JPH09194471A - 2,5-diarylfuran derivative and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce the subject compound useful as a fluorescent agent in a simple manner by dimerizing an acetophenone derivative under photoirradiation in the presence of phenol followed by dewatering cyclization. SOLUTION: 2,5-Diarylfuran derivative of formula I [R<1> and R<2> are each carboxy or methyoxycarbonyl; (m) and (n) are each an integer of 1-5] is produced by dimerizing an acetophenone derivative of formula II under photoirradiation in the presence of a catalytic amount of phenol and subjecting the obtained 1,4-diarylbutane-1,4-dione of formula III to dewatering cyclization in the presence of an acid catalyst. The acid catalyst is preferably boron trifluoride or sulfuric acid.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel 2,5-diarylfuran derivative and a method for producing the same. The 2,5-diarylfuran derivative of the present invention is useful as a novel fluorescent agent.

[0002]

2. Description of the Related Art As a compound similar to the 2,5-diarylfuran derivative having a carboxyl group or a methoxycarbonyl group of the present invention, 2,5-di (p-ethoxycarbonylphenyl) furan (Registration No. 61829-94-5).
It has been known. As a method for synthesizing this compound, 1, obtained by reacting fumaric acid chloride with bromobenzene,
4-di (p-bromophenyl) -2-butene-1,4-
The dione is reduced with metallic zinc to give 1,4-di (p-bromophenyl) butane-1,4-dione, which is then dehydrated and ring-closed with concentrated sulfuric acid to give 2,5-di (p-bromophenyl) butane. After that, this bromine group is sequentially cyano group,
Then, a method of converting into an ethoxycarbonyl group is described in, for example, Journal of Medical Chemistry (J.M.
ed. Chem. ), Volume 20 (4), Page 531 (1
977). However, this method is complicated and has a long process, and this product is only used as an intermediate for another compound, and no mention is made of its own properties or usage.

In addition, 1,4-diarylbutane-1,4-dione, which is an intermediate in the above reaction step, is converted to an acetophenone derivative or its silyl enol ether as an enolate, and then oxidatively dihydrated with copper chloride or silver oxide. A simple method of quantification is described in, for example, Journal of American Chemical Society (J. Am. Chem. Soc.), Vol. 97, No. 64.
9 and 2912 (1975), but this method is not practical because it uses a strong base such as lithium diisopropylamide in the preparation of silyl enol ethers or enolates. When applied to an acetophenone derivative having a carboxyl group or a methoxycarbonyl group, it may cause a side reaction, which is not preferable.

[0004]

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On the other hand, a method of dimerizing an acetophenone derivative such as p-methylacetophenone under light irradiation using a phenol as a catalyst is disclosed in, for example, Journal of Organic Chemistry (J. Org. Che.
m. ), 32, pp. 2140 (1967), etc., but no example of applying this method to the acetophenone derivative having a carboxyl group or a methoxycarbonyl group of the present invention has been known so far.

[0006]

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[0007]

As described above,
Although various methods have been disclosed for producing 5-diarylfuran derivatives, these methods are still insufficient from an industrial point of view. An object of the present invention is to provide a method for conveniently producing a 2,5-diarylfuran derivative and a corresponding acetophenone derivative or 1,4-diarylbutane-1,4-dione.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that by dimerizing an acetophenone derivative in the presence of a catalytic amount of phenol under light irradiation, , 4-diarylbutane-1,4
The present inventors have completed the present invention by finding that a 2,5-diarylfuran derivative can be easily and easily obtained by easily obtaining a dione and then subjecting it to a ring closure by dehydration in the presence of an acid catalyst. That is, the present invention provides a compound represented by the general formula (I):

[0009]

[Chemical 6]

(In the formula, R ¹ and R ² represent a carboxyl group or a methoxycarbonyl group, and may be the same or different, and m and n are integers of 1 to 5.) A 2,5-diarylfuran derivative represented by and a method for producing the same. Hereinafter, the compound of the present invention and the method for producing the same will be described in detail.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) 2,5-diaryl derivative The 2,5-diarylfuran derivative of the present invention has the general formula (I).

