JPH1160550A - Production of sulfonyloxytropone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful as a laser-absorption pigment of high purity in high yield through an industrially simple process by subjecting a tropolone to a specific treatment followed by sulfonylation reaction of the treated tropolone without isolation. SOLUTION: A compound of formula I (R<1> -R<5> are each H and the like; X<1> and X<2> are each a halogen) as 7,7-dichlorobicyclo[3.2.0]hepto-2-ene-6-one, is allowed to react with a base as sodium hydroxide in a solvent as acetic acid to form a tropolone of formula II as tropolone. The reaction mixture without isolation of the tropolone is acidified by using a mineral acid as hydrochloric acid and extracted with an organic solvent as toluene or the like. Then, the extract is washed with a washing solution mainly comprising water as a saturated sodium chloride solution to remove the acidic components. Without removal of the compound of formula II, the remaining extract is subjected to sulfonylation reaction to prepare the objective compound of formula III [R<6> is a (substituted) aliphatic group], typically 2-(p-toluenesulfonyloxy) tropone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing sulfonyloxytropones. Sulfonyloxytropones are important synthetic raw materials for azulene useful as laser recording dyes, liquid crystal devices, optical recording materials such as electrophotographic photoreceptors, organic conductors, catalyst ligands, pharmaceuticals, dyes and the like.

[0002]

2. Description of the Related Art Tropons having a substituent at the 2-position are important synthetic raw materials for various fine chemicals. Among them, sulfonyloxytropones are the most important intermediates and are convenient and suitable for industrial production. There is a demand for a manufacturing method. For example, 2- (p-toluenesulfonyloxy) tropone, which is one of sulfonyloxytropones, can be synthesized by reacting tropolone with p-toluenesulfonyl chloride in the presence of a base such as triethylamine. I can do it.

However, tropolone, which is the most useful raw material, has a problem that it is difficult to handle, for example, its melting point is as low as about 50 ° C., and it has a phenolic hydroxyl group and is easily oxidized. Also, for example, Or
g. Synth. , Coll. Vol. , 4,1037
In a general method for synthesizing tropolone described in (1963), high-purity tropolone is obtained by distillation under reduced pressure. However, we tried this method again,
Examination of the isolation method of tropolone revealed that tropolone thermally decomposes at around 130 ° C., which requires a high degree of reduced pressure in order to purify by distillation while suppressing decomposition, and is not suitable for industrial production. I understand. For example, even at 110 ° C., a reduced pressure of 10 mmHg was required, and it was found that this was not an industrially advantageous method.

[0004] Further, as one method of isolating by avoiding distillation, recrystallization from a solution, for example, a method of adding a poor solvent such as hexane to a solution of toluene or tetrahydrofuran has been studied. As a result, crystals did not precipitate, and tropolone could not be isolated. For these reasons, it has been difficult to produce sulfonyloxytropones on an industrial scale from tropolone as a raw material.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for industrially and advantageously producing sulfonyloxytropones. Another purpose is
An object of the present invention is to provide a method for obtaining sulfonyloxytropones in high yield by preventing the decomposition of tropolones.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have determined that tropolone which is a problem can be continuously subjected to a sulfonylation reaction without isolation, It has been found that sulfonyloxytropones can be obtained in good yield by performing the above treatment, and the present invention has been completed. That is, the present invention provides the following formula (1)

[0007]

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(Wherein, R ¹ to R ⁵ each independently represent a hydrogen atom, a halogen atom or an aliphatic or aromatic hydrocarbon group which may have a substituent,
X ¹ and X ² represent a halogen atom. However, R ^{1 to} R ⁵ may be arbitrarily combined to form a ring. The compound represented by the following formula (2) is reacted with a base in a solvent.

