Highly purified bromotriazine and method for its preparation

Abstract

The application relates to the field of chemical substance preparation and purification, and particularly discloses a highly purified brominated triazine and a preparation method thereof. The preparation method of the highly purified brominated triazine comprises the following steps: (1) a bromination reaction: phenol, bromine and hydrogen peroxide are reacted in a mixed solvent of water and dichloromethane at 5-40 DEG C to obtain a bromination reaction liquid; (2) washing treatment: after the bromination reaction liquid is reacted with a sodium sulfite solution, washing is performed to obtain tribromophenol; (3) a condensation reaction: tribromophenol, liquid alkali, a recyclable catalyst and cyanuric chloride are subjected to a condensation reaction in a synthesis kettle; (4) crystallization and post-treatment: process water is added into the condensation reaction liquid in an amount equal to that of the condensation reaction liquid, crystallization is performed, and the final product is obtained through filtration and drying; in addition, the preparation method has the advantages of improving the product purity of a brominated triazine synthesis process.

Description

Technical Field

[0001] This application relates to the field of chemical substance preparation and purification, and more specifically, to a highly efficient purified bromotriazine and its preparation method. Background Technology

[0002] In the flame retardant industry, the development of flame retardants for plastic products is crucial. With the widespread application of plastic products in various fields, the requirements for their flame-retardant performance are increasingly stringent. High-quality flame retardants can effectively improve the safety of plastic products, reduce fire hazards, and play an indispensable role in many industries such as electronics, electrical appliances, automobiles, and construction. They not only protect people's lives and property but also promote technological progress and product upgrades in related industries, contributing to the stable development of the entire industrial system.

[0003] In the prior art, Chinese invention patent application number CN202610083774.8 discloses a method for preparing bromotriazine with improved thermal stability, including the following steps: S1: Phenol, water and dichloromethane are added to a reaction vessel, the temperature is controlled at 5-40℃, and bromine and hydrogen peroxide are added dropwise to carry out the reaction. After the reaction is completed, the mixture is treated with sodium sulfite and washed with water to separate the organic phase containing tribromophenol; S2: The organic phase containing tribromophenol is transferred to a synthesis vessel, and liquid alkali, cyanuric chloride and organic amine catalyst are added to carry out a condensation reaction; S3: Process water is added to the washed organic phase, and the temperature is first controlled at 38-42℃ for azeotropic desolvation until dichloromethane is distilled off; then the temperature is raised to 85-95℃ and stirred for 8-10 hours to carry out crystallization; finally, the bromotriazine is obtained by cooling, filtering and drying.

[0004] Regarding the existing technologies mentioned above, the inventors believe that bromotriazine often produces many byproducts during the preparation process, resulting in low product purity. Therefore, there is an urgent need for a highly efficient and selective preparation method to further improve product purity. Summary of the Invention

[0005] To improve the purity of products synthesized from bromotriazine, this application provides a method for efficiently purifying bromotriazine and preparing it.

[0006] In a first aspect, this application provides a method for preparing highly efficient purified bromotriazine, employing the following technical solution: A method for preparing highly efficient purified bromotriazine includes the following steps: (1) Bromination reaction: Phenol, bromine and hydrogen peroxide are reacted in a mixed solvent of water and dichloromethane at 5-40℃ for 3-6 hours to obtain the bromination reaction solution; (2) Washing treatment: After reacting the brominated reaction solution obtained in step (1) with sodium sulfite solution, wash at 30-35℃ for 1 h to obtain tribromophenol; (3) Condensation reaction: Tribromophenol obtained in step (2) is condensed with liquid alkali, recyclable catalyst and cyanuric chloride; (4) Crystallization and post-treatment: Add process water of the same volume as the condensation reaction solution to the condensation reaction solution obtained in step (3), crystallize at 38-95℃ for 8-10 hours, and obtain the final product by filtration and drying. The recyclable catalyst is prepared by supporting a main catalyst and a co-catalyst on a magnetic support; the main catalyst is an organic amine catalyst; and the co-catalyst is titanium-manganese co-doped zinc oxide.

