JPH03271267A - Production of bis(3,5-dibromo-4-(dibromopropoxy)phenyl) sulfone - Google Patents

Abstract

PURPOSE:To obtain the subject substance in high yield by adding a specific solvent to an aqueous solution of alkaline slurry of a product derived from allylation reaction of bis(4-hydroxy-3,5-dibromophenyl) sulfone, selectively extracting the product and subjecting to a bromination process. CONSTITUTION:Bis(4-hydroxy-3,5-dibromophenyl) sulfone is used as a raw material and subjected to allylation reaction. Then, a halogenated hydrocarbon solvent (especially methylene chloride is preferable) is added to an aqueous solution of alkaline slurry of resultant bis(4-allyloxy-3,5-dibromophenyl) sulfone so as substrate concentration of the product to be in a range of 5-25wt.%. Subsequently, resultant bis(4-allyloxy-3,5-dibromophenyl) sulfone is selectively extracted into an organic phase and separated, then bromine is added to the organic phase, thus reacted to afford the aimed compound. Said compound is useful as a flame retarder of polyolefin resin, etc.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to bis[3,5-dibromo-4-(2゜3-dibromopropoxy)phenyl]sulfone (hereinafter referred to as TBS).
The present invention relates to a manufacturing method for industrially obtaining BP (abbreviated as BP) in high yield and purity.

TBS-BP is useful as a flame retardant for polyolefin resins, etc., and is particularly useful as a flame retardant for polypropylene, as disclosed in Japanese Patent Publication No. 50-35103.
This is described in Japanese Patent Publication No. 50-23693.

[Conventional technology]

Conventionally, TB was produced using bis(4-hydroxy-3,5-dibromophenyl)sulfone (hereinafter abbreviated as TBS) as a raw material.
As a method for producing S-BP, first, TBS is converted into bis(4-allyloxy-3
,5-dibromophenyl)sulfone (hereinafter referred to as TBS-B
A) is reacted and precipitated, the crystal is separated by filtration and dried, and then this crystal is reacted with bromine to form T.
A method for manufacturing BS-BP is known (Special Publication Act of 1973).
-35103, Special Publication 50-23693, Special Publication 1986-
39585).

However, this method requires filtration separation and washing steps for the TBS-BA crystals precipitated by the allylation reaction, and the resulting crystals need to be transferred to the next bromination step after drying, making it difficult for industrial use. The manufacturing process was extremely complicated for a scale of production.

In addition, a trace amount of unreacted allylating agent remains during filtration and produces a strong odor, which poses a problem in terms of the working environment.

[Problem to be solved by the invention]

An object of the present invention is to simplify the complicated unit operations in the prior art and to provide an industrial method for producing TBS-BP with high yield and high purity.

[Means to solve the problem]

In view of the above-mentioned current situation, the present inventors conducted intensive studies to streamline the manufacturing process. As a result, TBS was produced using TBS as raw material.
- In the method for producing BP, after the allylation reaction of TBS is completed, TBS-BA is prepared using a halogenated hydrocarbon solvent.
By performing the extraction, not only can only TBS-BA be selectively extracted, but also the resulting TBS-BA can be subjected to the next bromination step in the extracted solution state.
-BP has high purity and high yield, and the inventors have discovered that the working environment during production can be greatly improved, and have completed the present invention.

That is, the gist of the present invention is to add a halogenated hydrocarbon solvent to an alkaline slurry aqueous solution of TBS-BA obtained by an allylation reaction of TBS, selectively extract TBS-BA into an organic phase, and separate the liquid into one liquid. Thereafter, the method for producing TBS-BP is characterized in that bromine is added to the organic phase and reacted.

The details will be explained below.

[Effect]

The reaction of allylating TBS using allyl bromide or allyl chloride as an allylating agent in the presence of an alkali can be explained using the following reaction formula.

The amount of allylating agent used in the method of the present invention is TB
2 moles or more per mole of S, preferably 2.0
~3.0 mol. Even if 3.0 mol or more is added, no improvement in yield is observed. The method of adding the allyl bromide is not particularly limited, but when allyl bromide is used, it is unstable to alkali, so it is preferably added dropwise at a rate of 1.5 mol/hour or less per 1 mol of TBS. Furthermore, after the reaction,
If unreacted allylating agent remains, it is preferable to remove it by distillation from the viewpoint of high purity of TBS-BP.

The reaction solvent used in the allylation reaction is water alone or a homogeneous aqueous solution mixed with a water-soluble organic solvent. In particular, when allyl chloride is used as the allylating agent, it is preferable from the viewpoint of reactivity to use a homogeneous aqueous solution prepared by mixing a water-soluble organic solvent at a concentration of 25 to 60% by volume.

