JPH11130716A - Production of bromine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a high-purity bromine compound in a short time by a compact and simple apparatus by continuously feeding a specific compound, a specific amount of bromine and a specific solvent to a reactor and removing reaction heat by a specific method. SOLUTION: (A) A compound having an aliphatic unsaturated bond of formula I [Ar<1> and Ar<2> are each a (halogen-substituted) 5-16C aromatic hydrocarbon or the like; Y is a 1-6C saturated hydrocarbon or the like; R<1> and R<2> are each a 2-11C hydrocarbon having aliphatic unsaturated group and in either one of R<1> and R<2> , a halogen may be added to a part of the unsaturated group], (B) bromine in an amount corresponding to number of 1-5 bromine molecules per unsaturated group in the component A and (C) a solvent which is inert to reaction are continuously fed to a reactor and reaction of the compound A with the compound B is carried out while removing substantial amount of reaction heat by vaporization heat of component B or A and the reaction mixture is taken to continuously provide the objective bromine compound of formula II (R<3> and R<4> are each a group in which unsaturated groups of R<1> and R<2> are saturated by bromine).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for continuously producing a bromine compound by brominating a compound having an aliphatic unsaturated bond. More specifically, the present invention relates to a method for industrially and continuously producing a high-purity bromine compound from a compound having an aliphatic unsaturated bond.

[0002]

2. Description of the Related Art Generally, in the field of organic chemistry, a bromination reaction to an aliphatic unsaturated group is a reaction that is frequently employed when synthesizing a brominated derivative. Due to the intensity of the reaction, it is essential to remove the reaction heat from within the reaction system.For this reason, the operation of cooling the reaction system and adding bromine over time in a mild state is generally adopted. ing.

For example, Japanese Patent Publication No. 49-39655 discloses a method for producing β, γ dibromopropylbenzene, but at a low temperature such that no side reaction occurs when bromine is added. The reaction is described.

Japanese Patent Application Laid-Open No. 55-111429 discloses that diallyl ether obtained from 2,2-bis-{(4-hydroxy-3,5-dibromo) phenyl} propane and allyl chloride is aromatic. It is disclosed that the bromination is carried out in a halogenated hydrocarbon solvent, but it is described that such bromination is carried out at a temperature of 10 to 30 ° C, especially 15 to 25 ° C. A method of adding bromine under cooling at a temperature of about 20 ° C. is illustrated.

Japanese Patent Application Laid-Open No. 50-30853 relates to a method for recovering a solid.
The reaction of 5-dibromo-4-allyloxy) phenyl} propane with bromine specifically describes a method of dropping bromine at a temperature of 20 ° C. or lower.

In Japanese Patent Application Laid-Open No. 7-173092, as a method for obtaining a 2,3-dibromopropyl compound, specifically, 2,2-bis {(3,5-dibromo-4-
For the reaction of bromine with allyloxy) phenyl-propane or the like, a method in which bromine is added dropwise at a reaction temperature of 10 to 20 ° C. over 1 hour is described.

Further, in Japanese Patent Application Laid-Open No. 7-316087, as a specific example, a reaction with 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane in methylene chloride by using a cooling tube. 24 to 27 ° C
A method is disclosed in which bromine is dropped over 1 hour while controlling the temperature.

On the other hand, for example, Japanese Patent Publication No. 50-23693 discloses a specific example of bis {(3,5-dibromo-
In bromination of 4-allyloxy) phenyl disulfone, a method is disclosed in which such a compound is dissolved in methylene chloride and bromine is reacted with the compound at the boiling point of methylene chloride.

The bromination of bis {(3,5-dibromo-4-allyloxy) phenyl} sulfone is described in JP-A-3-271267 and JP-A-4-234.
As disclosed in JP-A-354-354, specifically, the former is a method in which bromine is dropped at 39 ° C. or 40 ° C. over 1 hour to a methylene chloride solution of the compound, and the latter is bromine at 35 to 39 ° C. For 1.5 hours. In each of these methods, the reaction is carried out in a vessel having a cooling pipe.

[0010] The methods described in these patent publications are all small-scale reactions at the laboratory level. In many cases, a flask is used as a reactor, and most of the reactions are performed by cooling the reactor itself. A method of removing heat is employed. Although these publications disclose conditions and means at a laboratory level, they are effective on an industrial scale to effectively remove a large amount of heat of reaction and to obtain a high-purity bromide with a high yield. No specific conditions or means are disclosed.

In order to carry out bromination, particularly polybromination, of a compound having an aliphatic unsaturated bond on an industrial scale, it is necessary to effectively remove large amounts of reaction heat.
Development of means and devices for that purpose is required. In addition, when the heat of reaction is not effectively removed, bromine must be gradually supplied, so that the reaction time is prolonged, resulting in a decrease in yield and a decrease in purity.

[0012]

In view of the above situation, the present inventor has proposed that a compound having an aliphatic unsaturated bond and bromine can be efficiently produced on an industrial scale with a very compact and simple apparatus and with a short reaction time. As a result of intensive studies aimed at providing a method for continuously producing a good and high-purity bromine compound, a method of reacting a compound having an aliphatic unsaturated bond with bromine to form a bromine compound has a A compound having an unsaturated bond, bromine and a solvent inert to the reaction are continuously supplied to the reactor, and at this time, a certain ratio or more of bromine is supplied to the compound having an aliphatic unsaturated bond to obtain bromine. It was found that by removing a substantial amount of the heat of reaction of the reaction to the outside of the reaction system by the heat of vaporization of the solvent or bromine, no side reaction occurred and a high-purity bromine compound could be produced in high yield. invention It has been reached.

