阅读说明：本技术 一种2,4,6-三溴苯酚的合成方法 (Synthetic method of 2,4, 6-tribromophenol ) 是由 孙宏伟 孙刚 张玉芬 张立山 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种2,4,6-三溴苯酚的合成方法,包括如下步骤：将苯酚和金属溴化物溶于水中得到苯酚和金属溴化物的混合溶液,记为第一混合液；将溴酸盐溶液和盐酸滴加到第一混合液中进行反应；待反应结束,向反应液中添加亚硫酸钠至反应液中浅棕色完全消失、过滤、洗涤、干燥,即得所述2,4,6-三溴苯酚；本发明上述合成方法以溴化盐作为溴源以提升可使用资源的充分利用,避免有机溶剂的使用；待反应结束后粗产物在水相中析出,经简单过滤处理后即得到足够纯度的产品；本发明的工艺方法极大降低生产成本,同时还降低了运输和生产中的安全隐患以及改善了工作环境。(The invention discloses a method for synthesizing 2,4, 6-tribromophenol, which comprises the following steps: dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution; dropwise adding bromate solution and hydrochloric acid into the first mixed solution for reaction; after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing and drying to obtain the 2,4, 6-tribromophenol; the synthesis method of the invention takes bromide salt as bromine source to improve the full utilization of available resources and avoid the use of organic solvent; after the reaction is finished, the crude product is separated out in a water phase, and a product with enough purity is obtained after simple filtration treatment; the process method greatly reduces the production cost, simultaneously reduces the potential safety hazard in transportation and production and improves the working environment.)

1. A method for synthesizing 2,4, 6-tribromophenol is characterized by comprising the following steps:

(a) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution;

(b) dropwise adding bromate solution and hydrochloric acid into the first mixed solution for reaction;

(c) and after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing and drying to obtain the 2,4, 6-tribromophenol.

2. The synthesis method according to claim 1, wherein the concentration of phenol in the mixed solution of phenol and metal bromide is 0.8-1.2 mmol/ml, and the concentration of metal bromide is 1.6-2.4 mmol/ml;

the metal bromide is sodium bromide and/or potassium bromide; the bromate is sodium bromate and/or potassium bromate.

3. The synthesis method according to claim 1, wherein the volume ratio of the bromate solution to the hydrochloric acid to the first mixed solution is 5: 2-4: 8-12;

the concentration of the bromate solution is 1.8-2.2 mmol/ml; the concentration of the hydrochloric acid is 30-40%.

4. The method of claim 1, wherein the dropwise addition of the bromate solution and the hydrochloric acid into the first mixed solution for reaction comprises:

under the condition of stirring, adding a bromate solution and hydrochloric acid dropwise into the first mixed solution, and reacting for 2-4 h at 20-45 ℃.

5. The method of synthesizing of claim 1 wherein step (c) further comprises: and recrystallizing and drying the dried product by adopting an ethanol water solution.

6. A method for synthesizing 2,4, 6-tribromophenol is characterized by comprising the following steps:

(1) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and adding hydrochloric acid to obtain a second mixed solution;

(2) dropwise adding the hypochlorite solution into the second mixed solution for reaction;

(3) and after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing and drying to obtain the 2,4, 6-tribromophenol.

7. The synthesis method according to claim 6, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 1.6 to 2.4mmol/ml, and the concentration of the metal bromide is 5 to 7 mmol/ml;

the metal bromide is sodium bromide and/or potassium bromide; the hypochlorite is sodium hypochlorite and/or potassium hypochlorite.

8. The synthesis method according to claim 6, wherein the volume ratio of the hypochlorite solution to the mixed solution of the hydrochloric acid and the phenol to the metal bromide is (8-12) to (2-4) to 5;

the concentration of the hypochlorite solution is 20-25%; the concentration of the hydrochloric acid is 30-40%.

9. The method of claim 6, wherein the step of adding the hypochlorite solution dropwise to the second mixed solution for reaction comprises:

dropwise adding the hypochlorite solution into the second mixed solution under the stirring condition, and reacting for 3-5 h at 46-50 ℃.

