JP2024045045A - Fluorene compound and method for producing same - Google Patents

Abstract

［式中、Ｒ^１は置換基、ｋは０～８の整数、Ｒ^{２ａ ～ ２ ｄ}、Ｒ^{３ａ ～ ３ ｄ}は独立してＨまたは置換基、Ｒ^{４ａ ～ ４ｂ}は独立して－ＯＲ^ｈ（式中、Ｒ^ｈはＨもしくは炭化水素基）、グリシジルオキシ基、２－メチルグリシジルオキシ基またはハロゲン原子を示す。］
【選択図】なしThe present invention provides a method for simply or efficiently producing a specific fluorene compound with a high reaction conversion rate, and a fluorene compound obtained by this production method.
[Solution] A fluorene compound represented by the following formula (3) is produced through a reaction process in which 9H-fluorenes that are unsubstituted at the 9,9-positions are reacted with an unsaturated compound such as methyl acrylate in a reaction solvent containing at least a ketone.

[In the formula, R ¹ is a substituent, k is an integer of 0 to 8, R ^{2a to 2 d} and R ^{3a to 3 d} are independently H or a substituent, and R ^{4a to 4b} are independently -OR ^h (in the formula, R ^h is H or a hydrocarbon group), a glycidyloxy group, a 2-methylglycidyloxy group, or a halogen atom.]
[Selection diagram] None

Description

This disclosure relates to a method for producing a fluorene compound and the compound obtained by this method.

Compounds with a fluorene skeleton have excellent optical properties, such as a high refractive index, and thermal properties, such as heat resistance, and are effectively used as resin raw materials and additives.

JP 2002-179611 A (Patent Document 1) discloses a method for producing a carboxylic acid compound having a fluorene skeleton by reacting fluorene with an unsaturated carboxylic acid compound in the presence of a strong base catalyst.

JP 2005-89422 A (Patent Document 2) discloses a method for producing fluorenedicarboxylic acid esters by reacting a specific fluorene with a carboxylic acid ester in the presence of a strong base catalyst.

JP 2002-179611 A JP 2005-89422 A

Example 6 of Patent Document 1 describes the synthesis of dimethyl 3',3'-(9-fluorenylidene)dipropionate, represented by the following formula, by reacting fluorene with methyl acrylate in dioxane in the presence of a strong base catalyst.

Furthermore, in Example 1 of Patent Document 2, fluorene and t-butyl acrylate are reacted in 1,4-dioxane in the presence of a strong base catalyst, and 9,9-bis(t-butyl propionate is It is described that fluorene (butyl) was synthesized.

However, there is a need for a method for preparing fluorene compounds more easily or efficiently.

In addition, depending on the usage environment or storage conditions, these fluorene compounds may not have sufficient thermal stability, and may be prone to coloration under harsh conditions, particularly high temperature environments, which may limit their applications. Therefore, there is a demand for even higher thermal stability or storage stability in high temperature environments.

Therefore, the object of the present invention (or the present disclosure) is to provide a method for producing a specific fluorene compound simply (or easily) or efficiently with a high reaction conversion rate, and to provide a fluorene compound obtained by this production method.

As a result of intensive research to achieve the above object, the present inventors discovered that by reacting fluorenes with a compound having an α,β-unsaturated carbonyl group (α,β-unsaturated carbonyl compound) in a specific solvent, a fluorene compound that can effectively suppress coloration even in a high-temperature environment can be obtained, and thus completed the present invention (or the present disclosure).

That is, the present disclosure may include the following aspects.

Aspect [1]: A method for producing a fluorene compound represented by the following formula (3), comprising a reaction step of reacting fluorenes represented by the following formula (1) (9H-fluorenes unsubstituted at the 9,9-positions) with compounds represented by the following formulas (2a) and (2b) in a reaction solvent containing at least ketones.

(In the formula, ^R1 represents a substituent, and k represents an integer of 0 to 8).

[In the formula, R ^2a , R ^2b , R ^2c and R ^2d independently represent a hydrogen atom or a substituent,
R ^3a and R ^3b independently represent a hydrogen atom or a substituent,
R ^4a and R ^4b independently represent a hydroxyl group, a group [-OR ^h ] (in the formula, R ^h represents a hydrocarbon group), a glycidyloxy group, a 2-methylglycidyloxy group, or a halogen atom].

(In the formula, R ¹ , k, R ^2a , R ^2b , R ^2c , R ^2d , R ^3a , R ^3b , R ^4a and R ^4b are each the same as defined above).

Aspect [2]: The method according to aspect [1], wherein the ketone is a dialkyl ketone.

Aspect [3]: The production method according to Aspect [1] or [2], wherein the reaction solvent in the reaction step further contains hydrocarbons in addition to the ketones.

Aspect [4]: In the formulas (1), (2a), (2b) and (3),
R ¹ is a halogen atom, a hydrocarbon group, an alkoxy group, an acyl group, a nitro group, a cyano group or a substituted amino group, and k is an integer of about 0 to 4;
R ^2a and R ^2b are independently a hydrogen atom, a hydrocarbon group, a carboxyl group or an alkoxycarbonyl group, and R ^2c and R ^2d are independently a hydrogen atom or a hydrocarbon group,
R ^3a and R ^3b are independently a hydrogen atom, a hydrocarbon group, a carboxyalkyl group or an alkoxycarbonylalkyl group,
Embodiments [1] to 1, wherein R ^4a and R ^4b are independently a hydroxyl group, a group [-OR ^h ] (in the formula, R ^h represents a hydrocarbon group), a glycidyloxy group, or a 2-methylglycidyloxy group The manufacturing method according to any one of [3].

Aspect [5]: The manufacturing method according to any one of aspects [1] to [4], in which the reaction temperature in the reaction step is about -20°C to 100°C.

Aspect [6]: The production method according to any one of Aspects [1] to [5], wherein the reaction conversion rate of the 9H-fluorene represented by the formula (1) is about 95% or more.

Aspect [7]: A fluorene compound represented by formula (3) according to any one of Aspects [1] to [6] above, which exhibits a hue (APHA ) is 150 or less.

Aspect [8]: The fluorene compound according to aspect [7], having a purity of about 99.8 area % or more by HPLC.

Aspect [9]: The fluorene compound according to aspect [7] or [8], in which the content of 9H-fluorenes represented by formula (1) according to any one of aspects [1] to [6] (content of unreacted raw materials as impurities) is about 0.03 area % or less by HPLC.

Aspect [10]: Represented by the formula (3) according to any one of the above aspects [1] to [9], R ^4a and R ^4b are a group [-OR ^h ] (wherein R ^h is a hydrocarbon group The content of a fluorene compound having the formula (3) in which one of R ^4a and R ^4b is a hydroxyl group and the other is the group [-OR ^h ] (content as an impurity) ) is about 0.1 area % or less in HPLC.

Aspect [11]: A method for improving the thermal stability of a fluorene compound represented by formula (3) according to any one of aspects [1] to [10], which is obtained by reacting a 9H-fluorene represented by formula (1) according to any one of aspects [1] to [6] with a compound represented by formula (2a) and formula (2b) according to any one of aspects [1] to [6] in a reaction solvent containing at least a ketone.

Aspect [12]: The method according to aspect [11], wherein the reaction temperature is 80°C or less.

Aspect [13]: 9H-fluorenes represented by the formula (1) according to any one of the above aspects [1] to [6] and the formula according to any one of the above aspects [1] to [6] Formula (3) according to any one of the embodiments [1] to [10] obtained by reacting (2a) and the compound represented by formula (2b) in a reaction solvent containing at least a ketone. A method for reducing the content of impurities in a fluorene compound represented by

Aspect [14]: The method according to aspect [13], wherein the reaction temperature is 45°C or less.

Aspect [15]: The fluorene compound represented by the formula (3) is a fluorene compound in which R ^4a and R ^4b are a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group),
The impurity is a compound in which in the formula (3), one of R ^4a and R ^4b is a hydroxyl group and the other is the group [-OR ^h ], and unreacted 9H represented by the formula (1) - The method according to the above aspect [13] or [14], which contains at least one selected from fluorenes.

Note that the present invention (or the present disclosure) may achieve the following sub-objects (or solve the problems).

That is, another object of the present disclosure is to provide a fluorene compound with excellent thermal stability (or storage stability in a high-temperature environment) and a method for producing the same.

A further object of the present disclosure is to provide a method for producing a fluorene compound that can suppress the remaining unreacted raw materials, and a fluorene compound obtained by this production method.

Note that in this specification and claims, the number of carbon atoms may be indicated as C ₁ , C ₆ , C ₁₀ , etc. For example, an alkyl group having 1 carbon number is indicated as a "C ₁ alkyl group", and an aryl group having 6 to 10 carbon atoms is indicated as a "C _6-10 aryl group".

In this specification and claims, "independently" means that two components are each independent components, and in the case of R ^2a , R ^2b , R ^2c and R ^2d , This means that R ^2a , R ^2b , R ^2c and R ^2d may be the same group (hydrogen atom or substituent) or different groups (hydrogen atom or substituent).

