WO2025142699A1 - Method for producing fluorene compound - Google Patents

Abstract

The purpose of the present invention is to provide a method for producing a fluorene compound (fluorenediol compound having a cyclohexane structure), the method being excellent in terms of yield and purity. The method for producing a fluorene compound includes a hydrogenation step in which a fluorene compound represented by formula (1) is hydrogenated in the presence of a catalyst and a solvent to obtain a fluorene compound represented by formula (2), wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel and the solvent is at least one solvent selected from the group consisting of ether-based solvents and ester-based solvents. [In formulae (1) and (2), each m independently indicates an integer of 0 or 1 and each n independently indicates an integer of 0-6.]

Description

Method for producing fluorene compound

The present invention relates to a method for producing a fluorene compound.

Fluorene compounds having two hydroxyl groups (also called fluorene diol compounds) are known to be useful as raw material monomers for resins such as polyester resins, polyester polycarbonate resins, polycarbonate resins, epoxy resins, polyurethane resins, polyacrylic ester resins, and polymethacrylic ester resins.
In addition, the fluorenediol compound can be used as a resin modifier to widely adjust the physical properties of the resin, such as the glass transition temperature, refractive index, birefringence, and Abbe number, and is therefore used in optical materials such as optical lenses and optical films.

In particular, fluorenediol compounds with a cyclohexane structure have attracted attention as highly heat-resistant compounds with adjustable refractive index.

For example, Patent Document 1 discloses a fluorenediol compound having a cyclohexane structure as a compound that has heat resistance, solubility, flexibility, and a high refractive index as an optical material, as well as impact resistance. It also discloses a method for producing the compound, in which fluorenone and a cyclohexylphenol compound are reacted in the presence of an acid catalyst.

JP 2000-026349 A

The method for synthesizing a fluorenediol compound having a cyclohexane structure described in Patent Document 1 uses a cyclohexylphenol compound as a raw material.

Cyclohexylphenol compounds can be obtained by hydrogenating phenylphenol compounds, but this reaction does not provide a sufficient yield (approximately 35%).
Therefore, a synthetic route in which a phenylphenol compound is hydrogenated to obtain a cyclohexylphenol compound, and then the cyclohexylphenol compound is reacted with fluorenone to synthesize a fluorenediol compound having a cyclohexane structure has a problem that the yield is low (total yield is about 25%).

Because the conventional methods had the above problems, a method (synthetic route) was sought that could produce fluorenediol compounds having a cyclohexane structure in high yield.

The present invention provides a method for producing a fluorene compound (a fluorene diol compound having a cyclohexane structure) with excellent yield and purity.

The present inventors have found that a method for synthesizing a fluorene compound represented by formula (1) described below by reacting a phenylphenol compound with fluorenone has a sufficiently high yield (about 85%).
The present inventors have conducted extensive research into a method for hydrogenating a fluorene compound represented by formula (1) as a method for synthesizing a fluorene compound represented by formula (2) described below (a fluorene diol compound having a cyclohexane structure).
As a result, it has been found that the fluorene compound represented by formula (2) can be obtained in high yield and purity by hydrogenating the fluorene compound represented by formula (1) in the presence of a specific catalyst and solvent.
It has been found that by using such a method, the fluorene compound represented by formula (2) can be obtained in high yield and purity even if a phenylphenol compound and fluorenone are used as starting materials, as in the method described in Patent Document 1.

［式（１）、（２）中、ｍは、それぞれ独立に０又は１の整数を表し、ｎは、それぞれ独立に０～６の整数を表す。］ That is, the present invention is a method for producing a fluorene compound, comprising a hydrogenation step of hydrogenating a fluorene compound represented by the following formula (1) in the presence of a catalyst and a solvent to obtain a fluorene compound represented by the following formula (2), wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel, and the solvent is at least one selected from the group consisting of ether-based solvents and ester-based solvents.

[In formulas (1) and (2), each m independently represents an integer of 0 or 1, and each n independently represents an integer of 0 to 6.]

