JPH10251174A - Production of chlorinated aromatic compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the easy and high-efficiency production of the subject compound having a structure that the hydroxyl group in an aromatic alcohol is substituted with a chlorine atom by using a specific aromatic alcohol. SOLUTION: An aromatic alcohol of formula I (Ar is an n-valent aromatic group, for example, monovalent phenyl or tosyl, divalent phenylene or methylphenylene or a trivalent aromatic hydrocarbon group as 1,3,5-benzenetriyl; R<1> and R<2> are each a monovalent hydrocarbon group which may be substituted, for example, methyl, ethyl; (n) is an integer of 1 or more), for example, p- dicumyl alcohol is allowed to react with an organic acid chloride (for example, p-toluenesulfonyl chloride) to give a chlorinated aromatic compound of formula II (for example, p-dicumyl chloride). The product is useful as a cationic polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for easily and efficiently producing a chlorinated aromatic compound having a structure in which a hydroxyl group of the aromatic alcohol is substituted with a chlorine atom from a specific aromatic alcohol. On how you can do it. One such as p-dicumyl chloride (i.e., 1,4-bis (1-chloro-1-methylethyl) benzene; hereinafter sometimes referred to as "DCC") obtained by the production method of the present invention. Chlorinated aromatic compounds having a structure in which a 1,1-dihydrocarbyl-1-chloromethyl group is bonded to an aromatic ring can be used as a cationic polymerization initiator for producing polyisobutylene or the like (US Pat. No. 4,276,631).
No. 94).

[0002]

2. Description of the Related Art One of the methods for producing DCC is p-dicumyl alcohol (ie, α, α, α ′, α′-tetramethyl-), as shown in the following (1) and (2).
A method using 1,4-benzenedimethanol (hereinafter sometimes referred to as "DIOL") as a raw material is known.

(1) A method for producing DCC, which comprises reacting gaseous hydrogen chloride by reacting DIOL in a solution under ice cooling (VSC Ch).
andang J. P. Kennedy, Polym.
Bull. (Berlin), 4 (9), 513-52
0 (1981))

(2) A method for producing DCC, which comprises reacting DIOL with hydrochloric acid in the presence or absence of an organic solvent to carry out the reaction (JP-A-8-29109).
No. 0)

[0005]

The method of the above (1) is as follows.
Since hydrogen chloride gas is used, which is inferior in handling property and has restrictions on equipment, it is disadvantageous as an industrial production method.

In the above method (2), Japanese Patent Application Laid-Open No. 8-291
According to the description of Japanese Patent Publication No. 090, it is recommended to use hydrochloric acid at a ratio such that the amount of hydrogen chloride is at least twice as much as the molar amount of hydroxyl groups in DIOL in order to efficiently obtain the desired DCC. Also, in the specific production example described as an example in this publication, hydrochloric acid is used in such a ratio that the amount of hydrogen chloride is about 3 to 6 times the molar amount of the hydroxyl group in DIOL. When hydrochloric acid is used in a large excess amount as described above, waste liquid treatment of hydrochloric acid remaining in a large amount after the reaction becomes extremely inefficient. In the method (2), since water is inevitably present in the reaction system due to the use of hydrochloric acid and the by-product of water at the same time as the generation of DCC, the separation of the aqueous phase and the organic phase after the reaction is performed. Further, complicated post-treatment such as drying of the separated organic phase is required. Therefore, the method (2) is hardly an industrially advantageous production method.

It is an object of the present invention to provide an image processing system such as DCC,
A chlorinated aromatic compound having a structure in which a dihydrocarbyl-1-chloromethyl group is bonded to an aromatic ring, a structure in which a 1,1-dihydrocarbyl-1-hydroxymethyl group is bonded to an aromatic ring, such as DIOL; Can be easily and efficiently produced from an aromatic alcohol having
It is to provide an industrially advantageous production method.

[0008]

The above object is achieved by the following general formula (1):

[0009]

Embedded image ^{Ar [-C (-R 1) (} - R 2) (- OH)] n (1)

[In the formula, Ar represents an n-valent aromatic group having a free valence at n carbon atoms of the atoms constituting the aromatic ring, and R ¹ and R ² each have a substituent. Represents an optionally substituted monovalent hydrocarbon group (provided that when n is an integer of 2 or more, n groups R ¹ contained in the molecule may be different from each other, n number of radicals R ² may be different respectively) which, n represents an integer of 1 or more]

Wherein the aromatic alcohol represented by the general formula (2) is reacted with an organic acid chloride.