In this specification and claims, the numerical ranges indicated with " to " are used to mean both ends of the range unless otherwise specified.

In the method of the present disclosure, a specific fluorene and a compound having a specific α,β-unsaturated carbonyl group (α,β-unsaturated carbonyl compound) are reacted in a specific solvent, so that the reaction conversion rate is high. A predetermined fluorene compound can be produced simply (or easily) or efficiently.

FIG. 1 is a chart showing the powder X-ray diffraction pattern of the crystals of FDP-m obtained in Example 1. FIG. 2 is a chart showing the powder X-ray diffraction pattern of the crystals of FDP-m obtained in Example 2. FIG. 3 is a chart showing the powder X-ray diffraction pattern of the crystals of FDP-m obtained in Comparative Example 1.

[Reaction process]
The production method of the present disclosure comprises a 9H-fluorene compound represented by the following formula (1) with unsubstituted 9,9-positions, a compound represented by the below-described formula (2a), and a compound represented by the below-mentioned formula (2b). The method includes at least a reaction step of reacting (Michael addition reaction) with a compound to be used in a reaction solvent containing at least ketones.

(9H-fluorenes represented by formula (1))
9H-fluorenes unsubstituted at the 9,9-positions are compounds represented by the following formula (1), and may hereinafter be simply referred to as "compound (1)" or "9H-fluorenes".

(In the formula, R ¹ represents a substituent, and k represents an integer of 0 to 8).

In the formula (1), the group R ¹ may be a non-reactive group that is inert to the reaction, such as a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; an alkyl group (linear or Branched alkyl groups), hydrocarbon groups such as aryl groups; alkoxy groups; acyl groups; nitro groups; cyano groups; and substituted amino groups (mono- or di-substituted amino groups).

Examples of the alkyl group (linear or branched alkyl group) include C _1-12 alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and t-butyl group. and preferably a C _1-8 alkyl group, particularly a C _1-4 alkyl group such as a methyl group.

Examples of the aryl group include C _6-12 aryl groups such as a phenyl group, a naphthyl group, and a biphenyl group, and are preferably C _{6-10 aryl groups such as a phenyl group, a naphthyl group, and are preferably C 6-10} aryl groups such as a phenyl group, a naphthyl group, and are preferably a 1-naphthyl group, a 2-naphthyl group, and are preferably a 2-naphthyl group.

Examples of the alkoxy group include C _1-12 alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, and t-butoxy group, preferably C _1-8 alkoxy group. Mention may be made of groups, especially C _1-4 alkoxy groups such as methoxy groups.

Examples of the acyl group include C _1-6 alkyl-carbonyl groups such as an acetyl group.

Examples of the substituted amino group (mono- or di-substituted amino group) include mono- or di-alkylamino group, mono- or diarylamino group, mono- or bis(alkylcarbonyl)amino group, etc. Examples of the mono- or di-alkylamino group include mono- or di-C _1-4 alkylamino group such as dimethylamino group. Examples of the mono- or diarylamino group include mono- or di-C _6-12 arylamino group such as diphenylamino group, N-phenyl-N-tolylamino group, N-phenyl-N-naphthylamino group, etc. Examples of the mono- or bis(alkylcarbonyl)amino group include mono- or bis(C _1-4 alkyl-carbonyl)amino group such as diacetylamino group.

A preferred group R ¹ is a halogen atom or a hydrocarbon group, more preferably a hydrocarbon group such as an alkyl group or an aryl group, especially an aryl group.

The number of substitutions k may be, for example, an integer of about 0 to 6, and is preferably an integer of 0 to 4, an integer of 0 to 3, an integer of 0 to 2, stepwise, more preferably 0 or 1, or 0 or 2, and particularly preferably 0. The numbers of substitutions of the group R ¹ in the two benzene rings constituting the fluorene ring (the number of substitutions at the 1st to 4th positions and the number of substitutions at the 5th to 8th positions) may be different from each other, but are preferably the same.

In addition, when the number k of substitutions of the group R ¹ is more than one (2 or more), the types of the two or more groups R ¹ substituted on one of the two benzene rings constituting the fluorene ring may be the same or different; the types of the groups R ¹ substituted on both benzene rings may be different, but are preferably the same. In addition, the bonding position (substitution position) of the group R ¹ is not particularly limited as long as it is the 1st to 8th positions of the fluorene ring, and examples thereof include the 2nd position, 7th position, and 2,7th positions of the fluorene ring, with the 2nd and 7th positions being preferred.

Representative compounds (9H-fluorenes) represented by the formula (1) include, for example, 9H-fluorene, diaryl-9H-fluorene, dihalo-9H-fluorene, and the like.

Examples of diaryl-9H-fluorene include 2,7-diphenyl-9H-fluorene, 2,7-di(1-naphthyl)-9H-fluorene, 2,7-di(2-naphthyl)-9H-fluorene, DiC _6-12 aryl such as 2,7-di(biphenylyl)-9H-fluorene, 1,8-diphenyl-9H-fluorene, 3,6-diphenyl-9H-fluorene, 4,5-diphenyl-9H-fluorene Examples include -9H-fluorene.

Examples of dihalo-9H-fluorene include 2,7-dibromo-9H-fluorene, 2,7-dichloro-9H-fluorene, 2,7-diiodo-9H-fluorene, 1,8-dibromo-9H-fluorene, Examples include 3,6-dibromo-9H-fluorene and 4,5-dibromo-9H-fluorene.

These compounds (1) may be commercially available products or may be prepared by a conventional method. These compounds (1) may be used alone or in combination of two or more. Among these compounds (1), 9H-fluorene, 2,7-diaryl-9H-fluorene, and 2,7-dibromo-9H-fluorene are preferred, and 9H-fluorene, 2,7- _diC6-10aryl -9H-fluorene, and 2,7-dibromo-9H-fluorene are more preferred, with 9H-fluorene being particularly preferred.

(Compounds represented by formulas (2a) and (2b))
The compound represented by the following formula (2a) may be hereinafter simply referred to as "compound (2a)", and the compound represented by the following formula (2b) may hereinafter simply be referred to as "compound (2b)". The compounds represented by formulas (2a) and (2b) may be hereinafter simply referred to as "compounds (2a) (2b)".

It is preferable that compound (2a) and compound (2b) have the same chemical structure.

[In the formula, R ^2a , R ^2b , R ^2c and R ^2d each independently represent a hydrogen atom or a substituent,
R ^3a and R ^3b each independently represent a hydrogen atom or a substituent;
R ^4a and R ^4b each independently represent a hydroxyl group, a group [—OR ^h ] (wherein R ^h represents a hydrocarbon group), a glycidyloxy group, a 2-methylglycidyloxy group, or a halogen atom.

In the formulas (2a) and (2b), the substituents represented by R ^2a , R ^2b , R ^2c and R ^2d may be non-reactive groups that are inactive in the reaction, and examples thereof include hydrocarbon groups such as alkyl groups, cycloalkyl groups, aryl groups and aralkyl groups, carboxyl groups and alkoxycarbonyl groups.

Examples of the alkyl group (linear or branched alkyl group) include _C1-12 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group and t-butyl group, and preferably, in the following stepwise order, _C1-6 alkyl group, _C1-4 alkyl group, _C1-3 alkyl group, _C1-2 alkyl group and methyl group.

Examples of the cycloalkyl group include a C _5-10 cycloalkyl group such as a cyclopentyl group and a cyclohexyl group.

Examples of the aryl group include C _6-12 aryl groups such as a phenyl group, an alkylphenyl group, a biphenylyl group, a naphthyl group, etc. Examples of the alkylphenyl group include mono- to tri-C _1-4 alkyl-phenyl groups such as a methylphenyl group (or a tolyl group) and a dimethylphenyl group (or a xylyl group).

Examples of the aralkyl group include a C _6-10 aryl-C _1-4 alkyl group such as a benzyl group or a phenethyl group.

Examples of the alkoxycarbonyl group (linear or branched alkoxycarbonyl group) include C _1-6 alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, and t-butoxycarbonyl group.

Preferred examples of R ^2a , R ^2b , R ^2c and R ^2d include a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a carboxyl group or an alkoxycarbonyl group, more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom.

The types of R ^2a , R ^2b , R ^2c and R ^2d may be the same or different, but it is preferable that the types of R ^2a and R ^2b are the same, and the types of R ^2c and R ^2d are the same.

Preferred examples of R ^2a and R ^2b include a hydrogen atom, a hydrocarbon group, a carboxyl group, or an alkoxycarbonyl group, more preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a carboxyl group, or an alkoxycarbonyl group, still more preferably a hydrogen atom, an alkyl group, a carboxyl group, or an alkoxycarbonyl group, of which a hydrogen atom or an alkyl group is preferred, and particularly preferably a hydrogen atom.

Preferred examples of R ^2c and R ^2d include a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, still more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom. be.

The substituents represented by ^R3a and ^R3b may be non-reactive groups that are inactive in the reaction, and examples thereof include hydrocarbon groups such as alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups, carboxyalkyl groups, and alkoxycarbonylalkyl groups.