[0009]

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(Wherein R ¹ to R ⁵ have the same meanings as in formula (1)), and the compound of formula (2) is extracted with an organic solvent. The solution was subjected to an operation for removing an acid component, and then subjected to a sulfonylation reaction without isolating the compound of the formula (2) from the extract to obtain a compound of the following formula (3)

[0011]

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(Wherein, R ¹ to R ⁵ have the same meaning as in formula (1), and R ⁶ represents an aliphatic or aromatic hydrocarbon group which may have a substituent). The production of sulfonyloxytropones, which is characterized by producing sulfonyloxytropones, and the reaction of a compound represented by formula (1) with a base in a solvent gives a compound represented by formula (2). Are obtained, and after extracting the compound of formula (2) with an organic solvent,
The extract is washed with a water-based washing solution,
A method for producing a sulfonyloxytropone represented by the formula (3) by subjecting a compound of the formula (2) to a sulfonyl substitution reaction without isolation from an extract solution. is there.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(Precursor) The compound represented by the formula (1) used in the method of the present invention is described in, for example, Org. Synth. , C
all. Vol. , 4, 1037 (1963), by reacting cyclopentadiene with dichloroacetyl chloride in the presence of a base. The compound used as a raw material in the present invention is specifically represented by the following formula (1)

[0014]

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Is a compound represented by the formula: R in the formula (1)
¹Or R^FiveSpecific examples of a hydrogen atom and a halogen atom
Lower alkyl such as methyl, methyl, ethyl, isopropyl, etc.
Substitution of a kill group, fluoromethyl group, methoxymethyl group, etc.
Alkyl group, phenyl group, p-chlorophenyl group, p-
Substituted aryl groups such as tolyl group and p-methoxyphenyl group
And further R ¹Or R^FiveAre paired with each other
Together they may form a cyclic substituent. Also,
X¹, X^TwoAs a specific example, halogen such as Cl and Br
Atoms. Specific compound names include 7,7
-Dichlorobicyclo [3.2.0] hept-2-ene-
6-one, 3-isopropyl-7,7-dichlorobisic
B [3.2.0] hept-2-en-6-one, 7,7
-Dichloro-2,3-benzobicyclo [3.2.0]-
6-heptanone and the like.

(Method for Producing Tropolones) As a method for producing a tropolone represented by the formula (2) from a compound of the formula (1), for example, as described in the above-mentioned literature, a solvent such as acetic acid is used. A method of reacting a compound of the formula (1) with a base is mentioned.

[0017]

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(Wherein, R ¹ to R ⁵ have the same meanings as in formula (1).) As the solvent used here, a lower carboxylic acid such as acetic acid or propionic acid may be used alone or as a mixture at an arbitrary ratio. Can be used. Also, the amount used is usually the formula (1)
5 to 100-fold molar amount, preferably 10-fold molar amount to compound
To 50 times the molar amount. Further, the solvent may contain water in an amount of about 1 to 100 times the molar amount of the compound of the formula (1).

As the base to be used, sodium hydroxide, potassium hydroxide, ammonia, sodium acetate, potassium acetate, ammonium acetate, triethylamine and the like can be used. The amount of the compound to be used is generally 2 to 10 times the molar amount of the compound of the formula (1), preferably 2 to 7 times the molar amount in view of the reaction rate and economy. The reaction temperature and pressure may be any reaction temperature and pressure at which the system can maintain a liquid phase, but from the viewpoint of reaction rate and economy, it is sufficient to perform the reaction at normal pressure and near the boiling point of the solvent used.

The reaction time varies depending on the concentration, the type of base and the amount used, but is usually 1 to 20 hours. The generated tropolone is usually extracted with an organic solvent after acidifying the reaction solution with a mineral acid such as hydrochloric acid and sulfuric acid,
This is an extract of tropolone. Examples of the solvent used for the extraction include hydrocarbon-based, ether-based, and halogen-based solvents such as toluene, xylene, diethyl ether, dibutyl ether, dichloromethane, chloroform, and chlorobenzene. Usually, toluene and dichloromethane are used. The extraction solvent is usually used alone,
A mixture of more than one species may be used.

(Method of subjecting a tropolone to a sulfonylation reaction without isolation) Then, the tropolone obtained by this reaction is subjected to a sulfonylation reaction to convert the sulfonyloxytropone represented by the formula (3). To manufacture.

[0022]

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(Wherein, R ¹ to R ⁵ have the same meaning as in formula (1), and R ⁶ represents an aliphatic or aromatic hydrocarbon group which may have a substituent.) In the technique described in the above, after the obtained extract of tropolone is concentrated, the tropolone is distilled under reduced pressure, or the tropolone is crystallized by an operation such as cooling or adding a poor solvent. And subjected to the next sulfonylation reaction. However, in this method, as described above, it is difficult to safely distill tropolone on an industrial scale, and the obtained tropolone is also difficult to handle.

