WO2020171039A1

WO2020171039A1 - Novel fluorene compound

Info

Publication number: WO2020171039A1
Application number: PCT/JP2020/006175
Authority: WO
Inventors: 大地佐久間
Original assignee: 本州化学工業株式会社
Priority date: 2019-02-21
Filing date: 2020-02-18
Publication date: 2020-08-27
Also published as: JPWO2020171039A1; KR20210132006A; JP7415110B2; CN113329989A; TW202041494A

Abstract

This invention addresses the problem of providing a novel fluorene compound, which has a 2,3-benzofluorene skeleton, is highly versatile as a "dicarboxylic acid component" of a resin starting material, has a high refractive index, and is highly soluble in organic solvents. This problem can be solved by a fluorene compound represented by general formula (1).

Description

New fluorene compound

The present invention relates to a novel fluorene compound. Specifically, it relates to a novel fluorene compound having a 2,3-benzofluorene skeleton.

Conventionally, a compound group having a fluorene skeleton such as 9,9-bis(4-hydroxyphenyl)fluorene exhibits excellent functions in heat resistance, optical properties, etc., and therefore, a thermoplastic synthetic resin raw material such as a polycarbonate resin, It is used in applications such as raw materials for thermosetting resins such as epoxy resins, raw materials for antioxidants, raw materials for thermosensitive recording materials, and raw materials for photosensitive resists. Among them, the following chemical formula

A resin produced from 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene represented by the following is noted as having excellent optical properties (for example, Patent Document 1).
This 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene or a compound in which a hydroxyethoxy group widely used in recent years is introduced, for example, 9,9-bis{4-(2-hydroxy) Ethoxy)phenyl}-2,3-benzofluorene has been utilized or attracted attention as a "diol component" as a resin raw material such as a polyester resin and a polyarylate resin in addition to a polycarbonate resin raw material.
Like the examples of these compounds, "diol component" has been actively developed as a resin raw material, and many proposals for "diol component" according to desired resin performance have been made.
On the other hand, the development of the “dicarboxylic acid component” has been delayed due to the fact that two components, a “diol component” and a “dicarboxylic acid component”, are required as raw materials for resins such as polyester resin and polyarylate resin. There is a problem that there are few kinds of "dicarboxylic acid components" that can be formed.

JP, 2017-036249, A

The present invention has been made under the circumstances described above, has high versatility as a "dicarboxylic acid component" of a resin raw material, has a high refractive index, and also has excellent solubility in an organic solvent. An object is to provide a novel fluorene compound having a 2,3-benzofluorene skeleton.

The present inventor has conducted extensive studies to solve the above-mentioned problems, and found that a fluorene compound having a 2,3-benzofluorene skeleton such as 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene It is a novel compound, and because of its chemical structure, it has high versatility as a "dicarboxylic acid component" of a resin raw material, has a high refractive index, and further has excellent solubility in organic solvents. The present invention has been completed.

The present invention is as follows.
1. A fluorene compound represented by the following general formula (1).

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkali metal atom, an alkaline earth metal atom, and R ₃ and R ₄ are independently carbon atoms. An alkyl group having 1 to 6 atoms, a phenyl group, R ₅ and R ₆ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, carbon (Indicated by an alkoxy group having 1 to 6 atoms and an aryl group having 6 to 12 carbon atoms, a, b and c are each independently an integer of 0 to 4 and d is an integer of 0 to 6.)

According to the present invention, as represented by the above general formula (1), a new resin raw material is provided as a new “dicarboxylic acid component” having a chemical structure having two carboxylic acids/carboxylic acid esters at the terminals. be able to.
As will be described later, since the compound of the present invention is a compound having a high refractive index, by using it as a “dicarboxylic acid component” of a resin raw material, a resin having a high refractive index can be obtained, and a resin having excellent optical properties can be obtained. It can be expected as a raw material.
In particular, the "dicarboxylic acid component" that can be used as a resin raw material for optical applications is a new fluorene compound of the present invention because of its optical properties, heat resistance, solvent solubility, etc. It is considered to be a novel compound that is very useful in applications.

FIG. 3 is a diagram showing a differential scanning calorimetry (DSC) curve of the crystal obtained in Example 1. 6 is a diagram showing a differential scanning calorimetry (DSC) curve of the crystal obtained in Example 3. FIG. FIG. 3 is a diagram showing a differential thermal/thermogravimetric analysis (DTG) curve of the crystal obtained in Example 3. FIG. 6 is a diagram showing a differential scanning calorimetry (DSC) curve of the crystal obtained in Example 4. FIG. 7 is a diagram showing a differential thermal analysis/thermogravimetric analysis (DTG) curve of the crystal obtained in Example 7. FIG. 8 is a diagram showing a differential thermal analysis/thermogravimetric analysis (DTG) curve of the crystal obtained in Example 8. FIG. 9 is a diagram showing a differential thermal analysis/thermogravimetric analysis (DTG) curve of the crystal obtained in Example 9. FIG. 6 is a diagram showing a differential thermal analysis/thermogravimetric analysis (DTG) curve of the crystal obtained in Example 10.

Hereinafter, the present invention will be described in detail.
The novel fluorene of the present invention is a compound represented by the following general formula (1).