[0007] By adopting the above technical solution, in the bromination reaction, phenol, bromine, and hydrogen peroxide are reacted in a mixed solvent of water and dichloromethane at 5-40℃ for 3-6 hours. The suitable temperature range ensures the activity and stability of the reaction, allowing the reaction to proceed fully. The mixed solvent of water and dichloromethane facilitates the dissolution and dispersion of the reactants, promoting the smooth occurrence of the bromination reaction, thus obtaining a bromination reaction solution. The reaction equation is as follows: ; The brominated reaction solution is reacted with sodium sulfite solution and then washed. The sodium sulfite solution removes impurities from the reaction solution. Specific temperature and time can effectively ensure the washing effect, thus obtaining pure tribromophenol. Tribromophenol is then subjected to a condensation reaction with liquid alkali, a recyclable catalyst, and cyanuric chloride. The substances cooperate with each other to undergo a condensation reaction to generate the precursor of the target product. The reaction equation is as follows: ; Organic amine catalysts are selected because of their strong nucleophilic substitution selectivity. The metal active centers on the surface of the co-catalyst possess unique electronic effects, effectively polarizing the C-Cl bonds in cyanuric chloride molecules. This enhances the positive charge of the carbon atoms in the reaction center, significantly improving electrophilic reactivity and drastically reducing the activation energy required for the reaction. This allows for precise targeting of the desired reaction sites, minimizing unnecessary side reactions and reducing the amount of byproducts generated, thereby effectively improving the purity of the final product, bromotriazine. Loading the main catalyst and co-catalyst onto a magnetic support enables efficient separation and repeated recycling of the catalyst. The magnetic support stably supports the active components of the catalyst, preventing them from detaching or being lost during the reaction, thus reducing production costs. Adding an equal volume of process water to the condensation reaction solution, along with appropriate temperature and time, helps the target product crystallize out. After filtration and drying, a highly purified bromotriazine product can be obtained. The entire preparation process achieves highly efficient purification and preparation of bromotriazine through reasonable condition settings and operations in each step.

[0008] Optionally, the method for preparing the recyclable catalyst includes the following steps: The main catalyst and co-catalyst are added to ethanol, a magnetic support is added, and the mixture is stirred, refluxed, filtered, washed, and vacuum dried to obtain a recyclable catalyst. The mass ratio of the main catalyst, co-catalyst, and magnetic support is 0.2-0.3:0.1:1.

[0009] Optionally, the method for preparing the magnetic carrier includes the following steps: Iron oxide (Fe3O4) was dispersed in an ethanol-water solution, ultrasonically treated, and then CTAB was added. Ammonia was then added and the temperature was raised to 40-50°C. Tetraethyl orthosilicate was added dropwise, and the mixture was stirred, magnetically separated, washed, and dried to obtain magnetic silicon dioxide. The mass ratio of iron oxide (Fe3O4), CTAB, ammonia, and tetraethyl orthosilicate was 1:0.2-0.4:5-10:3-4. The magnetic silica was dispersed in ethanol, ultrasonically treated, and then APTES was added. Under nitrogen protection, the mixture was refluxed at 60-80°C for 8-24 hours. After the reaction was completed, the product was magnetically separated, washed, and dried to obtain a magnetic carrier. The mass ratio of the magnetic silica to APTES was 1:0.5-0.8.

[0010] By adopting the above technical solution, magnetic silica possesses the magnetism of iron(II,III) oxide and the abundant pore structure and high specific surface area of ​​silica. The high specific surface area and abundant pores endow it with excellent loading capacity. After amination, it can form covalent bonds with the catalyst to achieve stable loading. Meanwhile, the magnetism endows the support with the ability to quickly separate from the reaction system, realizing the recyclability of the catalyst and thus reducing production costs.

[0011] Optionally, the method for preparing the co-catalyst includes the following steps: Zinc nitrate, titanium nitrate, and manganese nitrate are added to water, the temperature is raised to 60-70℃, sodium hydroxide is added dropwise after stirring, the pH of the system is adjusted to 9-10, the mixture is kept warm and stirred to obtain a reaction solution, the reaction solution is hydrothermally reacted at 120℃ for 12-14 hours, centrifuged, washed, and dried to obtain a co-catalyst, wherein the mass ratio of zinc nitrate, titanium nitrate, and manganese nitrate is 9-10:1:1.

[0012] By employing the above technical solution, titanium-manganese co-doped zinc oxide is prepared using a hydrothermal synthesis method. The zinc oxide surface possesses numerous active sites, which can adsorb nitrogen atoms from organic amine molecules through coordination bonds. This reduces the electron cloud density of the nitrogen atoms in the organic amine, thereby enhancing the nucleophilic attack ability of the organic amine on the C-Cl bond in cyanuric chloride molecules. This promotes the formation of a highly reactive amine-triazine intermediate between the organic amine and cyanuric chloride, lowering the activation energy of the nucleophilic substitution reaction; Ti 4+ Zn replacing zinc oxide lattice 2+Subsequently, due to the charge difference, a donor level is formed, injecting free electrons into the conduction band, Mn 2+ Replace Zn 2+ Afterwards, an acceptor level is formed, which captures electrons from the valence band. The two work together to lower the activation energy of the reaction and reduce the electron transition energy barrier, significantly improving the surface electron transfer efficiency. This makes it easier for the organic amine to react with cyanuric chloride to form a highly active intermediate, thereby increasing the reaction rate, greatly improving the reaction selectivity, reducing by-products and impurities, and ultimately improving product purity.

