JPH0441473A - Production of bis 4-allyloxy-3,5-dibromophenyl) sulfone - Google Patents

Abstract

PURPOSE:To obtain the subject compound in high yield and high purity by reacting bis(4-hydroxy-3,5-dibromophenyl) sulfone with allyl chloride, separating and recovering an intermediate from reaction product in a solution state and circulating to the reaction process. CONSTITUTION:Bis(4-hydroxy-3,5-dibromophenyl) sulfone is reacted with allyl chloride in an uniform aqueous solution mixed with a water-soluble organic solvent (preferably isopropanol or dioxane) in the presence of alkali and resul tant slurry solution is distilled to reduce concentration of the organic solvent to <=15 vol %. Next, halogenated hydrocarbon solvent is added to form three phases of an organic phase selectively extracted the aimed compound, an inter mediate phase containing 4-allyloxy-4'-hydroxy-3,3',5,5'-tetrabromodiphenyl sulfone as a principal component and a water phase and individual solution is divided, then the intermediate phase containing reacting intermediate as a principal component is circulated to the reaction process.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to bis(4-allyloxy-3,5-dibromophenyl)sulfone (hereinafter abbreviated as TBS-BA).
The present invention relates to a manufacturing method for industrially obtaining high yield and high purity.

TBS-BA is useful as a flame retardant for polyolefin resins and as an intermediate for flame retardants, especially bis[3,5-dibromo-4-(2
,3-dibromopropoxy)phenyl]sulfone (hereinafter abbreviated as TBS-BP) is extremely useful as a flame retardant for polypropylene, etc., as reported in Japanese Patent Publication No. 50-351.
This is described in Publication No. 03, Japanese Patent Publication No. 50-23693, etc.

[Conventional technology]

Conventionally, allyl chloride was used as an allylating agent to produce TBS-
When BA is produced, the etherification rate is very slow unless a catalyst such as bromide or iodide is added, and TBS-B
It is known that A is hardly produced (Special Publication Act 1986-
39585).

This production method uses bis(4-hydroxy-3,5-dibromophenyl)sulfone (hereinafter abbreviated as TBS),
It is dissolved in a solvent such as alcohol or water together with an alkali, then a catalyst such as bromide or iodide is added, and allyl chloride is added all at once, followed by heating under reflux to obtain T.
This is a method of generating BS-BA.

However, since this method uses a relatively large amount of an expensive catalyst such as bromide or iodide, it has not always been economically satisfactory as an industrial-scale production process.

Therefore, the present inventors investigated a method for improving the reaction rate in a system in which no catalyst is added. As a result, the reaction was carried out using a homogeneous aqueous solution containing a specific water-soluble organic solvent mixed in a certain concentration range, and after the reaction, the reaction intermediate 4-allyloxy-4'-hydroxy- 3,
When 3'',5,5-tetrabromodiphenylsulfone (hereinafter abbreviated as TBS-MA) is separated and recovered in the form of crystals and recycled into the reaction system, a significant reaction acceleration is observed, side reactions are suppressed, and TBS-BA It was discovered that the yield of this method was improved, and a patent application was previously filed (Japanese Patent Application No. 1-228340).

However, in this method, the reaction solution was filtered, and after separating the TBSBA crystals, -tanic acid was added to the filtrate to crystallize the dissolved TBS-MA, and the product was obtained by filtering again. It was necessary to circulate the TBS-MA crystals into the reaction. Therefore, this method still requires complexity as an industrial-scale production method.

[Problem to be solved by the invention]

An object of the present invention is to provide an industrial method for producing TBS-BA with high yield and high purity by simplifying complicated unit operations.

[Means to solve the problem]

The present inventors conducted intensive studies to improve the method of separating TBA-MA and circulating it to the reaction system, which requires such complicated operations in the conventional technology. As a result, after the reaction between TBS and allyl chloride was completed, the organic solvent in the reaction solution was distilled off to reduce the organic solvent concentration to 15% by volume or less, and when a halogen hydrocarbon solvent was added, the organic phase, intermediate phase, and water It was discovered that three aspects of harmony are formed. Analyzing each phase,
Only TBS-BA is selectively extracted in the organic phase, and the intermediate phase mainly contains TBS-MA, which is a reaction intermediate.
contains an organic solvent, a halogenated hydrocarbon solvent, and water, and during hydration, the target product TBS-BA and the intermediate TBS-MA are hardly dissolved, and the inorganic metal It was discovered that only salt was dissolved.