Examples ^of hydrocarbon groups such as ^alkyl groups, cycloalkyl groups, aryl groups, and ^{aralkyl groups} include the hydrocarbon groups (alkyl groups, (cycloalkyl group, aryl group, aralkyl group) and the like. Among these hydrocarbon groups, alkyl groups (linear or branched chain alkyl groups) are preferred, and more preferably C _1-12 alkyl groups, C _1-6 alkyl groups, C _1-4 These are an alkyl group, a C _1-3 alkyl group, a C _1-2 alkyl group, and a methyl group.

Examples of the carboxyalkyl group include carboxyC _1-6 alkyl groups such as carboxymethyl group and carboxyethyl group.

Examples of the alkoxycarbonylalkyl group include C _1-6 alkoxy-carbonyl C _1-6 alkyl groups such as a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, a t-butoxycarbonylmethyl group, and a methoxycarbonylethyl group.

Preferred examples of R ^3a and R ^3b include a hydrogen atom, an alkyl group, a carboxyalkyl group, or an alkoxycarbonylalkyl group, more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom.

Note that the types of R ^3a and R ^3b may be different from each other, but are preferably the same.

In the group [-OR ^h ] in R ^4a and R ^4b (wherein R ^h represents a hydrocarbon group), examples of the hydrocarbon group R ^h include an alkyl group (a linear or branched alkyl group), a cycloalkyl group, an aryl group, an aralkyl group, etc. Examples of these hydrocarbon groups R ^h include the same groups as the hydrocarbon groups (alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups) exemplified as the substituents represented by R ^2a , R ^2b , R ^2c , and R ^2d .

Examples of the group [—OR ^h ] include an alkoxy group (a linear or branched alkoxy group), a cycloalkyloxy group, an aryloxy group, and an aralkyloxy group.

Examples of alkoxy groups (straight-chain or branched-chain alkoxy groups) include C _1-12 alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, and t-butoxy groups, and preferably, in the following stepwise order, a C _1-6 alkoxy group, a C _1-4 alkoxy group, a C _1-3 alkoxy group, a C _1-2 alkoxy group, and a methoxy group.

Examples of the cycloalkyloxy group include C _5-10 cycloalkyloxy groups such as a cyclopentyloxy group and a cyclohexyloxy group.

Examples of the aryloxy group include C _6-12 aryloxy groups such as phenyloxy group (phenoxy group), alkylphenyloxy group, biphenylyloxy group, and naphthyloxy group (naphthoxy group). Examples of the alkylphenyloxy group include mono- to triC _1-4 alkyl-phenyloxy groups such as methylphenyloxy group (or tolyloxy group) and dimethylphenyloxy group (or xylyloxy group).

Examples of the aralkyloxy group include C _6-10 aryl-C _1-4 alkyloxy groups such as benzyloxy group and phenethyloxy group.

In R ^4a and R ^4b , examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom.

Preferred examples of R ^4a and R ^4b include a hydroxyl group, a group [-OR ^h ], a glycidyloxy group, or a 2-methylglycidyloxy group, more preferably a hydroxyl group or a group [-OR ^h ], and particularly preferably a group [-OR ^h ]. Among the groups [-OR ^h ], alkoxy groups (linear or branched alkoxy groups) are preferred.

Note that the types of R ^4a and R ^4b may be different from each other, but are preferably the same.

Representative compounds (2a) and (2b) include, for example, (meth)acrylic acid, acrylic acid substituted with a hydrocarbon group at the α-position (or 2-position) and/or β-position (or 3-position) (but (excluding methacrylic acid), acrylic acid substituted with a carboxyalkyl group at the α-position (or 2-position), acrylic acid substituted with a carboxyl group at the β-position (or 3-position), and esters corresponding to these acids. Examples include.

Acrylic acid (excluding methacrylic acid) in which the α-position (or 2-position) and/or β-position (or 3-position) is substituted with a hydrocarbon group, for example, the α-position (or 2-position) is substituted with a hydrocarbon group. (excluding methyl group), acrylic acid substituted with a hydrocarbon group at the β-position (or 3-position), hydrocarbon at the α-position (or 2-position) and β-position (or 3-position) Examples include acrylic acid substituted with a group.

Examples of acrylic acids in which the α-position (or 2-position) is substituted with a hydrocarbon group (excluding methyl group) include α-alkylacrylic acids, specifically α-C 2-6 alkyl-acrylic acids such as α-ethylacrylic acid, α-propylacrylic acid, α-isopropylacrylic acid, α-n-butylacrylic acid, α-isobutylacrylic acid, and α-sec-butylacrylic acid; α-cycloalkylacrylic acids, specifically α-C _5-10 cycloalkyl-acrylic acids such as α-cyclohexylacrylic acid; α-arylacrylic acids, specifically α-C _6-10 aryl-acrylic acids such as α-phenylacrylic acid; and α-aralkylacrylic acids, specifically α-C _5-10 aryl C _1-4 alkyl-acrylic acids such as α _- benzylacrylic acid.

Examples of acrylic acids in which the β-position (or 3-position) is substituted with a hydrocarbon group include β-alkylacrylic acid, specifically β-C _1- such as β-methylacrylic acid (or crotonic acid). _β- cycloalkyl acrylic acid, specifically β-C _5-10 cycloalkyl-acrylic acid such as β-cyclohexyl acrylic acid; β-aryl acrylic acid, specifically β -β-C _6-10 aryl-acrylic acids such as -phenylacrylic acid (or cinnamic acid).

Examples of acrylic acids in which the α-position (or 2-position) and β-position (or 3-position) are substituted with hydrocarbon groups include α,β-dialkylacrylic acids, specifically, α,β-di-C _1-6 alkylacrylic acids such as α,β-dimethylacrylic acid (or tiglic acid).

Examples of acrylic acids substituted with a carboxyalkyl group at the α-position (or 2-position) include α-carboxyalkylacrylic acids, specifically α-carboxyC _1-6 alkyl-acrylic acids such as α-carboxymethylacrylic acid (or itaconic acid).

An example of an acrylic acid in which the β-position (or 3-position) is substituted with a carboxyl group is maleic acid.

Examples of esters corresponding to these acids include alkyl esters, cycloalkyl esters, aryl esters, aralkyl esters, glycidyl esters, and 2-methylglycidyl esters. Examples of alkyl esters (linear or branched alkyl esters) include C _1-6 alkyl esters such as methyl ester, ethyl ester, and t-butyl ester. Examples of cycloalkyl esters include C _5-10 cycloalkyl esters such as cyclohexyl ester. Examples of aryl esters include C _{6-10 aryl esters such as phenyl ester. Examples of aralkyl esters include C 6-10 aryl} C _1-4 alkyl esters such as benzyl ester.

These compounds (2a) and (2b) may be commercially available products or may be prepared by conventional methods. Among these compounds (2a) and (2b), (meth)acrylic acid, acrylic acid in which the α-position (or 2-position) and/or β-position (or 3-position) is substituted with a hydrocarbon group (however, methacrylic acid is ) and esters corresponding to these acids are preferred, and (meth)acrylic acid and corresponding esters are more preferred, with (meth)acrylic acid alkyl esters being particularly preferred. Note that although different types of compounds may be used as compound (2a) and compound (2b), it is preferable to use the same compounds.

The ratio of the 9H-fluorenes represented by the formula (1) to the total amount of the compounds (2a) and (2b) may be, for example, the former/latter (molar ratio) = about 1/2 to 1/10, and is preferably 1/2.1 to 1/5, 1/2.3 to 1/3, and 1/2.5 to 1/2.8 in the following stepwise manner.

(Reaction Solvent)
In the reaction step, the reaction is carried out in a reaction solvent containing at least ketones (ketone-based solvent). By using ketones as the reaction solvent, the reaction conversion rate can be effectively improved, and the fluorene compound represented by formula (3) can be efficiently (or with high productivity) prepared. In addition, by using ketones as the reaction solvent, the thermal stability (storage stability under high temperature environment) of the obtained fluorene compound can be effectively improved (coloration occurring when heated can be effectively (easily or efficiently) suppressed).

The ketones may be any solvent that has at least a ketone structure [-C(=O)-] in its chemical structure and is inert to the reaction, such as chain ketones, cyclic ketones, and the like.

The chain ketone (linear or branched ketone) may be any compound having a ketone skeleton in a linear or branched structure, such as a dialkyl ketone that may have an ether bond. and alkyl-cycloalkyl ketones, and preferably C _3-12 chain ketones, C _3-10 chain ketones, C _4-8 chain ketones, and C _5-7 chain ketones. be.