In the general formula (1), when any one or more of R ₁ to R ₆ is an alkyl group having 1 to 6 carbon atoms, a preferable alkyl group is a linear or branched chain having 1 carbon atom. Alkyl groups of 4 to 4, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, and a tert-butyl group. To be
When one or both of R ₅ and R ₆ is an alkenyl group having 2 to 6 carbon atoms, a preferable alkenyl group is a linear or branched alkenyl group having 2 to 4 carbon atoms, Specific examples thereof include a vinyl group, a 1-methylethenyl group, a propenyl group, a butenyl group, an isobutenyl group, a pentenyl group and a hexenyl group.
When one or both of R ₅ and R ₆ is an alkoxy group having 1 to 6 carbon atoms, a preferable alkoxy group is a linear or branched alkoxy group having 1 to 4 carbon atoms, Specific examples thereof include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group and t-butoxy group.
When one or both of R ₅ and R ₆ are an aryl group having 6 to 12 carbon atoms, a phenyl group and a naphthyl group are preferable.

In the general formula (1), R ₁ and R ₂ are preferably each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkali metal atom, and each independently being a hydrogen atom or 1 to 4 carbon atoms. Is more preferable, a lithium atom, a potassium atom and a sodium atom are more preferable, and a hydrogen atom, a methyl group and an ethyl group are each independently preferable. Among them, it is particularly preferable that both R ₁ and R ₂ are hydrogen atoms.
In the general formula (1), R ₃ and R ₄ are preferably each independently an alkyl group having 1 to 4 carbon atoms or a phenyl group, and more preferably each independently a methyl group or a phenyl group. Each of a and b is preferably 0, 1, 2, or 3, independently, more preferably 0 or 1, and particularly preferably both a and b are 0. Further, the substitution position of R ₃ and R ₄ is preferably 2-position, 3-position or 5-position, and more preferably 3-position and/or 5-position.
In the general formula (1), R ₅ and R ₆ are each independently a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms. , Phenyl group and naphthyl group are preferred. It is preferable that c and d are independently 0 and 1, and it is more preferable that both c and d are 0.

Preferred examples of the fluorene compound represented by the above general formula (1) include 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene represented by the following chemical formula, potassium salts and sodium salts thereof. , Methyl ester and ethyl ester.

Other preferred compounds include
9,9-bis[(4-carboxymethoxy-3-methyl)phenyl]-2,3-benzofluorene, its potassium salt, sodium salt, methyl ester, ethyl ester 9,9-bis[(4-carboxymethoxy -2-Methyl)phenyl]-2,3-benzofluorene, its potassium salt, sodium salt, methyl ester, ethyl ester 9,9-bis[(4-carboxymethoxy-3,5-dimethyl)phenyl]-2 ,3-benzofluorene, its potassium salt, sodium salt, methyl ester, ethyl ester 9,9-bis[(4-carboxymethoxy-2,5-dimethyl)phenyl]-2,3-benzofluorene and its potassium salt Salt, sodium salt, methyl ester, ethyl ester 9,9-bis[(4-carboxymethoxy-3-phenyl)phenyl]-2,3-benzofluorene, its potassium salt, sodium salt, methyl ester, ethyl ester 9 , 9-bis[(4-carboxymethoxy-2-phenyl)phenyl]-2,3-benzofluorene, its potassium salt, sodium salt, methyl ester and ethyl ester.

<About synthesis method>
The method for synthesizing the fluorene compound represented by the above general formula (1) of the present invention is not particularly limited, and includes, for example, 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorenes and halogenated compounds. It can be obtained by an etherification reaction in which an alkyl acetate or the like is reacted under alkaline conditions.
The reaction formula of the etherification reaction for obtaining the compound of the present invention, 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene, is shown below.
<Reaction formula of etherification reaction>

For 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene, the known method for producing a compound having a fluorene skeleton such as 9,9-bis(4-hydroxyphenyl)fluorene can be applied. For example, 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene is prepared by using phenol and 2,3-benzo-9-fluorenone as raw materials and using them as an acid catalyst as shown in the following reaction formula. It can be obtained by a condensation reaction of reacting in the presence of
<Reaction formula of condensation reaction>