Therefore, if the intermediate phase containing T B S -MA is separated and recovered, it is recycled to the next reaction for re-reaction, and this operation is repeated and continued, T B
An extremely simplified production process that allows TBS-MA to be recycled without going through the crystallization and filtration separation steps required to obtain S-MA in the form of crystals, and the resulting TBS-BA has a high yield and high purity. They discovered this and completed the present invention.

That is, the gist of the present invention is to allyl etherify TBS with allyl chloride in a homogeneous aqueous solution containing a water-soluble organic solvent in the presence of an alkali, and to obtain TBS-BA.
(A) After the reaction, the resulting slurry solution is distilled to reduce the organic solvent concentration in the reaction solution to 15% by volume or less: (B) The slurry solution obtained in step (A) , an organic phase in which TBS-BA was selectively extracted by adding a halogenated hydrocarbon solvent, an intermediate phase composed of a component mainly consisting of TBS-MA, which is a reaction intermediate, and a hydrated phase. and (C) a step of circulating the intermediate phase composed of a component mainly consisting of TBS-MA obtained in step (B) to the allyl etherification reaction. The present invention provides a method for manufacturing TBS-BA.

The details will be explained below.

[Effect]

TBS is allyl etherified using allyl chloride in the presence of an alkali.

This process can be explained using the following reaction formula.

The amount of allyl chloride used in the method of the present invention is 2 mol or more, preferably 2.0 to 3.0 mol, per 1 mol of TBS.

Even if 3.0 mol or more is added, no improvement in yield is observed.

The reaction solvent used in the method of the present invention is a homogeneous aqueous solution prepared by mixing a water-soluble organic solvent in a concentration range 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. , dioxane, THF, methyl cellosolve, ethyl cellosolve, etc. Among these, water-isopropanol and water-
A dioxane mixed solvent system is particularly preferred due to its high reactivity.

The substrate concentration of TBS in these reaction solvents is not particularly limited, but is usually about 15 to 35% by weight.

The alkalis used in the method of the present invention include alkali metal hydroxides, carbonates, and hydrogen carbonates, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and carbonate. Potassium hydrogen, etc. can be mentioned.

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.

In addition, if the amount of alkali used is 2.2 mol or less per 1 mol of TBS, TBS and TBS-MA tend to precipitate during the reaction, so it is necessary to add a small amount of alkali during the reaction. .

In addition, it is necessary to maintain the reaction solution after the reaction in an alkaline state in consideration of the subsequent extraction step, especially at a pH of 10 to 10.
It is preferable to keep it within the range of 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.

(A) Step After the above-mentioned allylation reaction, the resulting TBS-BA slurry solution is distilled to reduce the organic solvent concentration in the reaction solution to 15% by volume or less. Note that the organic solvent concentration is preferably 10 to 5% by volume.
If the amount is 15% by volume or more, the alkali metal salt of TBS-MA will be distributed to the organic phase side and a three-phase system will not be formed during the next halogenated hydrocarbon solvent extraction.

Moreover, when distilling off the organic solvent, water may be added while distilling so as not to increase the slurry concentration. The slurry concentration after distillation is preferably about 15 to 35% by weight in order to maintain good stirring conditions. Incidentally, the distillation can be carried out either under normal pressure or under reduced pressure.

(B) Step An organic phase obtained by adding a halogenated hydrocarbon solvent to the slurry solution obtained in the above step (A) to selectively extract TBS-BA, a component mainly consisting of TBS-MA, which is a reaction intermediate. Three phases, an intermediate phase and hydration, are formed and each phase is separated.

As the extraction solvent for TBS-BA used in this step, a halogenated hydrocarbon solvent suitable for the bromination reaction is selected in consideration of the subsequent production of TBS-BP. For example, methylene chloride, chloroform, carbon tetrachloride, dichloroethane,
Examples include trichloroethane and chlorobenzene.

The amount of this solvent to be used is determined by considering the partition coefficient depending on the type of solvent, extraction conditions, etc., but usually TBS-
Add the required amount so that the substrate concentration of BA is about 5 to 25% by weight.

The obtained organic phase containing TBS-BA can be subjected to the next fJl m of TBS-BP without requiring any purification steps or the like.

In addition, the intermediate phase contains TBS-MA as a main component, and also contains unextracted TBS-BA, a halogenated hydrocarbon solvent of about 30 to 70% by weight, and an organic solvent of about 0 to 70% by weight. 10% by weight and water in a concentration range of about 30-70% by weight.