Examples of dialkyl ketones include acetone (or 2-propanone), methyl ethyl ketone (MEK), methyl propyl ketone (or 2-pentanone), methyl isopropyl ketone (3-methyl-2-butanone), and diethyl ketone (or 3-pentanone). ), methyl butyl ketone (or 2-hexanone), methyl isobutyl ketone (MIBK), methyl-sec-butyl ketone (or 3-methyl-2-pentanone), methyl-t-butyl ketone (or 3,3-dimethyl-2- butanone), ethylpropylketone (or 3-hexanone), ethylisopropylketone (or 2-methyl-3-pentanone), methylpentylketone (or 2-heptanone), methylisoamylketone (or 5-methyl-2-hexanone) , methyl-1-methylbutyl ketone (or 3-methyl-2-hexanone), ethyl butyl ketone (or 3-heptanone), ethyl isobutyl ketone (or 5-methyl-3-hexanone), dipropyl ketone (or 4- heptanone), propyl isopropyl ketone (or 2-methyl-3-hexanone), diisopropyl ketone (or 2,4-dimethyl-3-pentanone), methylhexyl ketone (or 2-octanone), methyl-4-methylpentyl ketone (or or 6-methyl-2-heptanone), ethylpentylketone (or 3-octanone), ethyl-2-methylbutylketone (or 5-methyl-3-heptanone), propylbutylketone (or 4-octanone), propylisobutyl Ketone (or 2-methyl-4-heptanone), propyl-sec-butyl ketone (or 3-methyl-4-heptanone), isopropyl butyl ketone (or 2-methyl-3-heptanone), isopropyl isobutyl ketone (or 2,5 -dimethyl-3-hexanone), methylheptylketone (or 2-nonanone), methyl-3-methylhexylketone (or 5-methyl-2-octanone), ethylhexylketone (or 3-nonanone), propylpentylketone (or 4-nonanone), dibutylketone (or 5-nonanone), diisobutylketone (or 2,6-dimethyl-4-heptanone), methyloctylketone (or 2-decanone), ethylheptylketone (or 3-decanone), etc. Examples include C _3-12 dialkyl ketones.

Examples of alkyl cycloalkyl ketones include C _1-6 alkyl-C _5-10 cycloalkyl ketones such as methyl cyclopentyl ketone (or 1-cyclopentylethanone).

Examples of dialkyl ketones having an ether bond include alkoxy-dialkyl ketones, specifically C _1-6 alkoxy-C _3-12 dialkyl ketones such as methoxyacetone.

The cyclic ketone may be any compound having a ketone skeleton in its ring structure, such as cycloalkanone, specifically cyclopentanone, 2,2-dimethylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, C _5-10 cycloalkanones such as 3-methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 3,3-dimethylcyclohexanone, cycloheptanone; bridged cyclic cycloalkanones, specifically tricyclo[ 5.2.1.0 ^2.6 ] decan-8-one and the like.

These ketones (ketone-based solvents) can be used alone or in combination of two or more. Among these ketones, chain ketones (straight-chain or branched-chain ketones) are preferred, and dialkyl ketones are more preferred. Among dialkyl ketones, the following are preferred in the following order of steps: _C3-10 dialkyl ketone, _C4-8 dialkyl ketone, _C5-7 dialkyl ketone, _C6 dialkyl ketone, and MIBK.

The reaction solvent may be a ketone alone, or may contain a solvent (second solvent) different from a ketone (ketone-based solvent or first solvent) as long as the effect of the present disclosure is not significantly impaired. By combining with a second solvent, it may be possible to improve solubility and further improve productivity.

The other solvent (second solvent) is preferably inert to the reaction and capable of dissolving 9H-fluorenes and compounds (2a) and (2b), and may be either a nonpolar solvent or a polar solvent. The other solvent (second solvent) may be either a protic solvent or an aprotic solvent.

Examples of nonpolar solvents include hydrocarbons, halogenated hydrocarbons, and ethers. Examples of the protic polar solvent include alcohols and water. Examples of the aprotic polar solvent include sulfoxides.

Examples of hydrocarbons include aliphatic hydrocarbons such as hexane, heptane, and dodecane; alicyclic hydrocarbons such as cyclohexane; and aromatic hydrocarbons such as toluene and xylene.

Examples of halogenated hydrocarbons include chlorinated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, and dichlorobenzene.

Examples of ethers include cyclic ethers such as tetrahydrofuran (THF) and 1,4-dioxane; chain ethers, etc. Examples of chain ethers include dialkyl ethers such as diethyl ether and diisopropyl ether; alkyl phenyl ethers such as anisole; and (poly)alkylene glycol dialkyl ethers such as dimethoxyethane.

Examples of the alcohols include _C1-4 alcohols such as methanol, ethanol, propanol, and isopropyl alcohol (IPA).

Examples of sulfoxides include dimethyl sulfoxide (DMSO).

These other solvents (second solvents) can be used alone or in combination of two or more. Among these second solvents, preferably nonpolar solvents such as hydrocarbons and/or alcohols such as methanol may be used. When non-polar solvents such as hydrocarbons, especially aromatic hydrocarbons such as toluene, are combined with the first solvent, the reaction conversion rate can be improved and the purity of the target product [fluorene compound represented by formula (3)] can be improved. at least one property selected from improvement of impurities (such as reduction of monoesters described below) and improvement of thermal stability [improvement of storage stability or suppression of coloring (reduction of APHA) in high-temperature environments]. Or the properties may be improved. In addition, if a protic solvent such as water or alcohol is present in the reaction system (reaction solvent), the anion form of 9H-fluorene, which is a reaction intermediate, may be deactivated. The solvent may be removed. When adding a protic solvent such as water or alcohol, it may be added in the form of a solution containing a base, which will be described later.

The proportion of ketones (ketone-based solvent or first solvent) in the reaction solvent may be, for example, 10% by mass or more relative to the total reaction solvent, and may preferably be 30 to 100% by mass, 50 to 100% by mass, 70 to 100% by mass, 90 to 100% by mass, or 95 to 100% by mass in the following stepwise manner. When ketones are combined with a non-polar solvent such as a hydrocarbon, the proportion may preferably be 30 to 95% by mass, 50 to 90% by mass, 60 to 85% by mass, 65 to 80% by mass, or 70 to 75% by mass in the following stepwise manner. When the proportion of ketones is within a moderate range that is not too small, the reaction conversion rate can be sufficiently improved, the fluorene compound can be easily or efficiently produced, and the thermal stability (storage stability in a high-temperature environment) of the obtained fluorene compound tends to be effectively (easily or efficiently) improved.

The ratio of ketones (ketone-based solvent or first solvent) to other solvent (second solvent) may be selected from the range of former/latter (mass ratio) = about 10/90 to 100/0, preferably in the following stepwise manner: 30/70 to 100/0, 50/50 to 100/0, 70/30 to 100/0, 90/10 to 100/0, 95/5 to 99/1. The ratio may be the ratio of ketones to protic polar solvent; or it may be the ratio of ketones to alcohols such as methanol. In addition, the ratio of ketones (first solvent) to other solvents (second solvents) may be preferably in the following stepwise manner: former/latter (mass ratio) = 30/70 to 95/5, 50/50 to 90/10, 60/40 to 85/15, 65/35 to 80/20, 70/30 to 75/25. The ratio may be the ratio of ketones to non-polar solvents such as hydrocarbons and/or protic polar solvents such as alcohols as the second solvent; or the ratio of ketones such as dialkyl ketones to aromatic hydrocarbons such as toluene and/or alcohols such as methanol as the second solvent. When the ratio of ketones is in a moderate range that is not too small, the reaction conversion rate can be sufficiently improved, the fluorene compound can be easily or efficiently produced, and the thermal stability (storage stability in a high-temperature environment) of the obtained fluorene compound tends to be effectively (easily or efficiently) improved.

As the second solvent, preferably, a non-polar solvent such as a hydrocarbon, particularly an aromatic hydrocarbon such as toluene, may be combined with a ketone (first solvent), and the ratio of the ketone (first solvent) to the non-polar solvent such as a hydrocarbon may be, for example, the former/latter (mass ratio) = about 10/90 to 100/0, and preferably the following stepwise ratios are 30/70 to 99/1, 50/50 to 95/5, 60/40 to 90/10, 65/35 to 85/15, and 70/30 to 80/20. The ratio may be the ratio of a ketone such as a dialkyl ketone to an aromatic hydrocarbon such as toluene. If the ratio of the ketone is within a moderate range that is not too small, the reaction conversion rate can be sufficiently improved, the fluorene compound can be easily or efficiently produced, and the thermal stability (storage stability in a high-temperature environment) of the obtained fluorene compound tends to be effectively (easily or efficiently) improved. When the proportion of ketones is within a moderate range that is not too high, it tends to be easier to improve at least one characteristic or property selected from improving the reaction conversion rate, improving the purity of the target product [the fluorene compound represented by formula (3)], reducing impurities, and improving thermal stability [improving storage stability in high-temperature environments or suppressing coloration (reducing APHA)].

