomethanetriazine, potassium carbonate, tetrabutylammonium iodide, and the second catalyst is 0.9:(0.3-0.9):(2.5-2.9):(0.8-1.0):(0.0040-0.0050); and the mass ratio of N,N-dimethylformamide to the intermediate is (30-31):1.

[0022] Furthermore, the ortho-alkylation reaction conditions are as follows: nitrogen protection and light irradiation at room temperature, wherein the reaction time is 15-20 h and the light source wavelength is 450-480 nm.

[0023] The catalyst for the ortho-alkylation reaction of this invention is tris(2,2'-bipyridine)ruthenium dichloride. Under illumination with a light source wavelength of 450-480 nm, tris(2,2'-bipyridine)ruthenium dichloride is converted to an excited state. The excited-state tris(2,2'-bipyridine)ruthenium dichloride is oxidized by 2,4,6-triiodo-1,3,5-triazine, and through single-electron transfer, tetravalent tris(2,2'-bipyridine)ruthenium dichloride and a triazine radical are generated. The electron-deficient triazine radical adds to the electron-rich intermediate to obtain a triazine-containing 5-(hexyloxy)-6-methylcyclohexyl radical. Then, in… Under the oxidation of high-valence tris(2,2'-bipyridine)ruthenium dichloride, the triazine-containing 5-(hexyloxy)-6-methylcyclohexyl radical undergoes electron transfer transformation and deprotonation in the presence of potassium carbonate. This improves the selectivity of the intermediate and the ortho-alkylation reaction of 2,4,6-triiodo-1,3,5-triazine, thereby reducing byproducts and increasing the yield of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol. Moreover, this reaction can be carried out under ambient temperature and light conditions, which can effectively reduce energy consumption in the production process.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects:

[0025] (1) In the synthesis of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol of the present invention, 2-methylresorcinol and halohexane are first used as raw materials, and a monoetherification reaction is carried out under the action of a first catalyst to obtain an intermediate. The symmetrical structural properties of 2-methylresorcinol are used for monoetherification, and the reaction conditions are controlled to obtain the intermediate 5-(hexoxy)-6-methylphenol with a high yield. Then, the intermediate and trihalomycin are used as raw materials, and an ortho-alkylation reaction is carried out under the action of a second catalyst to obtain 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol. The 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexoxy)-6-methyl]phenol prepared by the present invention has high yield and high purity.

[0026] (2) The catalyst for the ortho-alkylation reaction of the present invention is tris(2,2'-bipyridine)ruthenium chloride. Under illumination with a light source wavelength of 450-480 nm, tris(2,2'-bipyridine)ruthenium chloride is converted to an excited state. The excited state of tris(2,2'-bipyridine)ruthenium chloride is oxidized by 2,4,6-triiodo-1,3,5-triazine, and through single-electron transfer, tetravalent tris(2,2'-bipyridine)ruthenium chloride and triazine radical are generated. The electron-deficient triazine radical adds to the electron-rich intermediate to obtain a triazine-containing 5-(hexyloxy)-6-methylcyclohexyl radical. Then, in the high-valence state of the triazine... Under the oxidation of (2,2'-bipyridine)ruthenium dichloride, the triazine-containing 5-(hexyloxy)-6-methylcyclohexyl radical undergoes electron transfer transformation and then deprotonation in the presence of potassium carbonate. This improves the selectivity of the intermediate and the ortho-alkylation reaction of 2,4,6-triiodo-1,3,5-triazine, thereby reducing byproducts and increasing the yield of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol. Furthermore, this reaction can be carried out under ambient temperature and light conditions, using clean energy as the reaction conditions, which effectively reduces energy consumption in the production process. Attached Figure Description

[0027] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0028] Figure 1 The 1H NMR spectrum of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol is shown in one embodiment of the present invention. Detailed Implementation

[0029] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0032] Halogenated n-hexane is replaced by chlorohexane.

[0033] The trihalomethane triazine used is 2,4,6-triiodo-1,3,5-triazine.

[0034] Example 1

[0035] A method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, comprising the following preparation steps:

[0036] (1) Add 2-methylresorcinol, sodium carbonate, potassium iodide, and methyl isobutyl ketone to the reactor, seal, heat, and stir. When the temperature of the reaction solution rises to 102℃, slowly add halohexane dropwise over 90 minutes. Continue the reaction for 9 hours, then cool down. After the reaction is complete, allow it to cool and stand. Then pour the mixture into a vacuum filter funnel. Use a vacuum pump to generate negative pressure and draw the liquid into a vacuum flask. Solid salt residue remains in the funnel. Wash the salt residue with methyl isobutyl ketone solution, and then draw the liquid back into the vacuum flask under vacuum. Combine the filtrates. The solution was washed with 5% dilute hydrochloric acid until the pH of the filtrate was neutral, then washed twice with deionized water. The organic layer was collected and then rotary evaporated at 50°C and 10 mmHg to recover the methyl isobutyl ketone solvent. The solution was then dissolved in ethanol at 70°C, filtered while hot, and then cooled to 0°C to crystallize. After filtration, the solution was washed with cold n-hexane and dried under vacuum to obtain the intermediate. The molar ratio of 2-methylresorcinol, sodium carbonate, potassium iodide, methyl isobutyl ketone, and halohexane was 1:0.6:0.18:8:1.

