The invention relates to a method for preparing 2, 4, 6-tri (4apos; -butoxy-2apos,-butoxy-2apos; process for the preparation of-hydroxyphenyl)-triazines

Abstract

The invention provides a method for preparing 2, 4, 6-tri (4 '-butoxy-2'-hydroxyphenyl)-triazine, which comprises the following steps: in the presence of an alkaline reagent, dissolving m-bromophenol and n-butyl bromide in a first solvent to carry out nucleophilic substitution reaction, and after the reaction is finished, carrying out post-treatment to obtain 1-bromo-3-butoxybenzene; magnesium chips and an initiator are dissolved in a second solvent for a reaction, then the 1-bromo-3-butoxybenzene is dropwise added for a Grignard reaction, and a 3-butoxybenzene Grignard reagent is obtained; dropwise adding boric acid ester into the 3-butoxybenzene Grignard reagent for reaction, and then adding an oxidizing agent for oxidation reaction to obtain 3-butoxyphenol; 3-butoxyphenol and cyanuric chloride are dissolved in a third solvent for a reaction, lewis acid is added for a Friedel-Crafts reaction, after the reaction is finished, aftertreatment is conducted, and the 2, 4, 6-tri (4 '-butoxy-2'-hydroxyphenyl)-triazine is obtained.The preparation method is lower in cost, higher in yield, high in product quality and easy to control.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine. Background Art

[0002] Commonly used UV absorbers include benzophenones, salicylates, benzotriazoles, and triazines. Triazine UV absorbers are a new class of UV absorbers that have been developed in recent years. As their research and application value gradually become apparent, triazine compounds have become a very important research field, and scientists are increasingly conducting theoretical and experimental research on them.

[0003] 2,4,6-Tris(4'-butoxy-2'-hydroxyphenyl)-triazine is an oil-soluble organic compound added to sunscreens to effectively absorb UV rays. Its preparation is known in the art. The commonly used preparation method involves a Friedel-Crafts alkylation reaction between cyanuric chloride and resorcinol in the presence of aluminum chloride to produce a 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine intermediate. This intermediate is then etherified with a halogenated alkane to produce the target product. However, when the intermediate product 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine is subjected to an etherification reaction with a halogenated alkane, the selection of solvents, temperature, and base does not effectively improve the selectivity of the reaction. Overreaction is likely to occur to produce the byproduct 2,4-bis(2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3,5-triazine, resulting in an unsatisfactory reaction yield. The presence of the byproduct also brings great difficulties to the subsequent purification, resulting in very high cost pressure and being unfavorable for industrial production. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine. The method provided by the present invention has lower cost, higher yield, high product quality and is easy to control.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine, comprising the following steps:

[0007] S1: dissolving m-bromophenol and n-butyl bromide in a first solvent in the presence of an alkaline reagent, performing a nucleophilic substitution reaction, completing the reaction, and post-processing to obtain 1-bromo-3-butoxybenzene;

[0008] S2: dissolving magnesium chips and an initiator in a second solvent for reaction, and then dropwise adding 1-bromo-3-butoxybenzene to carry out a Grignard reaction to obtain a 3-butoxybenzene Grignard reagent;

[0009] S3: adding borate ester dropwise to 3-butoxybenzene Grignard reagent to react, and then adding an oxidant to carry out oxidation reaction to obtain 3-butoxyphenol, and

[0010] S4: dissolving 3-butoxyphenol and cyanuric chloride in a third solvent for reaction, then adding Lewis acid to carry out Friedel-Crafts reaction. After the reaction is completed, post-treatment is performed to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine.

[0011] Preferably, in step S1, the alkaline agent is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate and sodium carbonate; and the first solvent is acetonitrile, ethanol, dimethyl sulfoxide or N-dimethylformamide.

[0012] Preferably, in step S1, the alkaline agent is selected from one or more of sodium hydroxide, potassium hydroxide and sodium carbonate; and the first solvent is acetonitrile, ethanol or dimethyl sulfoxide.

[0013] Preferably, in step S1, the alkaline reagent is selected from one or both of sodium hydroxide and potassium hydroxide; and the first solvent is acetonitrile, ethanol or dimethyl sulfoxide.

[0014] Preferably, in step S1, the molar ratio of the alkaline reagent to m-bromophenol is 0.8 to 1.5:1.

[0015] Preferably, in step S1, the post-treatment process includes cooling, solid-liquid separation, water washing and drying.