As the second solvent, a non-polar solvent such as a hydrocarbon (particularly, an aromatic hydrocarbon such as toluene) and a protic polar solvent (alcohols such as methanol) may be combined. The ratio of the non-polar solvent such as a hydrocarbon (particularly, an aromatic hydrocarbon such as toluene) to the protic polar solvent (alcohols such as methanol) may be, for example, the former/latter (mass ratio) = about 10/90 to 100/0, and is preferably in the following stepwise order: 30/70 to 99.9/0.1, 50/50 to 99.5/0.5, 65/35 to 99/1, 80/20 to 97/3, 90/10 to 95/5. When the ratio of the protic polar solvent is within a moderate range where the ratio is not too high, the reaction conversion rate can be sufficiently improved, the fluorene compound can be easily or efficiently produced, and the thermal stability (storage stability in a high-temperature environment) of the obtained fluorene compound tends to be effectively (easily or efficiently) improved. In addition, at least one characteristic or property selected from the following tends to be more easily improved: an improvement in the reaction conversion rate, an improvement in the purity of the target product [fluorene compound represented by formula (3)], a reduction in impurities, and an improvement in thermal stability [improvement in storage stability in a high-temperature environment or suppression of coloration (reduction of APHA)].

The amount of the reaction solvent to be used is not particularly limited as long as it does not hinder the progress of the reaction, and is, for example, about 10 to 1000 parts by mass based on 100 parts by mass of the total amount of compound (1), compound (2a) and compound (2b). It is preferably 50 to 500 parts by weight, more preferably 70 to 150 parts by weight, particularly 80 to 120 parts by weight.

(base)
The reaction may be carried out in the presence of a base (basic catalyst) for producing an anion of the 9H-fluorene, which is a reaction intermediate. Examples of the base (basic catalyst) include inorganic bases and organic bases.

Examples of inorganic bases include metal hydroxides, metal carbonates, and hydrogen carbonates.

Examples of the metal hydroxide include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, and alkaline earth metal hydroxides such as calcium hydroxide and barium hydroxide.

Examples of the metal carbonate or hydrogen carbonate include alkali metal carbonates or hydrogen carbonates such as sodium carbonate, potassium carbonate, and sodium hydrogen carbonate.

Organic bases include metal alkoxides, quaternary ammonium hydroxides, etc.

Examples of metal alkoxides include alkali metal alkoxides such as sodium methoxide, sodium ethoxide, and potassium t-butoxide.

Examples of the quaternary ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-n-butylammonium hydroxide, tetra-n-hexylammonium hydroxide, Tetraalkylammonium hydroxides such as hexadecyltrimethylammonium hydroxide; monocyclic or bridged cyclic cycloalkyltrialkylammonium hydroxides such as 1-adamantyltrimethylammonium hydroxide; phenyltrimethylammonium hydroxide, 3-(trifluoromethyl ) Aryltrialkylammonium hydroxide which may have a substituent such as phenyltrimethylammonium hydroxide; Aralkyltrialkylammonium hydroxide such as benzyltrimethylammonium hydroxide and benzyltriethylammonium hydroxide; 2-hydroxyethyltrimethylammonium Examples include quaternary ammonium hydroxides having a hydroxyl group such as hydroxide (or choline), tris(2-hydroxyethyl)methylammonium hydroxide, and tris(polyoxyethylene)methylammonium hydroxide.

These bases (basic catalysts) can be used alone or in combination of two or more. Among these bases, quaternary ammonium hydroxides are preferred, aralkyltrialkylammonium hydroxides are more preferred, and C _6-10 aryl C _1-4 alkyltriC _1-4 alkylammonium hydroxides such as benzyltrimethylammonium hydroxide are particularly preferred. The base may be added in the form of a solution dissolved in a solvent, for example, a solution dissolved in a solvent exemplified in the above section on reaction solvents, specifically, in the form of an aqueous solution or an alcohol solution such as a methanol solution.

The ratio of the base may be, for example, about 0.001 to 0.1 moles per mole of 9H-fluorenes, preferably 0.01 to 0.08 moles, and more preferably 0.02 to 0.05 moles.

(other ingredients)
The reaction may be carried out in the presence or absence of other components such as phase transfer catalysts and dehydrating agents. These other components can be used alone or in combination of two or more.

Examples of the phase transfer catalyst include ammonium salts and phosphonium salts. Examples of ammonium salts include quaternary ammonium salts such as tetrabutylammonium bromide (TBAB), tetraamylammonium chloride, tetraamylammonium bromide, tetraheptylammonium bromide, trioctylmethylammonium chloride, decyltrimethylammonium bromide, tetradecylammonium Examples thereof include tetraalkyl ammonium halides such as bromide and dimethyldipalmitylammonium bromide; aryltrialkylammonium halides such as trimethylphenylammonium chloride; and aralkyltrialkylammonium halides such as benzyltrimethylammonium iodide. Examples of the phosphonium salt include tetraalkylphosphonium halides such as tetraethylphosphonium bromide, tributylhexylphosphonium bromide, and tributyl-n-octylphosphonium bromide; and tetraarylphosphonium halides such as tetraphenylphosphonium bromide. These phase transfer catalysts can be used alone or in combination of two or more.

The proportion of the phase transfer catalyst may be, for example, about 0.001 to 0.1 mol, preferably 0.01 to 0.05 mol, per 1 mol of the 9H-fluorene.

Examples of dehydrating agents include molecular sieves such as molecular sieves (zeolites), inorganic salts, specifically alkali metal sulfates such as sodium sulfate, alkali metal sulfates such as magnesium sulfate and calcium sulfate, and alkali metal carbonates such as potassium carbonate. These dehydrating agents can be used alone or in combination of two or more. There are no particular restrictions on the proportion of the dehydrating agent, and it is sufficient that it is capable of dehydrating the reaction system.

The reaction may be accelerated by performing it in the presence of a phase transfer catalyst and/or a dehydrating agent, and the present disclosure provides a method for easily (or easily) or efficiently producing a fluorene compound even in the absence of these. Can be manufactured.

(Reaction conditions, etc.)
The reaction step may be any step in which compound (1) is reacted with compounds (2a) and (2b) in the presence of a ketone, and the order in which each component is added to the reaction system is not particularly limited.

Further, compound (1) may be subjected to the reaction in the form of a mixed solution with a reaction solvent containing ketones, and compounds (2a) (2b), a base, other components, etc. are added to the mixed solution. It may be added and reacted. The liquid mixture may be a solution in which compound (1) is dissolved, or may be in a state where it is not completely dissolved (suspension), and is preferably a solution.

The reaction may be carried out in air or in an inert gas atmosphere, for example, nitrogen or a rare gas such as helium or argon, preferably in an inert gas atmosphere. The reaction may also be carried out in the absence of water (dehydrated or non-aqueous environment), with stirring, and at normal pressure or under pressure.

The reaction temperature may be, for example, about -30°C to 150°C, preferably in the following steps: -20°C to 100°C, -10°C to 60°C, 0 to 50°C, 5 to 40°C, 10°C. ~30°C, 15~25°C, more preferably the following steps: -20°C ~ 45°C, -15°C ~ 40°C, -10°C ~ 30°C, -8°C ~ 20°C, The temperature may be -5°C to 10°C, -3°C to 5°C, and in consideration of higher productivity, it is more preferably stepwise as follows: 0 to 45°C, 5 to 40°C, 10 to 35°C, 15-30°C, 20-25°C. When the reaction temperature is within a moderate range that is not too low, the reaction tends to proceed more easily (reaction conversion rate improves), and it is also easier to dissolve in the reaction solvent, allowing the reaction to proceed easily or efficiently. It tends to improve productivity. When the reaction temperature is within a moderate range that is not too high, the reaction tends to proceed more easily (reaction conversion rate improves), and the increase in impurity content tends to be suppressed, probably because side reactions can be suppressed. . In addition, when the reaction temperature is within a moderate range that is not too high, the increase in impurity content can be easily suppressed, and the thermal stability (storage stability in high-temperature environments) of the resulting fluorene compound is also suppressed. It tends to be difficult to color. In addition, when the reaction temperature is in an appropriate range that is neither too low nor too high, temperature control is easy and productivity tends to be further improved.

In the method of the present disclosure, even in a relatively low temperature range, the reaction can proceed effectively or efficiently without greatly reducing the reaction conversion rate. Therefore, while maintaining or improving a high reaction conversion rate, it is also possible to reduce the impurity content and improve the thermal stability of the obtained fluorene compound. Therefore, in the present disclosure, in a reaction solvent containing at least a ketone, the temperature is lower than about 80°C, preferably lower than or equal to 70°C, lower than 60°C, lower than 50°C, lower than 45°C, etc., and more preferably lower than or equal to 70°C. Step by step, higher production such as -20℃~45℃, -15℃~40℃, -10℃~30℃, -8℃~20℃, -5℃~10℃, -3℃~5℃, etc. Considering the properties, it is more preferable to carry out the reaction stepwise in a relatively low temperature range such as 0 to 45 °C, 5 to 40 °C, 10 to 35 °C, 15 to 30 °C, 20 to 25 °C, etc. A method of reducing the content of impurities in the obtained fluorene compound [the fluorene compound represented by formula (3) above]; a method of improving the thermal stability of the obtained fluorene compound (suppressing coloring in a high temperature environment) method).