[0012]

Embedded image Ar [—C (—R ¹ ) (— R ² ) (— Cl)] n (2)

(Wherein, Ar, R ¹ , R ² and n are as defined above)

This is achieved by providing a method for producing a chlorinated aromatic compound represented by the formula:

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the aromatic alcohol represented by formula (1) used in the present invention, n represented by Ar
Examples of the monovalent aromatic group include a monovalent aromatic hydrocarbon group such as a phenyl group and a tosyl group; a phenylene group (p-, m-
-Or o-), a divalent aromatic hydrocarbon group such as a methylphenylene group and a t-butylphenylene group; and a trivalent aromatic hydrocarbon group such as a 1,3,5-benzenetriyl group. . Examples of the monovalent hydrocarbon group which may have a substituent represented by R ¹ and R ² include, for example, a lower alkyl group such as a methyl group and an ethyl group; Examples thereof include a substituted lower alkyl group in which an atom is substituted with a chlorine atom or the like. n is a group represented by the formula -C (-R ¹ ) (-R ² ) (-
OH), and is not particularly limited as long as it is an integer of 1 or more. The purpose is to obtain a compound suitable as a cationic polymerization initiator as a chlorinated aromatic compound represented by the general formula (2). Is usually an integer in the range of 1 to 6. Representative examples of the aromatic alcohol represented by the general formula (1) used in the present invention include α, α-dimethylbenzenemethanol, α, α, α ′, α′-tetramethyl-
1,4-benzenedimethanol (DIOL), α, α,
α ′, α′-tetramethyl-1,3-benzenedimethanol, α, α, α ′, α′-tetramethyl-5- (1,
1-dimethylethyl) -1,3-benzenedimethanol, α, α, α ′, α ′, α ″, α ″ -hexamethyl-
1,3,5-benzenetrimethanol and the like.

The organic acid chloride used in the present invention is a compound having a structure in which a hydroxyl group in an acidic group of an organic acid such as carboxylic acid and sulfonic acid is substituted with a chlorine atom. As the organic acid chloride, for example, carboxylic acid chlorides such as formic acid chloride, acetic acid chloride and trifluoroacetic acid chloride; and sulfonic acid chlorides such as methanesulfonic acid chloride, trifluoromethanesulfonic acid chloride and p-toluenesulfonic acid chloride are used. Preferably,
It is more preferable to use sulfonic acid chloride as exemplified above. In the present invention, it is desirable to use the organic acid chloride in such an amount that the molar ratio of the organic acid chloride to the hydroxyl group to be converted into the chlorine atom contained in the aromatic alcohol used is 0.8 times or more. Even if the organic acid chloride is used in a large excess amount, for example, twice or more moles with respect to the hydroxyl group to be converted to a chlorine atom contained in the aromatic alcohol, the reaction itself is not hindered, but the large excess is used. Since the use of the amount is not only meaningless but may reduce the efficiency of the treatment operation, the amount of the organic acid chloride is usually 0.8 to the hydroxyl group to be converted to the chlorine atom contained in the aromatic alcohol. It is preferable to use the compound in an amount such that the ratio is within a range of 1.5 to 1.5 times the molar amount.

The reaction between the aromatic alcohol and the organic acid chloride according to the present invention is not necessarily limited,
The reaction is preferably carried out in the presence of an organic solvent, and the starting compound (aromatic alcohol and organic acid chloride) present in the reaction system is substantially converted into an organic solvent in that the reaction can be carried out at a high rate under a stable condition. More preferably, it is carried out under conditions that completely dissolve it. Examples of the organic solvent usable in the reaction between the aromatic alcohol and the organic acid chloride include, for example, pentane, cyclopentane, neopentane, hexane, heptane, octane, cyclohexane, norbornane, methylcyclohexane, and ethylcyclohexane. Aromatic hydrocarbon solvents such as benzene, toluene, xylene and ethylbenzene; halogenated hydrocarbon solvents such as carbon tetrachloride, chloroform, methylene chloride, chloroethane, dichloroethane, propyl chloride and butyl chloride; acetone, methyl ethyl ketone and diethyl ketone Ketone solvents such as
Examples include ether solvents such as diethyl ether, dimethyl ether, and tetrahydrofuran. Among them, halogenated hydrocarbon solvents, ether solvents and the like are preferred from the viewpoint of high solubility in aromatic alcohols and organic acid chlorides as raw materials. There is no particular limitation on the amount of the organic solvent used, but in view of the fact that the reaction can be performed at a high rate under a stable condition, the aromatic alcohol and the organic acid chloride as the raw materials are substantially completely dissolved. Although it is preferable to obtain the amount, it is disadvantageous to use an unnecessarily large amount, such as an increase in the size of the device and a decrease in the operation efficiency. Therefore, it is necessary to appropriately determine the amount of use in consideration of these points. Good.