[0013]

That is, according to the present invention, a compound having an aliphatic unsaturated bond represented by the following formula (1) is reacted with bromine and represented by the following formula (2). In the method for producing a bromine compound, the compound represented by the formula (1), bromine and a solvent inert to the reaction are continuously supplied to a reactor separately or as a mixture of any combination. At this time, an amount of bromine corresponding to the number of bromine molecules of 1 to 5 per unsaturated group in the compound is supplied to the compound represented by the formula (1), and The reaction is carried out while removing a substantial amount of heat of reaction by the solvent or the heat of vaporization of bromine, a reaction mixture is taken out from the reactor, and a bromine compound represented by the following formula (2) is recovered from the reaction mixture. Of continuous production of bromine compounds That.

[0014]

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(In the formula, Ar ¹ and Ar ² may be the same or different and represent an aromatic hydrocarbon group having 5 to 16 carbon atoms or a saturated alicyclic hydrocarbon group having 5 to 12 carbon atoms. The hydrogen group may be substituted by at least one halogen atom, and Y is a saturated hydrocarbon group having 1 to 6 carbon atoms, a sulfone group, a sulfide group, a ketone group, an alkylene oxide group having 2 to 6 carbon atoms or a single atom. Represents a bond, R
¹ and R ² may be the same or different and represent a C ^{2 to} C 11 hydrocarbon group having at least one aliphatic unsaturated group, and one of R ¹ and R ² is an unsaturated group May be added by a halogen atom. )

[0016]

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(Wherein Ar ¹ , Ar ² and Y have the same meanings as defined in the above formula (1). R ³ and R ⁴ each represent an unsaturated group in R ¹ and R ² in the above formula (1)) Means a group wherein the group is saturated by a bromine atom.)

The compound having an aliphatic unsaturated bond used in the method of the present invention is represented by the above formula (1). In the above formula (1), Ar ¹ and Ar ² may be the same or different and each have an aromatic hydrocarbon group having 5 to 16 carbon atoms, preferably 6 to 12 carbon atoms, or 5 to 12 carbon atoms, preferably 5 to 12 carbon atoms. It is a saturated alicyclic hydrocarbon group having 6 to 10 carbon atoms. It is industrially advantageous that Ar ¹ and Ar ² are the same and are aromatic hydrocarbon groups. Specific examples of Ar ¹ and Ar ² include 1,4-phenylene group, 1,4-methylphenylene group, 1,4-dimethylphenylene group, 2,6-
A naphthylene group and a 2,7-naphthylene group;
A 4-phenylene group is preferred.

In these Ar ¹ and Ar ² , the carbon atom forming the hydrocarbon may be substituted with a halogen atom. Particularly, for the purpose of producing a flame retardant, a halogen atom, especially a bromine atom Is preferably substituted.
The number of halogen atoms substituted for each of Ar ¹ and Ar ² is preferably 1 to 6, preferably 2 to 4, with respect to Ar ¹ (or Ar ² ).

In the above formula (1), Y is a group or a bond connecting Ar ¹ and Ar ² and has 1 to 6 carbon atoms.
Preferably a saturated hydrocarbon group having 1 to 3 carbon atoms; sulfone group (-SO ₂ -); sulfide groups (-S-); ketone group (-CO-); 2 to 6 carbon atoms, preferably 2 to carbon atoms 4
Or an alkylene oxide group of the formula: or a single bond.
Desirable Y is a methylene group, an isopropylidene group, a cyclohexylidene group, a sulfone group, a sulfide group, a ketone group or a single bond.

In the above formula (1), R ¹ and R ² may be the same or different and have 2 to 11 carbon atoms having at least one aliphatic unsaturated group, preferably 2 to 2 carbon atoms.
5 represents a hydrocarbon group, and any one of R ¹ and R ² may have a part of the unsaturated group added by a halogen atom, preferably a bromine atom. Specific examples of R ¹ and R ² are preferably a vinyl group, an allyl group and an isobutenyl group.

As the compound having an aliphatic unsaturated bond represented by the above formula (1) of the present invention, specifically, 2,2-
Bis {(3,5-dibromo-4-allyloxy) phenyl} propane, 2,2-bis} (3,5-dibromo-4
-Isobutenyloxy) phenyl {propane, bis {(3,5-dibromo-4-allyloxy) phenyl}
Methane, bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane, (3,3 ', 5,5'-tetrabromo-4,4'-diallyloxy) biphenyl,
(3,3 ', 5,5'-Tetrabromo-4,4'-divinyloxy) biphenyl, bis {(3,5-dibromo-
4-allyloxy) phenyl} sulfone and bis {(3,5-dibromo-4-isobutenyloxy) phenyl} sulfone, among which 2,2-bis} (3,5-dibromo-4- Allyloxy) phenyl {propane, 2,2-bis} (3,5-dibromo-4)
-Isobutenyloxy) phenyl {propane, bis {(3,5-dibromo-4-allyloxy) phenyl}
Methane, bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane, (3,3 ', 5,5'-tetrabromo-4,4'-diallyloxy) biphenyl and (3,3' , 5,5'-Tetrabromo-4,4'-
Divinyloxy) biphenyl is preferred,
2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane, 2,2-bis {(3,5-dibromo-4-isobutenyloxy) phenyl} propane, bis {(3,5- Dibromo-4-allyloxy) phenyl
Methane and bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane are more preferred, and 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane is particularly preferred. You.