<One Example of Raw Material Synthesis-Condensation Reaction->
First, as an example of raw material synthesis of the compound of the present invention, synthesis of 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene by condensation reaction of phenol and 2,3-benzo-9-fluorenone The method will be described.
The molar ratio of the phenol charged to 2,3-benzo-9-fluorenone is not particularly limited as long as it is the theoretical value (2.0) or more, but it is usually in the range of 2 to 20 times the molar amount, preferably It is used in the range of 3 to 10 times the molar amount.
The acid catalyst used is not particularly limited, and a known acid catalyst can be used. Specific acid catalysts include, for example, inorganic acids such as hydrochloric acid, hydrogen chloride gas, 60 to 98% sulfuric acid, 85% phosphoric acid, p-toluenesulfonic acid, methanesulfonic acid, oxalic acid, formic acid, trichloroacetic acid or triacetic acid. Examples thereof include organic acids such as fluoroacetic acid and solid acids such as heteropolyacid. Hydrogen chloride gas is preferred. The amount of such an acid catalyst used varies depending on the reaction conditions, but in the case of hydrogen chloride gas, for example, after replacing the air in the reaction system with an inert gas such as nitrogen gas, blowing in hydrogen chloride gas, It is preferable that the concentration of hydrogen chloride gas in the gas phase in the reaction vessel is 75 to 100% by volume and the concentration of hydrogen chloride in the reaction solution is saturated. In the case of 35% hydrochloric acid, it is used in an amount of 5 to 70 parts by weight, preferably 10 to 40 parts by weight, more preferably 20 to 30 parts by weight, based on 100 parts by weight of phenol.
In the reaction, a cocatalyst may be used together with the acid catalyst, if necessary. For example, when hydrogen chloride gas is used as a catalyst, the reaction rate can be accelerated by using thiols as a co-catalyst. Examples of such thiols include alkyl mercaptans and mercapto carboxylic acids, preferably alkyl mercaptans having 1 to 12 carbon atoms and mercapto carboxylic acids having 1 to 12 carbon atoms, such as methyl mercaptan and ethyl. Examples thereof include alkali metal salts such as mercaptan, n-octyl mercaptan, n-dodecyl mercaptan and their sodium salts, thioacetic acid, β-mercaptopropionic acid and the like. Moreover, these can be used individually or in combination of 2 or more types. The amount of thiols used as a cocatalyst is usually in the range of 1 to 30 mol% and preferably in the range of 2 to 10 mol% based on 2,3-benzo-9-fluorenone as a raw material.

A reaction solvent may not be used in the reaction, but may be used for reasons such as operability in industrial production and improvement of reaction rate. The reaction solvent is not particularly limited as long as it does not distill from the reaction vessel at the reaction temperature and is inert to the reaction, but examples thereof include aromatic hydrocarbons such as toluene and xylene, methanol, ethanol, 1-propanol and 2- Examples thereof include lower aliphatic alcohols such as propanol, organic solvents such as saturated aliphatic hydrocarbons such as hexane, heptane and cyclohexane, water, or a mixture thereof. Of these, aromatic hydrocarbons are preferably used.
The reaction temperature varies depending on the type of raw material phenol or acid catalyst, but when hydrogen chloride gas is used as the acid catalyst, it is usually in the range of 10 to 60° C., preferably 25 to 50° C. The reaction pressure is usually under normal pressure, but depending on the boiling point of the organic solvent which may be used, it may be carried out under pressure or under reduced pressure so that the reaction temperature falls within the above range.
The reaction time varies depending on the reaction conditions such as the raw material phenol and the type of acid catalyst and the reaction temperature, but it is usually completed in about 1 to 30 hours.
The end point of the reaction can be confirmed by liquid chromatography or gas chromatography analysis. The end point of the reaction is preferably the time point at which the unreacted 2,3-benzo-9-fluorenone disappears and no increase in the target substance is observed.

<Post-treatment of raw material synthesis reaction>
After the completion of the reaction, known post-treatment methods can be applied. For example, in order to neutralize the acid catalyst, an alkaline aqueous solution such as an aqueous solution of sodium hydroxide or an aqueous solution of ammonia is added to the reaction completed liquid to neutralize the acid catalyst. The neutralized reaction mixture is allowed to stand, a solvent that separates from water is added if necessary, and the aqueous layer is separated and removed. Distilled water is added to the obtained oil layer if necessary, and after stirring and washing with water, the operation of separating and removing the water layer is repeated once or more times to remove the neutralized salt, and the excess oil is obtained from the obtained oil layer. Phenol is removed by vacuum distillation. A solvent such as an aromatic hydrocarbon that separates from water is added to the obtained residue to form a uniform solution, which is cooled to separate the precipitated crystal to obtain a crude crystal.

<Synthesis Examples of Compounds of the Present Invention-Etherification Reaction->
Next, as a synthesis example of the compound of the present invention, 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene was prepared from 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene. The etherification reaction to be obtained will be described.
Examples of the halogenated alkyl acetate to be reacted with 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene include, for example, methyl chloroacetate, ethyl chloroacetate, n-propyl chloroacetate, isopropyl chloroacetate and chloroacetic acid. Examples include n-butyl, isobutyl chloroacetate, tert-butyl chloroacetate, methyl bromoacetate, ethyl bromoacetate, n-propyl bromoacetate, isopropyl bromoacetate, n-butyl bromoacetate, isobutyl bromoacetate, tert-butyl bromoacetate, etc. To be Of these, methyl chloroacetate or ethyl chloroacetate is preferable.
The charged molar ratio of the alkyl halide to the 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene is not particularly limited as long as it is the theoretical value (2.0) or more. It is usually used in a range of 2 to 20 times the molar amount, preferably in the range of 2 to 10 times the molar amount, and more preferably in the range of 2 to 6 times the molar amount.
The reaction is carried out in the presence of a base, and examples of the base used include triethylamine, pyridine, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and the like. Of these, sodium carbonate and potassium carbonate are preferable. The molar ratio of the charged base is usually 0.8 to 4 times, preferably 0.85 to 3 times, and more preferably 0.9 to 2 times the molar amount of alkyl halide. The range of quantity.
Further, a catalyst may be used, for example, alkali metal bromide such as sodium bromide or potassium bromide, alkali metal iodide salt such as sodium iodide or potassium iodide, ammonium bromide or ammonium iodide, etc. Is mentioned. The amount of the catalyst used is usually in the range of 0.1 to 100% by weight, preferably in the range of 0.1 to 20% by weight, based on 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene. , And more preferably 0.1 to 10% by weight.