In addition, during hydration, the target substances TBS-BA and T B
Almost no S-MA was dissolved, and only the inorganic metal salt was dissolved.

(C) Step The intermediate phase composed of a component mainly consisting of TBS-MA obtained in the above step (B) is circulated to the allyl etherification reaction for re-reaction. Specifically, when charging TBS, the intermediate phase obtained in step (B) from which components mainly composed of TBS-MA are extracted is directly charged, and then alkali,
After adding the reaction solvent and allyl chloride, the reaction is carried out again. The reaction conditions and reaction operations are carried out according to the method described above.

In addition, when carrying out the reaction under normal pressure, the reaction temperature cannot be raised with the halogenated hydrocarbon solvent contained in the intermediate phase, especially a solvent with a low boiling point such as methylene chloride, so the reaction temperature cannot be raised, so it is necessary to use distillation etc. before adding allyl chloride. It is necessary to remove it.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, TBS-MA, which is a reaction intermediate, can be separated, recovered, and circulated in a solution state, so that crystallization and filtration of TBS-MA are easier than in conventional methods. The separation process can be simplified. Furthermore, since the obtained TBS-BA has a higher yield and higher purity than the conventional method, this method represents an extremely useful technology that can industrially advantageously produce TBS-BA.

〔Example〕

The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited thereto.

(Example 1) (Allylation reaction) Capacity 1000rn1 equipped with thermometer, stirring blade and cooling pipe
In a Yotsuro flask, add 174 d of isopropanol and 2 d of water.
Prepare 60rRI, 16.8g (420mmol) of NaOH, and further add 113.2g of TBS (200mff1o
l) was added and dissolved.

Next, 38.3 g of allyl chloride (500 mmo
1) was added in batches, heated to reflux temperature,
The reaction was carried out for 15 hours.

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

(A) Step 200g of water is added dropwise to the isopropanol in the slurry solution obtained in the allylation reaction, and the azeotropic temperature with water is 81~
It was distilled off at 88°C. At this time, unreacted allyl chloride was also removed by distillation.

After the removal by distillation, the pH of the reaction solution was measured and found to be pH 11,
It was 7. Furthermore, the concentration of isopropanol in the reaction solution was analyzed by gas chromatography and was found to be 9.1% by volume.

(B) Step (A) 480 g of methylene chloride was added to the slurry solution obtained in step (A) at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 539 g of organic phase + 82 g of intermediate phase and 484 g of hydrate. Analysis of each phase by liquid chromatography revealed that the organic phase contained 98.6 g of TBS-BA alone, and the intermediate phase contained 5.9 g of TBS-BA and 1 ml of Na salt of TBS-MA.
8.5g is dissolved in TBS-BA and TBS-BA for hydration.
Almost no Na salt of BS-MA was dissolved.

Furthermore, as a result of gas chromatography analysis of the composition of the solvent contained in the intermediate phase, methylene chloride 4
5% by weight, 5% by weight of isopropanol, and 45% by weight of water. Furthermore, the yield of TBS-BA is 76% only in the organic phase.
．． 4%, and the three-phase total was 81.0%. In addition, the raw material TBS does not remain in any of the three phases, and the conversion rate of TBS is 1.
It was 00%.

(C) Step (B) The intermediate phase containing Na salt of TBS-MA obtained in Step (B) was mixed with 2 g (200 mmo
1) in a Yotsuro flask, and 174 mj of isopropanol! , water 260-1 NaOH16, 8g
(420 twol) was charged, stirred, and circulated to the allylation reaction. Note that the intermediate phase contained a small amount of methylene chloride, which was removed by distillation.

Next, 38.3 g of allyl chloride (500iio1
) 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.

Thereafter, steps (A), (B), and (C) were performed in the same manner as the first step, and this series of two operations was repeated a total of 5 times.

Table 1 shows the TBS conversion rate and TBS-BA yield in each round.
~2.

(Example 2) (Alylation reaction) Isopropanol 174-1 water 26
0d, 16.8 g (420 full mol) of NaOH were added, and 113.2 g (20 C 1 mol) of TB5 was added and dissolved.

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

In addition, 3°2 g of NaOH (801
1 mol) was added.

(A) Step Improper tool in the slurry solution obtained in the allylation reaction is heated to an azeotropic temperature of 79 to 79% while adding 180 g of water dropwise.
It was distilled off at 89°C. At this time, unreacted allyl chloride was also removed by distillation.

After the removal by distillation, the pH of the reaction solution was measured and found to be pH 1.
It was 6. In addition, as a result of gas chromatography analysis of the isopropanol concentration in the reaction solution, it was found to be 13.2
It was % by volume.