On the other hand, in the present invention, the obtained tropolone is subjected to an acid content removing operation, distillation and washing with a washing solution without isolation, and is then subjected to another concentration after being subjected to the same concentration or concentration. The solvent is added and subjected to the subsequent sulfonylation reaction. In this case, "without isolation" means that, unlike the conventional method, the produced tropones are not separated as a high-purity product.Therefore, the reaction product liquid is used as it is, and some intermediate crystals are precipitated. However, it does not mean that this is the case, without being separated.

More specifically, as a method for removing acid components, a high-boiling extraction solvent is used, and the acid components (mineral acids such as acetic acid which is a commonly used solvent and hydrochloric acid added after the reaction) are distilled off. There are ways to remove it. Further, the obtained extract of tropolone can be washed with a washing solution containing water as a main component. Preferably, the latter method is used. Normally,
An aqueous solution near the saturated concentration of salts such as sodium chloride or sodium sulfate is used. The used amount is 1/30 to 1/5 times the volume of the extract of tropolone, and it may be washed three or four times.

The extract after washing may be used as it is, or the concentration of tropolone may be reduced from 1 to 5 by a concentration operation.
After increasing to about 0% by weight, it is subjected to the subsequent sulfonylation reaction. It is preferable to perform a concentration operation from the viewpoint of productivity and the like. The concentration of the concentrated solution may be such that the reaction solution can be stirred. Even if the tropolone is not completely dissolved before the reaction, if the tropolone is partially dissolved, no problem occurs in the reaction.
Here, if necessary, the extract may be concentrated and then subjected to a sulfonylation reaction by adding a solvent different from the extraction solvent. The solvent used in this case includes, for example, tetrahydrofuran.

(Sulfonylation Reaction) The subsequent sulfonylation reaction is usually carried out by mixing a sulfonylating agent as described later in the obtained tropolone solution and then adding a tertiary amine. It is sufficient that these three components are brought into contact in a solvent, and any of a method of adding one component remaining in the presence of two components and a method of adding two components remaining in the presence of one component may be used. The concentration of the tropolone used for the reaction in the solution is usually 1 to 50% by weight, preferably 1 to 20% by weight. The sulfonylating agent used in the present invention has the following formula (4):

[0028]

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(Wherein, R ⁶ represents an aliphatic or aromatic hydrocarbon group which may have a substituent, R ⁷ represents a halogen atom,
It represents an alkoxy group or an aryloxy group which may have a substituent, or a sulfonyloxy group having an aliphatic or aromatic hydrocarbon group which may have a substituent. ).

Specific examples of R ⁶ in the formula (4) include a lower alkyl group such as a methyl group and an ethyl group, a lower substituted alkyl group such as a trifluoromethyl group and a methoxymethyl group, a phenyl group and an o-tolyl group. , P-tolyl group, p-fluorophenyl group, p-methoxyphenyl group and other (halo) aryl groups. Specific examples of R ⁷ include C
a halogen atom such as l or Br, or a lower (halo) alkoxy group such as a methoxy group, an ethoxy group, a trifluoromethoxy group, a methoxymethoxy group, a phenoxy group, an o-tolyloxy group, a p-tolyloxy group, or a p-fluorophenoxy group And a (halo) allyloxy group such as a p-methoxyphenoxy group, and a sulfonyloxy group such as a methanesulfonyloxy group, an o-toluenesulfonyloxy group, a p-toluenesulfonyloxy group, and a trifluoromethanesulfonyloxy group. Commonly used sulfonylating agents include methanesulfonyl chloride, p-toluenesulfonyl chloride, trifluoromethanesulfonyl chloride, methyl p-toluenesulfonate, methanesulfonic anhydride, p-toluenesulfonic anhydride, trifluoromethanesulfonic acid Anhydrides. If R ⁶ is the same, the structure of the tropolone to be formed is the same, so that there is no problem even if R ⁷ is a mixture of two or more kinds. The amount of the sulfonylating agent required to complete the reaction may theoretically be equimolar to that of the tropolone, but is usually 0.9 to 10.0-fold, preferably 1.0 to 1.0.
To 1.2-fold molar.