[0013] Optionally, the mass ratio of phenol, bromine and hydrogen peroxide is 1:(2.5-2.8):(2.1-2.4); the mass ratio of phenol to water is 1:1.

[0014] By adopting the above technical solution and controlling the mass ratio of phenol, bromine, and hydrogen peroxide, bromine and hydrogen peroxide can fully contact and react with phenol. As a brominating agent, bromine can more efficiently carry out the bromination reaction of phenol under the oxidizing environment provided by hydrogen peroxide, reducing the occurrence of side reactions and improving the yield and purity of tribromophenol. This provides high-quality raw materials for subsequent condensation reactions and is conducive to the final preparation of highly efficient purified bromotriazine.

[0015] By controlling the mass ratio of water to phenol to be 1:1, water, as a solvent, provides a suitable reaction environment in the bromination reaction. An appropriate amount of water can fully mix phenol, bromine, and hydrogen peroxide, and disperse them evenly in the reaction system, promoting effective intermolecular collisions, accelerating the reaction rate, and allowing the bromination reaction to proceed more fully. At the same time, an appropriate water content helps maintain the stability of the reaction system, avoiding changes in reaction conditions due to too much or too little water, thereby ensuring the yield and quality of tribromophenol, providing high-quality raw materials for subsequent condensation reactions and other steps, and facilitating the preparation of the final highly purified bromotriazine product.

[0016] Optionally, the mass ratio of dichloromethane to phenol is 10:1; the molar ratio of tribromophenol, liquid alkali, and cyanuric chloride is (3.1-3.2):(3.1-3.2):1.

[0017] By adopting the above technical solution and controlling the mass ratio of dichloromethane to phenol, the reactants can be fully dispersed, increasing the contact area between them, thereby accelerating the reaction rate and making the reaction of phenol, bromine, and hydrogen peroxide more complete. This is beneficial to improving the efficiency and yield of the bromination reaction. At the same time, this ratio helps to control the reaction process, reduce the occurrence of side reactions, and result in higher purity of the tribromophenol obtained later. This provides high-quality raw materials for subsequent condensation reactions and other steps, ultimately facilitating the preparation of a highly efficient and purified bromotriazine product.

[0018] The interaction of tribromophenol, liquid alkali, and cyanuric chloride in this ratio directs the reaction toward the formation of bromotriazine, reducing side reactions and thus improving the selectivity of the reaction and the purity of the product. This is because the appropriate ratio ensures that the molecules of each reactant can effectively collide and combine, avoiding the increase of by-products due to an excess or deficiency of a certain reactant, thereby obtaining highly purified bromotriazine.

[0019] Optionally, the organic amine catalyst may be selected from dimethylamine, pyridine, and pyrrole.

[0020] By adopting the above technical solution, the organic amine catalyst is selected from one of dimethylamine, pyridine and pyrrole, which makes the catalyst highly selective, reduces the formation of by-products and improves the purity of bromotriazine products.

[0021] Optionally, the amount of the main catalyst added is 0.05 wt% of cyanuric chloride.

[0022] By adopting the above technical solution, organic amine catalysts have the characteristic of strong nucleophilic substitution selectivity. With appropriate addition, they can give full play to their catalytic role in condensation reaction, effectively promote the reaction between tribromophenol, liquid alkali and cyanuric chloride, and avoid the problem of increased side reactions due to excessive addition or poor catalytic effect due to insufficient addition. This reduces the generation of by-products, improves the purity of the product, and ultimately achieves the goal of efficient purification of bromotriazine.

[0023] Secondly, this application provides a highly efficient purified bromotriazine, employing the following technical solution: A highly purified bromotriazine was prepared according to a method for preparing a highly purified bromotriazine.

[0024] By adopting the above technical solution and using organic amine catalysts, which have strong nucleophilic substitution selectivity, the reaction of tribromophenol, liquid alkali and cyanuric chloride can be precisely promoted in the condensation reaction, reducing the occurrence of side reactions, thereby reducing the formation of by-products and improving the purity of bromotriazine.

[0025] In summary, this application has the following beneficial effects: 1. In this application, phenol, bromine, and hydrogen peroxide are reacted in a mixed solvent of water and dichloromethane at 5-40℃ for 3-6 hours. The suitable temperature range ensures the activity and stability of the reaction, allowing the reaction to proceed fully. The mixed solvent of water and dichloromethane facilitates the dissolution and dispersion of the reactants, promoting the smooth occurrence of the bromination reaction, thus obtaining a bromination reaction solution. After reacting the bromination reaction solution with sodium sulfite solution, washing is performed. Sodium sulfite solution can remove impurities in the reaction solution. Specific temperature and time can effectively ensure the washing effect, thereby obtaining pure tribromophenol. In the condensation reaction, tribromophenol is reacted with liquid alkali, a recyclable catalyst, and cyanuric chloride. The substances cooperate to undergo a condensation reaction to generate the precursor of the target product. The condensation reaction solution is crystallized, and an equal volume of process water is added. Suitable temperature and time help the target product crystallize out. After filtration and drying, a highly purified bromotriazine product can be obtained. The entire preparation process achieves the highly efficient purification and preparation of bromotriazine through reasonable condition setting and operation of each step.