A reaction solvent may not be used in the reaction, but it is preferably used for reasons such as operability in industrial production and improvement of reaction rate. The reaction solvent is not particularly limited as long as it does not distill from the reaction vessel at the reaction temperature and is inert to the reaction. For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones, tetrahydrofuran, 1,4- Examples thereof include ethers such as dioxane, 1,3-dioxane and diethoxyethane, aprotic polar solvents such as acetonitrile, dimethylsulfoxide, dimethylformamide and N-methylpyrrolidone. These organic solvents may be used alone or in combination of two or more kinds in order to adjust the polarity. Of these, methyl isobutyl ketone and acetonitrile are preferable.
The reaction temperature is usually 25 to 120°C, preferably 40 to 110°C, more preferably 50 to 100°C. If the reaction temperature is high, the yield decreases due to hydrolysis of the produced ester compound, and if the reaction temperature is low, the reaction rate becomes slow, which is not preferable. The reaction pressure is usually under normal pressure, but depending on the boiling point of the organic solvent used, it may be carried out under pressure or under reduced pressure so that the reaction temperature falls within the above range.
The end point of the reaction can be confirmed by liquid chromatography or gas chromatography analysis. The end point of the reaction is preferably the time point at which the unreacted 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene disappears and no increase in the target substance is observed. The reaction time varies depending on the reaction conditions such as the reaction temperature, but it is usually completed in about 1 to 30 hours.

When the target product is an ester compound such as 9,9-bis(4-methoxycarbonylmethoxyphenyl)-2,3-benzofluorene, after the etherification reaction is completed, the target ester compound is purified from the reaction product mixture. It is preferably isolated, and can be obtained, for example, by performing a post-treatment operation such as neutralization, washing with water, crystallization, filtration, distillation, and separation by column chromatography according to a conventional method. In order to further increase the purity, distillation, recrystallization, or purification by column chromatography may be performed according to a conventional method.
When the target product is a carboxylic acid salt such as 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene, after the etherification reaction, post-reaction treatment such as neutralization and water washing is performed. The carboxylic acid salt can be obtained by subjecting the obtained ester compound to alkaline hydrolysis according to a conventional method without purification of the obtained ester compound as it is as a crude product. Here, the alkali compound used for the alkali hydrolysis is not particularly limited, but for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferable, and the concentration is usually 12 to 60% by weight. It is used as an aqueous solution of. In addition, such an alkali compound is usually 2 mol or more, preferably 2. mol, relative to 1 mol of the ester compound such as 9,9-bis(4-methoxycarbonylmethoxyphenyl)-2,3-benzofluorene. It is used in the range of 1 to 10 mol. Usually, water is used as a reaction solvent in the hydrolysis reaction, but if necessary, an organic solvent such as an alcohol or a ketone that is miscible with water at an arbitrary ratio, or a mixture of such an organic solvent and water. Solvents are also used. It is also possible to continue to use the reaction solvent used for the above etherification reaction, such as methyl isobutyl ketone or acetonitrile. The reaction temperature for hydrolysis is usually 30 to 100° C., preferably 50 to 90° C., and under such reaction conditions, it is usually completed in about 3 to 5 hours. By this hydrolysis reaction, an alkali metal salt of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene can be obtained.

When the target product is a carboxylic acid such as 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene, the hydrolysis reaction product is treated with concentrated hydrochloric acid or the like and then treated with water. Immiscible organic solvents, for example, aromatic hydrocarbons such as toluene, xylene and benzene, aliphatic hydrocarbons having 5 or more carbon atoms such as hexane, heptane and cyclohexane, and 5 or more carbon atoms such as methyl isobutyl ketone After washing with an aliphatic ketone or the like, it is preferable to purify and isolate. In order to further increase the purity, distillation, recrystallization, and purification by column chromatography may be performed according to a conventional method.

