JP3176103B2 - Method for producing bis (4-allyloxy-3,5-dibromophenyl) sulfone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to bis (4-allyloxy-3,5-dibromophenyl) sulfone [hereinafter referred to as TB
[Abbreviated as S-BA] in an industrially advantageous process with a high yield. This TB
S-BA is useful as a flame retardant for resins and as an intermediate for flame retardants. In particular, bis (3,5-dibromo-4-) obtained by brominating the allyl group of TBS-BA.
(2,3-Dibromopropyloxy) phenyl) sulfone (hereinafter abbreviated as TBS-BP) is known to be extremely effective as a flame retardant such as polypropylene (Japanese Patent Publication No. 50-35103).

[0002]

2. Description of the Related Art In general, TBS-BA is obtained by brominating bis (4-hydroxyphenyl) sulfone (commonly known as bisphenol S; hereinafter abbreviated as BPS) to form bis (4-hydroxyphenyl) sulfone.
A first step of obtaining hydroxy-3,5-dibromophenyl) sulfone (commonly known as tetrabromobisphenol S, hereinafter referred to as TBS) and a second step of allylating TBS obtained in the first step to obtain TBS-BA It is manufactured in two steps. Regarding the first step, a method in which BPS dissolved in a mixed solvent of water and a water-soluble solvent is brominated with a brominating agent to precipitate TBS as a target substance out of the system,
Disclosed are a method of brominating BPS in a suspended state in a two-layer system of an organic solvent (JP-A-54-44636) and a method of brominating BPS in water (JP-A-54-119430). Have been.

[0003] Regarding the allylation of TBS in the second step,
A method of reacting allyl bromide with TBS in a mixed solution of water and a lower alcohol or an ether-based water-soluble solvent in the presence of an alkali is disclosed (Japanese Patent Publication No. 50-3510).
No. 3). Further, with respect to this method, TBS-BA
In order to improve the yield of the compound, a method of dropping allyl bromide into the raw material system (JP-A-3-11051) and a method in which the ratio of water-water-soluble organic solvent as a reaction solvent is carried out within a certain range (JP-A-Hei. An improved method is disclosed.
In addition, TBS-
As a method for producing BA, KBr or Na is used as a catalyst in a raw material system.
A production method for improving the yield by adding Br or the like has also been disclosed (Japanese Patent Publication No. 63-39585). However,
With any of these techniques, a filtration step is required after the first step and after the second step, which is complicated in the production process.

As a method of continuously performing the first step and the second step, BPS is brominated in a water-water-soluble organic solvent, then neutralized with an alkali, and then allylation is performed. A method for performing the method is disclosed (JP-B-63-39585). However, also in this production method, since the reaction is performed in a mixed solution of water and a lower alcohol or an ether-based water-soluble solvent, the target substance TBS-BA precipitates out of the system. In addition, a complicated filtration step is required. Further, since water is used for washing the filtered TBS-BA, a long time is required for drying. In addition, since the filtrate is a mixture of water and alcohol, a large cost is required for the treatment.

On the other hand, the presence of certain quaternary ammonium salts, phase transfer conditions, also known for the reaction of allyl the BPS (JP 61 -137854 discloses). However, the high fat-soluble 4 described in the above patents
According to the present inventors' studies, when a quaternary ammonium salt, for example, trioctylmethylammonium chloride is used as a phase transfer catalyst in the allylation of TBS, the conversion is extremely small and there is no effect as a phase transfer catalyst at all. I understood. That is, a quaternary ammonium salt having a high fat solubility is not effective for allylation of TBS.
There has been no knowledge about a phase transfer catalyst exhibiting high activity for the allylation reaction under the phase transfer conditions of BS.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to continuously perform bromination of BPS and allylation of TBS without the need for complicated filtration and purification steps in an industrial process. It is an object of the present invention to provide a production method for obtaining TBS-BA with high efficiency and high purity.