The operation of the reaction between the aromatic alcohol and the organic acid chloride according to the present invention is not particularly limited as long as the aromatic alcohol can be brought into contact with the organic acid chloride. For example, as a method of performing a reaction in the presence of an organic solvent, a method of preparing an organic solvent solution containing an aromatic alcohol and an organic acid chloride, and reacting the solution with stirring, a method of stirring an aromatic alcohol organic solvent solution And a method of reacting while adding an organic acid chloride or an organic solvent solution thereof.

In the reaction of the aromatic alcohol and the organic acid chloride according to the present invention in the presence or absence of an organic solvent, other additives may be added to the reaction system, if necessary. For example, when a basic substance, an inorganic chloride or the like is blended, the reaction rate may be improved in some cases. Examples of the basic substance include amines, pyridines, and the like. When an organic solvent is used, a substance that can be dissolved in the organic solvent is preferable. As the pyridines,
For example, one or more kinds of pyridine, 2,6-lutidine, N, N-dimethyl-4-aminopyridine (hereinafter sometimes referred to as “DMAP”) can be used. When a basic substance is used, it is usually sufficient that the amount of the basic substance is 1.5 times or less the molar amount of the hydroxyl group to be converted into a chlorine atom in the aromatic alcohol used. Further, as the inorganic chloride, for example, a metal chloride such as lithium chloride, hydrogen chloride or the like can be used. When an inorganic chloride is used, it is usually sufficient that the amount of the inorganic chloride used is 1.5 times or less the molar amount of the hydroxyl group to be converted into a chlorine atom in the aromatic alcohol used.

The reaction between the aromatic alcohol and the organic acid chloride according to the present invention is preferably carried out at such a temperature that these starting compounds and the target chlorinated aromatic compound do not undergo a side reaction such as a decomposition reaction. Therefore, although the optimum reaction temperature varies depending on the starting compound and the target compound, usually, the temperature condition can be appropriately set at a temperature of about room temperature or lower, and a range of about −10 ° C. to about + 10 ° C. It is good to adopt the temperature inside.

The reaction according to the present invention is not necessarily limited, but is preferably carried out in an atmosphere of a dry inert gas, for example, under a stream of the inert gas, under a pressure by the inert gas, or the like. Can be done with Examples of the inert gas include nitrogen and argon.

When the reaction according to the present invention is carried out in the presence of an organic solvent, even if the reaction is initially in the form of a homogeneous solution, insolubles such as supersaturated chlorinated aromatic compounds formed as the reaction proceeds. May be deposited and the reaction system may be non-uniform, but the state in which the contact between the starting compounds (aromatic alcohol and organic acid chloride) is sufficiently performed is maintained by performing sufficient stirring. As long as there is no particular problem.

The time required for the reaction according to the present invention depends on the reaction temperature, the type of aromatic alcohol, the type of organic acid chloride,
It is not necessarily uniform depending on the type of organic solvent, the type and amount of other additives, but is usually 0.1 to 20.
Within the time range.

By the reaction according to the present invention, a chlorinated aromatic compound having a structure in which the hydroxyl group in the aromatic alcohol used is substituted with a chlorine atom is produced. Representative examples of the chlorinated aromatic compound include (1-chloro-1-methylethyl) benzene and 1,4-bis (1-chloro-1-
Methylethyl) benzene (DCC), 1,3-bis (1
-Chloro-1-methylethyl) benzene, 1,3-bis (1-chloro-1-methylethyl) -5- (1,1-dimethylethyl) benzene, 1,3,5-tris (1-chloro- 1-methylethyl) benzene and the like.

Since the chlorinated aromatic compound produced as described above has high crystallinity in many cases, the obtained reaction mixture is subjected to an operation such as filtration, if necessary, and then recrystallized. It is possible to easily separate and purify by the above operation. Even if the crystallinity is not high, the reaction mixture is washed with water as necessary, and then subjected to operations such as distillation and column chromatography to separate and purify the target chlorinated aromatic compound. It is possible to Unreacted aromatic alcohol may be recovered in the above separation operation, and the recovered aromatic alcohol can be reused for the reaction with the organic acid chloride.

[0026]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Tetrahydrofuran 300 stirred at 0 ° C. under a nitrogen stream
pyridine, 89.0 ml (1.10 mol) in a mixed solution consisting of 99.1 g (0.50 mol) of DIOL and
A mixed solution comprising 6.1 g (0.05 mmol) of DMAP, 227.3 g (1.10 mol) of p-toluenesulfonic acid chloride and 300 ml of tetrahydrofuran was added, and the mixture was stirred at 0 ° C. for 5 hours. The obtained reaction mixture was filtered, and the filtrate was allowed to stand at −20 ° C. for 12 hours to precipitate DCC. The DCC thus obtained was 101.7 g (0.44 mol, yield 88
%)Met. The obtained DCC was analyzed by ¹ H-NMR.
(400 MHz, Lambda 400 manufactured by JEOL Ltd.), it was found that the purity was 99% or more.