INDUSTRIAL APPLICABILITY The novel fluorene compound of the present invention has excellent properties such as high refractive index, high heat resistance, and high solubility in a wide range of organic solvents, and is suitable for resin raw materials (monomers), reaction components of derivatives, etc. Can be used. Therefore, the novel fluorene compound or its derivative of the present invention, or the resin using the novel fluorene compound as a resin raw material (monomer) is, for example, a film (for example, an optical film, a liquid crystal film, an organic EL (electroluminescence) film, or EMI). Shield film etc.), lens (eg pickup lens etc.), protective film (eg electronic device, protective film for liquid crystal member etc.), electric/electronic material (carrier transport material, light emitter, organic photoconductor, organic photosensitizer) Body, thermosensitive recording material, hologram recording material, photochromic material, etc., electric/electronic parts or devices (for example, optical disc, ink jet printer, digital paper, organic semiconductor laser, dye-sensitized solar cell, EMI shield film, organic EL element) , Color filters, etc.), mechanical parts or devices (automobiles, aerospace materials, sensors, sliding members, etc.) and the like. In particular, the resin of the present invention, which is the novel fluorene compound, is excellent in optical properties, and thus is useful for forming a molded article for optical use. Examples of such a molded article for optics include an optical film. As the optical film, a polarizing film (and a polarizing element and a polarizing plate protective film constituting the same), a retardation film, an alignment film (alignment film), a viewing angle widening (compensation) film, a diffusion plate (film), a light guide plate, Brightness enhancement film, near infrared absorption film, reflection film, antireflection (AR) film, reflection reduction (LR) film, antiglare (AG) film, transparent conductive (ITO) film, anisotropic conductive film (ACF), electromagnetic wave Examples include a shielding (EMI) film, an electrode substrate film, a barrier film, a color filter layer, a black matrix layer, and an adhesive layer or a release layer between optical films. In particular, the film is useful as an optical film used for display of equipment. As a display member (or display) provided with such an optical film, specifically, an FPD device (for example, LCD, monitor, personal computer monitor, television, mobile phone, car navigation, touch panel, etc.) PDP etc.) and the like.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
The analysis method is as follows.
<Analysis method>
1. Differential scanning calorimetry (DSC)
The crystals (2 to 3 mg) were weighed in an aluminum pan and measured using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60) under the following operating conditions with aluminum oxide as a control.
(Operating conditions)
Temperature rising rate: 10°C/min
Measuring temperature range: 30-260°C
Measurement atmosphere: Open, nitrogen 50mL/min
2. Differential thermal and thermogravimetric analysis (DTG)
8 to 12 mg of the crystal was weighed in an aluminum pan and measured using a differential thermal/thermogravimetric analyzer (DTG-60A manufactured by Shimadzu Corporation) under the following operating conditions.
(Operating conditions)
Temperature rising rate: 10°C/min
Measurement temperature range: 30~300℃
Measurement atmosphere: Open, nitrogen 50 mL/min
3. Confirmation of reaction end point and purity measurement device: Shimadzu Corporation Prominence UFLC (liquid chromatography)
Pump: LC-20AD
Column oven: CTO-20A
Detector: SPD-20A
Column: HALO C18 inner diameter 3mm, length 75mm
Oven temperature: 50℃
Flow rate: 0.7 ml/min
Mobile phase: (A) 0.1 wt% phosphoric acid aqueous solution, (B) acetonitryl gradient condition: (A) volume% (time from the start of analysis)
<Reaction solution analysis>
70% (0min) → 100% (12min) → 100% (15min)
<Crystal analysis>
70% (0min) → 100% (12min) → 100% (15min)
Sample injection volume: 5 μl
Detection wavelength: 254nm
4. Refractive Index Device: Kyoto Denshi Kogyo Co., Ltd. Refractometer RA-500N
With respect to the compound to be measured, 3 samples of THF solutions having arbitrary concentrations were prepared, and the refractive index of each solution was measured. The relationship between the concentration and the refractive index was derived from the obtained value, and the value when the concentration was 100% was calculated by extrapolation, and this value was used as the refractive index of the compound.

<Synthesis example>
Synthesis of 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene A 1 liter four-necked flask equipped with a thermometer, a stirrer, and a condenser was replaced with nitrogen to give 119 g of phenol (1.2 mol). ) Was charged, and hydrogen chloride gas was blown into the flask to replace the inside of the flask with hydrogen chloride gas. 13 g of a 15% methylmercaptan sodium salt aqueous solution was added dropwise thereto, and then a mixed solution of 145 g (0.63 mol) of 2,3-benzo-9-fluorenone, 119 g (1.2 mol) of phenol and 58 g of toluene was added for 1 hour. It dripped over, and stirred at reaction temperature 40 degreeC for 3 hours. The disappearance of the raw materials was confirmed by liquid chromatography analysis, and the reaction was completed. Aqueous sodium hydroxide solution was added to the reaction mixture to neutralize the reaction solution, 60 g of toluene was added and the mixture was allowed to stand, and the aqueous layer was removed. Distilled water was added to the obtained oil layer, and the mixture was stirred, allowed to stand and then the operation of removing the water layer was repeated twice to remove neutralized salts, and excess phenol was removed by vacuum distillation. To this distillation residue, 1009 g of toluene was added to form a uniform solution, which was cooled to precipitate crystals. Then, the mixture was cooled to 25° C., and the precipitated crystals were filtered off to obtain 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene, which was a target substance.

<Example 1>
Synthesis of 9,9-bis(4-ethoxycarbonylmethoxyphenyl)-2,3-benzofluorene 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene 40.0 g (0.1 mol), 120 g of acetonitrile, 31.7 g of potassium carbonate, and 4.0 g of potassium iodide were charged into a four-necked flask, heated to 70° C., and stirred at the same temperature for 1 hour. Then, 34.3 g (0.28 mol) of ethyl chloroacetate was added dropwise while maintaining the temperature of the reaction solution at 70 to 80°C. After stirring for 6 hours, 100 g of water was added and the temperature was raised to 70° C., and then the aqueous layer was removed. After that, acetonitrile was distilled off under normal pressure, 800 g of ethanol was added, the temperature was raised to 70° C., and the mixture was cooled to 25° C. to precipitate crystals. The crystals were separated by filtration and dried to obtain 42.5 g of the target product, 9,9-bis(4-ethoxycarbonylmethoxyphenyl)-2,3-benzofluorene. The figure which shows the differential scanning calorimetry (DSC) curve of the obtained crystal is shown in FIG.
Purity 99.2% (high performance liquid chromatography)
Proton nuclear magnetic resonance spectrum (400 MHz, solvent CDCl ₃ , standard TMS)
Chemical shift (signal shape, number of protons): 1.26 ppm (t, 6H), 4.23 ppm (q, 4H), 4.54 ppm (s, 4H), 6.73-6.78 ppm (m, 4H), 7.14-7.19 ppm (m, 4H), 7.28-7.33 ppm (m, 1H), 7.36-7.47 ppm (m, 4H), 7.75 ppm (d, 2H), 7. 88-7.92 ppm (m, 2H), 8.17 (s, 1H).
From the differential scanning calorimetry (DSC) curve shown in FIG. 1, it was confirmed that the crystal had a peak top at 96° C. and 176° C. The refractive index was 1.620.