In the method for producing a fluorene compound of the present invention, the catalyst is preferably at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, and nickel.
The catalyst is preferably supported on at least one carrier selected from the group consisting of carbon, alumina, silica gel, diatomaceous earth, titanium oxide, zirconium, and calcium carbonate.
In addition, when the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, and platinum, the supported amount is preferably 0.1 to 10 mass %, and when the catalyst is a nickel catalyst, the supported amount is preferably 40 to 50 mass %.
The solvent is preferably at least one selected from the group consisting of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether.
In addition, the reaction temperature in the hydrogenation step is preferably 80°C to 150°C.
In the hydrogenation step, the hydrogen pressure is preferably 1 MPa to 10 MPa in terms of gauge pressure.
In addition, the reaction time of the hydrogenation step is preferably 4 to 10 hours.

The present invention provides a method for producing a fluorene compound (a fluorene diol compound having a cyclohexane structure) with excellent yield and purity.

［式（１）、（２）中、ｍは、それぞれ独立に０又は１の整数を表し、ｎは、それぞれ独立に０～６の整数を表す。］
以下、本発明のフルオレン化合物の製造方法について詳述する。 The present invention is a method for producing a fluorene compound, comprising a hydrogenation step of hydrogenating a fluorene compound represented by the following formula (1) in the presence of a catalyst and a solvent to obtain a fluorene compound represented by the following formula (2), wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel, and the solvent is at least one selected from the group consisting of ether-based solvents and ester-based solvents.

[In formulas (1) and (2), each m independently represents an integer of 0 or 1, and each n independently represents an integer of 0 to 6.]
The method for producing the fluorene compound of the present invention will be described in detail below.

<Hydrogenation step>
The method for producing a fluorene compound of the present invention includes a hydrogenation step of hydrogenating the fluorene compound represented by the above formula (1) in the presence of a catalyst and a solvent.

[Fluorene compound represented by formula (1)]
In the above formula (1), each m independently represents an integer of 0 or 1; each n independently represents an integer of 0 to 6.
Note that m and n in the above formula (1) are the same as m and n in the above formula (2) obtained by the hydrogenation step.

In the above formula (1), m is preferably 0 from the viewpoint of suitably increasing the purity of the fluorene compound represented by the above formula (2).

In the above formula (1), n is preferably 0 from the viewpoint of suitably increasing the purity of the fluorene compound shown in the above formula (2).

The method for obtaining the fluorene compound represented by the above formula (1) is not particularly limited, and any known method can be used.

For example, as described in JP-A-2001-206863, the fluorene compound represented by the above formula (1) may be synthesized by reacting a phenylphenol compound with fluorenone.
This method is preferred because the yield of the fluorene compound represented by the above formula (1) is high, at about 85%.

(catalyst)
The catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel.

From the viewpoint of reactivity, the catalyst is preferably at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, and nickel.

In addition, from the viewpoint of suitably increasing the purity of the fluorene compound represented by the above formula (2), the catalyst is preferably supported on at least one carrier selected from the group consisting of carbon, alumina, silica gel, diatomaceous earth, titanium oxide, zirconium, and calcium carbonate.

When the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, and platinum, the amount supported is preferably 0.1 to 10% by mass.
When the catalyst is a nickel catalyst, the supported amount is preferably 40 to 50 mass %.

Specific examples of the catalyst supported on the above carrier include palladium-carbon (Pd/C), palladium-alumina (Pd/Al ₂ O ₃ ), ruthenium-carbon (Ru/C), ruthenium-alumina (Ru/Al ₂ O ₃ ), rhodium-carbon (Rh/C), rhodium-alumina (Rh/Al ₂ O ₃ ), nickel-carbon (Ni/C), nickel-silica (Ni/SiO ₂ ), nickel-diatomaceous earth (Ni/diatomaceous earth), Raney nickel (Ni/Al), and the like.

Among these, ruthenium is more preferable from the viewpoint of suitably increasing the purity of the fluorene compound represented by the above formula (2).

The amount of the catalyst used is preferably 0.01 to 50 parts by mass per 100 parts by mass of the fluorene compound represented by formula (1) above.

(solvent)
The solvent is at least one selected from the group consisting of ether-based solvents and ester-based solvents.

The ether solvent may be at least one selected from the group consisting of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ethylene glycol dimethyl ether, diethyl ether, tetrahydrofuran, dioxane, dibutyl ether, diethylene glycol diethyl ether, and ethylene glycol dibutyl ether.

The ester solvent may be at least one selected from the group consisting of ethyl acetate, butyl acetate, methyl isobutyrate, isobutyl acetate, normal propyl acetate, isopropyl acetate, diethylene glycol monoethyl ether acetate, butyl propionate, and cellosolve acetate.