Water-soluble organic solvents include monovalent lower alcohols having 1 to 3 carbon atoms and ethers having 2 to 5 carbon atoms, and specifically include methanol, ethanol, n-propanol, and isopropanol. tools, dioxane, THF, methyl cellosolve, ethyl cellosolve, etc. Among these,
A water-itubrobanol mixed solvent system is particularly preferred due to its high reactivity.

Further, the substrate concentration of TBS in the reaction solvent is not particularly limited, but is usually about 15 to 35% by weight.

In addition, when an organic solvent is mixed, it is necessary to remove the organic solvent by distillation after the reaction is completed. TBS-B without distillation removal
When A is extracted, the alkali metal salt of TBS-MA is also extracted, which is not preferable.

Moreover, when the slurry concentration becomes high when the organic solvent is distilled off, water is added as necessary.

The alkali used in the allylation reaction is an alkali metal hydroxide, carbonate, or hydrogen carbonate, such as sodium hydroxide or potassium hydroxide.

Sodium carbonate, potassium carbonate, sodium bicarbonate,
Examples include potassium hydrogen carbonate.

The amount of alkali to be used is 2 mol or more, preferably 2.0 to 3.0 mol, per 1 mol of TBS, and even if 3.0 mol or more is added, the yield will not be significantly improved. unacceptable.

It should be noted that the reaction solution after the reaction must be kept in an alkaline state for the subsequent extraction step, especially at p'H10.
It is preferable to keep it within the range of 14 to 14.

The reaction is usually carried out at a temperature ranging from room temperature to 150° C. under normal pressure or increased pressure. In the reaction under normal pressure, it is desirable to carry out the reaction at the reflux temperature of the reaction solution in order to increase the reaction rate. The reaction time also depends on the reaction temperature - although it cannot be determined generally, it is usually from 1 hour to 30 hours.

Then, the obtained TBS-BA is extracted using a halogenated hydrocarbon solvent.

In the method of the present invention, TBS-BA is added to the halogenated hydrocarbon solvent.
The reason why it is possible to selectively extract only the following can be considered as follows. The target substance, TBS-B, is mainly present in the aqueous solution before extraction.
A, alkali metal salt, alkali metal chloride, etc. of 4-allyloxy-4゛-hydroxy-3,3-5゜5-1-tetrabromodiphenylsulfone (hereinafter abbreviated as TBS-MA), which is a reaction intermediate. However, under alkaline conditions, everything except the hydrophobic TBS-BA becomes hydrophilic or nearly hydrophilic, so it is thought that TBS-BA can be selectively extracted.

Furthermore, the halogenated hydrocarbon that is the extraction solvent is inert to bromine, and the bromination of TBS-BA proceeds smoothly.

Examples of the halogenated hydrocarbon solvent used include methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, and tetrachloroethane, which are usually used industrially. Among these, methylene chloride is particularly preferred from the viewpoint of solubility of TBS-BA and toxicity of the solvent.

The amount of this solvent to be used is determined experimentally by taking into consideration the partition coefficient depending on the type of solvent, extraction conditions, etc.
- Add the necessary amount so that the substrate concentration of BA is usually about 5 to 25% by weight.

Extraction is carried out once or divided into several times.

The temperature at which the extraction is performed is not particularly limited, but is below the boiling point of the solvent used, usually about 10 to 80°C.

Next, bromine was added to the extraction solution containing TBS-BA.
The reaction for producing BS-BP can be explained using the following reaction formula.

The amount of bromine used in the TBS-BP reaction is 2 moles or more, preferably about 2.1 to 2.5 moles, per mole of TBS-BAI. Even if 2.5 mol or more is added, no improvement in yield or purity is observed.

Bromine is added dropwise, and the dropping rate is T.
The amount is 5 moles/hour or less per mole of BS-BAI, preferably about 1 to 3 moles/hour. If the dropping rate of bromine is 5 moles/hour or more per mole of TBS-BAI, it is not preferable because heat generation during the reaction becomes intense.

The reaction temperature is below the boiling point temperature of bromine, preferably 5
~50°C is selected.

If the reaction temperature is less than 5°C, the reaction becomes extremely slow, which is not preferable.

Furthermore, after the completion of the dropwise addition, it is necessary to further ripen the mixture for at least one hour at the same dropwise temperature in order to complete the reaction.

The reaction solution containing TBS-BP obtained in the method of the present invention can remove unreacted residual bromine using a reducing agent that is usually used industrially, such as sodium bisulfite, sodium thiosulfate, or sodium formate. After treatment with hydrazine etc.
A product is obtained by washing with water and further removing the solvent. The TBS-BP crystals obtained are of high purity and can be used as is as a flame retardant for polyolefin resins and the like.