(B) Step (A) 480 g of methylene chloride was added to the slurry solution obtained in step (A) at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 543 g of organic phase + 86 g of intermediate phase and 490 g of hydrate. As a result of liquid chromatography analysis of each phase, the organic phase contained 99.0 g of TBS-BA alone, and the intermediate phase contained 5.6 g of TBS-BA and 1 ml of Na salt of TBS-MA.
8.2g was dissolved in TBS-BA and TBS-BA for hydration.
Almost no Na salt of BS-MA was dissolved.

Furthermore, as a result of gas chromatography analysis of the composition of the solvent contained in the intermediate phase, methylene chloride 4
0% by weight, 7% by weight of isopropanol, and 53% by weight of water. Furthermore, the yield of TBS-BA is 76% only in the organic phase.
．． 6%, and the three-phase total was 81.0%. In addition, the raw material TBS does not remain in any of the three phases, and the conversion rate of TBS is 1.
It was 00%.

(Example 3) (Allylation reaction) In a 1000-capacity four-eye flask equipped with a thermometer, a stirring blade, and a cooling tube, 174 d of isopropanol and 260 d of water were added.
d. Prepare 16.8 g (420 5 ol) of NaOH,
Furthermore, 113.2 g (200 on) of TBS was added and dissolved.

Next, 38.3 g of allyl chloride (500 smol
) was added in batches and the temperature was raised to 11 reflux temperature.
The reaction took place for 5 hours.

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

(A) Step 230g of water is added dropwise to the isopropanol in the slurry solution obtained in the allylation reaction, and the azeotropic temperature with water is 81~
It was distilled off at 90°C. At this time, unreacted allyl chloride was also removed by distillation.

After removing by distillation, the pH of the reaction solution was measured, and the results showed that pull,
It was 9. Furthermore, the concentration of isopropanol in the reaction solution was analyzed by gas chromatography and was found to be 0.6% by volume.

(B) Step (A) 480 g of methylene chloride was added to the slurry solution obtained in step (A) at room temperature, and the mixture was stirred and separated for 10 minutes to obtain 548 g of an organic phase, 80 g of an intermediate phase, and 493 g of hydrate. As a result of liquid chromatography analysis of each phase, the organic phase contained 98.0 g of TBS-BA alone, and the intermediate phase contained 5.3 g of TBS-BA and 1 liter of Na salt of TBS-MA.
9.1g was dissolved, and TBS-BA and TBS were used for hydration.
Almost no Na salt of BS-MA was dissolved.

Furthermore, as a result of gas chromatography analysis of the composition of the solvent contained in the intermediate phase, methylene chloride 5
5% by weight, 1.0% by weight of isopropyl, and 44% by weight of water. The yield of TBS-BA was 75.9% only in the organic phase and 80.0% in total for the three phases. Furthermore, no TBS as a raw material remained in any of the three phases, and the conversion rate of TBS was 100%.

(Comparative Example 1) (Allylation reaction) Capacity 10100O with thermometer, stirring blade and cooling pipe!
Into a four-eye flask, charge Improper Tool 174rd, water 260-1, 16.8 g (420++ mol) of NaOH, and further add 113.2 g (200 mmol) of TBS.
was added and dissolved.

Next, 38.3 g of allyl chloride (500e+a+
oI) was added in batches, heated to the reflux temperature, and reacted for 15 hours.

In addition, 3.2 g of NaOH (80 m
ll1ol) was added.

(a) Step The slurry solution obtained in the allylation reaction was suction-filtered and separated into crystals and filtrate. The obtained crystals were washed with water and then dried to obtain white needle-like crystals of TBS-BA99. Obtained Og.

Regarding the isolated TBS-BA crystals and filtrate,
As a result of liquid chromatography analysis, TB
S conversion rate 100%, isolated crystal yield of TBS-BA 76.
It was 7%.

In addition, the reaction intermediate T B 5-MA19 is contained in the filtrate.
．． 3 g was dissolved, and the target product, TBS-BA, was not dissolved at all.

(b) Step (a) Add 15% HC to the filtrate obtained in step (a) under stirring at room temperature.
, 17 aqueous solution was added dropwise to crystallize TBS-MA crystals. At this time, the pH in the filtrate was approximately 2. Next, the obtained slurry solution was suction filtered and washed with water, and then TBS-
67.5 g of wet crystals of MA were obtained.