In the continuous production method of the present invention, the compound having an aliphatic unsaturated bond represented by the above formula (1), bromine and a solvent inert to the reaction may be used separately or as a mixture of any combination. Supply continuously. In the following description, a compound having an aliphatic unsaturated bond may be simply abbreviated as “unsaturated compound”, and a solvent inert to the reaction may be simply abbreviated as “solvent”.

In carrying out the continuous production method of the present invention, the method of supplying the unsaturated compound, bromine and the solvent to the respective reactors is classified into the following (i) to (iii). (I) The solution of the unsaturated compound and the bromine are separately supplied. (Ii) separately providing a solution of the unsaturated compound and a solution of bromine. (Iii) The unsaturated compound, bromine and the solvent are separately supplied.

The above (i) to (iii) are for explaining the combination of the supplying means for the unsaturated compound, bromine and the solvent required for carrying out the method of the present invention. Natural modifications are naturally included in the present invention.

When there is another component to be added, the component may be added independently, may be added as a solvent solution, or may be added to a solution of an unsaturated compound or a solution of bromine. You may. Other components to be added include, for example, alcohol.

The solvent supplied to the reactor needs to be inert without adversely affecting the reaction. The solvent inert to the reaction means inert to bromine, the compound having an aliphatic unsaturated bond, and the bromine compound represented by the formula (2). Such a solvent is preferably as high as possible in solubility for a compound having an aliphatic unsaturated bond, but may be partially soluble. Further, it is preferable that the bromine compound produced by the bromination reaction of the compound having an aliphatic unsaturated bond substantially dissolves in the solvent.

The solvent in the method of the present invention is not only used as a mere solvent for uniformly conducting the reaction, but also preferably functions as a solvent for effectively removing the heat of reaction out of the reaction system. Have. So the solvent is
Those having a normal pressure boiling point of 0 to 100 ° C, preferably 20 to 90 ° C, are advantageous. Especially 2
Those having a range of 0 to 60 ° C are desirable.

Examples of the solvent include halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, 1,1-dichloroethane, bromoethane, butyl chloride and chloropropane; diethyl ether, ethyl isopropyl ether, tetrahydrofuran, dioxane and the like. Examples include ether hydrocarbon compounds, aromatic hydrocarbon compounds such as benzene, carbon disulfide, pentane, and the like. Also, bromine can be used as a solvent.

Of these solvents, halogenated hydrocarbons are preferred, and methylene chloride and chloroform are particularly preferred as solvents. These solvents are used alone or in combination of two or more. These halogenated hydrocarbons can also be used as a mixed solvent with dioxane.

These solvents may be used in an amount of 2 to 10 per unsaturated group in the compound represented by the formula (1).
An amount corresponding to the number of 00 solvent molecules, preferably 2.5
It is used in an amount corresponding to the number of ~ 800 solvent molecules. In the reaction of the present invention, since it is a preferable embodiment to remove a substantial amount of the reaction heat out of the reaction system by the heat of vaporization of the solvent, the solvent is more preferably in an amount corresponding to the number of 3 to 700 solvent molecules. It is particularly advantageous to use them in an amount corresponding to the number of solvent molecules from 4 to 600.

The method of the present invention is characterized in that the reaction heat is discharged by the heat of vaporization of the solvent or bromine, so that the solvent or bromine is present in the reaction system in an amount that can provide the heat of vaporization corresponding to the heat of reaction. However, since bromine participates in the reaction, it is reasonable and advantageous to remove the heat of reaction preferably by the heat of vaporization with a solvent.

In the reaction of the present invention, as the physicochemical background, the reaction heat of bromine to the aliphatic unsaturated bond,
It can be analyzed by the heat balance with the heat of vaporization of the solvent.
For example, in the addition reaction of Br ₂ to -CH = CH _2, the total binding energy is determined as follows.

The binding energy of C = C is 145 Kca
1 / mol and that of CH is 98.8 Kcal
/ Mol, there are three bonds. Since the binding energy value of Br-Br is 46.1 Kcal / mol, the sum of all is 145+ (98.8 × 3) + 46.1 = 48.
It becomes 7.5 Kcal / mol.

On the other hand, considering the product containing bromine after the reaction, the bond energy of C—Br in —CHBr—CH ₂ Br is 65.9 Kcal / mol,
There are two of these bonds, and CH is the same as the starting material (9
8.8 × 3) At Kcal / mol, the binding bond energy of C—C is 83.1 Kcal / mol, so the total is 511.3 Kcal / mol, and the difference between these two values, 23.8 Kcal / mol, is Pure heat of reaction (both are based on Chemical Handbook, edited by The Chemical Society of Japan, Vol. 122)
See page 5.)

The heat of vaporization of the solvent described so far is
Generally, it is 7 to 8 Kcal / mol (see Chemical Handbook, Vol. 2, pp. 271 of the Chemical Society of Japan), and the solvent is defined as the amount of the solvent contributing to the removal of the heat of reaction, based on the amount of the compound having an aliphatic unsaturated bond. The content is preferably within the above range per unsaturated group in the compound.

The amount of bromine used in the method of the present invention is an amount corresponding to the number of 1 to 5 bromine molecules per unsaturated group in the compound having an aliphatic unsaturated bond, preferably 1. Bromine is advantageously used in an amount corresponding to the number of 1 to 3 bromine molecules. In particular, a range of an amount corresponding to the number of 1.2 to 3 bromine molecules is industrially advantageous.

In the method of the present invention, bromine is used as it is or as a bromine solution. As the solvent used in the bromine solution, the same solvent as described above is used, and in that case, the concentration of bromine is 10 to 90% by weight.
Is preferable.