〔Effect of the invention〕

When TBS-BP is manufactured using TBS as a raw material, as mentioned above, in the conventional manufacturing method, TBS-BA, which is an intermediate raw material, precipitates as crystals, so it is necessary to perform steps such as filtering and separating the crystals. Therefore, from an industrial point of view, this method was extremely complicated.

However, as is clear from the above explanation, according to the present invention, only TBS-BA is selectively extracted with a solvent and TBS-BA is brominated in the solvent. Therefore, the next bromination step can be performed without requiring a washing step or a drying step, resulting in a simplified manufacturing process. Furthermore, the problem of odor caused by unreacted allylating agent during TBS-BA filtration is also eliminated, resulting in an improvement in the working environment. In other words, the method of the present invention makes it possible to simplify the manufacturing process such as filtration separation and washing steps compared to the conventional method, improve the working environment, and produce high-yield, high-quality TBS-BP industrially. It has also become possible to manufacture it advantageously.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these.

(Example 1) Capacity 1000rRi with thermometer, stirring blade and cooling pipe
In a Yotsuro flask, add isopropanol 256-1 water 1
80rd and 16.8 g (420 mmol) of NaOH, and further 113.2 g of TBS (200 mmol 1
) was added and dissolved.

Next, the temperature was raised to 70°C, and while maintaining that temperature, 60.5 g (500 mmo 1) of allyl bromide was added.
was added dropwise over 5 hours. After the completion of dropping allyl bromide, the temperature was raised to 70 to 80°C, and the reaction was carried out at that temperature for 3 hours.

After the reaction was completed, impropatol and unreacted allyl bromide in the obtained slurry solution were removed by distillation at an azeotropic temperature with water while dropping 200 g of water. After removal by distillation, the pH of the reaction solution was measured and found to be pH 10.7.

Next, 650 g of methylene chloride was added to the obtained slurry solution at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 749 g of an organic phase solution. As a result of liquid chromatography analysis of the components contained in this solution, T
Only 119.0 g of BS-BA was contained. TBS-
The yield of BA corresponds to 92.1%. Note that the Na salt of TBS-MA, which is a reaction intermediate, was not detected.

Furthermore, as a result of liquid chromatography analysis of the aqueous phase, it was found that Na of TBS-MA, which is a reaction intermediate,
6.5 g of salt and 2.1 g of unextracted TBS-BA remained. Further, no TBS as a raw material remained in either the organic phase or the aqueous phase, the TBS conversion rate was 100%, and the total yield of TBS-BA was 93.7%.

Next, the obtained organic phase was charged into a 1000 d capacity Yotsuya flask equipped with a thermometer, stirring blade and cooling tube, and the bromine 6
7.7 g (423 mmol 1) was added dropwise at 39°C over 1 hour, and after the dropwise addition, aging was carried out at that temperature for 2 hours.

After the reaction, residual bromine was reduced with an aqueous sodium bisulfite solution, and after further washing with water, the solvent was removed and TBS-BP
173.6 g of crystals were obtained.

As a result of liquid chromatography analysis of the obtained crystals, the TBS-BA conversion rate was 100%.
The purity of TBS-BP was 97.3%, and the yield of TBS-BP was 95.0% (based on TBS-BA). Also, T
The yield of TBS-BP from BS was 87.5%.

The reaction conditions and results in each step are shown in Tables 1 and 2.

(Example 2) 174-1 isopropanol and 260 ml of water were placed in a 1,000 d capacity four-tube flask equipped with a thermometer, stirring blade, and cooling tube.
Al! and 16.8 g (420 mmol) of NaOH, and further 113.2 g (200 mmol) of TBS.
was added and dissolved.

Next, 38.3 g (500 mmol) of allyl chloride
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

In addition, 3.2 g of NaOH (80 m
m o 1) was added.

After the reaction was completed, isopropanol and unreacted allyl chloride in the obtained slurry solution were removed by distillation at an azeotropic temperature with water while dropping 200 g of water. After removal by distillation, the pH of the reaction solution was measured and found to be pH 11.8.

Next, 480 g of methylene chloride was added to the obtained slurry solution at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 539 g of an organic phase solution. As a result of liquid chromatography analysis of the components contained in this solution,
Only 98.8g of TBS-BA was contained. TBS-
The yield of BA corresponds to 76.5%. Note that the Na salt of TBS-MA, which is a reaction intermediate, was not detected.

Furthermore, as a result of liquid chromatography analysis of the aqueous phase, it was found that Na of TBS-MA, which is a reaction intermediate,
Salt 16. og, 6.6 g of unextracted TBS-BA remained. Further, no TBS as a raw material remained in either the organic phase or the aqueous phase, the TBS conversion rate was 100%, and the total yield of TBS-BA was 81.6%.