[0007]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies to find a phase transfer catalyst effective for allylation of TBS. As a result, we surprisingly found that in the allylation of TBS, B
Contrary to the case of PS, a phase transfer catalyst having high hydrophilicity was found to be particularly effective, and the present invention was completed. That is, the present invention provides bis (4-hydroxy-3,5-dibromophenyl) sulfone by brominating bis (4-hydroxyphenyl) sulfone in water and an organic solvent immiscible with water in a suspended state with bromine. Without separating and purifying this, the base and the following formula
(1) Bis (4-allyloxy-3,5-dibromophenyl) sulfone characterized by reacting with allyl halide in the presence of a phase transfer catalyst represented by ( Chem. 3) or (2) ( Chem. 4) It relates to a method of production,

[0008]

Embedded image (Wherein, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a benzyl group or an alkyl group having 4 or less carbon atoms , and X represents Cl, Br or HSO ₄ )

[0009]

Embedded image (Wherein, n to table an integer from 5 to 70.) Further,
The above bis (4-
The present invention relates to a method for producing (allyloxy-3,5-dibromophenyl) sulfone.

The production method of the present invention is characterized in that the bromination of BPS in the first step and the allylation of TBS in the second step are carried out in the same mixed solvent two-layer system and with high selectivity. It is a continuous process that eliminates the filtration step, which is complicated in operation, and furthermore, the screw (4) that enables the filtration step to be omitted not only after the completion of the first step but also after the completion of the second step.
-Allyloxy-3,5-dibromophenyl) sulfone. The reaction of the present invention is performed in water and an organic solvent immiscible with water in both the first step and the second step. The organic solvent used in the present invention is not miscible with water and may be any solvent that is inert to the raw material system including bromine, and in particular, halogenated aromatic hydrocarbons such as chlorobenzene, dichloromethane, and chloroform. And halogenated hydrocarbons such as dichloroethane, trichloroethane and tetrachloroethane. The amounts of water and organic solvent used are each 300 moles per mole of BPS.
３3500 ml, preferably 500-3500 ml, and the ratio of water to the organic solvent is preferably in the range of 0.5 to 2 times the volume of water 1.

The first step of the present invention is a step of producing TBS by brominating BPS. The amount of bromine used in the first step may be at least 4 times mol of BPS, and preferably 4 to 4.25 times mol in consideration of cost and the like. The reaction temperature of the first step is preferably 40 ° C. or less from the viewpoint of suppressing the vaporization of bromine during the dropping of bromine, and the aging temperature depends on the boiling point of the solvent used. preferable. The reaction time is 1 to 10 hours. The progress of the reaction can be monitored using, for example, high performance liquid chromatography. Coloring due to unreacted bromine remaining after completion of the first step can be removed by adding a reducing agent such as hydrazine or sodium thiosulfate. Next, the reaction mixture obtained in the first step is added with an alkali to neutralize HBr, and then an alkali metal salt of TBS is prepared. Examples of the alkali used in the present invention include hydroxides, carbonates, and hydrogencarbonates of alkali metals. However, sodium hydroxide is preferred in terms of price and the like, and the amount of the alkali used is based on BPS. The molar amount is 6 times or more, preferably 6 to 8 times.

The second step of the present invention is a step of reacting the alkali metal salt of TBS obtained by the above method with allyl halide in the presence of a highly hydrophilic phase transfer catalyst. The phase transfer catalyst having high hydrophilicity used in the present invention is BP
It is known that the allylation of S is not effective at all. For example, when using benzyltriethylammonium chloride as a phase transfer catalyst, the yield of diallyl ether is low it is stated in JP-A-6 1 -137854. However, TBS has a higher acidity than BPS because the ortho structure of the hydroxyl group in the molecular structure is completely replaced by Br, which is an electron-withdrawing group. As a result of various studies, the present inventors found that the allylation reaction of TBS was B
Unlike the case of PS, it was found to occur mainly in the aqueous layer, and a phase transfer catalyst having high hydrophilicity was effective. Highly hydrophilic phase transfer catalysts for use in the present invention include polyethylene grayed <br/> Ricoh represented by quaternary ammonium <br/> salt or formula represented by the general formula (1) (2) It is.

[0013] Specific examples of the highly hydrophilic quaternary ammonium two <br/> ium salt used in the present invention, tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride , Benzyltributylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, benzyltrimethylammonium bromide, benzyltriethylammonium bromide,
Benzyltributylammonium bromide, tetramethylammonium hydrosulfate, tetraethylammonium hydrosulfate, tetrabutylammonium hydrosulfate, benzyltrimethylammonium hydrosulfate, benzyltriethylammonium hydrosulfate, benzyltributylammonium hydrosulfate , and the like .