[0026] 2. In this application, a main catalyst and a co-catalyst are used in synergy. The main catalyst is an organic amine catalyst, and the co-catalyst is titanium-manganese co-doped zinc oxide. Zinc oxide has a large number of active sites on its surface, which can adsorb nitrogen atoms from organic amine molecules through coordination bonds, reducing the electron cloud density of nitrogen atoms in the organic amine. This enhances the nucleophilic attack ability of the organic amine on the C-Cl bond in cyanuric chloride molecules, thereby lowering the activation energy of the nucleophilic substitution reaction; Ti 4+ Replace Zn 2+ Later, donor energy levels are formed, Mn 2+ Replace Zn 2+ Subsequently, acceptor energy levels are formed, and the two work together to lower the electronic transition energy barrier and reduce the reaction activation energy. At the same time, titanium-manganese co-doping can induce the generation of oxygen vacancies, optimize the adsorption and activation capabilities of active sites, and suppress low-substitution and hydrolysis byproducts from the source, thereby improving product purity.

[0027] 3. In this application, the main catalyst and co-catalyst are supported on a magnetic carrier. The core function is to rapidly separate the catalyst from the reaction system through magnetic action, thereby improving the catalyst recovery rate, reducing loss, and thus reducing production costs.

[0028] 4. In this application, the mass ratio of phenol, bromine and hydrogen peroxide is controlled so that bromine and hydrogen peroxide can fully contact and react with phenol. As a brominating agent, bromine can more efficiently carry out the bromination reaction of phenol in the oxidizing environment provided by hydrogen peroxide, reducing the occurrence of side reactions, improving the yield and purity of tribromophenol, and thus providing high-quality raw materials for subsequent condensation reactions, which is beneficial to the final preparation of highly purified bromotriazine. Attached Figure Description

[0029] Figure 1 This is a liquid chromatogram of the product from Example 1 of this application; Figure 2 This is the liquid chromatogram of the product of Comparative Example 2 of this application. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments.

[0031] Example of co-catalyst preparation

[0032] Preparation Example 1-1: Add 10g zinc nitrate, 1g titanium nitrate and 1g manganese nitrate to 100g deionized water, heat to 70℃, stir at 500rpm for 40min, add sodium hydroxide dropwise to adjust the pH of the system to 10, keep warm and stir for 3h to obtain the reaction solution, transfer the reaction solution to a stainless steel high-pressure reactor lined with tetrafluoroethylene, place the reactor in an oven, set the temperature to 120℃, react for 14h, centrifuge at 8000rpm, wash three times with deionized water, and dry at 60℃ for 12h to obtain the co-catalyst.

[0033] Preparation Example 1-2: Add 9.5g zinc nitrate, 1g titanium nitrate and 1g manganese nitrate to 100g deionized water, heat to 65℃, stir at 500rpm for 35min, add sodium hydroxide dropwise to adjust the pH of the system to 9.5, keep warm and stir for 2.5h to obtain the reaction solution, transfer the reaction solution to a stainless steel high-pressure reactor lined with tetrafluoroethylene, place the reactor in an oven, set the temperature to 120℃, react for 13h, centrifuge at 8000rpm for 5min, wash three times with deionized water, and dry at 60℃ for 12h to obtain the co-catalyst.

[0034] Preparation Examples 1-3: Add 9g zinc nitrate, 1g titanium nitrate, and 1g manganese nitrate to 100g deionized water, heat to 60℃, stir at 500rpm for 30min, add sodium hydroxide dropwise, adjust the pH of the system to 9, keep warm and stir for 2h to obtain a reaction solution, transfer the reaction solution to a stainless steel high-pressure reactor lined with tetrafluoroethylene, place the reactor in an oven, set the temperature to 120℃, react for 12h, centrifuge at 8000rpm, wash three times with deionized water, and dry at 60℃ for 12h to obtain a co-catalyst.

[0035] Preparation Example 1-4: The difference from Preparation Example 1-1 is that titanium nitrate was not added. 10g of zinc nitrate and 1g of manganese nitrate were added to 100g of deionized water, the temperature was raised to 70℃, and the mixture was stirred at 500rpm for 40min. Sodium hydroxide was added dropwise to adjust the pH of the system to 10. The mixture was kept warm and stirred for 3h to obtain a reaction solution. The reaction solution was transferred to a stainless steel high-pressure reactor lined with tetrafluoroethylene. The reactor was placed in an oven and the temperature was set to 120℃. The reaction was carried out for 14h. The reactor was centrifuged at 8000rpm, washed three times with deionized water, and dried at 60℃ for 12h to obtain the co-catalyst.