[0012]

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(In the formula, R ¹ and R ² represent a carboxyl group or a methoxycarbonyl group, and may be the same or different. M and n are integers of 1 to 5.) Is a compound represented by. Specific examples of the compound include 2,5-di (p-methoxycarbonylphenyl) furan, 2,5-di (3,4-dimethoxycarbonylphenyl) furan and 2,5-di (3,4,5).
-Trimethoxycarbonylphenyl) furan, 2,5-
Examples thereof include di (p-carboxyphenyl) furan, 2,5-di (3,4-dicarboxyphenyl) furan, and 2,5-di (3,4,5-tricarboxyphenyl) furan. The compound according to the present invention is useful as a fluorescent agent, and for example, polyethylene terephthalate produced by adding a trace amount of 2,5-di (p-methoxycarbonylphenyl) furan during the copolymerization of terephthalic acid and ethylene glycol. An improvement effect was observed in the polymerization b value of.

(2) Method for Producing 2,5-Diarylfuran Derivative The 2,5-diarylfuran derivative represented by the general formula (I) of the present invention can be produced by the acetophenone derivative (III) as shown in the reaction formula (1). Is dimerized under light irradiation in the presence of a catalytic amount of phenol to give 1,4-diaryl-
It is prepared by synthesizing 1,4-dione (II) and then subjecting this to dehydration ring closure in the presence of an acid catalyst as shown in the reaction formula (2).

[0015]

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(Photodimerization Reaction) The acetophenone derivative used in the photodimerization reaction may be any acetophenone derivative substituted with a methoxycarbonyl group, and the number and position of the substituents are not particularly limited. Specifically, 4
-Methyl acetylbenzoate, 3,4-di (methoxycarbonyl) acetophenone, 3,4,5-tri (methoxycarbonyl) acetophenone, 2,3,4,5-tetra (methoxycarbonyl) acetophenone, 2,3,4 ，
Examples thereof include 5,6-penta (methoxycarbonyl) acetophenone.

The solvent used for the photodimerization reaction of the acetophenone derivative may be inert as long as it is, for example, ketones such as acetone, ethyl methyl ketone and cyclohexanone, ethers such as tetrahydrofuran, diethyl ether and dibutyl ether, methyl alcohol. , Alcohols such as ethyl alcohol and butyl alcohol, (halo) aromatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene and dichlorobenzene, aliphatic or alicyclic hydrocarbons such as hexane, heptane and cyclohexane, dichloromethane , Halogenated hydrocarbons such as dichloroethane, chloroform, carbon tetrachloride, acetonitrile, water and the like. Among them, particularly when acetone is used, the target product is precipitated as crystals as it is formed, which is preferable from the viewpoint of separation and purification of the product.
The solvent is usually used in an amount of 1 to 20 times the volume of the acetophenone derivative.

Examples of the catalyst used for the photodimerization reaction of the acetophenone derivative include phenols such as phenol, cresol and xylenol. Further, these phenols may be added as they are, but those supported on a carrier such as silica gel or alumina may be used. In order to carry out the reaction simply, it is sufficient to use commercially available phenol as it is. The amount of the catalyst used is usually 0.1 to 2 equivalents, preferably 0.1 to the acetophenone derivative.
~ 0.5 equivalent.

The dimerization reaction of the acetophenone derivative is carried out in the presence of light, but any substance containing ultraviolet light may be used, and examples thereof include a high pressure mercury lamp, a low pressure mercury lamp and scattered light.
From the viewpoint of reaction rate and yield, it is preferable to carry out the reaction under light irradiation by a high pressure mercury lamp. The dimerization reaction of the acetophenone derivative is usually performed at -20 to 100 ° C, preferably 20 to 60 ° C. The reaction pressure may be any pressure as long as the reaction system maintains a liquid phase, and the reaction is usually performed at normal pressure, but the reaction may be performed under reduced pressure or increased pressure if desired. The reaction time varies depending on the reaction temperature or the irradiation amount of light, but is usually about 0.5 to 20 hours. In the photodimerization reaction of an acetophenone derivative, the easiest way is to charge an inert solvent, an acetophenone derivative and a catalyst in a photoreactor and perform light irradiation with or without stirring.

Separation and purification of 1,4-diarylbutane-1,4-dione from the reaction product solution can be carried out by any conventional separation and purification method, for example, when acetone is used as a solvent. With the progress of the reaction, only the target product is precipitated as crystals. Therefore, after the completion of the reaction, the precipitated crystals are collected by filtration, washed with an inert solvent such as acetone, and dried to obtain the desired 1,4-diarylbutane-1,4-dione in high purity. Can be done.