[0037] (2) Tris(2,2'-bipyridine)ruthenium dichloride, potassium carbonate, intermediate, 2,4,6-triiodo-1,3,5-triazine, N,N-dimethylformamide, methanol, and tetrabutylammonium iodide were reacted under nitrogen protection by irradiation with a 5W LED blue light and stirring for 15 h. The mixture was then cooled to 15 °C, kept at that temperature for 50 min, and then filtered, washed, and dried to obtain 2,2',2”-(1,3,5-triazine-2 The product is 4,6-trimethyl)tris[5-(hexyloxy)-6-methyl]phenol; wherein the molar ratio of the intermediate, trihalomethanetriazine, potassium carbonate, tetrabutylammonium iodide, and the second catalyst is 0.9:0.3:2.5:0.8:0.0040; the amount of the second catalyst added is 6 mol%; the mass ratio of N,N-dimethylformamide to the intermediate is 30:1; and the volume ratio of N-dimethylformamide to methanol is 4:1.

[0038] Example 2

[0039] A method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, comprising the following preparation steps:

[0040] (1) Add 2-methylresorcinol, sodium carbonate, potassium iodide, and methyl isobutyl ketone to the reactor, seal, heat, and stir. When the temperature of the reaction solution rises to 104°C, slowly add halohexane dropwise over 90 minutes. Continue the reaction for 11 hours, then cool down. After the reaction is complete, allow it to stand and cool, then pour it into a vacuum filter funnel. Use a vacuum pump to generate negative pressure to draw the liquid into a vacuum filtration flask. Solid salt residue remains in the funnel. Then wash the salt residue with methyl isobutyl ketone solution, and draw the liquid back into the vacuum filtration flask through a vacuum pump. Combine the filtrates. The filtrate was washed with 5% dilute hydrochloric acid until the pH of the filtrate was neutral, then washed three times with deionized water. The organic layer was collected and then rotary evaporated at 60°C and 20 mmHg to recover the methyl isobutyl ketone solvent. The solvent was then dissolved in ethanol at 70°C, filtered while hot, and then cooled to 0°C to crystallize. The mixture was then filtered again, washed with cold n-hexane, and dried under vacuum to obtain the intermediate. The molar ratio of 2-methylresorcinol, sodium carbonate, potassium iodide, methyl isobutyl ketone, and halohexane was 1:0.6:0.36:10:1.2.

[0041] (2) Tris(2,2'-bipyridine)ruthenium dichloride, potassium carbonate, intermediate, 2,4,6-triiodo-1,3,5-triazine, N,N-dimethylformamide, methanol, and tetrabutylammonium iodide were reacted under nitrogen protection by irradiation with a 5W LED blue light and stirring for 18 h. The mixture was then cooled to 15 °C, kept at that temperature for 60 min, and then filtered, washed, and dried to obtain 2,2',2”-(1,3,5-triazine-2, 4,6-Trimethyl)tris[5-(hexyloxy)-6-methyl]phenol; wherein the molar ratio of the intermediate, trihalomethanetriazine, potassium carbonate, tetrabutylammonium iodide, and the second catalyst is 0.9:0.6:2.7:0.9:0.0045; the amount of the second catalyst added is 5 mol%; the mass ratio of N,N-dimethylformamide to the intermediate is 30.5:1; and the volume ratio of N-dimethylformamide to methanol is 4:1.

[0042] Example 3

[0043] A method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, comprising the following preparation steps:

[0044] (1) Add 2-methylresorcinol, sodium carbonate, potassium iodide, and methyl isobutyl ketone to the reactor, seal, heat, and stir. When the temperature of the reaction solution rises to 106°C, slowly add halohexane dropwise over 90 minutes. Continue the reaction for 11 hours, then cool down. After the reaction is complete, allow it to stand and cool, then pour it into a vacuum filter funnel. Use a vacuum pump to generate negative pressure to draw the liquid into a vacuum filtration flask. Solid salt residue remains in the funnel. Then wash the salt residue with methyl isobutyl ketone solution, and draw the liquid back into the vacuum filtration flask through a vacuum pump. Combine the filtrates. The filtrate was washed with 5% dilute hydrochloric acid until the pH of the filtrate was neutral, and then washed three times with deionized water. The organic layer was collected and then rotary evaporated at 60°C and 20 mmHg to recover the methyl isobutyl ketone solvent. The solvent was then dissolved in ethanol at 80°C, filtered while hot, and then cooled to 5°C to crystallize. The mixture was then filtered again, washed with cold n-hexane, and dried under vacuum to obtain the intermediate. The molar ratio of 2-methylresorcinol, sodium carbonate, potassium iodide, methyl isobutyl ketone, and halohexane was 1:0.6:0.45:12:1.5.