[0036] Preparation Example 1-5: The difference from Preparation Example 1-1 is that manganese nitrate was not added. 10g of zinc nitrate and 1g of titanium nitrate were added to 100g of deionized water, the temperature was raised to 70℃, and the mixture was stirred at 500rpm for 40min. Sodium hydroxide was added dropwise to adjust the pH of the system to 10. The mixture was kept warm and stirred for 3h to obtain a reaction solution. The reaction solution was transferred to a stainless steel high-pressure reactor lined with tetrafluoroethylene. The reactor was placed in an oven and the temperature was set to 120℃. The reaction was carried out for 14h. The reactor was centrifuged at 8000rpm, washed three times with deionized water, and dried at 60℃ for 12h to obtain the co-catalyst.

[0037] Example of magnetic carrier preparation

[0038] Preparation Example 2-1: 1g of iron oxide was dispersed in 50g of 75wt% ethanol aqueous solution, ultrasonically dispersed at 300W for 30min, 0.4g of CTAB was added, then 10g of 25wt% ammonia was added and the temperature was raised to 50℃. 4g of tetraethyl orthosilicate was added dropwise, and the mixture was stirred at 500rpm for 30h. After magnetic separation, washing three times with anhydrous ethanol, and drying at 60℃ for 8h, magnetic silicon dioxide was obtained. 1g of magnetic silica was dispersed in 50g of anhydrous ethanol and ultrasonicated at 300W for 30min. Then, 0.8g of APTES was added and the mixture was refluxed at 80℃ for 24h under nitrogen protection. After the reaction was completed, the product was collected by magnetic separation, washed three times with anhydrous ethanol, and dried at 60℃ for 12h to obtain the magnetic carrier.

[0039] Preparation Example 2-2: 1g of iron oxide was dispersed in 50g of 75wt% ethanol aqueous solution, ultrasonically dispersed at 300W for 30min, 0.3g of CTAB was added, then 8g of 25wt% ammonia was added and the temperature was raised to 45℃. 3.5g of tetraethyl orthosilicate was added dropwise, and the mixture was stirred at 500rpm for 28h. After magnetic separation, washing three times with anhydrous ethanol, and drying at 60℃ for 8h, magnetic silicon dioxide was obtained. 1g of magnetic silica was dispersed in 50g of anhydrous ethanol and ultrasonicated at 300W for 30min. Then, 0.6g of APTES was added and the mixture was refluxed at 80℃ for 20h under nitrogen protection. After the reaction was completed, the product was collected by magnetic separation, washed three times with anhydrous ethanol, and dried at 60℃ for 12h to obtain the magnetic carrier.

[0040] Preparation Example 2-3: 1g of iron oxide was dispersed in 50g of 75wt% ethanol aqueous solution, ultrasonically dispersed at 300W for 30min, 0.2g of CTAB was added, then 5g of 25wt% ammonia water was added and the temperature was raised to 40℃. 3g of tetraethyl orthosilicate was added dropwise, and the mixture was stirred at 500rpm for 24h. After magnetic separation, washing three times with anhydrous ethanol, and drying at 60℃ for 8h, magnetic silicon dioxide was obtained. 1g of magnetic silica was dispersed in 50g of anhydrous ethanol and ultrasonicated at 300W for 30min. Then, 0.5g of APTES was added and the mixture was refluxed at 60℃ for 8h under nitrogen protection. After the reaction was completed, the product was collected by magnetic separation, washed three times with anhydrous ethanol, and dried at 60℃ for 12h to obtain the magnetic carrier.

[0041] Example of preparation of recyclable catalyst

[0042] Preparation Example 3-1: 0.3g of main catalyst and 0.1g of co-catalyst were added to 50g of anhydrous ethanol, 1g of magnetic support was added, and the mixture was stirred, refluxed, filtered, and vacuum dried for 12h to obtain a recyclable catalyst. The co-catalyst was prepared by Preparation Example 1-1, and the magnetic support was prepared by Preparation Example 2-1.

[0043] Preparation Example 3-2: 0.25g of main catalyst and 0.1g of co-catalyst were added to 50g of anhydrous ethanol, and 1g of magnetic support was added. The mixture was stirred, refluxed, filtered, and vacuum dried for 12h to obtain a recyclable catalyst. The co-catalyst was prepared in Preparation Example 1-2, and the magnetic support was prepared in Preparation Example 2-2.

[0044] Preparation Example 3-3: 0.2g of main catalyst and 0.1g of co-catalyst were added to 50g of anhydrous ethanol, 1g of magnetic support was added, and the mixture was stirred, refluxed, filtered, and vacuum dried for 12h to obtain a recyclable catalyst. The co-catalyst was prepared in Preparation Example 1-3, and the magnetic support was prepared in Preparation Example 2-3.