[0016] Preferably, in step S2, the second solvent is diethyl ether, tetrahydrofuran or 2-methyltetrahydrofuran; and the initiator is selected from elemental iodine, dibromoethane and iodomethane.

[0017] Preferably, in step S2, the second solvent is tetrahydrofuran or 2-methyltetrahydrofuran; and the initiator is selected from elemental iodine, dibromoethane and iodomethane.

[0018] Preferably, in step S2, the second solvent is tetrahydrofuran; and the initiator is selected from elemental iodine.

[0019] Preferably, in step S2, the molar ratio of magnesium chips to 1-bromo-3-butoxybenzene is 1.05 to 1.2:1.

[0020] Preferably, in step S3, the borate ester is trimethyl borate or triethyl borate; and the oxidant is hydrogen peroxide or sodium hypochlorite.

[0021] Preferably, in step S3, the borate ester is trimethyl borate; and the oxidant is hydrogen peroxide.

[0022] Preferably, in step S3, the molar ratio of 3-butoxybenzyl Grignard reagent to borate ester is 0.9 to 1:1.

[0023] Preferably, in step S4, the third solvent is toluene or chlorobenzene; the Lewis acid is one or more of aluminum trichloride, zinc chloride, ferric chloride and tin tetrachloride; and the molar ratio of 3-butoxyphenol to Lewis acid is 1:1 to 1.5.

[0024] Preferably, in step S4, the third solvent is toluene or chlorobenzene; the Lewis acid is one or more of aluminum trichloride, zinc chloride, ferric chloride and tin tetrachloride; and the molar ratio of 3-butoxyphenol to Lewis acid is 1:1 to 1.2.

[0025] Preferably, in step S4, the post-processing process includes:

[0026] 1) quenching the reaction solution, adding an acidic reagent to the reaction solution after the reaction is completed to quench the reaction and precipitate a crude 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine product;

[0027] 2) Filtration and crude product treatment: Filter the crude product and purify it by recrystallization to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine.

[0028] Technical Effects

[0029] In the preparation method of the present invention, m-bromophenol is used as a raw material to realize an etherification reaction of a single phenolic hydroxyl group, and then a Grignard reagent is prepared in a one-pot method, followed by an oxidation reaction and a Friedel-Crafts alkylation reaction. This overcomes the difficulty of overreaction in the process of the prior art to generate UV-460, which leads to cumbersome purification and high cost, thereby realizing a preparation method of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine with lower cost, higher yield, high product quality and easy control. DETAILED DESCRIPTION

[0030] The present invention is described in detail below by way of examples, but is not intended to limit the present invention in any way. While the present invention has been described in detail herein, and specific embodiments thereof have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention.

[0031] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art can be used.

[0032] The present invention provides a method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine, comprising the following steps:

[0033] S1: dissolving m-bromophenol and n-butyl bromide in a first solvent in the presence of an alkaline reagent, performing a nucleophilic substitution reaction, completing the reaction, and post-processing to obtain 1-bromo-3-butoxybenzene;

[0034] S2: dissolving magnesium chips and an initiator in a second solvent for reaction, and then dropwise adding 1-bromo-3-butoxybenzene to carry out a Grignard reaction to obtain a 3-butoxybenzene Grignard reagent;

[0035] S3: adding borate ester dropwise to 3-butoxybenzene Grignard reagent to react, and then adding an oxidant to carry out oxidation reaction to obtain 3-butoxyphenol, and

[0036] S4: dissolving 3-butoxyphenol and cyanuric chloride in a third solvent for reaction, then adding Lewis acid to carry out Friedel-Crafts reaction. After the reaction is completed, post-treatment is performed to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine.

[0037] The temperature of the nucleophilic substitution reaction in step S1 of the present invention is preferably 65-85°C, more preferably 70-85°C, and most preferably 70-80°C; the time of the nucleophilic substitution reaction in step S1 is preferably 6-8h, more preferably 7-8h, and most preferably 7h.

[0038] After the nucleophilic substitution reaction is completed, the present invention preferably performs post-treatment on the product obtained by the nucleophilic substitution reaction to obtain 1-bromo-3-butoxybenzene. The present invention can purify 1-bromo-3-butoxybenzene by adopting post-treatment.

[0039] In the present invention, the post-treatment process of the product obtained by the nucleophilic substitution reaction in the post-treatment process of step S1 includes cooling, solid-liquid separation, water washing and drying.

[0040] The present invention has no special limitation on the cooling operation during the post-treatment process of step S1, and cooling to room temperature is sufficient.