From the viewpoint of the solubility of the fluorene compound represented by the above formula (1), the above solvent is preferably at least one selected from the group consisting of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether.

The amount of the solvent used is preferably 100 to 10,000 parts by mass per 100 parts by mass of the fluorene compound represented by formula (1) above.

(Reaction temperature)
In the hydrogenation step, the reaction temperature is preferably 80°C to 150°C.
By setting the reaction temperature within the above range, the yield and purity of the fluorene compound represented by the above formula (2) can be suitably increased.

(Hydrogen pressure)
In the hydrogenation step, the hydrogen pressure is preferably 1 MPa to 10 MPa in terms of gauge pressure.
By setting the hydrogen pressure within the above range, the yield and purity of the fluorene compound represented by the above formula (2) can be suitably increased.
The hydrogen pressure is more preferably 1 MPa to 5 MPa in terms of gauge pressure.
The gauge pressure means a pressure not including atmospheric pressure (atmospheric pressure is set to 0 MPa).

(Reaction Time)
The hydrogenation step preferably has a reaction time of 4 to 10 hours. By setting the reaction time within the above range, the yield and purity of the fluorene compound represented by the formula (2) can be suitably increased.
The reaction time is more preferably 5 to 8 hours.
The reaction time means the time from when the reaction temperature is reached to when the reaction is completed.

(others)
The hydrogen used in the hydrogenation step may be any hydrogen that is used in conventional hydrogenation reactions. Specifically, pure hydrogen or a mixed gas of hydrogen and an inert gas such as nitrogen may be used.

The hydrogenation process can be carried out as a batch or continuous suspension reaction using a powder catalyst, or as a fixed bed reaction using a tablet catalyst, etc.

The equipment used in the hydrogenation process is not particularly limited, and any known equipment may be appropriately selected.

(purification)
After the hydrogenation step, purification may be carried out.
The purification may be carried out by filtering the catalyst used in the hydrogenation step or by purification through recrystallization.
The purification method is not particularly limited, and any known method may be used.
The recrystallization can be carried out, for example, by adding ion-exchanged water to a filtrate obtained by filtering the catalyst used in the hydrogenation step to obtain crude crystals, adding ethyl acetate and normal hexane to the crude crystals, raising the temperature to dissolve the crude crystals, and then cooling to crystallize the crude crystals.

(Analysis method)
The fact that the fluorene compound represented by the above formula (2) has been obtained can be confirmed by gas chromatography (GC).
As a specific method, the method described in the Examples and the like of this specification may be used.

［式（１）、（２）中、ｍは、それぞれ独立に０又は１の整数を表し、ｎは、それぞれ独立に０～６の整数を表す。］ The present specification discloses the following:
The present disclosure (1) is a method for producing a fluorene compound, comprising a hydrogenation step of hydrogenating a fluorene compound represented by the following formula (1) in the presence of a catalyst and a solvent to obtain a fluorene compound represented by the following formula (2), wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel, and the solvent is at least one selected from the group consisting of ether-based solvents and ester-based solvents.

[In formulas (1) and (2), each m independently represents an integer of 0 or 1, and each n independently represents an integer of 0 to 6.]

The present disclosure (2) is the method for producing a fluorene compound according to the present disclosure (1), wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, and nickel.
The present disclosure (3) is the method for producing a fluorene compound according to the present disclosure (1) or (2), wherein the catalyst is supported on at least one carrier selected from the group consisting of carbon, alumina, silica gel, diatomaceous earth, titanium oxide, zirconium, and calcium carbonate.
The present disclosure (4) is a method for producing a fluorene compound according to any one of (1) to (3), in which the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, and platinum, and the supported amount is 0.1 to 10 mass %. In the case of a nickel catalyst, the supported amount is 40 to 50 mass %.
The present disclosure (5) is a method for producing a fluorene compound according to any one of the present disclosures (1) to (4), wherein the solvent is at least one selected from the group consisting of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether.
The present disclosure (6) is a method for producing a fluorene compound according to any one of the present disclosures (1) to (5), wherein the reaction temperature in the hydrogenation step is 80° C. to 150° C.
The present disclosure (7) is the method for producing a fluorene compound according to any one of the present disclosures (1) to (6), wherein the hydrogen pressure in the hydrogenation step is 1 MPa to 10 MPa in terms of gauge pressure.
The present disclosure (8) is the method for producing a fluorene compound according to any one of the present disclosures (1) to (7), wherein the reaction time of the hydrogenation step is 4 to 10 hours.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Reagents were used for compounds not specifically mentioned.