[0045] Preparation Example 3-4: The difference from Preparation Example 3-1 is that the co-catalyst was prepared by Preparation Example 1-4.

[0046] Preparation Example 3-5: The difference from Preparation Example 3-1 is that the co-catalyst was prepared by Preparation Example 1-5.

[0047] Example

[0048] Example 1

[0049] A method for preparing highly efficient purified bromotriazine includes the following steps: (1) Bromination reaction: At 40℃, 10g of phenol, bromine and 27.5wt% hydrogen peroxide were reacted in a mixed solvent of water and dichloromethane for 6h to obtain a bromination reaction solution. The mass ratio of phenol, bromine and 27.5wt% hydrogen peroxide was 1:2.8:2.4, and the mass ratio of water to phenol was 1:1. (2) Washing treatment: After reacting the brominated reaction solution obtained in step (1) with 80g of 5wt% sodium sulfite solution, the solution was transferred to a washing tank and washed at 35℃ for 1h to obtain tribromophenol. (3) Condensation reaction: In the synthesis vessel, the tribromophenol obtained in step (2) is subjected to a condensation reaction with liquid alkali, recyclable catalyst and cyanuric chloride. The molar ratio of tribromophenol, liquid alkali and cyanuric chloride is 3.2:3.2:1. The main catalyst is dimethylamine, and the amount of the main catalyst added is 0.05 wt% of cyanuric chloride. The recyclable catalyst is prepared by preparation example 3-1. (4) Crystallization and post-treatment: The condensation reaction solution obtained in step (3) is transferred to a crystallization kettle, and process water of the same volume as the condensation reaction solution is added. The solution is crystallized at 95°C for 10 hours, and then filtered and dried to obtain the final product.

[0050] Example 2

[0051] A method for preparing highly efficient purified bromotriazine includes the following steps: (1) Bromination reaction: At 20℃, 10g of phenol, bromine and 27.5wt% hydrogen peroxide were reacted in a mixed solvent of water and dichloromethane for 4h to obtain a bromination reaction solution. The mass ratio of phenol, bromine and 27.5wt% hydrogen peroxide was 1:2.6:2.2, and the mass ratio of water to phenol was 1:1. (2) Washing treatment: After reacting the brominated reaction solution obtained in step (1) with 80g of 5wt% sodium sulfite solution, the solution was transferred to a washing tank and washed at 32℃ for 1h to obtain tribromophenol; (3) Condensation reaction: In the synthesis vessel, the tribromophenol obtained in step (2) is condensed with liquid alkali, catalyst and cyanuric chloride. The molar ratio of tribromophenol, liquid alkali and cyanuric chloride is 3.15:3.15:1. The main catalyst is dimethylamine. The amount of catalyst added is 0.05 wt% of cyanuric chloride. The recyclable catalyst is prepared by preparation example 3-2. (4) Crystallization and post-treatment: The condensation reaction solution obtained in step (3) is transferred to a crystallization kettle, and process water of the same volume as the condensation reaction solution is added. The solution is crystallized at 60°C for 9 hours, and then filtered and dried to obtain the final product.

[0052] Example 3

[0053] A method for preparing highly efficient purified bromotriazine includes the following steps: (1) Bromination reaction: At 5℃, 10g of phenol, bromine and 27.5wt% hydrogen peroxide were reacted in a mixed solvent of water and dichloromethane for 3h to obtain a bromination reaction solution. The mass ratio of phenol, bromine and 27.5wt% hydrogen peroxide was 1:2.5:2.1, and the mass ratio of water to phenol was 1:1. (2) Washing treatment: After reacting the brominated reaction solution obtained in step (1) with 80g of 5wt% sodium sulfite solution, the solution was transferred to a washing tank and washed at 30℃ for 1h to obtain tribromophenol; (3) Condensation reaction: In the synthesis vessel, the tribromophenol obtained in step (2) is subjected to a condensation reaction with liquid alkali, recyclable catalyst and cyanuric chloride. The molar ratio of tribromophenol, liquid alkali and cyanuric chloride is 3.1:3.1:1. The main catalyst is dimethylamine. The amount of catalyst added is 0.05 wt% of cyanuric chloride. The recyclable catalyst is prepared by preparation example 3-3. (4) Crystallization and post-treatment: The condensation reaction solution obtained in step (3) is transferred to a crystallization kettle, and process water of the same volume as the condensation reaction solution is added. The solution is crystallized at 38°C for 8 hours, and then filtered and dried to obtain the final product.

[0054] Example 4

[0055] The difference between Example 4 and Example 1 is that the recyclable catalyst was prepared by Example 3-4.

[0056] Example 5

[0057] The difference between Example 5 and Example 1 is that the recyclable catalyst was prepared by Examples 3-5.