<Example 2>
Synthesis of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene bispotassium salt 9,9-bis(4-ethoxycarbonylmethoxyphenyl)-2,3 obtained in Example 1 above -A solution of 40.0 g of benzofluorene in 120 g of acetonitrile was maintained at 70 to 80°C, 80.1 g of 35% aqueous potassium hydroxide solution was added dropwise, and the mixture was stirred at the same temperature for 2 hours. The reaction solution was cooled to 25° C., and the obtained crystals were separated by filtration and dried to obtain 56.5 g of crystals of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene bispotassium salt. did.
Purity 99.6% (high performance liquid chromatography)
Proton nuclear magnetic resonance spectrum (400 MHz, solvent D ₂ O)
Chemical shift (signal shape, number of protons): 4.37 ppm (s, 4H), 6.75-6.83 ppm (m, 4H), 7.04-7.13 ppm (m, 4H), 7.25-7 .47 ppm (m, 5H), 7.63-7.73 ppm (m, 2H), 7.83-7.95 ppm (m, 2H), 8.12-8.23 ppm (m, 1H).
From the resulting FT-IR of a crystal, disappeared peak around 1700 cm ^-1 observed in carbonyl moiety of the carboxylic acid, confirmed the presence of around 1600 cm ^-1 observed in carboxylate and 1400 cm ^-1, the peak ..

<Example 3>
Synthesis of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene (1) Method for synthesizing seed crystal 9,9-bis(4-carboxymethoxyphenyl)-obtained in Example 2 above 3.0 g of methyl isobutyl ketone and 1 g of concentrated hydrochloric acid were added to 1.0 g of 2,3-benzofluorene bispotassium salt, the temperature was raised to 80° C., and the aqueous layer was removed. To the obtained solution, 6.0 g of heptane was added, cooled and the precipitate was filtered to obtain seed crystals.
(2) Synthetic method using seed crystals 50.0 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene bispotassium salt obtained in Example 2 above, 250 g of methyl isobutyl ketone, 25.0 g of concentrated hydrochloric acid was added, and the mixture was stirred at 80° C. for 30 minutes. The aqueous layer was removed, water was added to the obtained oil layer, and the mixture was stirred to remove the aqueous layer. The water washing operation was repeated several times to remove the residual hydrochloric acid content. 100.0 g of heptane was added to the obtained solution, 50 mg of the seed crystal obtained in (1) above was added at 75° C., cooled to 25° C. at a cooling rate of 10° C./hour, and filtered. Then, it was dried to obtain 39.6 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene powder. A diagram showing a differential scanning calorimetry (DSC) curve of the obtained crystal is shown in FIG. 2, and a diagram showing a differential thermogravimetric analysis (DTG) curve is shown in FIG.
Yield 86.6% (yield through 3 steps of Examples 1 to 3)
Purity 99.8% (high performance liquid chromatography)
Proton nuclear magnetic resonance spectrum (400 MHz, solvent MeOH-d ₄ , standard TMS)
Chemical shift (signal shape, number of protons): 4.51 ppm (s, 4H), 6.71 ppm (d, 4H), 7.07 ppm (d, 4H), 7.22 ppm (dt, 1H), 7.31- 7.35 ppm (m, 3H), 7.38 ppm (dt, 1H), 7.65-7.69 ppm (m, 2H), 7.86-7.90 ppm (m, 2H), 8.18 (s, 1H).
The refractive index was 1.658.
From the differential scanning calorimetry (DSC) curve shown in FIG. 2, it was confirmed that the crystal had a peak top at 176° C. and 186° C. From the result of the DTG analysis shown in FIG. 3, since there is a weight loss at the melting point, it is presumed that the obtained crystal is an adduct crystal containing 2.0 wt% of methyl isobutyl ketone.
Results of NMR analysis, although OH peak of carboxylic acid was not observed, from the results of FT-IR, the peak in the vicinity of specific carbonyl group 1700 cm ^-1, the peak near the hydroxyl group-specific 3200 cm ^-1 were observed. From these facts, it was confirmed that the obtained crystal was the target product.
In addition, the target product is various general-purpose solvents for industrial use, specifically, for example, ketone solvents such as acetone and methyl isobutyl ketone (MIBK), alcohol solvents such as methanol and butanol, tetrahydrofuran (THF), cyclopentyl. It was confirmed that the compound has excellent solubility in ether solvents such as methyl ether (CPME), amide solvents such as N-methylpyrrolidone (NMP), and ester solvents such as ethyl acetate and butyl acetate. As one example, the solubility of the obtained 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene in an adduct crystal containing methyl isobutyl ketone in a solvent is shown in Table 1 below. "O" in Table 1 indicates that a 10 wt% solution can be easily prepared at room temperature.