10. The method of synthesizing as claimed in claim 6 wherein said step (3) further comprises: and recrystallizing and drying the dried product by adopting an ethanol water solution.

Technical Field

The invention relates to the technical field of compound synthesis, in particular to a synthesis method of 2,4, 6-tribromophenol.

Background

The 2,4, 6-Tribromophenol (TBP) is obtained by bromination of phenol, is used for flame-retardant modification of engineering plastics used in the fields of electronics, electrical appliances, textiles, automobiles and the like, can be used as a reaction type flame retardant of adhesives and sealants such as epoxy resin, polyurethane polycarbonate resin, phenolic resin and the like, and an intermediate of novel high-performance flame retardants such as bromine-containing polyphenyl ether, phosphite ester, phosphate ester and the like, can be used as a preservative of wood, paper and the like, and can also be used as a component of a compound type flame retardant for other resins. Tribromophenol is also an important fine chemical intermediate, and is an upstream raw material for preparing tris (2,4, 6-tribromophenoxy) s-triazine and the like. In addition, tribromophenol is used in the pharmaceutical industry for the preparation of preservatives and disinfectants such as bismuth tribromophenate and the like.

The traditional method for synthesizing tribromophenol is a bromination reaction of phenol and bromine, and bromine is a toxic and strong corrosive liquid with strong volatility, is not easy to transport and store, and has great potential safety hazard in production. In recent years, the price of bromine has increased remarkably, and hydrogen bromide generated in bromination reaction is researched and developed as bromine, and the reaction is continued to improve the utilization rate of the bromine. In addition, researchers have developed phenol bromination reactions with hydrobromic acid and hydrogen peroxide as the bromine. The process adopts organic solvents such as ethanol, hydrobromic acid has strong corrosivity and is very easy to corrode metal, and strong reducibility of the hydrobromic acid causes that the hydrobromic acid is gradually changed into yellow brown due to bromine dissociation when the hydrobromic acid is exposed in air and sunlight, so that the hydrobromic acid is not beneficial to long-time storage.

Disclosure of Invention

The invention aims to provide a synthesis method of 2,4, 6-tribromophenol, which takes bromide salt as a bromine source to promote the full utilization of available resources and avoid the use of organic solvents; effectively reduces the production cost and the potential safety hazard in transportation and production, and in addition, the synthesis method has higher product yield and purity.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the first aspect of the invention provides a method for synthesizing 2,4, 6-tribromophenol, which comprises the following steps:

(a) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution;

(b) dropwise adding bromate solution and hydrochloric acid into the first mixed solution for reaction;

(c) and after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing and drying to obtain the 2,4, 6-tribromophenol.

Preferably, the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 0.8-1.2 mmol/ml, and the concentration of the metal bromide is 1.6-2.4 mmol/ml;

the metal bromide is sodium bromide and/or potassium bromide; the bromate is sodium bromate and/or potassium bromate.

Preferably, the volume ratio of the bromate solution to the hydrochloric acid to the first mixed solution is 5 to (2-4) to (8-12);

the concentration of the bromate solution is 1.8-2.2 mmol/ml; the concentration of the hydrochloric acid is 30-40%.

Preferably, the dropwise addition of the bromate solution and the hydrochloric acid into the first mixed solution for reaction comprises:

under the condition of stirring, adding a bromate solution and hydrochloric acid dropwise into the first mixed solution, and reacting for 2-4 h at 20-45 ℃.

Preferably, the step (c) further comprises: and recrystallizing and drying the dried product by adopting an ethanol water solution.

The second aspect of the present invention also provides a method for synthesizing 2,4, 6-tribromophenol, comprising the following steps:

(1) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and adding hydrochloric acid to obtain a second mixed solution;

(2) dropwise adding the hypochlorite solution into the second mixed solution for reaction;

(3) and after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing and drying to obtain the 2,4, 6-tribromophenol.

Preferably, the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 1.6-2.4 mmol/ml, and the concentration of the metal bromide is 5-7 mmol/ml;

the metal bromide is sodium bromide and/or potassium bromide; the hypochlorite is sodium hypochlorite and/or potassium hypochlorite.