[0058] Example 6

[0059] The difference between Example 6 and Example 1 is that in Example 6, the mass ratio of phenol, bromine and 27.5 wt% hydrogen peroxide is 1:1.5:3.2.

[0060] Example 7

[0061] The difference between Example 7 and Example 1 is that in Example 7, the mass ratio of phenol, bromine and 27.5 wt% hydrogen peroxide is 1:3.2:1.8.

[0062] Example 8

[0063] The difference between Example 8 and Example 1 is that in Example 8, the molar ratio of tribromophenol, liquid alkali, and cyanuric chloride is 2.5:3.8:1.

[0064] Example 9

[0065] The difference between Example 9 and Example 1 is that in Example 9, the molar ratio of tribromophenol, liquid alkali, and cyanuric chloride is 3.8:2.5:1.

[0066] Example 10

[0067] The difference between Example 10 and Example 1 is that in Example 10, the amount of the main catalyst added is 0.02 wt% of cyanuric chloride.

[0068] Example 11

[0069] The difference between Example 11 and Example 1 is that in Example 11, the amount of the main catalyst added is 0.09 wt% of cyanuric chloride.

[0070] Comparative Example

[0071] Comparative Example 1 The brominated triazine prepared according to the Chinese invention patent document with application number CN202610083774.8.

[0072] Comparative Example 2 The commercially available tris(tribromophenoxy)triazine flame retardant (RDT-8) was purchased from Jiangsu Xinzhou Chemical Technology Co., Ltd.

[0073] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that zinc oxide was used to replace the co-catalyst in an equal amount.

[0074] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that silicon dioxide is used to replace the magnetic carrier in an equal amount.

[0075] Performance testing

[0076] Bromotriazine was prepared according to Examples 1-11 and Comparative Examples 1, 3-4. The purity of the bromotriazine was tested according to the following test methods, and the results are recorded in Table 1.

[0077] 1. Purity Instrument configuration: High performance liquid chromatograph equipped with a UV detector was used.

[0078] Chromatographic conditions: Chromatographic column: C18 reversed-phase column (size: 250mm×4.6mm, 5μm).

[0079] Mobile phase: Methanol (chromatographic grade): Water = 95:5 (volume ratio).

[0080] Flow rate: 1.0 mL / min.

[0081] Column temperature: 30℃.

[0082] Detection wavelength: 254nm.

[0083] Injection volume: 10 μL.

[0084] Determination Procedure: Weigh 0.05 g (accurate to 0.0001 g) of the dried sample to be tested, place it in a 50 mL volumetric flask, add tetrahydrofuran to dissolve and dilute to the mark, shake well, filter through a 0.45 μm organic filter membrane, and inject into the liquid chromatograph for analysis. Record the chromatogram, and calculate the percentage of the main peak area of ​​2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine using the area normalization method, as the purity of the sample.

[0085] Table 1 Purity of Bromotriazine project purity / % Example 1 99.63 Example 2 99.58 Example 3 99.32 Example 4 98.29 Example 5 98.22 Example 6 98.45 Example 7 98.72 Example 8 98.91 Example 9 98.84 Example 10 99.12 Example 11 99.05 Comparative Example 1 99.23 Comparative Example 2 98.02 Comparative Example 3 98.11 Comparative Example 4 98.17 As can be seen from Table 1, Examples 1-3 and Comparative Examples, the bromotriazine prepared in Examples 1-2 has a high purity, reaching 99.63%, 99.58% and 99.32% respectively, which is significantly higher than the purity of the products prepared in Comparative Examples 1 and 2. This indicates that the preparation method described in this application can significantly improve the purity of bromotriazine products.

[0086] Compared with Example 1, the purity of Examples 4-5 decreased, indicating that titanium-manganese co-doped zinc oxide can reduce the reaction activation energy, significantly improve the surface electron transfer efficiency, make the reaction of organic amines and cyanuric chloride to form highly active intermediates easier to occur, greatly improve the reaction selectivity, reduce by-products and impurities, and thus improve product purity.

[0087] Compared to Example 1, the purity of Examples 6-7 decreased. Examples 6-7 altered the mass ratio of phenol, bromine, and hydrogen peroxide. When the bromine ratio is too low, the bromination reaction may be incomplete, leaving unreacted phenol or some brominated intermediates, increasing the difficulty of subsequent separation and the content of impurities. When the hydrogen peroxide ratio is too low, insufficient oxidation environment may lead to decreased bromine utilization or the generation of other byproducts. Both of these factors affect the purity of tribromophenol, thus reducing the purity of the final product.

[0088] Compared to Example 1, the purity of Examples 8-9 also decreased. Examples 8-9 altered the molar ratio of tribromophenol, liquid alkali, and cyanuric chloride. When tribromophenol was relatively insufficient, cyanuric chloride might not react completely or other side reactions, such as hydrolysis, might occur. When liquid alkali was relatively insufficient, the alkalinity of the reaction system was insufficient, which could lead to a slow or insufficient condensation reaction rate, also increasing the formation of byproducts. Inappropriate molar ratios disrupted the reaction equilibrium, affected the selectivity of the product, and resulted in decreased purity.