[0045] (2) Tris(2,2'-bipyridine)ruthenium dichloride, potassium carbonate, intermediate, 2,4,6-triiodo-1,3,5-triazine, N,N-dimethylformamide, methanol, and tetrabutylammonium iodide were reacted under nitrogen protection by irradiation with a 5W LED blue light and stirring for 20 h. The mixture was then cooled to 20 °C, kept at that temperature for 70 min, and then filtered, washed, and dried to obtain 2,2',2”-(1,3,5-triazine-2 The product is 4,6-trimethyl(trimethyl)tris[5-(hexyloxy)-6-methyl]phenol; wherein the molar ratio of the intermediate, trihalomethanetriazine, potassium carbonate, tetrabutylammonium iodide, and the second catalyst is 0.9:0.9:2.9:1.0:0.0050; the amount of the second catalyst added is 4 mol%; the mass ratio of N,N-dimethylformamide to the intermediate is 31:1; and the volume ratio of N-dimethylformamide to methanol is 4:1.

[0046] Comparative Example 1

[0047] The difference between Comparative Example 1 and Example 2 is that the second catalyst used is aluminum chloride. The specific steps are as follows:

[0048] A method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, comprising the following preparation steps:

[0049] (1) Add 2-methylresorcinol, sodium carbonate, potassium iodide, and methyl isobutyl ketone to the reactor, seal, heat, and stir. When the temperature of the reaction solution rises to 104°C, slowly add halohexane dropwise over 90 minutes. Continue the reaction for 11 hours, then cool down. After the reaction is complete, allow it to stand and cool, then pour it into a vacuum filter funnel. Use a vacuum pump to generate negative pressure to draw the liquid into a vacuum filtration flask. Solid salt residue remains in the funnel. Then wash the salt residue with methyl isobutyl ketone solution, and draw the liquid back into the vacuum filtration flask through a vacuum pump. Combine the filtrates. The filtrate was washed with 5% dilute hydrochloric acid until the pH of the filtrate was neutral, then washed three times with deionized water. The organic layer was collected and then rotary evaporated at 60°C and 20 mmHg to recover the methyl isobutyl ketone solvent. The solvent was then dissolved in ethanol at 70°C, filtered while hot, and then cooled to 0°C to crystallize. The mixture was then filtered again, washed with cold n-hexane, and dried under vacuum to obtain the intermediate. The molar ratio of 2-methylresorcinol, sodium carbonate, potassium iodide, methyl isobutyl ketone, and halohexane was 1:0.6:0.36:10:1.2.

[0050] (2) Mix the intermediate, aluminum trichloride, nitrobenzene, and N,N-dimethylformamide, stir and heat until all materials are dissolved, cool to 5-10°C in a water bath and ice-water bath, add cyanuric chloride, and keep warm for 60 minutes; slowly heat to 10-20°C and keep in a cold water bath for 60 minutes, then heat to 25-30°C and keep for 60 minutes, then heat to the set reaction temperature of 90-95°C for 30 minutes and keep the reaction for 3 hours to obtain 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol; wherein, the molar ratio of intermediate, aluminum trichloride, nitrobenzene, and cyanuric chloride is 0.32:0.16:1.803:0.1; the mass ratio of N,N-dimethylformamide to intermediate is 31:1.

[0051] Comparative Example 2

[0052] Comparative Example 2 describes the existing method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, with the specific steps as follows:

[0053] Add 39.7 g of 2-methylresorcinol, 21.4 g of solid aluminum trichloride, and 222 g of nitrobenzene to a 500 ml four-necked flask equipped with a stirrer, thermometer, condenser, and connected to a hydrogen chloride absorption device. Stir and heat until all materials are dissolved, then cool to 5-10°C in a water bath and ice-water bath. Turn on the hydrogen chloride absorption device and add 18.5 g of cyanuric chloride to the four-necked flask, maintaining the temperature for 60 minutes. Slowly heat to 10-20°C and maintain in a cold water bath for 60 minutes, then heat to 25-30°C and maintain for 60 minutes. Finally, heat to the set reaction temperature of 90-95°C over 30 minutes and maintain the reaction temperature for 3.0 hours.