In the examples and comparative examples, the following catalysts and solvents were used.
(catalyst)
Ru/C (ruthenium-carbon, manufactured by N.E. Chemcat Corporation)
Pd/C (palladium-carbon, manufactured by N.E. Chemcat Corporation)
Ni/diatomaceous earth (nickel-diatomaceous earth, manufactured by Sakai Chemical Industry Co., Ltd.)
Rh/C (rhodium-carbon, manufactured by N.E. Chemcat Corporation)
The above Ru/C, Pd/C, and Rh/C all have a metal loading of 5% and are dry products, while the Ni/diatomaceous earth has a metal loading of 40 to 50% and is a dry product.
(solvent)
- Diethylene glycol dimethyl ether (Nacalai Tesque)
- Triethylene glycol dimethyl ether (Nacalai Tesque)
- Ethyl acetate (Nacalai Tesque)
-Butyl acetate (Nacalai Tesque)
- Cyclohexanone (Kishida Chemical Co., Ltd.)
N-methyl-2-pyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[Synthesis of fluorene compound represented by formula (1)]
45 g of fluorenone with a purity of 99.5% by mass and 170 g of 2-phenylphenol were charged into a 1000 mL vessel equipped with a stirrer, a cooling tube, and a buret, and 0.2 mL of a thiol, specifically β-mercaptopropionic acid, was added and melted by heating to 65° C., and 40 mL of 95% sulfuric acid was added dropwise over 10 minutes. Thereafter, the reaction solution was stirred for 1 hour while being heated to 65° C. to complete the reaction.
After the reaction was completed, 200 g of methanol was added to the reaction solution, which was then heated to 60° C. and stirred for 1 hour, after which it was cooled to 30° C., 900 g of pure water was added, and the resulting solid was filtered and dried.
By the above method, 9-9-bis-(3'-phenyl-4'-hydroxyphenyl)-fluorene [fluorene compound represented by the above formula (1) where m=0 and n=0] was obtained in a yield of 85.6%.

A 1000 mL vessel equipped with a stirrer, a cooling tube, and a buret was charged with 100 g of fluorenone with a purity of 99.5% by mass and 480 g of o-phenylphenol (2-hydroxyethyl) ether, 0.5 mL of β-mercaptopropionic acid was added, and the mixture was heated to 65° C. and melted, and 40 mL of 36% hydrochloric acid was added dropwise over 10 minutes. Thereafter, the reaction solution was stirred for 1 hour while being heated to 65° C. to complete the reaction.
After the reaction was completed, 600 g of methanol was added to the reaction solution, which was then heated to 60° C. and stirred for 1 hour. Then, 300 g of pure water was added to precipitate the reaction product, which was then cooled to room temperature and separated by filtration. The resulting solid was filtered and dried.
By the above method, 9-9-bis-[4-(2-hydroxyethoxy)-3-phenyl]-fluorene (a fluorene compound represented by the above formula (1) where m=1 and n=2) was obtained in a yield of 83.6%.

Example 1
In a 1500 mL stainless steel autoclave equipped with a magnetic stirrer, 80 g of 9-9-bis-(3'-phenyl-4'-hydroxyphenyl)-fluorene [fluorene compound in the above formula (1) where m = 0, n = 0], 12 g of 5% Ru/C, and 452 g of diethylene glycol dimethyl ether were charged, and the system was replaced with hydrogen, and then hydrogenation was carried out for 7.5 hours under conditions of 100 ° C. and 5 MPa (gauge pressure) while stirring. After the reaction was completed, 600 g of diethylene glycol dimethyl ether was added to the reaction product, heated to 60 ° C., and the catalyst was filtered off.
The obtained filtrate was transferred to a 2 L eggplant flask, and 211 g of the reaction solvent was distilled off using an evaporator under conditions of an oil temperature of 80° C. and a reduced pressure of 20 mmHg. The concentrated reaction product was added to a 2000 mL four-neck flask equipped with a stirrer and a thermometer, and then cooled to 20° C. with stirring. The generated crystals were filtered off, and the obtained crystals were rinsed with 320 g of ion-exchanged water.
The wet crystals were dried under reduced pressure at 100°C for 31 hours to obtain 52 g (0.1 mol) of 9-9-bis(4-hydroxy-3-cyclohexylphenyl)fluorene [fluorene compound in the above formula (2), where m = 0 and n = 0] with a purity of 98.9% (GC area percentage). The melting point of the crystals was 210°C.
The yield of 9-9-bis(4-hydroxy-3-cyclohexylphenyl)fluorene [the fluorene compound represented by the above formula (2), where m=0 and n=0] was 64.0%.