[0014] Polyethylene glycol for use in the present invention
Is a polyethylene glycol of high hydrophilicity having a certain amount of oxyethylene chain in. Since the function of polyethylene glycol as a phase transfer catalyst is expressed by complex formation of an oxygen atom and an alkali metal cation in the molecule, as in the case of crown ether and the like, a certain amount of oxyethylene chains are present in the molecule. It is necessary to have. As a result of various investigations, the present inventors have found that as a phase transfer catalyst in the reaction of the present invention, it was found that polyethylene glycol having at least 6 or more oxyethylene chain is very effective.

[0015] Quaternary A used as a phase transfer catalyst in the present invention
Nmo salts and polyethylene glycol may be used alone, no problem be used as a mixture. The amount of the phase transfer catalyst used in the present invention is 1 to 50 mol%, preferably 2 to 30 mol%, based on TBS as a raw material. Note that high molecular weight polyethylene glycol is a mixture, to calculate the number of moles using an average molecular weight.
The allyl halide used in the present invention is allyl chloride or allyl bromide, and allyl chloride is preferable from the viewpoint of industrial price and the like. In addition, the amount may be at least twice the molar amount of BPS, and preferably 2 to 3 times the molar amount in view of the complexity of post-treatment and the like. The reaction of the second step is carried out at a temperature in the range of room temperature to 150 ° C, preferably 60 to 120 ° C. When the reaction temperature is higher than the boiling point of the solvent, a closed reaction vessel such as an autoclave can be used. The reaction is carried out by heating and stirring at this temperature for 1 to 15 hours. The progress of the reaction can be monitored, for example, using an analytical instrument such as high performance liquid chromatography, as in the first step.

After completion of the reaction, the product is contained in the organic layer and the inorganic salt is contained in the aqueous layer. The phase transfer catalyst is distributed between the organic layer and the aqueous layer according to the degree of hydrophilicity. After separating the aqueous layer,
Further, the phase transfer catalyst in the organic layer can be removed by washing the organic layer with water. Unreacted TBS remaining in the organic layer in a trace amount can be removed by washing the organic layer with an aqueous alkaline solution. Depending on the organic solvent used, TBS-B
A may precipitate. In such a case, there is no problem even if the washing and liquid separation steps are performed under heating.
The target substance, TBS-BA, can be obtained as a high-purity product by removing the organic solvent from the organic layer obtained after washing.

[0017]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. Example 1 A four-necked flask equipped with a thermometer, a reflux condenser and a stirrer was charged with 360 ml of water and 1,1,2-trichloroethane 3.
00 ml and 50 g (0.2 mol) of BPS were respectively charged to form a suspended state. There, 128.7g of bromine
(0.81 mol) was added dropwise at a temperature of 40 ° C. or lower over 3 hours. After the completion of the dropwise addition, the temperature was raised to 60 ° C. and the mixture was aged for 2 hours. At the end of the first step, the conversion to TBS was 98.5%. To the reaction mixture was added 50 g of NaOH (1.25
mol), benzyltri-n-butylammonium bromide 14 g (0.061 mol), allyl chloride 39 g
(0.51 mol), the mixture was heated under stirring and reacted at 90 ° C. for 7 hours. TB after 7 hours
The conversion to S-BA was 95% as measured by high performance liquid chromatography. After the reaction was completed, the organic layer was separated and washed with water. Further, the organic layer was washed with a 5% aqueous NaOH solution and then again with water. Then, the solvent of the organic layer was distilled off, and the obtained solid was dried under reduced pressure at 80 ° C./10 mmHg to obtain TBS-BA, which was a target substance. The yield was 114.0 g, and the yield was 88.2%.

Example 2 A four-necked flask equipped with a thermometer, a reflux condenser, and a stirrer was charged with 360 ml of water, 300 ml of chlorobenzene, and 50 g (0.2 mol) of BPS to form a suspension. There, 131 g (0.82 mol) of bromine was added dropwise at a temperature of 40 ° C. or lower over 3 hours. After completion of the dropwise addition, the temperature was raised to 70 ° C. and the mixture was aged for 2 hours. At the end of the first step, the conversion to TBS was 99%. 50 g (1.25 mol) of NaOH and 13 g (0.049 mol) of tetra-n-propylammonium bromide were added to the reaction mixture.
After l) and 39 g (0.51 mol) of allyl chloride were charged, the mixture was heated with stirring and reacted at 90 ° C. for 7 hours. After 7 hours, the conversion to TBS-BA is 93%.
After the completion of the reaction, the organic layer was separated and washed with water. Further, the organic layer was washed with a 5% aqueous NaOH solution and then again with water. When chlorobenzene was used, the target substance was precipitated at room temperature. Therefore, washing and liquid separation were performed under heating at 60 ° C. Next, the solvent of the organic layer was distilled off, and the obtained solid was washed with 8
It was dried under reduced pressure at 0 ° C./10 mmHg to obtain TBS-BA as a target substance. The yield was 112.9 g, and the yield was 87.4%.