In the continuous production method of the present invention, bromine is contained in the reaction mixture in the reactor in an amount corresponding to the number of 1 to 5 bromine molecules per unsaturated group in the unsaturated compound, preferably It is important that is maintained in a range corresponding to the number of 1.1 to 3 bromine molecules. In the reaction mixture, it is required that bromine always maintain the above ratio during the reaction in order to obtain a high-purity and high-quality bromine compound. There is no particular problem if the bromine ratio is momentarily (on the order of several seconds) smaller than the above range, but the substantial reaction time and the bromine ratio should be maintained in the above ranges. When the proportion of bromine is kept below the above range for a long time, the unsaturated group in the unsaturated compound causes a side reaction,
Undesirable side reaction products are formed, and the purity of the target brominated compound is reduced. This side reaction is considered to occur mainly due to the reaction of the active intermediate formed by the reaction of water and bromine in the reaction mixture with the unsaturated group.

In the continuous production method of the present invention, the ratio of bromine in the reaction mixture is determined by the amount of bromine corresponding to the number of 1 to 5 bromine molecules per unsaturated group in the unsaturated compound, preferably In order to keep the amount of bromine molecules in the range corresponding to the number of 1.1 to 3 bromine molecules, the supply ratio of the unsaturated compound to the reactor and the supply of bromine may always be maintained at the above ratio.

In the process of the present invention, the bromination reaction occurs immediately in the reactor, and it is necessary to remove a substantial amount of the generated heat of the reaction by vaporizing the solvent or bromine. The substantial amount of the heat of reaction means at least 80%, preferably at least 85% of the theoretical calorific value generated by the desired bromination reaction. A method in which the vaporized solvent or bromine vapor is cooled and liquefied by a condenser or the like provided in the upper part of the reactor and then returned to the reaction mixture, that is, a method of refluxing is preferred because the operation is easy and the operation is easy.

By removing a substantial amount of the heat of reaction for bromination with a solvent or the heat of vaporization of bromine, the resulting bromine compound becomes highly pure. Simply reacting the unsaturated compound with bromine at a high temperature easily generates by-products and lowers the purity as compared with the reaction at a low temperature, but in the method of the present invention, a high-purity bromine compound is obtained. be able to. this is,
It is considered that the unsaturated compound and bromine are uniformly dispersed in the solution due to the stirring effect when the solvent or bromine is vaporized, and the side reaction is less likely to occur.

The reaction temperature in the bromination reaction of the present invention is as follows:
It is sufficient that the substantial amount of the heat of reaction for bromination is a temperature at which the bromine or the solvent is removed by the heat of vaporization of the solvent, and the bromination reaction is not limited to normal pressure, and can be performed under pressure or under reduced pressure. . The reaction temperature is preferably at least 0 ° C, more preferably at least 5 ° C. Further, when the boiling point of the solvent used is lower than the boiling point of bromine, the reaction temperature can be increased by applying pressure, and when the boiling point of the solvent used is higher than the boiling point of bromine, the reaction is performed by reducing the pressure. The temperature can be lowered. Thus, the reaction temperature in the bromination reaction of the present invention can be controlled by the operating pressure in relation to the type (boiling point) of the solvent used and the amount of bromine. Usually, the reaction temperature is advantageously in the range from 0 to 60 ° C, preferably in the range from 5 to 55 ° C, particularly preferably in the range from 10 to 50 ° C.

In the continuous production method of the present invention, it is particularly preferable that the unsaturated compound is supplied as a solution in a solvent. In this case, the amount of the solution in which the unsaturated compound is dissolved in the solvent is A ( L / min), when the amount of bromine or bromine solution added is B (L / min) and the amount of the reaction mixture in the reactor is C (L), the residence time represented by the following formula is 0.1 to 200. Min, preferably 0.2 to 100 min.

[0045]

(Equation 2)

Here, the total amount of the addition amount (L / min) of the solution in which the unsaturated compound is dissolved in the solvent and the addition amount (L / min) of the bromine or the bromine solution are strictly speaking outside the reactor. Although different from the derived amount (L / min) of the derived reaction mixture, the amount of bromine (L / min) is usually much smaller than the amount (L / min) of the solution in which the unsaturated compound is dissolved in the solvent. Yes, the volume change due to the reaction is almost negligible. Further, since the amount of the solvent scattered outside the reactor is very small, the addition amount (L / min) of the solution in which the unsaturated compound is dissolved in the solvent and the addition amount (L / min) of the bromine or the bromine solution are reduced. The total amount will be close to the amount (L / min) of the reaction mixture discharged out of the reactor.

Recirculating a part of the reaction mixture to the reactor is advantageously employed because the reactor can be further compacted and the reaction efficiency is excellent. The method of circulation is not particularly limited, and another pipe dedicated to circulation may be attached to the reactor separately from the outlet of the reaction mixture, or a part of the derived reaction mixture may be circulated to the reactor. .

The circulated reaction mixture may be added to the reactor as it is, or it may be mixed with a solution of an unsaturated compound, bromine or a bromine solution, or a mixture of both, and the resulting mixture may be returned to the reactor. You may.

In the continuous production method of the present invention, the bromination reaction can be performed in a short time and the productivity is improved.
Said circulation method is preferred. Since the bromination reaction itself is almost completed in a few tens of seconds, the above-mentioned residence time is sufficient.

In carrying out the continuous production method of the present invention, the reactor is brought into uniform and effective contact with the unsaturated compound, bromine and the solvent, and a substantial amount of the heat of the reaction is vaporized from the solvent or bromine to the outside of the reactor. It is desirable to use a device equipped with a stirrer for discharging the gas to the solvent, and a device provided with a condenser at the top for refluxing the vaporized solvent or bromine.