Preferably, the volume ratio of the hypochlorite solution to the mixed solution of the hydrochloric acid and the phenol to the metal bromide is (8-12) to (2-4) to 5;

the concentration of the hypochlorite solution is 20-25%; the concentration of the hydrochloric acid is 30-40%.

Preferably, the dropwise addition of the hypochlorite solution into the second mixed solution for reaction includes:

dropwise adding the hypochlorite solution into the second mixed solution under the stirring condition, and reacting for 3-5 h at 46-50 ℃.

Preferably, the step (3) further comprises: and recrystallizing and drying the dried product by adopting an ethanol water solution.

Compared with the prior art, the invention has the beneficial effects that at least:

the synthesis method of the invention takes bromide salt (industrial product or recycled bromide salt) as bromine source to improve the full utilization of available resources and avoid the use of organic solvent; after the reaction is finished, the crude product is separated out in a water phase, and a product with enough purity is obtained after simple filtration treatment; the process method greatly reduces the production cost, simultaneously reduces the potential safety hazard in transportation and production and improves the working environment.

The synthetic process has the advantages of simple and easy operation process, high safety, small pollution, simple post-treatment and low production cost.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a scheme showing the scheme for the synthesis of tribromophenol according to example 1 of the present invention;

FIG. 2 is a scheme showing the synthesis of tribromophenol according to example 4 of the present invention;

FIG. 3 is a nuclear magnetic resonance spectrum of tribromophenol before recrystallization in example 1 of the present invention;

FIG. 4 is the NMR spectrum of tribromophenol after recrystallization in example 1 of the present invention;

FIG. 5 is a mass spectrum of tribromophenol after recrystallization in example 1 of the present invention;

FIG. 6 is the NMR spectrum of tribromophenol before recrystallization in example 4 of the present invention;

FIG. 7 is the NMR spectrum of tribromophenol after recrystallization in example 4 of the present invention;

FIG. 8 is a mass spectrum of tribromophenol after recrystallization in example 4 of the invention.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the following embodiments. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

Example 1

This example is a method for synthesizing 2,4, 6-tribromophenol, as shown in fig. 1, the method includes the following steps:

(a) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 1mmol/ml, and the concentration of the metal bromide is 2 mmol/ml; the metal bromide is sodium bromide;

(b) dropwise adding a bromate solution and hydrochloric acid into the first mixed solution under the stirring condition, and reacting for 3 hours at the temperature of 20-45 ℃, wherein the volume ratio of the bromate solution to the hydrochloric acid to the first mixed solution is 5: 3: 10; the concentration of the bromate solution is 2 mmol/ml; the concentration of hydrochloric acid is 36%; bromate is sodium bromate;

(c) after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing by distilled water and drying;

(d) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

Weighing the dried product of step (c) to calculate a yield of 96%; performing nuclear magnetic resonance hydrogen spectrum detection on the dried product, wherein the nuclear magnetic resonance hydrogen spectrum is shown in fig. 3;

as can be seen from fig. 3:

the bromine generated by the conversion of sodium bromide and sodium bromate under the action of hydrochloric acid and the bromination reaction of the bromine and phenol generate the target product 2,4, 6-tribromophenol. Hydrogen bromide generated in the bromination process circulates in the reaction, and is oxidized again to generate bromine, so that the bromination effect on the substrate phenol is continuously realized until the reaction is complete; the purity of the dried product 2,4, 6-tribromophenol is 95%;

weighing the product recrystallized in step (d) to calculate a yield of 90%; performing nuclear magnetic resonance hydrogen spectrum detection and electrospray mass spectrometry on the recrystallized product, wherein the nuclear magnetic resonance hydrogen spectrum is shown in figure 4; electrospray mass spectrometry is shown in figure 5;

as can be seen from fig. 4 and 5:

HNMR(CDCl₃,ppm):7.615(s,2Hs，m-CH),5.884(s,1H,OH)；

ESI-MS:negative mode,328.99,330.98(M-1)；

and removing a small amount of impurities in the brominated product through recrystallization to obtain a crystalline product of the 2,4, 6-tribromophenol with high purity of 99.5 percent.