Example 3 A four-necked flask equipped with a thermometer, a reflux condenser and a stirrer was charged with 360 ml of water, 1,1,2-trichloroethane 3
00 ml and 50 g (0.2 mol) of BPS were respectively charged to form a suspended state. There, 130 g of bromine (0.
81 mol) at a temperature of 40 ° C. or lower over 3 hours. After the completion of the dropwise addition, the temperature was raised to 60 ° C. and the mixture was aged for 2 hours. At the end of the first step, the conversion to TBS was 98%. 50 g (1.25 mol) of NaOH, 24 g (0.04 mol) of polyethylene glycol-600 (manufactured by Wako Pure Chemical Industries, average molecular weight 600) and 39 g of allyl chloride were added to the reaction mixture.
g (0.51 mol), and the mixture was heated under stirring and reacted at 90 ° C. for 7 hours. After the completion of the reaction, the organic layer was separated and washed with water. Further, the organic layer was washed with a 5% aqueous NaOH solution and then again with water. Then, the solvent of the organic layer was distilled off, and the obtained solid was dried under reduced pressure at 80 ° C./10 mmHg to obtain TBS-BA, which was a target substance. The yield was 113.2 g, and the yield was 87.6%.

Example 4 A reaction was carried out under the same conditions as in Example 2 using 60 g of polyethylene glycol-3000 (manufactured by Wako Pure Chemical Industries, average molecular weight 3000) as a phase transfer catalyst. The washing liquid separation step was performed under heating at 60 ° C. The yield was 114.6 g, and the yield was 88.7%. Example 5 A reaction was performed under the same conditions as in Example 2 except that 25 g of polyethylene glycol-1000 (manufactured by Wako Pure Chemical Industries, average molecular weight: 1000) was used as a phase transfer catalyst. The conversion after the completion of the reaction was 93%. The washing liquid separation step was performed under heating at 60 ° C. The yield was 112.9 g, 87.4%.
Met.

[0021] In Comparative Example 1 Example 1, in place of the quaternary ammonium salt in the Application Benefits octyl methyl ammonium chloride, as in Example 1 the
When the reaction was carried out under the same conditions, the conversion was 55%. Comparative Example 2 The reaction was carried out under the same conditions as in Example 1 without using a phase transfer catalyst, and the conversion was 45%. Comparative Example 3 Under the same conditions as in Example 1, when tetraethylene glycol (n = 3) was used as a phase transfer catalyst as a catalyst, the reaction hardly proceeded.

[0022]

Industrial Applicability According to the present invention, it is possible to omit the filtration step which has been industrially complicated in the process for producing TBS-BA, and to provide high-purity TBS-BA at a low cost. Became possible.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-10058 (JP, A) JP-A-61-137854 (JP, A) JP-A-3-38563 (JP, A) (58) Investigation Field (Int. Cl. ⁷ , DB name) C07C 317/00 C07C 315/00 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. Bis (4-hydroxy-3,5-) bromination of bis (4-hydroxyphenyl) sulfone in water and an organic solvent immiscible with water in a suspended state with bromine.
Dibromophenyl) sulfone was obtained, and without separation and purification, the base and the following formula (1) (Formula 1) or
In the presence of the phase transfer catalyst represented by (2)
Bis (4) characterized by reacting with allyl halide
-Allyloxy-3,5-dibromophenyl) sulfone. Embedded image (Wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently
A benzyl group or an alkyl group having 4 or less carbon atoms
And, X represents Cl, Br or HSO ₄₎ ## STR2 ## (Where n represents an integer from 5 to 70) 2. The bis (4-allyloxy-3,2,3-bis (4-allyloxy) -3,-(3)-(3)-(3)-(2)-(2)-(2) compound according to claim 1, wherein the organic solvent is a solvent selected from a halogenated hydrocarbon and a halogenated aromatic hydrocarbon.
Method for producing 5-dibromophenyl) sulfone.