(Dehydration and Ring Closure Reaction) The acid catalyst used in the reaction for dehydration and ring closure of 1,4-diarylbutane-1,4-dione to obtain a 2,5-diarylfuran derivative is
For example, Bronsted acid such as sulfuric acid or toluenesulfonic acid, and Lewis acid such as boron trifluoride or zinc chloride may be mentioned. Sulfuric acid and boron trifluoride are preferably used. The acid catalyst is usually used in a large excess amount with respect to 1,4-diarylbutane-1,4-dione. Whether or not a solvent is used in the reaction for obtaining the 2,5-diarylfuran derivative is not particularly limited and may be determined according to the desired reaction mode. For example, when concentrated sulfuric acid or the like is used as an acid catalyst, no solvent is sufficient, and when boron trifluoride or the like is used as an acid catalyst, an appropriate solvent may be used for easy handling. The reaction is usually 0 to 200 ° C., preferably 50 to 1
Performed at 50 ° C. The reaction time varies depending on the temperature or the type and amount of the catalyst, but is usually 0.
It is 1 to 5 hours, preferably 0.5 to 2 hours, and in the case of boron trifluoride, it is usually 0.1 to 5 hours, preferably 0.1 to 2 hours. The reaction is usually carried out at normal pressure, but it may be carried out under reduced pressure or increased pressure.

The 2,5-diarylfuran derivative can be separated and purified from the reaction product solution by any conventional separation and purification method. For example, when concentrated sulfuric acid or the like is used as a catalyst, methyl alcohol is used after the reaction is completed. By adding
When acetic acid or the like is used as a solvent with boron trifluoride or the like as a catalyst, the 2,5-diarylfuran derivative is precipitated as crystals as the reaction progresses. Therefore, after the completion of the reaction, the precipitated crystals are collected by filtration, washed with an inert solvent and dried to obtain the desired 2,5-diarylfuran derivative with high purity.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which, however, are not intended to limit the scope of the present invention. According to the method of the present invention,
Whatever the number and position of the substituents on the aryl group of the target 2,5-diarylfuran derivative, whatever the number and position of the substituents, the corresponding acetophenone derivative can be easily synthesized. Therefore, in the example, 2,5-
Only examples relating to the synthesis of di (p-methoxycarbophenyl) furan are given.

Example 1 In a 200 ml photoreactor equipped with a 100 W high pressure mercury lamp, 6.55 g of methyl 4-acetylbenzoate and 1.32 g of phenol were dissolved in 131 ml of acetone and the mixture was irradiated with light at 30 to 40 ° C. for about 8 hours. It was made to react. The reaction solution was cooled to around room temperature, the precipitated crystals were separated by filtration, washed with acetone, and dried in vacuum. The obtained crystals were analyzed by NMR spectroscopy, and as a result, 1,4-di (p-
It was methoxycarbonylphenyl) butane-1,4-dione. Yield 0.89 g, yield 27%. ¹ H-NMR spectrum (CDCl ₃ , 400 MHz,
δ / ppm): 8.13 (d, J = 8 Hz, phenyl ring CH, 4H) 8.07 (d, J = 8 Hz, phenyl ring CH, 4H) 3.94 (s, OCH ₃ , 6H) 3. _{48 (s, CH 2, 4H} ) 13 C-NMR spectrum (CDCl _3, 100MHz,
δ / ppm): 198.0 (ketone carbon) 166.2 (ester carbon) 139.9, 134.0, 129.9, 128.0 (phenyl ring) 52.5 (OCH ₃ ) 32.9 (CH ₂ )

Example 2 1.1 ml of boron trifluoride dimethyl etherate complex was dissolved in 5.2 ml of acetic acid in a 30 ml round-bottomed flask, and the mixture was stirred at room temperature for about 1 hour and then 1,4-di (p-methoxycarbonyl). Phenyl) butane-1,4-dione
0.14 g was added, and the mixture was further stirred at 100 ° C. for 30 minutes.
The reaction solution was cooled to around room temperature, the precipitated crystals were filtered off,
It was washed with demineralized water and then vacuum dried. The obtained crystals are N
As a result of analysis by MR and mass spectroscopy,
It was 2,5-di (p-methoxycarbonylphenyl) furan. Yield 0.11 g, yield 83%. ¹ H-NMR spectrum (CDCl ₃ , 400 MHz,
δ / ppm): 8.07 (d, J = 8 Hz, phenyl ring CH, 4H) 7.79 (d, J = 8 Hz, phenyl ring CH, 4H) 6.89 (s, furan ring CH, 2H) 3 .92 (s, OCH ₃ , 6H) ¹³ C-NMR spectrum (CDCl ₃ , 100 MHz,
δ / ppm): 166.7 (carbonyl carbon) 153.3 (furan ring 2,5-position) 134.2, 130.2, 128.9, 123.5 (phenyl ring) 109.7 (furan ring 3,) 4th position) 52.2 (OCH ₃ ) mass spectrum (m / z): 336 (m ⁺ ). Further, the fluorescence spectrum of this crystal was measured in methyl alcohol.
Fluorescence was observed at nm.