[0089] Compared with Example 1, the purity of Examples 10-11 decreased slightly, but was still higher than that of the comparative example. Examples 10-11 changed the amount of main catalyst added. In Example 10, too little main catalyst added may lead to insufficient catalytic efficiency of condensation reaction, slow reaction rate, and relatively increased side reactions. In Example 11, too much added may introduce excess catalyst residue or cause unnecessary side reactions. Although organic amine catalysts have strong selectivity, deviations in dosage will still have a certain impact on the purity of the final product.

[0090] In summary, this application has developed a synergistic and efficient purification and preparation process by optimizing the material ratio, reaction conditions, and selection and quantitative addition of catalysts in the bromination and condensation reaction stages. With the synergistic effect of co-catalysts and magnetic supports, the occurrence of side reactions is effectively suppressed, the selectivity of the reaction and the crystallization purity of the product are improved, and thus a high-purity bromotriazine product is successfully prepared, which has significant advantages over existing commercially available products.

[0091] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing highly efficient purified bromotriazine, characterized in that: Includes the following steps: (1) Bromination reaction: Phenol, bromine and hydrogen peroxide are reacted in a mixed solvent of water and dichloromethane at 5-40℃ for 3-6 hours to obtain the bromination reaction solution; (2) Washing treatment: After reacting the brominated reaction solution obtained in step (1) with sodium sulfite solution, wash at 30-35℃ for 1 h to obtain tribromophenol; (3) Condensation reaction: Tribromophenol obtained in step (2) is condensed with liquid alkali, recyclable catalyst and cyanuric chloride; (4) Crystallization and post-treatment: Add process water of the same volume as the condensation reaction solution to the condensation reaction solution obtained in step (3), crystallize at 38-95℃ for 8-10 hours, and obtain the final product by filtration and drying. The recyclable catalyst is prepared by supporting a main catalyst and a co-catalyst on a magnetic support; the main catalyst is an organic amine catalyst; and the co-catalyst is titanium-manganese co-doped zinc oxide.

2. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The method for preparing the recyclable catalyst includes the following steps: The main catalyst and co-catalyst are added to ethanol, a magnetic support is added, and the mixture is stirred, refluxed, filtered, washed, and vacuum dried to obtain a recyclable catalyst. The mass ratio of the main catalyst, co-catalyst, and magnetic support is 0.2-0.3:0.1:

1.

3. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The method for preparing the magnetic carrier includes the following steps: Iron oxide (Fe3O4) was dispersed in an ethanol-water solution, ultrasonically treated, and then CTAB was added. Ammonia was then added and the temperature was raised to 40-50°C. Tetraethyl orthosilicate was added dropwise, and the mixture was stirred, magnetically separated, washed, and dried to obtain magnetic silicon dioxide. The mass ratio of iron oxide (Fe3O4), CTAB, ammonia, and tetraethyl orthosilicate was 1:0.2-0.4:5-10:3-4. The magnetic silica was dispersed in ethanol, ultrasonically treated, and then APTES was added. Under nitrogen protection, the mixture was refluxed at 60-80°C for 8-24 hours. After the reaction was completed, the product was magnetically separated, washed, and dried to obtain a magnetic carrier. The mass ratio of the magnetic silica to APTES was 1:0.5-0.

8.

4. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The method for preparing the co-catalyst includes the following steps: Zinc nitrate, titanium nitrate, and manganese nitrate are added to water, the temperature is raised to 60-70℃, sodium hydroxide is added dropwise after stirring, the pH of the system is adjusted to 9-10, the mixture is kept warm and stirred to obtain a reaction solution, the reaction solution is hydrothermally reacted at 120℃ for 12-14 hours, centrifuged, washed, and dried to obtain a co-catalyst, wherein the mass ratio of zinc nitrate, titanium nitrate, and manganese nitrate is 9-10:1:

1.

5. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The mass ratio of phenol, bromine and hydrogen peroxide is 1:(2.5-2.8):(2.1-2.4); the mass ratio of phenol to water is 1:

1.

6. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The mass ratio of dichloromethane to phenol is 10:1; the molar ratio of tribromophenol, liquid alkali, and cyanuric chloride is (3.1-3.2):(3.1-3.2):

1.

7. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The organic amine catalyst is selected from one of dimethylamine, pyridine, and pyrrole.

8. The method for preparing a highly efficient purified bromotriazine according to claim 1, characterized in that: The amount of the main catalyst added is 0.05 wt% of cyanuric chloride.

9. A highly efficient purified bromotriazine, characterized in that: The brominated triazine was prepared according to any one of claims 1-8 using a highly efficient purification method.

Images