(Examples 2 to 11, Comparative Examples 1 and 2)
A fluorene compound was produced in the same manner as in Example 1, except that the catalyst, solvent, hydrogen pressure, reaction temperature, and reaction time were changed as shown in Table 1.
In addition, the term "target product" in Table 1 refers to 9-9-bis(4-hydroxy-3-cyclohexylphenyl)fluorene [a fluorene compound represented by the above formula (2) where m = 0 and n = 0]. The hydrogen pressure refers to the numerical value of the gauge pressure.

Example 12
A 1500 mL stainless steel autoclave equipped with a magnetic stirrer was charged with 80 g of 9-9-bis-(3'-phenyl-4'-hydroxyphenyl)-fluorene [fluorene compound in the above formula (1) where m = 0, n = 0], 40 g of 5% Ru/C, and 452 g of diethylene glycol dimethyl ether. After replacing the atmosphere in the system with hydrogen, hydrogenation was carried out for 8 hours under conditions of 150°C and 1 MPa (gauge pressure) with stirring.
Except for the above, the same procedure as in Example 1 was followed to produce a fluorene compound.

Example 13
A 1500 mL stainless steel autoclave equipped with a magnetic stirrer was charged with 90 g of 9-9-bis-[4-(2-hydroxyethoxy)-3-phenyl]-fluorene [a fluorene compound in which m = 1 and n = 2 in the above formula (1)], 18 g of 5% Ru/C, and 510 g of diethylene glycol dimethyl ether. The system was replaced with hydrogen, and then hydrogenation was carried out for 8 hours under conditions of 100°C and 5 MPa (gauge pressure) with stirring.
After the reaction was completed, the mixture was cooled to 30° C., and the catalyst was filtered off. 530 g of the obtained filtrate was added to a 1 L four-neck flask equipped with a stirrer, a thermometer, and a cooling tube, and 100 g of ion-exchanged water was added at 28° C. to precipitate crystals.
The resulting crystals were filtered off and rinsed with 260 g of ion-exchanged water.
As a result, 9-9-bis-[4-(2-hydroxyethoxy)-3-cyclohexyl]-fluorene (a fluorene compound represented by the above formula (2), where m=1 and n=2) having a purity of 93.6 GC% (GC area percentage) was obtained as a wet crystal.
98 g of the obtained wet crystals, 2500 g of ethyl acetate, and 320 g of normal hexane were added to a 5 L four-neck flask equipped with a stirrer, a thermometer, and a cooling tube, and the mixture was heated to 65°C and dissolved by heating, and then stirred for 30 minutes. The mixture was then cooled to 15°C, and the precipitated crystals were filtered off, and the crystals were rinsed with 50 g of ion-exchanged water. The wet crystals were dried under reduced pressure at 100°C for 30 hours to obtain 70 g (0.12 mol) of 9-9-bis-[4-(2-hydroxyethoxy)-3-cyclohexyl]-fluorene [fluorene compound in the above formula (2), where m = 1 and n = 2] with a purity of 99.5% (GC area percentage).
The yield of 9-9-bis-[4-(2-hydroxyethoxy)-3-cyclohexyl]-fluorene (the fluorene compound represented by the above formula (2), where m=1 and n=2) was 80.0%.

(Examples 14 to 15)
A fluorene compound was produced in the same manner as in Example 13, except that the catalyst, solvent, and reaction time were changed as shown in Table 2.
In Table 2, the term "target product" refers to 9-9-bis-[4-(2-hydroxyethoxy)-3-cyclohexyl]-fluorene (a fluorene compound represented by the above formula (2) where m = 1 and n = 2). The hydrogen pressure refers to the gauge pressure.

(Example 16)
A 1500 mL stainless steel autoclave equipped with a magnetic stirrer was charged with 90 g of 9-9-bis-[4-(2-hydroxyethoxy)-3-phenyl]-fluorene [a fluorene compound in which m = 1 and n = 2 in the above formula (1)], 36 g of 5% Ru/C, and 510 g of diethylene glycol dimethyl ether. The system was replaced with hydrogen, and then hydrogenation was carried out for 8 hours under conditions of 150°C and 1 MPa (gauge pressure) with stirring.
Except for the above, the same procedure as in Example 13 was followed to produce a fluorene compound.