Example 3 1,4-di (p-methoxycarbonylphenyl) butane-1,4-dione 9.7 m in a 10 ml round-bottomed flask.
g was reacted with 1 ml of concentrated sulfuric acid at about 0 ° C. for about 10 minutes. This reaction liquid was added to 3 ml of methyl alcohol, and the precipitated crystals were separated by filtration. The crystals were washed with demineralized water and dried under vacuum. The obtained crystal was 2,5-di (p-methoxycarbonylphenyl) furan. Yield 2.7 mg, 29% yield.

Example 4 0.29 g of 2,5-di (p-methoxycarbonylphenyl) furan and 0.30 g of 85% potassium hydroxide were suspended in 3 ml of water and 12 ml of ethyl alcohol,
The reaction was carried out at 90 ° C for 1.5 hours. The reaction solution was cooled to around room temperature and then acidified by adding hydrochloric acid. The precipitated crystals were filtered off, washed with demineralized water, and dried in vacuum. The obtained crystal was 2,5-di (p-carboxyphenyl) furan as a result of analysis by NMR and mass spectroscopy. Yield 0.26 g, yield 98%. ¹ H-NMR spectrum (DMSO-d ₆ , 400 MH
z, δ / ppm): 13.0 (br, OH) 8.00 (d, J = 8 Hz, phenyl ring CH, 4H) 7.94 (d, J = 8 Hz, phenyl ring CH, 4H) 7.31 (S, furan ring CH, 2H) ¹³ C-NMR spectrum (DMSO-d ₆ , 100 MH
z, δ / ppm): 166.7 (carbonyl carbon) 152.5 (furan ring 2,5-position) 133.1, 130.0, 129.8, 123.3 (phenyl ring) 110.4 (furan ring) (3rd and 4th positions) Mass spectrum (m / z): 308 (m ⁺ ). As a result of further measuring the fluorescence spectrum of this crystal in methyl alcohol, it was found that at an excitation wavelength of 350 nm,
Fluorescence was observed at nm.

[0028]

INDUSTRIAL APPLICABILITY The compound of the present invention is useful as a fluorescent agent, and according to the production method of the present invention, this compound can be produced simply and easily.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C07C 69/76 C07C 69/76 A // C07B 61/00 300 C07B 61/00 300 (72) Invention Person Yuki Satsuma 1-1 Kurosaki Shiroishi, Yawatanishi-ku, Kitakyushu City Mitsubishi Chemical Co., Ltd. Kurosaki Works (72) Inventor Toshiyuki Koyama 1-1 Kurosaki Shiroishi, Hachiman Nishi-ku, Kitakyushu City Mitsubishi Chemical Corporation Kurosaki Works

Claims (5)

[Claims] 1. A compound of the general formula (I) (In the formula, R ¹ and R ² represent a carboxyl group or a methoxycarbonyl group, and may be the same or different. Further, m and n are integers of 1 to 5.)
A 2,5-diarylfuran derivative represented by: 2. A compound of the general formula (II) (In the formula, R ¹ , R ² , m and n have the same meanings as in formula (I).) 1,4-diarylbutane-1,4
A method for producing a 2,5-diarylfuran derivative, which comprises dehydration ring-closing of dione in the presence of an acid catalyst. 3. A compound represented by the general formula (III): (In the formula, R ¹ and n have the same meanings as in formula (I).) 1,4-obtained by dimerizing an acetophenone derivative represented by the formula (I) in the presence of a catalytic amount of phenol under light irradiation.
The method for producing a 2,5-diarylfuran derivative according to claim 2, wherein diarylbutane-1,4-dione is used as a raw material. 4. The method for producing a 2,5-diarylfuran derivative according to claim 2, wherein boron trifluoride is used as the acid catalyst. 5. The method for producing a 2,5-diarylfuran derivative according to claim 2, wherein sulfuric acid is used as the acid catalyst.