Thus, the selection of the above-mentioned solvent and its ratio,
It is industrially advantageous that the ratio of bromine and the reaction temperature are set within the above ranges. Further, the presence of water in the reaction system affects the purity and quality of the bromine compound.

In the reaction of the present invention, impurities present in the reaction mixture are important factors for efficiently performing the bromination reaction of the present invention and for obtaining a bromine compound of high yield and high purity. . In particular, the water present in the reaction mixture reacts with bromine to form active intermediates, which react competitively with aliphatically unsaturated groups to produce active intermediates. It is necessary to pay close attention to the presence of water contained in the compound having an unsaturated bond, bromine and the solvent, and basically, coexistence of water should be avoided. Therefore, the concentration of water is preferably in a range corresponding to the number of water molecules of 0.1 or less per one unsaturated group of the compound having an aliphatic unsaturated bond.
It is more preferably in the range corresponding to the number of 0005 to 0.1 water molecules, and even more preferably in the range corresponding to the number of 0.0005 to 0.05 water molecules. As the concentration of water increases, the resulting bromine compounds tend to be low-purity, easily adhere to each other, and become solids that lack storage stability. The water content is measured by the Karl Fischer method.

As a method for adjusting the amount of water to be removed, a method in which a solvent to be used is brought into contact with anhydrous calcium carbonate, anhydrous calcium chloride, anhydrous sodium sulfate, or the like. There are a method of contact mixing and a contact treatment with a water-absorbing desiccant such as phosphorus pentoxide, molecular sieve, and the like. It is also necessary to prevent steam from entering the reactor.

The desired bromine compound can be separated and recovered from the reaction mixture obtained by the above bromination reaction by a method known per se. However, unreacted bromine remains in the reaction mixture. Therefore, the method of treating residual bromine with a reducing agent, converting bromine into hydrobromic acid once, and then adding an alkaline neutralizing agent is usually used. Has been adopted.

As the reducing agent used in such a treatment,
It is a reducing agent used in a normal reduction reaction, specifically, sodium bisulfite, sodium dithionite,
Sodium sulfite, oxalic acid, hydrogen sulfide, sodium nitrite, potassium nitrite, hydroxylamine sulfate, tin, stannous oxide, hydrazine, and the like; sodium bisulfite, sodium dithionite, sodium sulfite, oxalic acid, Sodium nitrate is preferably used. These reducing agents can also be used as an aqueous solution. These reducing agents are used alone or in combination of two or more.

Examples of such an alkaline neutralizing agent include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides and alkaline earth metal carbonates. ,Sodium hydroxide,
Potassium hydroxide, sodium carbonate, potassium carbonate, calcium hydroxide, calcium carbonate, and the like are preferable, and sodium hydroxide is particularly preferably used. These alkaline neutralizing agents are preferably used as an aqueous solution. These alkaline neutralizing agents are used alone or in combination of two or more.

From the reaction mixture treated in the manner described above,
The desired bromine compound is recovered by a method known per se, for example, by precipitation with a poor solvent.

Thus, according to the method of the present invention, by the bromination reaction of the unsaturated compound represented by the above formula (1), the unsaturated compound of the above formula (2) is saturated with a bromine atom. ) Is obtained as a highly pure bromine compound. Further, the obtained bromine compound can be identified by a usual analysis method, for example, analysis of ¹ H-NMR spectrum and IR spectrum.

The bromine compound obtained by the method of the present invention has a purity of 90% or more, preferably 92% or more. Such a high-purity bromine compound is useful as a flame retardant for thermoplastic resins, and is particularly suitable as a flame retardant for ABS resins and styrene resins.

[0060]

The present invention will be described below in detail with reference to examples. The compound having an aliphatic unsaturated bond used in Examples was dried at 80 ° C. for 48 hours. The solvent used was dried with 3A molecular sieves (pore diameter 3 Å) for 48 hours. The purity, bromine content, and specific gravity were measured according to the following methods.

(1) Purity of bromine compound The purity of the bromine compound was measured by high-performance liquid chromatography (SCL-6B, manufactured by Shimadzu Corporation).
The measurement was performed by a method of detecting the absorption in nm. The sum of the peak areas of the components obtained from the chromatography was defined as 100, and the ratio of the peak area of the bromine compound to the sum was determined.

(2) Bromine content The sample was heated in a closed vessel with fuming nitric acid to decompose the sample, and the generated hydrobromic acid was quantitatively analyzed using a method of titrating with silver nitrate (the Calius method). .

(3) Specific gravity The specific gravity was measured at 20 ° C. using a glass specific gravity bottle.

Example 1 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane (hereinafter sometimes abbreviated as starting compound (1)) 1000
g (1.60 mol) in 1703 g of methylene chloride (2
0.0mol). The specific gravity of this solution is 1.46.
And the result of measurement by the Karl Fischer method is 160p
pm of water.

In a glass reactor equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was introduced from the inlet 1 at a rate of 5.3 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.58 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (1) was 1.23). The solution mixed in the reaction vessel generated heat due to the reaction heat of bromination, and the vaporized vapor was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 20 minutes after the start of the solution of the raw material compound (1) and the addition of bromine, the reaction mixture started to be drawn out from the outlet 8 and continued to be drawn out continuously (residence time: 20.4 minutes). The reaction mixture in the reaction vessel (120 ml) is pumped by pumping a part of the reaction mixture from the time when the reaction mixture starts to be discharged.
And circulated through the reaction vessel at a rate of 0.03 L / min.