[0041] The solid-liquid separation in the post-treatment process of step S1 of the present invention is preferably performed by pressure filtration. The present invention does not limit the operation of pressure filtration, and any operation well known to those skilled in the art can be used.

[0042] The water used for water washing in the post-treatment process of step S1 of the present invention is preferably deionized water. The present invention has no limitation on the water washing operation, and operations well known to those skilled in the art may be used.

[0043] In step S1 of the present invention, the alkaline agent is preferably one or more of sodium hydroxide, potassium hydroxide, potassium carbonate and sodium carbonate, more preferably one or more of sodium hydroxide, potassium hydroxide and sodium carbonate, and most preferably one or both of sodium hydroxide and potassium hydroxide.

[0044] In step S1 of the present invention, the first solvent is preferably acetonitrile, ethanol, dimethyl sulfoxide or N-dimethylformamide, more preferably acetonitrile, ethanol or dimethyl sulfoxide, and most preferably acetonitrile or ethanol.

[0045] In the present invention, in step S1, the molar ratio of the alkaline reagent to m-bromophenol is preferably 0.8 to 2:1; more preferably 0.8 to 1.5:1.

[0046] In the present invention, in step S2, the second solvent is preferably diethyl ether, tetrahydrofuran or 2-methyltetrahydrofuran, more preferably tetrahydrofuran or 2-methyltetrahydrofuran, and most preferably tetrahydrofuran.

[0047] In step S2 of the present invention, the initiator is preferably elemental iodine, dibromoethane and iodomethane, and more preferably elemental iodine.

[0048] In step S2 of the present invention, the molar ratio of magnesium chips to 1-bromo-3-butoxybenzene is preferably 1.05 to 1.2:1.

[0049] The present invention does not require post-processing after the Grignard reaction, and the next step of reaction can be directly carried out while maintaining a nitrogen atmosphere.

[0050] In step S3 of the present invention, the borate ester is preferably trimethyl borate or triethyl borate, more preferably trimethyl borate. In step S3 of the present invention, the oxidant is preferably hydrogen peroxide or sodium hypochlorite, more preferably hydrogen peroxide.

[0051] In the present invention, in step S3, the molar ratio of 3-butoxybenzyl Grignard reagent to borate ester is preferably 0.9 to 1:1.5, more preferably 0.9 to 1:1.

[0052] After the oxidation reaction is completed, the present invention preferably performs post-treatment on the reaction solution after the oxidation reaction to obtain 3-butoxyphenol, and the post-treatment process includes the following steps:

[0053] Adding a reducing agent to reduce the unreacted oxidant in the reaction system, wherein the reducing agent used in the present invention is preferably sodium thiosulfate and sodium bisulfite, more preferably sodium thiosulfate;

[0054] The detection reaction solution is non-oxidizing, and the detection means used in the present invention is preferably starch potassium iodide test paper;

[0055] Concentrating the reaction solution, preferably removing the solvent in the reaction solution by heating;

[0056] Neutralizing the acidic substances in the reaction solution, the neutralizing agent used in the present invention is preferably sodium hydroxide and potassium hydroxide, more preferably sodium hydroxide;

[0057] Extracting the reaction liquid, the extractant of the present invention is preferably methyl tert-butyl ether;

[0058] Adjust the pH of the aqueous phase to 6-7. The pH adjuster of the present invention is preferably hydrochloric acid or sulfuric acid, more preferably hydrochloric acid, and the hydrochloric acid is a dilute hydrochloric acid with a mass fraction of 20%;

[0059] Extracting the aqueous phase, preferably re-extracting the aqueous phase with methyl tert-butyl ether;

[0060] The organic phase is collected, heated and concentrated to remove the solvent. In the present invention, the collected organic phase is preferably concentrated by heating to obtain 3-butoxyphenol.

[0061] In step S4 of the present invention, the third solvent is preferably toluene or chlorobenzene; the Lewis acid is preferably one or more of aluminum trichloride, zinc chloride, ferric chloride and tin tetrachloride, more preferably aluminum trichloride.

[0062] In step S4 of the present invention, the molar ratio of 3-butoxyphenol to Lewis acid is preferably 1:1 to 1.5, more preferably 1:1 to 1.2.