Next, the obtained organic phase was charged into a 1,000-capacity four-bottle flask equipped with a thermometer, stirring blade, and cooling tube, and bromine
1.4 g (321 mmol 1) was added dropwise at 40° C. over 1 hour, and after the dropwise addition, aging was carried out at that temperature for 2 hours.

After the reaction, residual bromine was reduced with an aqueous sodium bisulfite solution, and after further washing with water, the solvent was removed to obtain 147.5 g of white crystals.

As a result of liquid chromatography analysis of the obtained crystals, the TBS-BA conversion rate was 100%.
The TBS-BP line purity was 97.0%, and the yield of TBS-BP was 96.9% (TBS-BA standard). Also, T
The yield of TBS-BP from BS was 74.1%.

The reaction conditions and results in each step are shown in Tables 1 and 2.

(Examples 3 to 5) According to Example 1, raw materials were charged with the compositions shown in Tables 1 and 2, and reactions were carried out under the reaction conditions shown in Tables 1 and 2.

The same post-treatment as in Example 1 was carried out to obtain TBS-BP. The results obtained are shown in Table 1.2.

(Comparative Example 1) In a 1,000 d capacity four-tube flask equipped with a thermometer, stirring blade, and cooling tube, 174-1 isoprono-lol and 26-6 times water were added.
16.8 g (420 mmol) of 0-1 NaOH was charged, and 2 g (200 mmol 1) of TBS was further added and dissolved.

Next, 38.3 g (500 mmol) of allyl chloride
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

In addition, 3.2 g of NaOH (80 m
mol) was added.

After the reaction was completed, the obtained slurry solution was filtered and further washed with water to obtain 163.3 g of wet crystals of TBS-BA.

During the filtration, the odor of unreacted allyl chloride was present.

Next, the obtained wet crystals were dried under reduced pressure at 90° C. for 8 hours to obtain 98.0 g of dry crystals of TBS-BA. Regarding the obtained dry crystals of TBS-BA and the above filtrate,
As a result of liquid chromatography analysis, TB
The conversion rate of S is 100%, and the dry crystal yield of TBS-BA is 7
The dry crystal purity of TBS-BA was 100%. Note that the filtrate contains N of TBS-MA, which is a reaction intermediate.
Only the a salt was dissolved, and the target substance TBS-BA was hardly dissolved.

Next, the capacity 1000 with thermometer, stirring blade and cooling pipe
The dry crystals of TBS-BA were placed in a Yotsuro flask, and then 500 g of methylene chloride was added and dissolved.
5.8 g (349 mmol) was added dropwise at 40°C over 1 hour, and after the dropwise addition, it was aged at that temperature for 2 hours.

After the reaction, residual bromine was reduced with an aqueous sodium bisulfite solution, and after washing with water, the solvent was removed to obtain 142.3 g of white crystals.

As a result of liquid chromatography analysis of the obtained crystals, the TBS-BA conversion rate was 100%.
The purity of TBS-BP was 97.3%, and the yield of TBS-BP was 94.5% (based on TBS-BA). Also, T
The yield of TBS-BP from BS was 71.7%.

(Comparative Example 2) 174 d of isopropanol and 260 d of water were placed in a 1000 d capacity four-tube flask equipped with a thermometer, stirring blade, and cooling tube.
d. Prepare 16.8 g (420 mmol) of NaOH,
Furthermore, 113.2 g (200 mmol) of TBS was added and dissolved.

Next, 38.3 g (500 mmol) of allyl chloride
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

In addition, 3.2 g of NaOH (80 m
mol) was added. After the reaction was completed, the pH in the reaction solution was measured and found to be pH 11.0.

Next, 480 g of methylene chloride was added to the obtained slurry solution at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 730.5 g of an organic phase solution. As a result of liquid chromatography analysis of the components in this solution, TBS
-BA is 96.9g.

The Na salt of TBS-MA, which is a reaction intermediate, is 23.1
g, almost the entire amount of isopropanol charged at the beginning of the reaction,
It contained 2.1g of unreacted allyl chloride. Note that the yield of TBS-BA was 75.0%.

Furthermore, as a result of liquid chromatography analysis of the aqueous phase, it was found that Na of TBS-MA, which is a reaction intermediate,
0.3 g of salt and 1 g of unextracted TBS-BAo were dissolved. Furthermore, no TBS as a raw material remained in either the organic phase or the aqueous phase, and the TBS conversion rate was 100%.

Claims (1)

[Claims] A halogenated hydrocarbon solvent was added to an aqueous alkaline slurry solution of bis(4-allyloxy-3,5-dibromophenyl)sulfone obtained by an allylation reaction of bis(4-hydroxy-3,5-dibromophenyl)sulfone. Bis[3
,5-dibromo-4-(2,3-dibromopropoxy)
Process for producing [phenyl]sulfone.