The tertiary amine used in the sulfonylation reaction in the present invention is not particularly limited as long as it does not generate water by neutralization, but is preferably one that is mixed with an organic solvent or one that is in a liquid state. Preferably, a tertiary organic base is usually used. Specific examples include triethylamine, trimethylamine, N, N-dimethylaniline,
N, N-diethylaniline, pyridine and the like can be mentioned.
These tertiary amines may be used alone or as a mixture of two or more. The amount of the tertiary amine to be used is usually 0.5 to the sulfonylating agent.
To 30-fold molar, preferably 1.0 to 3.0-fold molar.

It is also possible to use a tertiary amine species as a solvent. In this case, the tropolone extract is concentrated, mixed with a tertiary amine in a solvent amount, and then reacted with a sulfonylating agent. Should be performed. The reaction temperature is usually -50 to 100C, preferably 0 to 50C. When the reaction temperature is low, the reaction takes a long time. On the other hand, when the reaction temperature is too high, a side reaction may occur, which may be a factor that lowers the yield. The reaction time varies depending on the conditions, but usually 1 to 20 hours, preferably 2 to 5 hours is sufficient.

The reaction pressure is not particularly limited and is usually carried out under normal pressure, but the reaction may be carried out under a pressure of 0.1 to 10 kg / cm ² or under a reduced pressure in consideration of the boiling point of the solvent. The resulting sulfonyloxytropones are brought into high purity by contacting the reaction solution with water, hydrolyzing an unreacted sulfonylating agent, filtering, washing with a solvent such as water or ethanol, and then drying. It can be manufactured easily.

[0034]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist. Comparative Example 1070 ml of acetic acid was charged into a 5 L glass flask, heated to 90 to 100 ° C., 242 g of sodium hydroxide was charged, and after confirming that sodium hydroxide was dissolved, 7,7-dichlorobicyclo [3. 2.0]
214.2 g of hept-2-en-6-one was charged. After the reaction was carried out for 10 hours under heating and reflux, the mixture was cooled to 55 ° C., 444 g of 35% hydrochloric acid was added, and 1.7 L of toluene was added, followed by stirring for 30 minutes. After filtering the reaction solution, the solid was washed three times with 230 ml of toluene,
The mixture was separated with the washing solution and the filtrate.

Further, the aqueous layer was extracted three times with 1.7 L of toluene to obtain 139.2 g (1.1%) of tropolone.
A toluene solution containing 3 mol (yield 94.2%) was obtained (this solution is referred to as toluene solution A). From the toluene solution A, an amount containing 1.0 g of tropolone was fractionated and concentrated by a rotary evaporator as it was until toluene almost disappeared. This concentrated solution is p-
It was dissolved in 4.0 g of tetrahydrofuran together with 1.64 g of toluenesulfonyl chloride. Subsequently, 0.96 g of triethylamine was added dropwise at 20 to 30 ° C. over 30 minutes. After the completion of dropping, the temperature in the system is reduced from 20 to 3 for about 4 hours.
It was kept at 0 ° C. As a result of analyzing the reaction solution by HPLC,
All tropolone had been converted. Then 11.5 water
g was added and stirred for an additional hour. The precipitated crystals were collected by filtration and washed three times with 2.3 g of ethanol.
After drying, 1.38 g (yield 61%, purity 100%) of 2- (p-toluenesulfonyloxy) tropone was obtained.

(Example) About 2870 ml of the toluene solution A obtained as described in the first half of the comparative example was collected and washed four times with 250 g of a saturated saline solution. The water layer after washing at this time was acidic (pH 1 or 2), and it can be seen that the acid component was removed from the toluene solution A. Thereafter, this toluene solution was concentrated until almost no toluene was present. This concentrated liquid (containing 48.3 g of tropolone) and 79.3 g of p-toluenesulfonyl chloride were dissolved in 139 ml of tetrahydrofuran. Then, from 20 to 30
At 6.5C, 46.5 g of triethylamine was added dropwise over 30 minutes. After the completion of the dropping, the temperature in the system is set to 20 to 30 for about 5 hours.
C. As a result of analyzing the reaction solution by HPLC, all tropolone was converted. Thereafter, 417 g of water was added, and the mixture was further stirred for 1 hour. More ethanol 1
After adding 77 ml and stirring for 30 minutes, the precipitated crystals were collected by filtration, washed twice with 119 ml of water and three times with 142 ml of ethanol, dried and dried, and dried with 2- (p-toluenesulfonyloxy) tropone. 7 g (yield 73
%, Purity 99.2%). From these results, it can be seen that the target sulfonyloxytropones can be obtained in a higher yield by washing the extract of tropolone with a saturated saline solution than in the case where the extract is not used.