In addition, examples of the impurities include unreacted compound (1), and when R ^4a and R ^4b of the fluorene compound represented by formula (3) are groups [-OR ^h ], the impurities also include monoesters and dicarboxylic acids described below. In the method for reducing the content of the impurities, at least one impurity selected from unreacted compound (1), monoesters, and dicarboxylic acids may be reduced, preferably at least one impurity selected from unreacted compound (1) and monoesters may be reduced, and more preferably both unreacted compound (1) and monoesters may be reduced.

The reaction time may be, for example, about 0.5 to 48 hours, and is preferably 0.8 to 12 hours and 1 to 3 hours in the following stepwise manner, since the method disclosed herein allows the fluorene compound to be produced easily and efficiently.

In the production method of the present disclosure, the reaction conversion rate can be effectively improved, and a specific fluorene compound can be produced easily or efficiently. The reaction conversion rate (reaction conversion rate based on 9H-fluorenes) after the completion of the reaction step (after the reaction completion) is, for example, 93% or more, preferably 95% or more, 97% or more, 98% or more, 99% or more, 99.3% or more, 99.5% or more, 99.7% or more, substantially 100%. The reaction conversion rate may be a reaction conversion rate 2 hours after the start of the reaction.

In this specification and claims, the reaction conversion rate can be measured by the method described in the examples below.

[Purification process]
After the reaction step, the method of the present disclosure may optionally include a purification step of subjecting the reaction mixture to a conventional separation and purification method to purify the obtained fluorene compound.

Examples of conventional separation and purification methods include neutralization, washing, extraction, filtration, decantation, concentration, dehydration, drying, crystallization, column chromatography, and combinations thereof.

For example, after the reaction step is completed, the obtained organic layer may be purified by washing with water to remove water-soluble impurities. At that time, the organic layer may be washed with water after neutralizing the reaction mixture by adding an acid, specifically, an acidic aqueous solution such as hydrochloric acid. Further, after distilling off the solvent (desolvation) from this water-washed organic layer, the product may be purified by crystallization and/or column chromatography, preferably by crystallization.

Examples of the crystallization solvent used during crystallization include alcohols, specifically C _1-4 alcohols such as methanol and isopropyl alcohol (IPA), with IPA being preferred. Alternatively, crystallization may be performed by adding seed crystals. Although crystallization may be performed multiple times, the method of the present disclosure has a high reaction conversion rate and can easily reduce the impurity content, so even if the number of crystallizations is small, the fluorene compound can be easily or efficiently purified. It seems that it can be purified.

[Fluorene compound represented by formula (3)]
In the production method of the present disclosure, a fluorene compound represented by the following formula (3) as a target product can be easily or efficiently produced at a high reaction conversion rate (reaction conversion rate based on 9H-fluorenes). Further, according to the method of the present disclosure, a fluorene compound with excellent thermal stability (or storage stability in a high-temperature environment) can also be prepared. Furthermore, in the method of the present disclosure, it is also possible to effectively or efficiently suppress residual unreacted raw materials. In addition, in this specification and the claims, the compound represented by the following formula (3) may be simply referred to as a "fluorene compound."

(In the formula, R ¹ , k, R ^2a , R ^2b , R ^2c , R ^2d , R ^3a , R ^3b , R ^4a and R ^4b are preferable for the formulas (1), (2a) and (2b), respectively) (same including aspects).

In the formula (3) [in the formulas (1), (2a) and (2b)], preferred representative embodiments include, for example,
R ¹ is a halogen atom, a hydrocarbon group, an alkoxy group, an acyl group, a nitro group, a cyano group or a substituted amino group, and k is an integer of 0 to 4;
R ^2a and R ^2b are independently a hydrogen atom, a hydrocarbon group, a carboxyl group or an alkoxycarbonyl group, and R ^2c and R ^2d are independently a hydrogen atom or a hydrocarbon group,
R ^3a and R ^3b are independently a hydrogen atom, a hydrocarbon group, a carboxyalkyl group or an alkoxycarbonylalkyl group,
Examples include embodiments in which R ^4a and R ^4b are independently a hydroxyl group, a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group), a glycidyloxy group, or a 2-methylglycidyloxy group; Preferably,
R ¹ is a halogen atom or a hydrocarbon group, k is an integer of 0 to 2,
R ^2a and R ^2b are independently a hydrogen atom or a hydrocarbon group, R ^2c and R ^2d are independently a hydrogen atom or a hydrocarbon group,
R ^3a and R ^3b are independently a hydrogen atom or a hydrocarbon group,
Examples include an embodiment in which R ^4a and R ^4b are independently a hydroxyl group or a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group);
R ¹ is a halogen atom, an alkyl group or an aryl group, k is 0 or 2,
R ^2a and R ^2b are independently hydrogen atoms, R ^2c and R ^2d are independently hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups or aralkyl groups,
R ^3a and R ^3b are independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group,
Examples include embodiments in which R ^4a and R ^4b are independently a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group); in particular,
R ¹ is a halogen atom, an alkyl group or an aryl group, k is 0 or 2,
R ^2a , R ^2b , R ^2c and R ^2d are hydrogen atoms,
R ^3a and R ^3b are independently a hydrogen atom or an alkyl group,
Examples include an embodiment in which R ^4a and R ^4b are independently a group [-OR ^h ] (wherein R ^h represents an alkyl group).

Typical fluorene compounds represented by the formula (3) include the typical 9H-fluorenes exemplified in the section on 9H-fluorenes represented by formula (1) and the fluorene compounds corresponding to the typical compounds (2a) and (2b) exemplified in the section on compounds represented by formulas (2a) and (2b).

Specific examples of fluorene compounds include 9,9-bis(carboxyalkyl)fluorene, 9,9-bis(carboxyalkyl)-diarylfluorene, 9,9-bis(carboxyalkyl)-dihalofluorene, and the esters or acid halides corresponding to these acids.

Examples of the 9,9-bis(carboxyalkyl)fluorene include 9,9-bis(carboxyC _2-4 alkyl)fluorenes such as 9,9-bis(2-carboxyethyl)fluorene.

Examples of 9,9-bis(carboxyalkyl)-diarylfluorene include 9,9-bis(2-carboxyethyl)-2,7-diphenylfluorene, 9,9-bis(2-carboxyethyl)-2, 9,9-bis(carboxyC _2-4 alkyl)-2 such as 7-di(2-naphthyl)fluorene, 9,9-bis(2-carboxyethyl)-2,7-di(1-naphthyl)fluorene , 7-di(C _6-10 aryl)fluorene and the like.

Examples of the 9,9-bis(carboxyalkyl)-dihalofluorene include 9,9-bis(carboxyC _2-4 alkyl)-2,7-dihalofluorene such as 9,9-bis(2-carboxyethyl)-2,7-dichlorofluorene and 9,9-bis(2-carboxyethyl)-2,7-dibromofluorene.

Examples of esters or acid halides corresponding to these acids include esters or acid halides corresponding to the types of R ^4a and R ^4b in formula (3), such as dimethyl ester, diethyl ester, di-t-butyl ester, etc. Examples include dialkyl esters such as esters, and preferably di-C _1-4 alkyl esters such as dimethyl ester.

Of these fluorene compounds, dialkyl esters of 9,9-bis(carboxyalkyl)fluorene are preferred, and diC _1-4 alkyl esters of 9,9-bis(carboxyC _2-4 alkyl)fluorene such as the dimethyl ester of 9,9-bis(2-carboxyethyl)fluorene are more preferred.

The fluorene compound obtained by the method of the present disclosure may be in the form of a crystal.

The method of the present disclosure seems to be able to effectively, easily, or efficiently improve the thermal stability (storage stability in high-temperature environments) of the obtained fluorene compound, and can effectively suppress discoloration even when heated. . The hue (APHA) of the fluorene compound obtained by the method of the present disclosure when heated to 280°C under a nitrogen atmosphere and held for 2 hours is, for example, 200 or less (i.e., 0 to 200), and preferably the hue is as follows: 150 or less, 125 or less, 100 or less, 90 or less, 80 or less, 70 or less, 60 or less, 50 or less. Further, the smaller the value of the hue (APHA), the more preferable it is, but it may be, for example, 5 or more, 10 or more, 20 or more, 30 or more, 40 or more.

In the method of the present disclosure, it seems that the purity of the obtained fluorene compound can be easily improved, probably because the reaction conversion rate is high.

The HPLC purity (LC purity) of the obtained fluorene compound may be, for example, about 95 area % or more (that is, 95 to 100 area %), and preferably the following stepwise purity: 97 area % or more, 98 area % The above is 99 area % or more, 99.5 area % or more, 99.8 area % or more, and 99.9 area % or more.

In addition, in the obtained fluorene compound, the content (content as an impurity) of 9H-fluorenes, which is an unreacted raw material, is, for example, 0.05 area % or less (i.e., 0 to 0 .05 area%), preferably in the following steps: 0.04 area% or less, 0.03 area% or less, 0.02 area% or less, 0.01 area% or less, and below the detection limit. Or 0 area%.

