JPH0390058A - Production of bis(4-allyloxy-3,5-dibromophenyl)sulfone - Google Patents

Abstract

PURPOSE:To easily obtain the title compound as a flame retardant without the need for any catalyst by reaction under specified conditions between bis (4-hydroxy-3, 5-dibromophenyl) sulfone and 4-allyloxy-4'-hydroxy-3,3',5,5'- tetrabromodiphenylsulfone. CONSTITUTION:In the presence of an alkali, using allyl chloride as allylating agent, (A) 1mol of bis (4-hydroxy-3,5-dibromophenyl) sulfone is incorporated with (B) 0.02-0.40 (pref. 0.05-0.30)mol of 4 allyloxy-4,-hydroxy-3,3',5,5' tetrabromodiphenylsulfone under normal or higher pressure at room temperature to 150 deg.C, thus obtaining the objective compound. The amount of the allylating agent to be used is >=1.0 molar times (pref. 1.25-1.50 molar times) based on the total of the hydroxyl groups in both the compounds A and B as raw materials. It is preferable that the amount of the alkali to be used be 1.0-1.50 molar times.

Description

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

TBS-BA is useful as a flame retardant for polyolefin resins and as an intermediate for flame retardants, and is particularly useful as a bis(3,5-dibromo-4-dibromopropoxyphenyl) sulfone (hereinafter referred to as TBS-BA) obtained by brominating an allyl group. , TBS-B
It is stated in Japanese Patent Publication No. 35103/1983 and Japanese Patent Publication No. 23693/1983 that P (abbreviated as P) is extremely useful as a flame retardant for polypropylene and the like.

[Conventional technology]

Conventionally, allyl chloride was used as an allylating agent to produce TB.
When producing S-BA, the etherification rate is very slow unless a catalyst such as bromide or iodide is added (TBS
- It is known that almost no BA is produced (Tokuko Sho 6
No. 0-39585).

This production method uses bis(4-hydroxy-3,5-dipromophenyl)sulfone (hereinafter abbreviated as TBS),
TB is dissolved together with an alkali in a solvent such as alcohol or water, then a catalyst such as bromide or iodide is added, and allyl chloride is added all at once, followed by heating under reflux.
This is a method of generating S-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, in order to solve the problem that the etherification rate is very slow in the conventional technology without adding a catalyst, the present inventors investigated ways to improve the reaction rate, and found that water was used as the reaction solvent. When a homogeneous aqueous solution containing a specific soluble organic solvent in a certain concentration range is used, a remarkable reaction acceleration is observed, side reactions are suppressed, and TBS-BA
They discovered that the yield of the new method was improved and filed a patent application earlier.

However, in order to obtain TBS-BA with a yield of 85% or more using this method, a reaction time of 24 hours or more is required, and further shortening of the reaction time has been desired in order to make it an industrial 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 in high yield and purity without requiring the addition of a catalyst.

[Means to solve the problem]

The present inventors focused on shortening the reaction time in such conventional techniques, and conducted intensive studies on methods for improving the reaction rate. As a result, in the allyl etherification method of TBS using allyl chloride in the presence of an alkali, the reaction intermediate 4-allyloxy-4゛-hydroxy-3゜3-5.5''-tetrabromodiphenyl When allylation reaction is carried out by adding sulfone (hereinafter abbreviated as TBS-MA) to TBS in a certain range, a remarkable reaction acceleration is observed, and a high yield can be achieved in a short period of time. However, the present inventors have discovered that even higher purity TBS-BA can be obtained, and have completed the present invention.

That is, the gist of the present invention is to provide a method for allyl etherifying TBS using allyl chloride in the presence of an alkali, in which TBS-MA is added in an amount of 0.0% to 1 mole of TBS.
0.02 to 0.40 mol of TBS-BA is added and reacted.

The details will be explained below.

[Effect]

The method of the present invention can be explained using the following reaction formula.

When allyl chloride is used as an allylating agent, as mentioned above, even without adding a catalyst such as NaBr or K1,
If a homogeneous aqueous solution containing a specific water-soluble organic solvent in a certain concentration range is used as the reaction solvent, the rate of etherification will be accelerated and the yield of TBS-BA will be improved, but from an industrial perspective, There is still a problem that the reaction time is not long.