As a result of analyzing the obtained wet crystals of TBS-MA, it was found that T
B S-MA contains 19.4g, the rest is water 4
It was only 8.2g.

(c) Step (b) The wet crystals of T B S-MA obtained in step (b) are
Add BS13.2g (200++ll1ol) to a four-eye flask, and add isopropanol 174i.
1 Water-212rd, NaOH19.5g (487sm
ol) was charged and circulated to the allylation reaction with stirring.

Next, 38.3g of allyl chloride (500s+mo
1) was added in batches, the temperature was raised to reflux temperature, and 1
The reaction took place for 5 hours.

In addition, 3.7 g of NaOH (93 m
mol) was added.

Thereafter, steps (a), (b), and (c) were performed in the same manner as the first time, and this series of operations was repeated a total of four times.

Table 3 shows the TBS conversion rate and TBS-BA yield in each round.
It was shown to.

(Comparative Example 2) (Allylation reaction) Capacity 10100O with thermometer, stirring blade and cooling pipe!
In a Yotsuro flask, add 174 d of isopropanol and 2 d of water.
16.8 g (420 gaol) of 60-1 NaOH was charged, and 113.2 g (200+ gmol) 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.

(A) Step 480 g of methylene chloride was added to the slurry solution obtained in the allylation reaction at room temperature and stirred for 10 minutes. As a result, the solution after extraction was separated into only two phases. After separation, 730 g of the obtained organic phase was analyzed by liquid chromatography, and the results showed that 96.9 g of TBS-BA and 23.1 g of Na salt of TBS-MA, which is a reaction intermediate.
It contained.

Note that the yield of TBS-BA corresponds to 75.0%.

Furthermore, as a result of liquid chromatography analysis regarding hydration, it was found that 0.3 g of Na salt of TBS-MA,
Unextracted TBS-BAOolg was dissolved. Also,
The raw material TBS does not remain in either the organic phase or the hydrated phase, and the TBS
The BS conversion rate was 100%.

(Comparative Example 3) (Allylation reaction) Isopropanol 174-1 water 260 g
-1 Add 16.8 g (420 gaol) 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, 3.2g of NaOH (80a
mol) was added.

(A) Step 150g of water is added dropwise to the isopropanol in the slurry solution obtained in the allylation reaction, and the azeotropic temperature with water is 80~
It was distilled off at 90°C. At this time, unreacted allyl chloride was also removed by distillation.

After distillation and removal, the pH of the reaction solution was measured and found to be pH 11.
, 4. In addition, as a result of analyzing the concentration of isopropanol in the reaction solution by gas chromatography, 16.
It was 1% by volume.

(B) Step (A) 480 g of methylene chloride was added to the slurry solution obtained in step (A) at room temperature and stirred for 10 minutes. As a result, the solution after extraction was separated into only two phases. After liquid separation, 636 g of the obtained organic phase was analyzed by liquid chromatography and found to contain 102.0 g of TBS-BA and 23.0 g of Na salt of TBS-MA, which is a reaction intermediate.

Note that the yield of TBS-BA was equivalent to 79.0%.

Furthermore, as a result of liquid chromatography analysis regarding hydration, it was found that the Na salt of T B S-MA was 0.3
g, unextracted TBS-BAO, Ig was dissolved. Furthermore, no TBS as a raw material remained in the organic phase or in the hydrated phase, and the TBS conversion rate was 100%.

Claims (1)

[Claims] Bis(4-hydroxy-3,5-dibromophenyl)
In a method for producing bis(4-allyloxy-3,5-dibromophenyl)sulfone by allyl etherifying sulfone with allyl chloride in a homogeneous aqueous solution containing a water-soluble organic solvent in the presence of an alkali. (A) After the reaction, the slurry solution obtained is distilled to reduce the organic solvent concentration in the reaction solution to 15% by volume or less: (B) A halogenated hydrocarbon solvent is added to the slurry solution obtained in step (A). and bis(4-allyloxy-3,
Organic phase from which 5-dibromophenyl) sulfone is selectively extracted, consisting mainly of the reaction intermediate 4-allyloxy-4'-hydroxy-3,3',5,5'-tetrabromodiphenyl sulfone Steps of forming three phases of hydrated intermediate phase and hydration and separating each phase: and (C) (B)
4-allyloxy-4'-hydroxy- obtained in the process
A step of circulating an intermediate phase composed of a component containing 3,3',5,5'-tetrabromodiphenyl sulfone into the allyl etherification reaction:
, 5-dibromophenyl) sulfone.