[0037]

The tropolone, which is unstable and difficult to handle and is difficult to produce industrially, is subjected to a sulfonylation reaction without being taken out, so that a highly pure sulfonyloxytropone can be obtained in an industrially simple manner. Could be produced in high yield.

Continued on the front page (72) Inventor Ken Ken Oue 1-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City Inside the Mitsubishi Chemical Corporation Kurosaki Office

Claims (11)

[Claims] [Claim 1] The following formula (1) (Wherein, R ¹ to R ⁵ each independently represent a hydrogen atom, a halogen atom or an aliphatic or aromatic hydrocarbon group which may have a substituent, and X ¹ and X ² represent a halogen atom. Provided that R ^{1 to} R ⁵ are arbitrarily bonded,
A ring may be formed. )) In a solvent,
By reacting with a base, the following formula (2) (In the formula, R ¹ to R ⁵ have the same meaning as in formula (1).)
The tropolone represented by the formula is obtained, the compound of formula (2) is extracted with an organic solvent, the extract is subjected to an operation of removing the acid component, and then the compound of formula (2) is isolated from the extract. Without subjecting it to a sulfonylation reaction to give the following formula (3): (Wherein, R ¹ to R ⁵ have the same meaning as in formula (1);
⁶ represents an aliphatic or aromatic hydrocarbon group which may have a substituent. A method for producing sulfonyloxytropones, characterized by producing the sulfonyloxytropones represented by the formula: 2. The method for producing sulfonyloxytropones according to claim 1, wherein the operation of removing the acid component is a distillation operation. 3. The method for producing sulfonyloxytropones according to claim 1, wherein the operation of removing the acid content is a cleaning operation using a cleaning solution containing water as a main component. 4. The following formula (1) (Wherein, R ¹ to R ⁵ each independently represent a hydrogen atom, a halogen atom or an aliphatic or aromatic hydrocarbon group which may have a substituent, and X ¹ and X ² represent a halogen atom. Provided that R ^{1 to} R ⁵ are arbitrarily bonded,
A ring may be formed. )) In a solvent,
By reacting with a base, the following formula (2) (In the formula, R ¹ to R ⁵ have the same meaning as in formula (1).)
Is obtained by extracting the compound of formula (2) with an organic solvent, washing the extract with a washing solution mainly composed of water, and then extracting the compound of formula (2) from the extract.
Subjecting the compound to a sulfonylation reaction without isolation,
The following formula (3) (Wherein, R ¹ to R ⁵ have the same meaning as in formula (1);
⁶ represents an aliphatic or aromatic hydrocarbon group which may have a substituent. A method for producing sulfonyloxytropones, characterized by producing the sulfonyloxytropones represented by the formula: 5. The method for producing sulfonyloxytropones according to claim 4, wherein the washing liquid containing water as a main component is an aqueous solution containing an inorganic salt. 6. The method for producing sulfonyloxytropones according to claim 4, wherein the cleaning liquid containing water as a main component is an aqueous solution containing a saturated amount of an inorganic salt. 7. The method for producing sulfonyloxytropones according to claim 5, wherein the inorganic salt is sodium chloride or sodium sulfate. 8. The method according to claim 1, wherein R ⁶ is a p-tolyl group.
A method for producing a sulfonyloxytropone according to any one of the above. 9. R ¹ to R ⁵ are hydrogen atoms,
The method for producing a sulfonyloxytropone according to any one of claims 1 to 8, wherein X ¹ and X ² are base atoms. 10. A tropone represented by the formula (2) is reacted with a sulfonylating agent in the presence of an organic base to produce a compound represented by the formula (3):
The method for producing a sulfonyloxytropone according to any one of claims 1 to 9, wherein a sulfonyloxytropone represented by the following formula is obtained. 11. The method for producing a sulfonyloxytropone according to claim 10, wherein the organic base is triethylamine or pyridine.