However, in the method of the present invention in which TBS-MA is added to TBS in a certain range and the reaction is carried out, the etherification rate is further accelerated, and TBS-BA can be produced in high yield in a shorter reaction time than in the conventional method. You can get it at

The reason for this is not necessarily clear, but if the reaction intermediate TBS-MA is present in the reaction system in a certain amount from the beginning of the reaction, the solubility of the TBS alkali salt in the organic solvent increases significantly. However, this is considered to be because the reactivity between TBS and allyl chloride is further accelerated. On the other hand, when TBS-MA is larger than a certain range,
Only TBS-MA dissolves in the organic solvent and inhibits the TBS alkali salt from dissolving in the organic solvent, which slows down the reaction.

The amount of TBS-MA used in the method of the present invention is T
It is preferably 0.02 to 0.40 mol, preferably 0.05 to 0.30 mol, per 1 mol of BS.
If the amount is less than 0.02 mol, no particular improvement in reaction rate will be observed. On the other hand, if the amount is 0.40 mol or more, a decrease in the reaction rate is observed, which is not preferable.

The amount of allyl chloride used in the method of the present invention is 1.0 times the mole or more, preferably 1.0 times the mole or more of the total value of hydroxyl groups contained in TBS and TBS-MA.
．． It is 25 to 1.50 times the mole.

Even if 1.50 times the mole or more is added, no improvement in the reaction rate 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 are monovalent lower alcohols having 1 to 3 carbon atoms or ethers having 2 to 5 carbon atoms, and specifically include methanol, ethanol,
n-propanol, isopropanol, dioxane, T
Examples include HF, methyl cellosolve, and ethyl cellosolve. Among these, water-isopropanol and water-
A dioxane mixed solvent system is particularly preferred due to its high reactivity.

Regarding the TBSo′) substrate concentration in these reaction solvents,
There is no particular limitation, but usually about 15 to 35% by weight is used.

The alkali used in the method of the present invention includes alkali metal hydroxides, carbonates, and hydrogen carbonates, and specifically sodium hydroxide.

Potassium hydroxide, sodium carbonate, potassium carbonate.

Examples include sodium hydrogen carbonate and potassium hydrogen carbonate.

Regarding the usage amount of this alkali, TBS and TBS-
The amount is 1.0 times or more by mole or more, preferably 1.0 to 1.50 times by mole, relative to the total value of hydroxyl groups contained in MA. Even if 1.50 times the mole or more is added, no particular improvement in the reaction rate is observed.

In addition, if the amount of alkali used is less than 1.1 times the mole of the total value of hydroxyl groups contained in TBS and TBS-MA, TBS and TBS-MA tend to precipitate during the reaction, and as a result, they is incorporated into the TBS-BA crystals and tends to cause a decrease in purity, so it is necessary to add a small amount of alkali during the reaction.

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 depends on the reaction temperature and cannot be determined generally, but is usually about 1 hour to 30 hours.

The reaction solution containing TBS-BA crystals obtained in the method of the present invention is filtered, washed with water, and then dried to obtain a product. The obtained TBS-BA crystals are of high purity and can be used as a raw material for TBS-BP, which is extremely useful as a flame retardant for polyolefin resins and polypropylene, without any special purification process. .

[Effects of the Invention] As is clear from the above explanation, according to the present invention, by adding TBS-MA, which is a reaction intermediate, to TBS within a certain range, the reaction is shorter than that of the conventional method. This shows an extremely useful technique that allows highly purified TBS-BA to be obtained in high yield in a short period of time.

〔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> 87 mj of isopropyl alcohol and 1 ml of water were placed in a 300-capacity four-bottle flask equipped with a thermometer, stirring blade, and cooling tube.
30-. Prepared NaOH9, Ig (227-■1), and further added TBS56.6g (100gaol) and T
9.7 g (16 Iol) of BS-MA was added and dissolved.

The amount of TBS-MA charged was equivalent to 0.16 mol per 1 mol of TBS. Further, the concentration of isopropyl alcohol in the water solvent corresponds to 40% by volume.

Next, 22.2 g (290 mmol) of allyl chloride
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

8 hours after starting the reaction, 1.6 g of NaOH (4
0 m5 ol) was added.

After the reaction was completed, the mixture was cooled to room temperature, the precipitated crystals were filtered off, washed with water, and dried to obtain white needle-like crystals of TBS-BA66, Og.

When this isolated TBS-BA crystal and the above filtrate were analyzed by liquid chromatography, the TBS conversion rate was 100%, and the isolated crystal yield of TBS-BA was the same as that of the charged TBS and TBS. The purity of the isolated crystal was 100%, which was 85.7% based on the total amount of S-MA.