In the reaction mixture discharged from the reaction vessel, excess bromine was reduced with an aqueous solution of sodium hydrogen sulfite (about 15% by weight), and the generated hydrogen bromide was neutralized with an aqueous solution of sodium hydroxide. Thereafter, 1000 g of ion-exchanged water was added to this solution, and the mixture was stirred. The methylene chloride layer was separated, and about 90% of methylene chloride was evaporated from the methylene chloride layer.
It was removed and methanol was added thereto to precipitate a reaction product. The precipitate was filtered to remove a massive solid. This blocky solid was pulverized in a mortar, dried at 80 ° C. under reduced pressure for 10 hours, and 2,2-bis {3,5-dibromo-4- (2,3-
Dibromopropyloxy) phenyl @ propane was obtained.
The bromine compound had a purity of 94.2% and a bromine content of 67.
3% (theoretical 67.8%).

Example 2 In Example 1, 1405 g of methylene chloride was replaced with 4405 g (51.8 mol) (specific gravity of the solution was 1.42 and water content was 130 ppm).
The rate of addition of the solution of 2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane was 10.5 × 10
^The reaction was carried out in the same manner as in Example 1 except that the reaction was performed at ^-3 L / min. 2,2-bis {3,5-dibromo-4 obtained
-(2,3-Dibromopropyloxy) phenyl} propane had a purity of 94.2%.

[Example 3] In Example 1, 900 g of methylene chloride was used instead of 1703 g of methylene chloride as the solvent.
(10.6 mol) and 803 g of chloroform (6.7 m
ol), and the reaction was carried out in the same manner as in Example 1 except that a mixed solvent with the same was used (the specific gravity of the solution was 1.48 and the water content was 260 ppm). The resulting 2,2-bis {3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl}
Propane was 94.0% pure.

[Example 4] In Example 1, 2,2-
The addition rate of the solution of bis {(3,5-dibromo-4-allyloxy) phenyl} propane was 135.2 × 10 ⁻³ L.
The reaction was carried out in the same manner as in Example 1 except that the rate of bromine addition was 14.8 × 10 ⁻³ L / min. The obtained 2,2-bis {3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl} propane has a purity of 94.
1%.

Example 5 2,2-bis {(3,5-dibromo-4-isobutenyloxy) phenyl} propane (hereinafter sometimes abbreviated as starting compound (2)) 10
43 g (1.60 mol) of methylene chloride 3400 g
(40.0 mol). The specific gravity of this solution is 1.
46, the result of Karl Fischer method measurement being 12
It contained 0 ppm of water.

In a glass reactor equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was introduced from the inlet 1 at a rate of 10.5 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.59 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (2) was 1.04). The solution mixed in the reaction vessel
The vapor generated by the reaction heat of the bromination and vaporized was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 11 minutes after the start of the solution of the raw material compound (2) and the addition of bromine, the reaction mixture began to be drawn out from the outlet 8,
Thereafter, it was continuously discharged (residence time: 10.8 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to give 2,2-bis @ 3,5-dibromo-4- (2,3-dibromo-2-methyl Propyloxy) phenyl @ propane was obtained. This bromine compound had a purity of 93.9%.

Example 6 Bis {(3,5-dibromo-
476 g (0.8 mol of 4-allyloxy) phenyl} methane (hereinafter sometimes abbreviated as starting compound (3))
l) was dissolved in a mixed solvent of 1700 g (20.0 mol) of methylene chloride and 1700 g (19.3 mol) of 1,4-dioxane. The specific gravity of this solution was 1.22, and the result of measurement by the Karl Fischer method was 320 ppm.
Water.

In a glass reactor equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was supplied from the inlet 1 at a rate of 10.6 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.43 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (3) was 1.57). The solution mixed in the reaction vessel
The vapor generated by the reaction heat of the bromination and vaporized was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 11 minutes after starting the addition of the solution of the raw material compound (3) and the bromine, the reaction mixture began to be drawn out from the outlet 8,
Thereafter, it was continuously discharged (residence time: 10.9 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to convert bis {3,5-dibromo-4- (2,3-dibromo-propyloxy) phenyl} methane. Obtained. This bromine compound has a purity of 93.
3%.

Example 7 Bis {(3,5-dibromo-
500 g of 4- (isobutenyloxy) phenyl} methane (hereinafter sometimes abbreviated as starting compound (4)) (0.5 g).
8 mol) in 1700 g (20.0 mol) of methylene chloride
l). The specific gravity of this solution was 1.41, and as a result of measurement by the Karl Fischer method, it contained 160 ppm of water.

In a glass reaction vessel equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was supplied from the inlet 1 at a rate of 10.5 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.62 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (4) was 1.12). The solution mixed in the reaction vessel
The vapor generated by the reaction heat of the bromination and vaporized was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 11 minutes after the start of the solution of the raw material compound (4) and the addition of bromine, a reaction mixture began to be drawn out from the outlet 8,
Thereafter, it was continuously discharged (residence time: 10.8 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to obtain bis {3,5-dibromo-4- (2,3-dibromo-2-methylpropyloxy) phenyl ｝ Methane was obtained. This bromine compound
Purity was 93.5%.

Example 8 Bis {(3,5-dibromo-
517 g (0.8) of 4-allyloxy) phenyl} sulfone (hereinafter sometimes abbreviated as starting compound (5))
mol) in 1700 g (20.0 mol) of methylene chloride
Was dissolved. The specific gravity of this solution was 1.42, and as a result of measurement by the Karl Fischer method, it contained 180 ppm of water.