[0063] In step S4 of the present invention, the post-processing process includes:

[0064] 1) quenching the reaction solution, adding an acidic reagent to the reaction solution after the reaction is completed to quench the reaction and precipitate a crude 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine product, wherein the acidic reagent used in the present invention is preferably hydrochloric acid or sulfuric acid, more preferably hydrochloric acid, and the hydrochloric acid is a dilute hydrochloric acid with a mass fraction of 20%;

[0065] 2) Filtration and crude product treatment: filtering the crude product and purifying the crude product by recrystallization to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine. In the present invention, the recrystallization solvent preferably includes one or more of tetrahydrofuran, methanol or ethanol, more preferably tetrahydrofuran and ethanol.

[0066] The technical scheme of the synthesis method of the piroctone olamine salt of the present invention will be described in detail below in conjunction with the specific embodiments of the present invention.

[0067] The present invention provides the following synthetic route of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine:

[0068]

[0069] Example 1

[0070] Step S1: Preparation of 1-bromo-3-butoxybenzene

[0071] Potassium carbonate (7.98 g, 0.0578 mol) was added to a 250 mL three-necked flask, m-bromophenol (10.0 g, 0.0578 mol) was dissolved in 20 mL of acetonitrile, and n-butyl bromide (9.5 g, 0.0693 mol) was added dropwise. The temperature was raised to 75-80 ° C and stirred for 7 h. After the reaction was completed, the reaction system was cooled to 20-30 ° C and filtered directly. The filter cake was collected, 10 mL of water was added to the filter cake, stirred, washed with water for 1 hour, filtered, and the filter cake was dried to obtain 12.1 g of 1-bromo-3-butoxybenzene. The product purity was 96.5%, and the yield was 90.1%.

[0072] Step S2: Preparation of 3-butoxybenzene Grignard reagent

[0073] To a 250 mL three-necked flask, magnesium chips (1.27 g, 0.0524 mol), 20 mL of tetrahydrofuran, and elemental iodine (0.1 g, 0.0004 mol) were added, the temperature was raised to 35-45 ° C, and the mixture was stirred for 1 h. Then, a mixed solution of 1-bromo-3-butoxybenzene (10 g, 0.0436 mol) and tetrahydrofuran (100 mL) prepared in step S1 was added dropwise. When the color of iodine gradually faded and the solution became turbid, heating was stopped and a mixed solution of 1-bromo-3-butoxybenzene (8 g, 0.0349 mol) and tetrahydrofuran (100 mL) was continued to be added dropwise. After the reaction was completed, the mixture was cooled and nitrogen protection was retained to obtain 3-butoxybenzene Grignard reagent with a yield of 100%.

[0074] Step S3: Preparation of 3-butoxyphenol

[0075] The 3-butoxybenzyl Grignard reagent (11 g, 0.0436 mol) prepared in step S2 was directly heated to 30-40° C., trimethyl borate (5.0 g, 0.0480 mol) was added dropwise, and stirred for 6 h; the temperature was slowly lowered to 20-25° C., and a nitrogen atmosphere was maintained. 10% hydrogen peroxide (17.8 g, 0.0523 mol) was slowly added dropwise. After the addition was completed, the temperature was slowly raised to 30-40° C., stirred for 6 h, sodium thiosulfate (3.4 g, 0.0218 mol) was added, and stirred again for 1 h. The reaction system was tested with starch potassium iodide paper, indicating that the system was non-oxidizing. The temperature was then raised to 40° C. to remove most of the tetrahydrofuran, and sodium hydroxide (1.75 g, 0.0436 mol) was added. The mixture was stirred for 1 hour, and then extracted with 20 mL of methyl tert-butyl ether. The organic phase was separated, and the aqueous phase was retained. The pH of the aqueous phase was adjusted to 6-7 with 20% hydrochloric acid (8 g, 0.0436 mol) and extracted once with 30 mL of methyl tert-butyl ether. The organic phase was collected and heated to 30-40° C. to remove the methyl tert-butyl ether, yielding 5.8 g of 3-butoxyphenol with a product purity of 95.4% and a yield of 80%.

[0076] Step S4: Preparation of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine

[0077] In a 100 mL three-necked flask, 3-butoxyphenol (5 g, 0.03 mol) obtained in step S3 and raw material cyanuric chloride (1.84 g, 0.01 mol) were dissolved in 18 mL of toluene and stirred for 1 h. Aluminum chloride (4 g, 0.03 mol) was added; the temperature was raised to 90-100° C. and stirred for 6 h. The temperature was slowly lowered to 20-25° C., 20% hydrochloric acid was added to quench the reaction, and the mixture was stirred for 1 h. After solids precipitated in the system, the crude product of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine was obtained by filtration. The crude product was recrystallized from 25 mL of tetrahydrofuran and 10 mL of ethanol to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine with a purity of 98.4% and a yield of 72%.