<Example 4>
Synthesis of 9,9-bis(4-methoxycarbonylmethoxyphenyl)-2,3-benzofluorene 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene 15.0 g (0.037 mol), Acetonitrile (45.0 g), potassium carbonate (11.9 g) and potassium iodide (1.5 g) were charged into a four-necked flask, heated to 70° C., and stirred at the same temperature for 1 hour. Then, 11.4 g (0.11 mol) of methyl chloroacetate was added dropwise while maintaining the temperature of the reaction solution at 70 to 80°C. After stirring for 6 hours, 300 g of water was added and the temperature was raised to 70° C. and then cooled to 25° C. to precipitate crystals. The crystals were separated by filtration and dried to obtain 16.3 g of the target product, 9,9-bis(4-methoxycarbonylmethoxyphenyl)-2,3-benzofluorene. The figure which shows the differential scanning calorimetry (DSC) curve of the obtained crystal is shown in FIG.
Purity 99.7% (high performance liquid chromatography)
Proton nuclear magnetic resonance spectrum (400 MHz, solvent CDCl ₃ , standard TMS)
Chemical shift (signal shape, number of protons): 3.77 ppm (s, 6H), 4.56 ppm (s, 4H), 6.72-6.77 ppm (m, 4H), 7.14-7.19 ppm (m , 4H), 7.28-7.32ppm (m, 1H), 7.36-7.47ppm (m, 4H), 7.75ppm (d, 2H), 7.87-7.92ppm (m, 2H) ), 8.17 (s, 1H).
From the differential scanning calorimetry (DSC) curve shown in FIG. 4, it was confirmed that the crystal had a peak top at 155°C. The refractive index was 1.621.

<Example 5>
Synthesis of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene bis sodium salt 9,9-bis(4-ethoxycarbonylmethoxyphenyl)-2,3 obtained in Example 1 above. -A solution of 10.0 g of benzofluorene in 30 g of acetonitrile was maintained at 70 to 80°C, 5.0 g of water and 7.3 g of 48% aqueous sodium hydroxide solution were added dropwise, and the mixture was stirred at the same temperature for 2 hours. The reaction solution was cooled to 25° C., and the obtained crystals were separated by filtration and dried to obtain 8.5 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene bis sodium salt crystals. did.
Purity 99.6% (high performance liquid chromatography)
Proton nuclear magnetic resonance spectrum (400 MHz, solvent D ₂ O)
Chemical shift (signal shape, number of protons): 4.37 ppm (s, 4H), 6.75-6.87 ppm (m, 4H), 7.05-7.13 ppm (m, 4H), 7.30-7 0.52 ppm (m, 5H), 7.70-7.78 ppm (m, 2H), 7.93-8.01 ppm (m, 2H), 8.27 ppm (s, 1H).
From the resulting FT-IR of a crystal, disappeared peak around 1700 cm ^-1 observed in carbonyl moiety of the carboxylic acid, confirmed the presence of around 1600 cm ^-1 observed in carboxylate and 1400 cm ^-1, the peak ..

<Example 6>
Synthesis of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene (reaction solvent: MIBK)
400 g (1.0 mol) of 9,9-bis(4-hydroxyphenyl)-2,3-benzofluorene, 1500 g of methyl isobutyl ketone, 370 g of potassium carbonate and 12 g of potassium iodide were charged in a four-necked flask, and the pressure was reduced to 95 700 g of methyl isobutyl ketone was distilled off at ℃. The reaction system was returned to normal pressure with nitrogen, and then 405 g (3.3 mol) of ethyl chloroacetate was added dropwise while maintaining the temperature of the reaction solution at 90 to 100°C. After stirring at the same temperature for 18 hours, 1900 g of water was added and the temperature was raised to 80° C., and then the aqueous layer was removed. 2200 g of methyl isobutyl ketone was added to the reaction solution, and then 333 g of a 48% sodium hydroxide aqueous solution was added dropwise while maintaining the temperature of the reaction solution at 70 to 80° C., and the mixture was stirred at the same temperature for 5 hours. Then, 1200 g of methyl isobutyl ketone was distilled off under reduced pressure at 70 to 80° C., 1000 g of water and 520 g of concentrated hydrochloric acid were added, and the mixture was stirred at 70 to 80° C. for 1 hour.
The aqueous layer was removed, water was added to the obtained oil layer, and the mixture was stirred to remove the aqueous layer. The water washing operation was repeated several times to remove the residual hydrochloric acid content. 750 g of methyl isobutyl ketone was distilled off from the resulting solution under reduced pressure, 500 g of heptane was added to the residue, 50 mg of seed crystals were added at 73° C., the mixture was cooled to 25° C. at a cooling rate of 10° C./hour, and filtered. 749.6 g of crude crystals of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene were obtained. The obtained crude crystals (710 g), toluene (1420 g) and water (710 g) were placed in a four-necked flask, stirred for 2 hours under heating under reflux, cooled to 25° C. at a cooling rate of 10° C./hour, filtered and dried. 432.6 g of crystals of 9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene were obtained. The purity was 99.6% and the yield was 83.7%.