Example 2 In a mixture of 1 liter of tetrahydrofuran and 97.1 g (0.50 mol) of DIOL while stirring at 0 ° C. under a nitrogen stream, 89.0 ml (1.10 mol) of pyridine were added.
A mixed solution consisting of 6.1 g (0.01 mmol) of DMAP, 126.0 g (1.10 mol) of methanesulfonic acid chloride and 46.6 g (1.1 mmol) of lithium chloride was added, and the mixture was stirred at 0 ° C. for 10 hours. Was done. The obtained reaction mixture was filtered, and the filtrate was concentrated under reduced pressure at a temperature of about 30 ° C. to about 500 ml. Concentrate to -2
The DCC was precipitated by allowing to stand at 0 ° C. for 12 hours. DCC obtained in this way is 80.7 g
(0.35 mol, 70% yield). As a result of analyzing the DCC in the same manner as in Example 1, the purity was 9%.
It turned out to be 9% or more.

Example 3 In a mixture of 1 liter of methylene chloride and 97.1 g (0.50 mol) of DIOL, stirred in a nitrogen stream at 0 ° C., 89.0 ml (1.10 mol) of pyridine, DMA
A mixed solution consisting of 6.1 g (0.01 mmol) of P and 227.3 g (1.10 mol) of p-toluenesulfonic acid chloride was added, and the mixture was stirred at 0 ° C. for 10 hours. The resulting reaction mixture was filtered, and the filtrate was concentrated under reduced pressure for 30 minutes.
It was concentrated at a temperature of about 100C to about 100 ml. By treating the concentrate with 2 liters of hexane, the D
CC was precipitated. The DCC thus obtained was 87.8 g (0.38 mol, yield 76%). As a result of analyzing this DCC in the same manner as in Example 1, it was found that the purity was 99% or more.

Example 4 Tetrahydrofuran 300 stirred at 0 ° C. under a nitrogen stream
ml of p-toluenesulfonic acid chloride in a mixture of 97.1 g (0.50 mol) of DIOL and 97.1 g (0.50 mol) of DIOL.
3 g (1.10 mol) and 300 ml of tetrahydrofuran
Was added, and the mixture was stirred at 0 ° C. for 5 hours. About 300 ml of the resulting reaction mixture was
And concentrated to. The concentrated solution was allowed to stand at −20 ° C. for 12 hours to precipitate DCC. The DCC thus obtained was 62.4 g (0.27 mol, yield 54%). The solution after removing the DCC precipitated from the concentrated solution was further concentrated and treated with a mixed solvent of hexane / tetrahydrofuran to precipitate unreacted DIOL, which was collected. The recovered DIOL was 36.9 g (0.19 mol, recovery rate 38%)
Met. In addition, the above DCC and recovered DIO
L was analyzed in the same manner as in Example 1, and as a result, it was found that the purity was 99% or more in each case.

[0031]

According to the reaction according to the present invention, a 1,1-dihydrocarbyl-1-chloromethyl group is converted from an aromatic alcohol having a structure in which a 1,1-dihydrocarbyl-1-hydroxymethyl group is bonded to an aromatic ring. A chlorinated aromatic compound having a structure bonded to an aromatic ring is converted into a waste liquid that requires inefficient treatment, such as hydrochloric acid, without using hydrogen chloride gas, which is inferior in handling property and imposes restrictions on equipment. The compound can be synthesized without generation and without complicated post-treatments such as liquid separation and drying. Therefore,
According to the present invention, there is provided an industrially advantageous production method capable of easily and efficiently producing the chlorinated aromatic compound from the aromatic alcohol.

Claims (1)

[Claims] 1. General formula (1): Ar [—C (—R ¹ ) (— R ² ) (— OH)] n (1) wherein Ar is an atom constituting an aromatic ring Represents an n-valent aromatic group having a free valence at n carbon atoms, and R ¹
And R ² each represent a monovalent hydrocarbon group which may have a substituent (provided that, when n is an integer of 2 or more, n groups R ¹ contained in the molecule are different from each other) And the n groups R ² contained in the molecule may be different from each other), and n represents an integer of 1 or more.
A general formula (2) characterized by reacting an aromatic alcohol represented by the following formula with an organic acid chloride: Ar [-C (-R ¹ ) (-R ² ) (-Cl)] n (2 (Wherein, Ar, R ¹ , R ² and n are as defined above).