In a glass reactor equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was introduced from the inlet 1 at a rate of 10.5 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.59 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (5) was 1.07). The solution mixed in the reaction vessel
The vapor generated by the reaction heat of the bromination and vaporized was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 11 minutes after the start of the solution of the raw material compound (5) and the addition of bromine, a reaction mixture began to be drawn out from the outlet 8,
Thereafter, it was continuously discharged (residence time: 10.8 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to convert bis {3,5-dibromo-4- (2,3-dibromo-propyloxy) phenyl} sulfone. Obtained. This bromine compound has a purity of 9
2.3%.

Example 9 466 g of (3,3 ', 5,5'-tetrabromo-4,4'-diallyloxy) biphenyl (hereinafter sometimes abbreviated as starting compound (6))
(0.8 mol) in 1700 g (20.0 g) of methylene chloride.
mol) and 1,700 g of 1,4-dioxane (19.3 m
ol) in a mixed solvent. The specific gravity of this solution is 1.
20 and 32 as measured by the Karl Fischer method.
It contained 0 ppm of water.

In a glass reactor equipped with a stirring blade 3, a condenser 4 and a thermometer 5 shown in FIG. 1, the solution was introduced from the inlet 1 at a rate of 10.6 × 10 ⁻³ L / min. Was continuously added from the inlet 2 at a rate of 0.43 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the starting compound (6) was 1.58). The solution mixed in the reaction vessel
The vapor generated by the reaction heat of the bromination and vaporized was refluxed to the reaction vessel by the condenser 4 which was sufficiently cooled. About 11 minutes after the start of the solution of the raw material compound (6) and the addition of bromine, a reaction mixture began to be drawn out from the outlet 8,
Thereafter, it was continuously discharged (residence time: 10.9 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to obtain # 3, 3 ', 5,
5'-tetrabromo-4,4 '-(2,3-dibromo-
(Propyloxy) オ キ シ biphenyl was obtained. This bromine compound had a purity of 93.0%.

[Embodiment 10] In the embodiment 1, 2, 2
The addition rate of the solution of -bis {(3,5-dibromo-4-allyloxy) phenyl} propane was 0.57 × 10 ⁻³ L
/ Min, the addition rate of bromine is 0.062 × 10 ⁻³ L /
The reaction was performed in the same manner as in Example 1 except that the reaction time was changed to minutes. The obtained 2,2-bis {3,5-dibromo-4-
(2,3-Dibromopropyloxy) phenyl} propane had a purity of 94.1%.

Comparative Example 1 The rate of addition of a solution of 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane was fixed at 5.3 × 10 ⁻³ L / min, and bromine was added. The rate was 0.28 × 10 ⁻³ L / min for the first 10 minutes (the number of bromine molecules / the number of unsaturated groups in the raw material compound (1) was 0.1%).
59), and the next 10 minutes was 0.84 × 10 ⁻³ L / min (the number of bromine molecules / the number of unsaturated groups in the raw material compound (1) was 1.
78), and reacted for 40 minutes in the same manner as in Example 1 except that the addition was repeated. About 20 minutes after the start of the solution of the raw material compound (1) and the addition of bromine, a reaction mixture starts to be drawn out from the outlet 8.
Thereafter, it was continuously discharged (residence time: 20.5 minutes).
The reaction mixture in the reaction vessel (120 ml) was partially circulated using the pump 6 at a rate of 0.03 L / min from the time when the reaction mixture began to be drawn out. .

The reaction mixture discharged from the reaction vessel was treated in the same manner as in Example 1 to obtain 2,2-bis {(3,5
(Dibromo-4-allyloxy) phenyl} propane was obtained. The bromine compound had a purity of 85.0%, and was a powder that easily adhered to each other and had poor storage stability.

Comparative Example 2 In Example 1, 2,2-
The addition rate of the solution of bis {(3,5-dibromo-4-allyloxy) phenyl} propane is 5.3 × 10 ⁻³ L / min, and the addition rate of bromine is 0.4 × 10 ⁻³ L / min. (The number of bromine molecules / the number of unsaturated groups in the raw material compound (1) is 0.
Except for 85), the reaction was carried out in the same manner as in Example 1, and treated in the same manner as in Example 1 to give 2,2-bis {3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl ｝ I got propane. The purity of the bromine compound is 71.
0%, indicating that the powder was easily adhered to each other and had poor storage stability.

Comparative Example 3 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane 100
0 g (1.60 mol) was converted to 1703 g of methylene chloride (2
0.0mol). 1694 g of this solution was equipped with a stirring blade, a condenser, a thermometer and a dropping funnel.
2,000 ml of a glass container, and with stirring, bromine 396
g was gradually dropped from the dropping funnel over 220 minutes. The solution temperature at the start of the dropping of bromine was 20 ° C., but as the bromine was dropped, the solution temperature gradually increased due to the heat of reaction, and reached 37 ° C. at the end of the dropping. During the addition of the bromine, the reaction vessel was not cooled, and the reflux of methylene chloride did not occur. After completion of the dropping of bromine, the reaction mixture was treated in the same manner as in Example 1 to obtain 2,2-bis {3,5-dibromo-4- (2,3-dibromopropyloxy) phenyl} propane. The purity of the bromine compound was as low as 82.1%, the appearance was colored, and it was easy to adhere to each other and storage stability was poor.

Examples 1 to 10 and Comparative Examples 1 and 2
Are shown in Tables 1 and 2. Here, the starting compounds (1) to (6) in the table are: (1) 2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane, (2) 2,2-bis} (3,5-dibromo-4-isobutenyloxy) phenyl {propane (3) bis} (3,5-dibromo-4-allyloxy)
Phenyl {methane, (4) bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane (5) bis {(3,5-dibromo-4-allyloxy)
Phenyl disulfone (6) (3,3 ', 5,5'-tetrabromo-4,4'
-Diallyloxy) biphenyl, and the solvents (A) to (C) have the following compositions.