[0078] Example 2

[0079] Step S1: Preparation of 1-bromo-3-butoxybenzene

[0080] Potassium carbonate (7.98 g, 0.0578 mol) was added to a 250 mL three-necked flask, m-bromophenol (10.0 g, 0.0578 mol) was dissolved in 20 mL of ethanol, and n-butyl bromide (9.5 g, 0.0693 mol) was added dropwise. The temperature was raised to 70-80 ° C and stirred for 7 h. After the reaction was completed, the reaction system was cooled to 20-30 ° C and filtered directly. The filter cake was collected, 10 mL of water was added to the filter cake, stirred, washed with water for 1 h, filtered, and the filter cake was dried to obtain 11.8 g of 1-bromo-3-butoxybenzene. The product purity was 96.1% and the yield was 89.1%.

[0081] Steps S2 and S3 are the same as those in Example 1.

[0082] Step S4: Preparation of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine

[0083] In a 100 mL three-necked flask, 3-butoxyphenol (5 g, 0.03 mol) obtained in step S3 and raw material cyanuric chloride (1.84 g, 0.01 mol) were dissolved in 18 mL of toluene and stirred for 1 h. Aluminum chloride (3 g, 0.02 mol) was added; the temperature was raised to 90-100° C. and stirred for 6 h. The temperature was slowly lowered to 20-25° C., 20% by mass hydrochloric acid was added to quench the reaction, and the mixture was stirred for 1 h. After solids precipitated in the system, the crude product of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine was obtained by filtration. The crude product was recrystallized from 25 mL of tetrahydrofuran and 10 mL of ethanol to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine with a product purity of 98.3% and a yield of 69%.

[0084] Example 3

[0085] Step S1: Preparation of 1-bromo-3-butoxybenzene

[0086] Potassium carbonate (7.98 g, 0.0578 mol) was added to a 250 mL three-necked flask, m-bromophenol (10.0 g, 0.0578 mol) was dissolved in 20 mL of N-N dimethylformamide, and n-butyl bromide (9.5 g, 0.0693 mol) was added dropwise. The temperature was raised to 75-80°C and stirred for 7 h. After the reaction was completed, the reaction system was cooled to 20-30°C and filtered directly to collect the filter cake. 10 mL of water was added to the filter cake, stirred, washed with water for 1 h, filtered, and the filter cake was dried to obtain 11 g of 1-bromo-3-butoxybenzene. The product purity was 97.0% and the yield was 83.0%.

[0087] Steps S2 and S3 are the same as those in Example 1.

[0088] Step S4: Preparation of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine

[0089] In a 100 mL three-necked flask, 3-butoxyphenol (5 g, 0.03 mol) obtained in step S3 and raw material cyanuric chloride (1.84 g, 0.01 mol) were dissolved in 18 mL of chlorobenzene and stirred for 1 h. Aluminum chloride (4 g, 0.03 mol) was added; the temperature was raised to 90-100° C. and stirred for 6 h. The temperature was slowly lowered to 20-25° C., 20% by mass hydrochloric acid was added to quench the reaction, and the mixture was stirred for 1 h. After solids precipitated in the system, the crude product of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine was obtained by filtration. The crude product was recrystallized from 25 mL of tetrahydrofuran and 10 mL of ethanol to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine with a purity of 98.2% and a yield of 73.4%.

[0090] Example 4

[0091] Step S1: Preparation of 1-bromo-3-butoxybenzene

[0092] Sodium hydroxide (1.84 g, 0.0468 mol) was added to a 250 mL three-necked flask, m-bromophenol (10.0 g, 0.0578 mol) was dissolved in 20 mL of acetonitrile, and n-butyl bromide (9.5 g, 0.0693 mol) was added dropwise. The temperature was raised to 75-80 ° C and stirred for 7 h. After the reaction was completed, the reaction system was cooled to 20-30 ° C and filtered directly. The filter cake was collected, 10 mL of water was added to the filter cake, stirred, washed with water for 1 hour, filtered, and the filter cake was dried to obtain 12.1 g of 1-bromo-3-butoxybenzene. The product purity was 96.5%, and the yield was 85%.

[0093] Steps S2 and S3 are the same as those in Example 1.