(GC analysis)
The products obtained in each of the Examples and Comparative Examples were subjected to GC analysis under the following measurement conditions to confirm that the target compounds were obtained.
<Measurement conditions>
Model: Gas chromatograph GC-2025 (Shimadzu Corporation)
Detector: FID, 325°C
Column: DB-1 (30 m x 0.25 mmφ x 0.25 μm) manufactured by Agilent Technologies, Inc.
Column temperature: 275°C, heating rate 10°C/min, 320°C (holding time 60 min)
Injection temperature: 300°C
Carrier gas: Helium (linear velocity: 30 cm/sec)
Injection volume: 1.0 μl (split ratio: 46.6)

<Purity>
The purity of the obtained product was calculated by the following method.
The purity of the obtained product was determined by preparing a trimethylsilylated sample by the method described below, and then carrying out GC analysis. The percentage of the trimethylsilylated sample relative to the total amount was determined by the area percentage method, and this value was regarded as the purity of the product.
(Sample Preparation)
5.0 g of pyridine (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 0.5 g of the obtained product (fluorene compound) and dissolved by shaking at room temperature. Then, 1.5 g of BSTFA-TMCS (99:1) [Derivatizing Reagent for GC] manufactured by Tokyo Chemical Industry Co., Ltd. was added and shaken at room temperature to prepare a sample.
The purity obtained was evaluated according to the following criteria, and the results are shown in Tables 1 and 2.
(Evaluation Criteria)
⊚: 80% or more.
A: 60% or more but less than 80%.
×: Less than 60%.

It was confirmed that the method for producing a fluorene compound described in the Examples can produce the target fluorene compound represented by the above formula (2) with high purity.
In addition, it was confirmed that the fluorene compound represented by the above formula (2) can be obtained from a phenylphenol compound and fluorenone in a yield of 50% or more by the method for producing the fluorene compound described in Examples 1 and 13. This shows that the yield is excellent, since the yield was about 25% in the conventional method (a method in which a phenylphenol compound is hydrogenated to obtain a cyclohexylphenol compound, and then the cyclohexylphenol compound is reacted with fluorenone).

The fluorene compounds obtained by the method for producing fluorene compounds of the present invention are useful as raw material monomers for resins such as polyester resins, polyester polycarbonate resins, polycarbonate resins, epoxy resins, polyurethane resins, polyacrylic ester resins, and polymethacrylic ester resins, and as resin modifiers.

Claims (8)

The method includes a hydrogenation step of hydrogenating a fluorene compound represented by the following formula (1) in the presence of a catalyst and a solvent to obtain a fluorene compound represented by the following formula (2),
the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, platinum, and nickel;
The method for producing a fluorene compound, wherein the solvent is at least one selected from the group consisting of ether-based solvents and ester-based solvents.

[In formulas (1) and (2), each m independently represents an integer of 0 or 1, and each n independently represents an integer of 0 to 6.] The method for producing a fluorene compound according to claim 1, wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, and nickel. The method for producing a fluorene compound according to claim 1, wherein the catalyst is supported on at least one carrier selected from the group consisting of carbon, alumina, silica gel, diatomaceous earth, titanium oxide, zirconium, and calcium carbonate. The method for producing a fluorene compound according to claim 3, wherein the catalyst is at least one metal catalyst selected from the group consisting of ruthenium, palladium, rhodium, osmium, iridium, and platinum, and the amount supported is 0.1 to 10 mass %, and when the catalyst is a nickel catalyst, the amount supported is 40 to 50 mass %. The method for producing a fluorene compound according to any one of claims 1 to 4, wherein the solvent is at least one selected from the group consisting of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether. The method for producing a fluorene compound according to any one of claims 1 to 4, wherein the hydrogenation step is carried out at a reaction temperature of 80°C to 150°C. The method for producing a fluorene compound according to any one of claims 1 to 4, wherein the hydrogenation step is carried out at a hydrogen pressure of 1 MPa to 10 MPa in terms of gauge pressure. The method for producing a fluorene compound according to any one of claims 1 to 4, wherein the reaction time of the hydrogenation step is 4 hours to 10 hours.