Since adduct crystals were obtained in Example 3 above, crystalline polymorphs of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene were examined in Examples 7 to 10 below.
<Example 7>
2.0 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene obtained in Example 3 above and 8.0 g of toluene were stirred at 90° C. for 1 hour, cooled to 25° C., and filtered. Crystals were obtained by separating. A diagram showing a differential thermal analysis/thermogravimetric analysis (DTG) curve of the obtained crystal is shown in FIG.
From the differential thermal and thermogravimetric analysis (DTG) curve of the crystal shown in FIG. 5, it was confirmed that the crystal had a single peak top at 200° C., and the adduct containing the methyl isobutyl ketone obtained in Example 3 was obtained. Unlike crystals, no weight loss was observed at the melting point, so it is considered to be a single crystal.

<Example 8>
2.0 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene obtained in Example 3 above, 8.0 g of toluene and 1.0 g of water were added, and the mixture was stirred with heating under reflux for 1 hour. Crystals were obtained by cooling to ℃ and filtering. FIG. 6 shows a diagram showing a differential thermal and thermogravimetric analysis (DTG) curve of the obtained crystal.
From the differential thermal/thermogravimetric analysis (DTG) curve shown in FIG. 6, it was confirmed that the crystal had a single peak top at 202° C., and the adduct crystal containing the methyl isobutyl ketone obtained in Example 3 was used. In contrast, no weight loss was observed at the melting point, so it is considered to be a single crystal.

<Example 9>
2.0 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene obtained in Example 3 above and 4.0 g of butyl acetate were stirred at 90° C. for 1 hour to form a uniform solution. After that, 4.0 g of heptane was added and the mixture was cooled to 25° C. and filtered to obtain crystals. FIG. 7 shows a diagram showing a differential thermal and thermogravimetric analysis (DTG) curve of the obtained crystal.
From the differential thermal/thermogravimetric analysis (DTG) curve shown in FIG. 7, it was confirmed that the crystal had a single peak top at 198° C., and the adduct crystal containing the methyl isobutyl ketone obtained in Example 3 was obtained. In contrast, no weight loss was observed at the melting point, so it is considered to be a single crystal.

<Example 10>
After 2.0 g of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene obtained in Example 3 above and 8.0 g of acetonitrile were stirred at 80° C. for 1 hour, a uniform solution was obtained. Crystals were obtained by cooling to 25° C. and filtering. FIG. 8 shows a diagram showing a differential thermal and thermogravimetric analysis (DTG) curve of the obtained crystal.
From the differential thermal/thermogravimetric analysis (DTG) curve shown in FIG. 8, it was confirmed that the crystals had peak tops at 94° C. and 145° C. It was also confirmed that acetonitrile was released from the adduct at the peak top of 94°C.

Similarly, for the single crystals obtained in Examples 7 to 9, various general-purpose solvents for industrial use, specifically, ketone-based solvents such as acetone and methyl isobutyl ketone (MIBK), methanol, butanol, etc. Excellent solubility in alcoholic solvents, tetrahydrofuran (THF), ether solvents such as cyclopentyl methyl ether (CPME), amide solvents such as N-methylpyrrolidone (NMP), ester solvents such as ethyl acetate and butyl acetate Was confirmed. As one example thereof, Table 2 below shows the solubility of a single crystal of 9,9-bis(4-carboxymethoxyphenyl)-2,3-benzofluorene obtained in a solvent. "O" in Table 2 indicates that a 10 wt% solution can be easily prepared at room temperature.
From the results of Table 1 and Table 2, it was confirmed that the fluorene compound represented by the general formula (1) of the present invention has no difference in solubility in a solvent between a single crystal and an adduct crystal. It is considered that this is largely related to the solvent solubility of the fluorene compound itself represented by the general formula (1) of the present invention.

Compounds having a fluorene skeleton are known to form adduct crystals with a reaction solvent or a solvent used for purification, but in order to remove the solvent from the adduct crystals, a high temperature and a large amount of time are required. Therefore, it is difficult to apply it on an industrial scale, and the compound having a fluorene skeleton that forms an adduct with a solvent is industrially used as a raw material for manufacturing epoxy resins, polyesters, and other applications. Is also known to have problems. Furthermore, depending on the flash point or ignition point of a compound such as an organic solvent contained in the adduct crystal, there is a risk of disaster prevention during transportation or storage of the adduct crystal. Considering these, it is considered that the method of obtaining a fluorene compound represented by the general formula (1) which is not an adduct crystal is also very useful in industrial applications.

Claims

A fluorene compound represented by the following general formula (1).

(In the formula, R 1 and R 2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkali metal atom, an alkaline earth metal atom, and R 3 and R 4 are independently carbon atoms. An alkyl group having 1 to 6 atoms, a phenyl group, R 5 and R 6 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, carbon (Indicated by an alkoxy group having 1 to 6 atoms and an aryl group having 6 to 12 carbon atoms, a, b and c are each independently an integer of 0 to 4 and d is an integer of 0 to 6.)