[0094] Step S4: Preparation of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine

[0095] In a 100 mL three-necked flask, 3-butoxyphenol (5 g, 0.03 mol) obtained in step S3 and raw material cyanuric chloride (1.84 g, 0.01 mol) were dissolved in 18 mL of toluene and stirred for 1 h. Aluminum chloride (3 g, 0.02 mol) was added; the temperature was raised to 90-100° C. and stirred for 6 h. The temperature was slowly lowered to 20-25° C., 20% by mass hydrochloric acid was added to quench the reaction, and the mixture was stirred for 1 h. After solids precipitated in the system, the crude product of 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine was obtained by filtration. The crude product was recrystallized from 25 mL of tetrahydrofuran and 10 mL of ethanol to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine with a purity of 97.3% and a yield of 72%.

[0096] As can be seen from the above examples, the present invention uses cheaper m-bromophenol as a raw material, and prepares 2,4,6-tris (4'-butoxy-2'-hydroxyphenyl) -triazine through nucleophilic substitution reaction, Grignard reaction, oxidation reaction and Friedel-Crafts-alkylation reaction, wherein the nucleophilic substitution reaction is purified by washing with water; the Grignard reagent is prepared in one pot, and after the Grignard reaction, no post-treatment is required. The borate ester is directly added dropwise to the Grignard reagent for nucleophilic addition reaction, and then an oxidant is added to oxidize to obtain 3-butoxyphenol, and finally, cyanuric chloride is reacted with Lewis acid to generate 2,4,6-tris (4'-butoxy-2'-hydroxyphenyl) -triazine. The post-treatment steps of the entire process are conventional and simple, the reaction selectivity is high, and the product purity is high and easy to control. This preparation method is more efficient, has a higher yield, and a better product purity, and is lower in cost in the actual industrial process.

[0097] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine, characterized in that: The following steps are involved: S1: In the presence of an alkaline reagent, dissolving m-bromophenol and n-butyl bromide in a first solvent to carry out a nucleophilic substitution reaction, completing the reaction, and post-treating to obtain 1-bromo-3-butoxybenzene; S2: dissolving magnesium chips and an initiator in a second solvent for reaction, and then dropwise adding the 1-bromo-3-butoxybenzene to carry out a Grignard reaction to obtain a 3-butoxybenzene Grignard reagent; S3: adding borate ester dropwise to the 3-butoxybenzene Grignard reagent to react, and then adding an oxidant to carry out oxidation reaction to obtain 3-butoxyphenol, and S4: dissolving the 3-butoxyphenol and cyanuric chloride in a third solvent for reaction, adding Lewis acid, and performing Friedel-Crafts reaction. After the reaction is completed, post-processing is performed to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine.

2. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 1, characterized in that In step S1, the alkaline reagent is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate and sodium carbonate; and the first solvent is acetonitrile, ethanol, dimethyl sulfoxide or N-dimethylformamide.

3. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 2, characterized in that In step S1, the molar ratio of the alkaline reagent to m-bromophenol is 0.8-1.5:

1.

4. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 3, characterized in that In step S1, the post-treatment process includes cooling, solid-liquid separation, water washing and drying.

5. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 1, characterized in that In step S2, the second solvent is diethyl ether, tetrahydrofuran or 2-methyltetrahydrofuran; and the initiator is selected from elemental iodine, dibromoethane and iodomethane.

6. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 5, characterized in that In step S2, the molar ratio of the magnesium chips to 1-bromo-3-butoxybenzene is 1.05-1.2:

1.

7. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 1, characterized in that In step S3, the borate ester is trimethyl borate or triethyl borate; and the oxidant is hydrogen peroxide or sodium hypochlorite.

8. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 7, characterized in that In step S3, the molar ratio of the 3-butoxybenzyl Grignard reagent to the borate ester is 0.9 to 1:

1.

9. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 1, characterized in that In step S4, the third solvent is toluene or chlorobenzene; the Lewis acid is one or more of aluminum trichloride, zinc chloride, ferric chloride and tin tetrachloride; and the molar ratio of 3-butoxyphenol to Lewis acid is 1:1 to 1.

5.

10. The method for preparing 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine according to claim 9, characterized in that In step S4, the post-processing process includes: 1) quenching the reaction solution, adding an acidic reagent to the reaction solution after the reaction is completed to quench the reaction and precipitate a crude 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine product; 2) Filtration and crude product treatment: Filter the crude product and purify it by recrystallization to obtain 2,4,6-tris(4'-butoxy-2'-hydroxyphenyl)-triazine.

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