In addition, only the reaction intermediate TBS-MA was dissolved in the filtrate, and the target product TBS-BA was hardly dissolved.

The reaction conditions and results are shown in Table 1.

(Examples 2 to 5) According to Example 1, raw materials with the composition shown in Table 1 were charged into a 300rR1 Yotsuro flask, and the reaction was carried out under the reaction conditions shown in Table 1.The same post-treatment as in Example 1 was carried out. ,implemented,TBS
- BA was obtained. The results obtained are shown in Table 1.

(Comparative Example 1) In a 300-capacity four-glass flask equipped with a thermometer, stirring blade, and cooling tube, 87-9 parts of isopropyl alcohol and 13 parts of water were added.
0rd, NaOH 10,0g (2501 dol) was added, and TBS 56.6 g (100 ml 5 ol) was further added and dissolved.

The isopropyl alcohol concentration in the water medium corresponds to 40% by volume.

Next, 19.1 g (250 mmol) of allyl chloride
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

After the reaction was completed, the mixture was cooled to room temperature, the precipitated crystals were filtered off, washed with water, and dried to obtain 4 and 6 g of TBS-BA as white needle-like crystals.

When this isolated TBS-BA crystal and the above filtrate were analyzed by liquid chromatography, the TBS conversion rate was 100%, the isolated crystal yield of TBS-BA was 75.2%, and the isolated TBS-BA crystal yield was 75.2%. Crystal purity was 100%.

In addition, only TBS-MA, which is a reaction intermediate, was dissolved in the filtrate, and TBS-BA, which was a target product, was hardly dissolved.

The reaction conditions and results are shown in Table 1.

(Comparative Example 2.3) According to Comparative Example 1, Table 1 was added to a 300rd Yotsuro flask.
The raw materials were charged with the composition shown in Table 1, and the reaction was carried out under the reaction conditions shown in Table 1. The same post-treatment as in Comparative Example 1 was carried out, and TBS-
Obtained BA. The results obtained are shown in Table 1.

(Comparative Example 4) 87 ml of isopropyl alcohol and 13 ml of water were placed in a 300-capacity four-bottle flask equipped with a thermometer, stirring blade, and cooling tube.
0rd, 6.9 g (173 maol) of NaOH was charged, and 36.8 g (65I 1 mol) of TBS and 21.2 g (35 msol) of TBS-MA were added and dissolved.

The amount of TBS-MA charged was equivalent to 0854 mol per 1 mol of TBS. Further, the concentration of isopropyl alcohol in the water solvent corresponds to 40% by volume.

Next, 15.8 g of allyl chloride (206 gaol
) was added in batches, heated to reflux temperature, and heated to reflux temperature.
Time reacted.

8 hours after starting the reaction, 1.3 g of NaOH (3
3■ol) was added.

After the reaction was completed, the mixture was cooled to room temperature, precipitated crystals were filtered off, washed with water, and dried to obtain 46.8 g of white needle-like crystals of TBS-BA.

When this isolated TBS-BA crystal and the above filtrate were analyzed by liquid chromatography, the TBS conversion rate was 100%, and the isolated crystal yield of TBS-BA was the same as that of the charged TBS and TBS. The purity of the isolated crystal was 100%, which was 72.4% based on the total amount of S-MA.

In addition, only TBS-MA, which is a reaction intermediate, was dissolved in the filtrate, and TBS-BA, which was a target product, was hardly dissolved.

The reaction conditions and results are shown in Table 1.

(Comparative Example 5.6) According to Comparative Example 1, raw materials having the compositions shown in Table 1 were charged into a 300-meter Yotsuya flask, and a reaction was carried out under the reaction conditions shown in Table 1. The same post-treatment as in Comparative Example 1 was carried out, and TBS-B
I got an A. The results obtained are shown in Table 1.

Claims (1)

[Claims] In a method for allyl etherifying bis(4-hydroxy-3,5-dipromophenyl)sulfone using allyl chloride in the presence of an alkali, 4-allyloxy-4'-hydroxy-3,3', 5,5'-tetrabromodiphenyl sulfone was converted into bis(4-hydroxy-3,
0.0 per mole of 5-dipromophenyl)sulfone
A method for producing bis(4-allyloxy-3,5-dipromophenyl) sulfone, which comprises adding and reacting in an amount of 2 to 0.40 mol.