Furthermore, in the formula (3), when preparing a fluorene compound (i.e., a diester compound) in which R ^4a and R ^4b are groups [-OR ^h ], the formula (3) An impurity in which at least one of R ^4a and R ^4b is a hydroxyl group, that is, a fluorene compound (monoester) in which one of R ^4a and R ^4b is a hydroxyl group and the other is the group [-OR ^h ], A fluorene compound (dicarboxylic acid form) in which both R ^4a and R ^4b are hydroxyl groups is often produced. Among these impurities, monoesters are often included, and the method of the present disclosure may be able to effectively reduce such impurities such as monoesters. In the obtained fluorene compound, the content of impurities in which at least one of R ^4a and R ^4b is a hydroxyl group, particularly the content of monoesters, is determined to be, for example, 0.2 area % or less (i.e., the area ratio in HPLC). , 0 to 0.2 area%), preferably in the following steps: 0.17 area% or less, 0.15 area% or less, 0.1 area% or less, 0.09 area% or less , 0.07 area % or less, 0.05 area % or less, 0.04 area % or less, 0.03 area % or less, 0.02 area % or less.

In this specification and claims, the melting point, APHA, LC purity, and impurity content can be measured by the methods described in the examples below.

In the method disclosed herein, not only is it easy to produce a high-purity fluorene compound, but it is also possible to easily or efficiently produce the fluorene compound in high yield. The yield of the obtained fluorene compound (yield based on 9H-fluorenes) may be, for example, about 75% or more (i.e., 75 to 100%), and is preferably 78% or more, 80% or more, in the following stepwise manner.

The present disclosure will be described in more detail below based on Examples, but the present disclosure is not limited by these Examples. The reagents used and each evaluation method are as follows.

[Evaluation method]
(Reaction Conversion Rate)
After the reaction was completed, the reaction mixture was subjected to high performance (or high speed) liquid chromatography (HPLC) to calculate the reaction conversion rate (consumption rate) of the raw fluorene (9H-fluorenes). That is, based on the HPLC chart, the remaining rate [%] of the unreacted raw fluorene after the reaction was completed (the ratio [%] of the unreacted amount to the amount of raw fluorene charged) was calculated, and the reaction conversion rate based on 9H-fluorenes was calculated as 100-(remaining rate of raw fluorene) [%]. Note that HPLC was measured by the same method as that described later in (HPLC purity and impurity content).

(HPLC Purity and Impurity Content)
The samples obtained in the examples and comparative examples were measured by high performance (or fast) liquid chromatography (HPLC) using the following measuring device and conditions, and the HPLC purity [area %] was calculated.

Equipment: “LC-2010A HT” manufactured by Shimadzu Corporation
Column: “TSKgel ODS-80TM” manufactured by Tosoh Corporation
Detection method: UV, detection wavelength 254nm
Eluent: Acetonitrile/water (volume ratio) = 60/40 (isocratic)
Flow rate: 1.0 mL/min.

From the results obtained by HPLC, in addition to the HPLC purity (LC purity) of the diester form of the target compound [a compound in which R ^4a and R ^4b are methoxy groups in the above formula (3)], the contents of the monoester form [a compound in which one of R ^4a and R ^4b is a methoxy group, and the other is a hydroxyl group in the above formula (3)] and 9H-fluorenes (unreacted raw material) as impurities were each determined as an area percentage ([area %]).

(Melting Point)
Using a differential scanning calorimeter ("Discovery DSC25" manufactured by TA Instruments Japan, Inc.), measurements were performed under conditions of a nitrogen atmosphere, a measurement temperature of 30 to 300° C., and a temperature rise rate of 10° C./min. From the obtained DSC chart (DSC curve), the peak top temperature of the endothermic peak due to melting was read and determined as the melting point.

(Hue APHA)
Hue (APHA) is measured using a JIS K0071 compliant device (simultaneous color and turbidity meter, Nippon Denshoku Kogyo Co., Ltd.) for a sample that has been melted and held at 280°C for 2 hours under a nitrogen stream (molten sample). It was measured using "COH-400" manufactured by ).

(X-ray diffraction (XRD))
Measured using a powder X-ray diffractometer (Rigaku Co., Ltd.'s "Fully automatic multi-purpose horizontal X-ray diffractometer Smart Lab") under conditions of output 3 kW, radiation source (Cu tube), and measurement angle of 5 to 90 degrees. did.

[reagent]
9H-fluorene: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Methyl acrylate: manufactured by Tokyo Chemical Industry Co., Ltd. Methyl isobutyl ketone (MIBK): manufactured by Kanto Chemical Industry Co., Ltd. 40% by mass solution of trimethylbenzylammonium hydroxide (Triton B) in methanol: manufactured by Tokyo Chemical Industry Co., Ltd. Isopropyl alcohol (IPA): manufactured by Kanto Chemical Industry Co., Ltd. Methanol: manufactured by Kanto Chemical Industry Co., Ltd.

[Example 1]
After adding 200 g of MIBK to 87.4 g of 9H-fluorene and stirring at 50°C, 120 g of methyl acrylate and 7.5 g of a 40% by mass methanol solution of trimethylbenzylammonium hydroxide were added dropwise, and the mixture was stirred at 50°C under a nitrogen atmosphere. Stir for hours. After the reaction was completed, the organic layer was washed with water. After distilling off the solvent from the obtained organic layer, it was dissolved in IPA and crystals were precipitated with stirring. After cooling to 10°C or lower, the precipitated crystals were filtered to obtain 145.6 g of 9,9-bis[ 2-(methoxycarbonyl)ethyl]fluorene (hereinafter also referred to as FDP-m) was obtained (yield: 81.7%).

The reaction conversion rate was 98.2%. The purity of the obtained crystals was 99.88 area%. It was confirmed that 0.09 area% of the monoester represented by the following formula remained as an impurity, and no peak of the unreacted raw material 9H-fluorene was detected. The melting point (peak top temperature of the endothermic peak in DSC) was 83°C, and the APHA after melting at 280°C for 2 hours was 74. The powder X-ray diffraction pattern of the obtained FDP-m is shown in Figure 1, and the main diffraction peaks (relative integrated intensity of 10% or more) are shown in Table 1 below.

[Example 2]
FDP-m was prepared in the same manner as in Example 1, except that methanol in an amount three times the amount of IPA used was used instead of IPA as a crystallization solvent.

The reaction conversion rate was 98.8%. The purity of the obtained crystals was 99.75 area %. 0.17 area % of the monoester represented by the above formula was confirmed as remaining impurities, and no peak of the unreacted raw material 9H-fluorene was detected. The melting point (peak top temperature of the endothermic peak in DSC) was 83°C, and APHA after melting at 280°C for 2 hours was 138. The powder X-ray diffraction pattern of the obtained FDP-m is shown in Figure 2, and the main diffraction peaks (relative integrated intensity 10% or more) are shown in Table 2 below.

[Comparative Example 1]
The procedure of Example 1 was repeated except that 1,4-dioxane was used as the reaction solvent instead of MIBK, to prepare 131.0 g of FDP-m (yield 73.5%).

The reaction conversion rate was 91.1%. The purity of the obtained crystals was 99.74 area%. It was confirmed that the monoester represented by the above formula remained as impurities at 0.11 area%, and that the unreacted raw material 9H-fluorene remained at 0.05 area%. The melting point (peak top temperature of the endothermic peak in DSC) was 83°C, and the APHA after melting at 280°C for 2 hours was 209. The powder X-ray diffraction pattern of the obtained FDP-m is shown in Figure 3, and the main diffraction peaks (relative integrated intensity 10% or more) are shown in Table 3 below.

[Example 3]
FDP-m was prepared in the same manner as in Example 1 except that the reaction temperature was changed to 40°C.

The reaction conversion rate was 98.7%. The purity of the obtained crystal was 99.92 area %. It was confirmed that 0.03 area % of the monoester represented by the above formula remained as an impurity, and no peak of 9H-fluorene, an unreacted raw material, was detected. The melting point (the peak top temperature of the endothermic peak in DSC) was 83°C, and it was 47 when APHA was measured after melting at 280°C for 2 hours.

[Example 4]
FDP-m was prepared in the same manner as in Example 1, except that the reaction temperature was changed to 20°C.

The reaction conversion rate was 99.9%. The purity of the obtained crystals was 99.82 area%. It was confirmed that 0.04 area% of the monoester represented by the above formula remained as an impurity, and no peak of the unreacted raw material 9H-fluorene was detected. The melting point (peak top temperature of the endothermic peak in DSC) was 83°C, and the APHA measured after melting at 280°C for 2 hours was 44.

[Example 5]
FDP-m was prepared in the same manner as in Example 1, except that the reaction temperature was changed to 0°C.

The reaction conversion rate was 100.0%. The purity of the obtained crystal was 99.95 area %. It was confirmed that 0.03 area % of the monoester represented by the above formula remained as an impurity, and no peak of 9H-fluorene, an unreacted raw material, was detected. The melting point (the peak top temperature of the endothermic peak in DSC) was 83°C, and the APHA after melting at 280°C for 2 hours was measured to be 43.