Example 2

This example is a method for synthesizing 2,4, 6-tribromophenol, which includes the following steps:

(a) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 1.2mmol/ml, and the concentration of the metal bromide is 2.4 mmol/ml; the metal bromide is potassium bromide;

(b) dropwise adding a bromate solution and hydrochloric acid into the first mixed solution under the stirring condition, and reacting for 2 hours at the temperature of 20-45 ℃, wherein the volume ratio of the bromate solution to the hydrochloric acid to the first mixed solution is 5: 2: 12; the concentration of bromate solution is 2.2 mmol/ml; the concentration of hydrochloric acid is 30 percent; bromate is potassium bromate;

(c) after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing by distilled water and drying;

(d) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

The yield of 2,4, 6-tribromophenol after drying in the above step (c) was 76% according to the method in example 1; the purity is 93%;

the yield of 2,4, 6-tribromophenol after recrystallization and drying in step (d) was 66% and the purity was 98%.

Example 3

This example is a method for synthesizing 2,4, 6-tribromophenol, which includes the following steps:

(a) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and recording the mixed solution as a first mixed solution, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 0.8mmol/ml, and the concentration of the metal bromide is 1.6 mmol/ml; the metal bromide is sodium bromide;

(b) dropwise adding a bromate solution and hydrochloric acid into the first mixed solution under the stirring condition, and reacting for 4 hours at the temperature of 20-45 ℃, wherein the volume ratio of the bromate solution to the hydrochloric acid to the first mixed solution is 5: 4: 8; the concentration of bromate solution is 1.8 mmol/ml; the concentration of hydrochloric acid is 40%; bromate is sodium bromate;

(c) after the reaction is finished, adding sodium sulfite into the reaction liquid until the light brown color in the reaction liquid completely disappears, filtering, washing by distilled water and drying;

(d) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

The yield of 2,4, 6-tribromophenol dried in the above step (c) was 97% according to the method in example 1; the purity is 97%;

the yield of 2,4, 6-tribromophenol after recrystallization and drying in step (d) was 92% and the purity was 99.3%.

Example 4

This example is a method for synthesizing 2,4, 6-tribromophenol, as shown in fig. 2, the method includes the following steps:

(1) dissolving phenol and metal bromide in water to obtain a mixed solution of phenol and metal bromide, and adding hydrochloric acid to obtain a second mixed solution, wherein the concentration of phenol in the mixed solution of phenol and metal bromide is 2mmol/ml, and the concentration of metal bromide is 6 mmol/ml; the metal bromide is sodium bromide; the volume ratio of the hydrochloric acid to the mixed solution of the phenol and the metal bromide is 3: 5; the concentration of hydrochloric acid is 36%;

(2) dropwise adding the hypochlorite solution into the second mixed solution under the stirring condition, and reacting for 4 hours at 46-50 ℃, wherein the volume ratio of the hypochlorite solution to the hydrochloric acid is 10: 3; the concentration of the hypochlorite solution is 22.5 percent; hypochlorite is sodium hypochlorite;

(3) after the reaction is finished, adding sodium sulfite into the reaction solution until the light brown color in the reaction solution completely disappears, filtering, washing with distilled water, drying,

(4) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

Weighing the dried product in the step (3), and calculating the yield to be 97%; performing nuclear magnetic resonance hydrogen spectrum detection on the dried product, wherein the nuclear magnetic resonance hydrogen spectrum is shown in fig. 6;

as can be seen from fig. 6:

converting sodium bromide and sodium hypochlorite into bromine under the action of hydrochloric acid, and carrying out bromination reaction on the bromine and phenol to generate a target product 2,4, 6-tribromophenol. Hydrogen bromide generated in the bromination process is recycled in the reaction, and is oxidized to produce bromine, so that the bromination effect on the substrate phenol is continuously realized until the reaction is complete; the purity of the dried product 2,4, 6-tribromophenol is 96%;

weighing the product recrystallized in the step (4), and calculating the yield to be 90%; performing nuclear magnetic resonance hydrogen spectrum detection and electrospray mass spectrometry on the recrystallized product, wherein the nuclear magnetic resonance hydrogen spectrum is shown in figure 7; electrospray mass spectrometry analysis is shown in figure 8;

as can be seen from fig. 7 and 8:

HNMR(CDCl₃,ppm):7.613(s,2Hs，m-CH),5.929(s,1H,OH)；

ESI-MS:negative mode,328.95,330.92(M-1)；

removing a small amount of impurities in the brominated product through recrystallization to obtain a high-purity 2,4, 6-tribromophenol crystalline product; specifically, the purity of the recrystallized 2,4, 6-tribromophenol is 99.5%.

Example 5

This example is a method for synthesizing 2,4, 6-tribromophenol, which includes the following steps:

(1) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and adding hydrochloric acid to obtain a second mixed solution, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 1.6mmol/ml, and the concentration of the metal bromide is 5 mmol/ml; the metal bromide is potassium bromide; the volume ratio of the hydrochloric acid to the mixed solution of the phenol and the metal bromide is 2: 5; the concentration of hydrochloric acid is 40%;

(2) dropwise adding the hypochlorite solution into the second mixed solution under the stirring condition, and reacting for 5 hours at 46-50 ℃, wherein the volume ratio of the hypochlorite solution to the hydrochloric acid is 8: 2; the concentration of the hypochlorite solution is 20 percent; hypochlorite is potassium hypochlorite;

(3) after the reaction is finished, adding sodium sulfite into the reaction solution until the light brown color in the reaction solution completely disappears, filtering, washing with distilled water, drying,

(4) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

The yield of 2,4, 6-tribromophenol dried in the above step (3) was 93% according to the method in example 4; the purity is 96%;

the yield of the 2,4, 6-tribromophenol after recrystallization and drying in the step (4) is 89%, and the purity is 99.4%.

Example 6

This example is a method for synthesizing 2,4, 6-tribromophenol, which includes the following steps:

(1) dissolving phenol and metal bromide in water to obtain a mixed solution of the phenol and the metal bromide, and adding hydrochloric acid to obtain a second mixed solution, wherein the concentration of the phenol in the mixed solution of the phenol and the metal bromide is 2.4mmol/ml, and the concentration of the metal bromide is 7 mmol/ml; the metal bromide is sodium bromide; the volume ratio of the hydrochloric acid to the mixed solution of the phenol and the metal bromide is 4: 5; the concentration of hydrochloric acid is 30 percent;

(2) dropwise adding the hypochlorite solution into the second mixed solution under the stirring condition, and reacting for 3 hours at 46-50 ℃, wherein the volume ratio of the hypochlorite solution to the hydrochloric acid is 12: 4; the concentration of the hypochlorite solution is 25 percent; hypochlorite is sodium hypochlorite;

(3) after the reaction is finished, adding sodium sulfite into the reaction solution until the light brown color in the reaction solution completely disappears, filtering, washing with distilled water, drying,

(4) and recrystallizing and drying the dried product by adopting 50% ethanol water solution to obtain the 2,4, 6-tribromophenol.

The yield of 2,4, 6-tribromophenol dried in the above step (3) was 92% according to the method in example 4; the purity is 94%;

the yield of the 2,4, 6-tribromophenol after recrystallization and drying in the step (4) is 85%, and the purity is 98.9%.

Comparative example 1

This comparative example is a synthesis method of 2,4, 6-tribromophenol, which is substantially the same as the synthesis method in example 4 except that the sodium hypochlorite solution is replaced with a sodium bromate solution of the same concentration.

The yield of 2,4, 6-tribromophenol after drying in step (c) in comparative example 1 was 63% according to the method in example 1; the purity is 89.5%;

the yield of 2,4, 6-tribromophenol after recrystallization and drying in step (d) was 53% and the purity was 96.8%.

The synthetic process has the advantages of simple and easy operation process, high safety, little pollution, simple post-treatment, low production cost and higher yield and purity of the synthetic product.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.