(A) methylene chloride (B) methylene chloride / chloroform = 53/47 (weight ratio) (C) methylene chloride / 1,4-dioxane = 50/50
(Weight ratio) The concentration of water is the number of water molecules with respect to the number of unsaturated groups in the raw material compound.

[0092]

[Table 1]

[0093]

[Table 2]

[0094]

According to the method of the present invention, on a commercial scale, a compound having an aliphatic unsaturated bond and bromine can be efficiently converted into a highly pure bromine compound in a short reaction time with a very compact and simple apparatus. The bromine compound is suitably used as a flame retardant for a thermoplastic resin, and its industrial effect is special.

[Brief description of the drawings]

FIG. 1 is an example of a reaction apparatus for performing a bromination reaction in the present invention.

FIG. 2 is another example of a reaction apparatus for performing a bromination reaction in the present invention.

[Explanation of symbols]

 1. 1. Input port for raw material compound solution 2. Bromine or bromine solution inlet Stirrer blade 4. Condenser 5. Thermometer 6. Pump 7. 7. Inlet for circulating fluid 8. Outlet for reaction mixture Reaction mixture

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Yasuhiro Shimizu 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Teijin Chemicals Limited

Claims (7)

[Claims] 1. A method for producing a bromine compound represented by the following formula (2) by reacting a compound having an aliphatic unsaturated bond represented by the following formula (1) with bromine: ), Bromine and a solvent inert to the reaction are continuously fed into the reactor separately or as a mixture of any combination, wherein the compound of the formula (1)
And the unsaturated group 1 in the compound
An amount of bromine corresponding to the number of bromine molecules of 1 to 5 per unit is supplied, and the reaction is carried out in the reactor while removing a substantial amount of heat of reaction by the solvent or the heat of vaporization of bromine. A method for continuously producing a bromine compound, comprising taking out a reaction mixture, and then recovering a bromine compound represented by the following formula (2) from the reaction mixture. Embedded image (In the formula, Ar ¹ and Ar ² may be the same or different, and have an aromatic hydrocarbon group having 5 to 16 carbon atoms or 5 carbon atoms.
To 12 saturated alicyclic hydrocarbon groups, which may be substituted with at least one halogen atom, and Y represents a saturated hydrocarbon group having 1 to 6 carbon atoms, a sulfone group, or a sulfide group. , A ketone group, an alkylene oxide group having 2 to 6 carbon atoms or a single bond, wherein R ¹ and R ² may be the same or different, and have 2 to 11 carbon atoms having at least one aliphatic unsaturated group. It represents a hydrogen group, and ^one of R ¹ and R ² may have a part of the unsaturated group added by a halogen atom. ) (In the formula, Ar ¹ , Ar ² and Y have the same meanings as defined in the above formula (1). R ³ and R ⁴ each represent a case where the unsaturated group in R ¹ and R ² in the above formula (1) is bromine. Means a group saturated by an atom.) 2. The addition amount of a solution obtained by dissolving a compound having an aliphatic unsaturated bond in a solvent inert to the reaction is defined as A (L / L
Min), the amount of bromine or bromine solution added is B (L / min) and the amount of the reaction mixture in the reactor is C (L), and the residence time represented by the following formula is 0.1 to 200 minutes. 2. A method for continuously producing a bromine compound according to claim 1. (Equation 1) 3. The continuous production method of a bromine compound according to claim 1, wherein a part of the reaction mixture led out of the reactor is circulated to the reactor. 4. A method according to claim 1, wherein the concentration of water in the reaction mixture is such that a compound having an aliphatic unsaturated bond has an unsaturated group of 1 in the compound.
2. The continuous production method of a bromine compound according to claim 1, wherein the amount is in a range corresponding to the number of water molecules of 0.1 or less per unit. 5. The method according to claim 1, wherein the solvent is used in an amount of 2 to 100 per one unsaturated group in the compound having an aliphatic unsaturated bond.
The continuous production method of a bromine compound according to claim 1, wherein the bromine compound is used in an amount corresponding to the number of 0 solvent molecules. 6. The method for continuously producing a bromine compound according to claim 1, wherein the compound having an aliphatic unsaturated bond is a compound represented by the following formula (3). Embedded image (In the formula, Ar ¹ and Ar ² may be the same or different, and have an aromatic hydrocarbon group having 5 to 16 carbon atoms or 5 carbon atoms.
Represents a saturated alicyclic hydrocarbon group of from 1 to 12, X represents a halogen atom, m and n represent an integer of from 1 to 6, and R ¹ , R ² and Y have the same meanings as defined in the above formula (1). I do. ) 7. The compound having an aliphatic unsaturated bond,
2,2-bis {(3,5-dibromo-4-allyloxy) phenyl} propane, 2,2-bis {(3,5-dibromo-4-isobutenyloxy) phenyl} propane, bis {(3 5-dibromo-4-allyloxy) phenyl {methane, bis {(3,5-dibromo-4-isobutenyloxy) phenyl} methane, (3,3 ′, 5,
5'-tetrabromo-4,4'-diallyloxy) biphenyl, (3,3 ', 5,5'-tetrabromo-4,
4'-divinyloxy) biphenyl, bis {(3,5-
The method for continuously producing a bromine compound according to claim 1, which is a compound selected from dibromo-4-allyloxy) phenyl} sulfone and bis {(3,5-dibromo-4-isobutenyloxy) phenyl} sulfone.