[0054] The reaction solution was slowly added to a 1000ml four-necked flask containing 55.5g of 37% hydrochloric acid, a stirrer, and a thermometer. The hydrolysis temperature was controlled at 70-80℃ for 1.0 hour to terminate the reaction. At this temperature, 0.93g of triethylenetetramine was added, and the material system gradually showed solid-liquid separation. The temperature was lowered to 40℃, and about 202g of liquid phase was poured out from the mouth of the four-necked flask (GC analysis showed nitrobenzene content ≥99.0%). Then, 351.5g of N,N-dimethylformamide solvent was added to the remaining material in the 1000ml four-necked flask, and the mixture was stirred and heated until completely dissolved. The mixture was then cooled in a water bath to 40-45℃ to precipitate solid material. The temperature was then lowered to 15-20℃ and kept at this temperature for 1.0 hour. After filtration, washing with DMF, and drying, the intermediate 2,4,6-tris(2,4-dihydroxy-3-methylphenyl)-1,3,5-triazine was obtained.

[0055] Example of effect

[0056] Table 1 below shows the yield and purity of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol in Examples 1-3 and Comparative Examples 1-2:

[0057] Table 1

[0058] Yield (%) purity(%) Example 1 94.8 98.9 Example 2 96.4 99.1 Example 3 93.9 98.6 Comparative Example 1 80.4 94.6 Comparative Example 2 89.6 98.8

[0059] As shown in Table 1 above, the yield and purity of 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol prepared in Examples 1 to 3 were both high.

[0060] The difference between Comparative Example 1 and Example 2 is that the catalyst used in step (2) of Comparative Example 1 is conventional aluminum trichloride, and the alkylation reaction is carried out using existing technology based on aluminum trichloride. The yield and purity of the 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol obtained are both low.

[0061] Prior art document 2 refers to 2,2',2”- in Chinese invention patent application number 22010723183.5.

[0062] The 2,2',2"-(1,3,5-triazine-2,4,6-triyl)tri[5-(hexyloxy)-6-methyl]phenol was prepared by a specific process. Experiments showed that the yield of 2,2',2"-(1,3,5-triazine-2,4,6-triyl)tri[5-(hexyloxy)-6-methyl]phenol was as high as 89.6%, and the purity was as high as 98.8%. Compared with Comparative Example 2, the 2,2',2"-(1,3,5-triazine-2,4,6-triyl)tri[5-(hexyloxy)-6-methyl]phenol prepared in Examples 1-3 of this invention had a higher yield and better purity.

[0063] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol, characterized in that, The preparation steps include the following: (1) Using 2-methylresorcinol and halohexane as raw materials, a monoetherification reaction is carried out under the action of a first catalyst to obtain an intermediate; (2) Using the intermediate and trihalotriazine as raw materials, an ortho-alkylation reaction is carried out under the action of a second catalyst to obtain 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol.

2. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 1, characterized in that, The solvent used in the etherification reaction is methyl isobutyl ketone, and an acid-binding agent is also added to the etherification reaction; the first catalyst is potassium iodide.

3. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 2, characterized in that, The molar ratio of 2-methylresorcinol, acid-binding agent, potassium iodide, methyl isobutyl ketone, and halohexane is 1:0.6:(0.18-0.45):(8-12):(1-1.5).

4. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 2, characterized in that, The acid-binding agent includes carbonates or bicarbonates.

5. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 2, characterized in that, The etherification reaction is carried out at a temperature of 102–106 °C for 9–11 hours.

6. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 1, characterized in that, The trihalomethane triazine includes 2,4,6-triiodo-1,3,5-triazine or 2,4,6-tribromo-1,3,5-triazine.

7. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 1, characterized in that, The second catalyst is tris(2,2'-bipyridine) ruthenium dichloride.

8. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 7, characterized in that, The solvent for the ortho-alkylation reaction is a mixed solution of N,N-dimethylformamide and methanol in a volume ratio of 4:1; potassium carbonate and tetrabutylammonium iodide are also added during the ortho-alkylation reaction.

9. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 8, characterized in that, The molar ratio of the intermediate, trihalomethanetriazine, potassium carbonate, tetrabutylammonium iodide, and the second catalyst is 0.9:(0.3-0.9):(2.5-2.9):(0.8-1.0):(0.0040-0.0050); the mass ratio of N,N-dimethylformamide to the intermediate is (30-31):

1.

10. The method for synthesizing 2,2',2”-(1,3,5-triazine-2,4,6-triyl)tris[5-(hexyloxy)-6-methyl]phenol according to claim 7, characterized in that, The ortho-alkylation reaction conditions are as follows: nitrogen protection and light irradiation at room temperature, wherein the reaction time is 15-20 h and the light source wavelength is 450-480 nm.

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