[Example 6]
FDP-m was prepared in the same manner as in Example 1, except that a mixture of 150 g of MIBK and 50 g of toluene was used as the reaction solvent instead of 200 g of MIBK, and the reaction temperature was changed to 40°C.

The reaction conversion rate was 99.3%. The purity of the obtained crystal was 99.94 area %. It was confirmed that 0.02 area % of the monoester represented by the above formula remained as an impurity, and no peak of 9H-fluorene, an unreacted raw material, was detected. The melting point (the peak top temperature of the endothermic peak in DSC) was 83°C, and the APHA after melting at 280°C for 2 hours was measured to be 43.

The results of Examples and Comparative Examples are shown in Table 4 below.

As is clear from the results in Table 4, in the examples using MIBK as the reaction solvent, the reaction conversion rate of 9H-fluorene was high, the reaction proceeded efficiently, and the resulting FDP-m contained No reaction 9H-fluorene was detected (N.D.).

Furthermore, the FDP-m obtained in the examples had low APHA even when melted at 280°C, and coloring was effectively suppressed. In particular, in Example 2, APHA was significantly reduced compared to Comparative Example 1, despite the LC purity being roughly the same.

In Examples 3 to 5, even though the reaction temperature was lower than in Example 1, the reaction conversion rate did not decrease, but rather increased. In addition, the lower the reaction temperature, the more effectively side reactions are suppressed, and the lower the content of monoesters as impurities and the tendency for APHA to decrease were observed.

Furthermore, in Example 6, even when the reaction solvent was a combination of ketones and a nonpolar solvent different from the ketones, the reaction conversion rate did not decrease and the LC purity, monoester content, and APHA were improved. The results were good.

In the method of the present disclosure, a given fluorene compound can be produced easily or efficiently with a high reaction conversion rate compared to conventional methods. In addition, the fluorene compound obtained by the method of the present disclosure can effectively suppress discoloration even in high-temperature environments and has excellent storage stability, so it can be used for various purposes, such as industrial products, organic synthesis, and resins. It may be suitably used as a raw material for synthesis, an additive such as a refractive index improver (or a resin additive), and the like.

Typical applications include resist compositions, and photosensitive resin compositions made of the fluorene compounds can be used, for example, as resists for semiconductor manufacturing, circuit forming materials such as printed wiring boards, printing plate materials, and image forming materials such as relief images. In particular, they can be advantageously used as resists for semiconductor manufacturing, since they can provide high sensitivity and resolution.

It can also be effectively used as a resin raw material, for example, as a raw material (polymerization component or monomer component) for thermoplastic resins, specifically, polyester resins such as polyester resins and polyester carbonate resins, polyamide resins, etc. The obtained resin can be used for various purposes, for example, coating agents or coating films, specifically, paints, inks, protective films for electronic devices and liquid crystal components, etc.; adhesives, pressure sensitive adhesives; resin fillers; electric and electronic materials or electric and electronic parts (electric and electronic devices), specifically, antistatic agents, carrier transport agents, light emitting bodies, organic photoreceptors, thermal recording materials, photochromic materials, hologram recording materials, antistatic trays, conductive sheets, optical disks, inkjet printers, digital paper, color filters, organic EL elements, organic semiconductor lasers, dye-sensitized solar cells, sensors, EMI shielding films, etc.; mechanical materials or mechanical parts (equipment), specifically, automotive materials or parts, aerospace-related materials or parts, sliding members, etc. The obtained resin also has excellent optical properties, so it can be effectively used as an optical member.

Typical optical members include optical films (optical sheets) such as liquid crystal films and organic EL films; optical lenses such as glasses lenses and camera lenses; prisms, holograms, and optical fibers.

Examples of optical films include polarizing films, polarizing elements and polarizing plate protective films that constitute polarizing films, retardation films, alignment films (orientation films), viewing angle expansion (compensation) films, diffusion plates (films), and prism sheets. , light guide plate, brightness enhancement film, near-infrared absorption film, reflective film, anti-reflection (AR) film, reflection reduction (LR) film, anti-glare (AG) film, transparent conductive (ITO) film, anisotropic conductive film ( ACF), an electromagnetic shielding (EMI) film, an electrode substrate film, a color filter substrate film, a barrier film, a color filter layer, a black matrix layer, an adhesive layer or a release layer between optical films, and the like. These optical films can be effectively used as optical films for displays such as liquid crystal displays (LCDs), organic EL displays (OLEDs), plasma displays (PDPs), field emission displays (FEDs), and electronic paper. Examples of equipment or devices include televisions; personal computers (PCs) such as desktop PCs, notebook PCs, or tablet PCs; smartphones, mobile phones; car navigation systems; and flat panel displays (FPD) such as touch panels. Examples include equipment or devices equipped with such equipment.

Examples of optical lenses include spectacle lenses, contact lenses, camera lenses, VTR zoom lenses, pickup lenses, Fresnel lenses, solar condensing lenses, objective lenses, and rod lens arrays.

Claims (15)

The following formula (1)

(In the formula, R ¹ represents a substituent, and k represents an integer from 0 to 8.)
9H-fluorenes in which the 9,9-position is unsubstituted and the following formulas (2a) and (2b)

[In the formula, R ^2a , R ^2b , R ^2c and R ^2d independently represent a hydrogen atom or a substituent,
R ^3a and R ^3b independently represent a hydrogen atom or a substituent,
R ^4a and R ^4b independently represent a hydroxyl group, a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group), a glycidyloxy group, a 2-methylglycidyloxy group, or a halogen atom. ]
The following formula (3) includes a reaction step of reacting a compound represented by in a reaction solvent containing at least ketones.

(In the formula, R ¹ , k, R ^2a , R ^2b , R ^2c , R ^2d , R ^3a , R ^3b , R ^4a and R ^4b are each the same as above.)
A method for producing a fluorene compound represented by The method according to claim 1, wherein the ketone is a dialkyl ketone. The manufacturing method according to claim 1 or 2, wherein the reaction solvent further contains hydrocarbons. In the formulas (1), (2a), (2b) and (3),
R ¹ is a halogen atom, a hydrocarbon group, an alkoxy group, an acyl group, a nitro group, a cyano group, or a substituted amino group, and k is an integer of 0 to 4;
R ^2a and R ^2b are independently a hydrogen atom, a hydrocarbon group, a carboxyl group, or an alkoxycarbonyl group, R ^2c and R ^2d are independently a hydrogen atom or a hydrocarbon group,
R ^3a and R ^3b are independently a hydrogen atom, a hydrocarbon group, a carboxyalkyl group, or an alkoxycarbonylalkyl group;
3. The process according to claim 1, wherein R ^4a and R ^4b are independently a hydroxyl group, a group [--OR ^h ] (wherein R ^h represents a hydrocarbon group), a glycidyloxy group or a 2-methylglycidyloxy group. The manufacturing method according to claim 1 or 2, wherein the reaction temperature in the reaction step is -20°C to 100°C. The manufacturing method according to claim 1 or 2, wherein the reaction conversion rate of the 9H-fluorene represented by the formula (1) is 95% or more. A fluorene compound represented by formula (3) according to claim 1, which has a hue (APHA) of 150 or less when held at 280° C. for 2 hours in a nitrogen atmosphere. The fluorene compound according to claim 7, which has a purity of 99.8 area % or more by HPLC. The fluorene compound according to claim 7 or 8, wherein the content of 9H-fluorenes represented by formula (1) according to claim 1 is 0.03 area % or less by HPLC. A fluorene compound represented by formula (3) according to claim 1, wherein R ^4a and R ^4b are groups [—OR ^h ] (wherein R ^h represents a hydrocarbon group),
A fluorene compound represented by the formula (3), in which one of R ^4a and R ^4b is a hydroxyl group, and the other is the group [—OR ^h ], has a content of 0.1 area % or less as determined by HPLC. 9H-fluorenes represented by formula (1) according to claim 1 and compounds represented by formulas (2a) and (2b) according to claim 1 in a reaction solvent containing at least ketones. A method for improving the thermal stability of a fluorene compound represented by the formula (3) according to claim 1 obtained by reacting. The method according to claim 11, wherein the reaction temperature is 80°C or less. A method for reducing the impurity content in the fluorene compound represented by formula (3) according to claim 1 obtained by reacting 9H-fluorenes represented by formula (1) according to claim 1 with compounds represented by formulas (2a) and (2b) according to claim 1 in a reaction solvent containing at least ketones. The method according to claim 13, wherein the reaction temperature is 45°C or less. The fluorene compound represented by the formula (3) is a fluorene compound in which R ^4a and R ^4b are a group [-OR ^h ] (wherein R ^h represents a hydrocarbon group),
The impurity is a compound in which in the formula (3), one of R ^4a and R ^4b is a hydroxyl group and the other is the group [-OR ^h ], and unreacted 9H represented by the formula (1) - The method according to claim 13 or 14, comprising at least one selected from fluorenes.

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