Composition containing dihydroxy compound having biphenanthrene skeleton and production method therefor

Abstract

The present invention addresses the problem of providing a composition containing a dihydroxy compound having a biphenanthrene skeleton, the composition making it possible to diminish troubles caused by metals remaining in large amounts in conventional dihydroxy compounds having a biphenanthrene skeleton. This composition contains a dihydroxy compound having a biphenanthrene skeleton, the dihydroxy compound being represented by general formula (1a) and having a total content of sodium, potassium, iron, and copper metals of 40 ppm or less. (In the formula, the R1 moieties each independently represent a C2-C4 alkylene group, the R2 moieties each independently represent a C1-C6 alkyl group, a C6-C18 aryl group, or a halogen atom, and each n independently indicates 0 or an integer of 1-4.)

Description

Composition containing a biphenanthrene skeleton-containing dihydroxy compound and method for producing the same

[0001] The present invention relates to a composition containing a dihydroxy compound containing a biphenanthrene skeleton and a method for producing the same, more particularly to a purified biphenanthrene skeleton-containing dihydroxy compound and a method for producing a biphenanthrene skeleton-containing dihydroxy compound comprising a step of purification thereof.

[0002] In recent years, resins for optical lenses have been developed, and various monomers have been considered as raw materials. Initially, bisphenol A was the main monomer, but monomers with a fluorene skeleton, such as 9,9-bis{4-(2-hydroxyethoxy)phenyl}fluorene (Patent Document 1, etc.), have been used, and it has been reported that dihydroxy compounds with a binaphthalene skeleton can be used as raw material monomers to increase the refractive index (Patent Document 2). Due to the increasing need for higher refractive indices in resins for optical lenses, compounds with higher refractive indices than those used as monomer raw materials in conventional polymers have been investigated, and dihydroxy compounds with a biphenanthrene skeleton have been reported (Patent Documents 3 and 4). Patent Documents 3 and 4 describe 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene (sometimes referred to as compound (1a-1)), which is one type of dihydroxy compound with a biphenanthrene skeleton. It has been described that compound (1a-1) can be synthesized by reacting 10,10'-dihydroxy-9,9'-biphenanthrene (sometimes referred to as compound (2a-1)) with ethylene carbonate in the presence of potassium carbonate using dimethylformamide as a solvent, followed by alkali treatment, and then adding the reaction solution to water to precipitate and isolate the crystals of compound (1a-1). It has also been reported that compound (1a-1) could not be obtained by reacting 10,10'-dihydroxy-9,9'-biphenanthrene with ethylene carbonate in the presence of potassium carbonate using toluene as a solvent.

[0003] International Publication No. 2007 / 142149, International Publication No. 2014 / 073496, International Publication No. 2021 / 187075, International Publication No. 2021 / 220811

[0004] When the inventors conducted a synthesis experiment of compound (1a-1) based on the description in Patent Document 3, it became clear that the reaction solution after the reaction contained residual 10,10'-dihydroxy-9,9'-biphenanthrene, as well as a large amount of by-products resulting from the excessive reaction of ethylene carbonate, indicating that the conversion rate of the raw materials and the reaction selectivity of the target compound were not high. Furthermore, dimethylformamide, which was described as a preferred reaction solvent and used, is known to decompose slowly at high temperatures above 100°C, releasing dimethylamine, which has a strong pungent odor. This raises safety and hygiene concerns, such as a rapid increase in pressure in the reactor due to the generation of volatile components. When an aqueous sodium hydroxide solution was added to the reaction solution after the reaction, the target compound (1a-1) produced in the reaction precipitated, resulting in a heterogeneous two-phase state of solid and liquid. Such a two-phase state makes post-treatment such as purification treatments prone to heterogeneity, and therefore, it was considered an unsuitable manufacturing method for industrial production where quality stability is required. In the manufacturing method described in Patent Document 3, when precipitating crystals, a treatment solution containing compound (1a-1) is added to water, and the resulting crystals are recovered. Synthesis experiments revealed that the obtained crystals contained large amounts of iron and copper from the raw material compound (2a-1), as well as bases and metals resulting from the potassium carbonate used during the reaction and the sodium hydroxide added after the reaction. When synthesizing biphenantrols (2a) such as compound (2a-1) used as a raw material, conventional methods using catalysts and equipment containing metals such as copper and iron can result in the contamination of these metals. In this way, there is concern that a manufacturing method for compound (1a-1) containing large amounts of bases and metals will cause similar problems as the metals contained in the raw material remain in compound (1a-1). Furthermore, when the liquid after crystal precipitation was filtered, it became clear that the filtrate drained slowly and required a long time during the filtration process, yet the filtered crystals were in a paste-like state containing a large amount of solvent. This revealed that the manufacturing method described in Patent Document 3 has problems with filtration operability and handling of the filtered material, making it unsuitable for industrial production.

[0005] Patent Document 3 describes the purification of a compound (1a-1) by recrystallization using crystals obtained through the above reaction and crystallization steps, with chloroform and hexane as solvents. The inventor attempted to conduct a recrystallization experiment based on the description in Patent Document 3, but the crystals of compound (1a-1) did not dissolve in the described amounts of chloroform. In light of the results of the solubility of compound (1a-1) in chloroform measured by the inventor, it was clear that the amount was insoluble, and therefore purification by recrystallization based on the description in Patent Document 3 was not possible. As described above, it became clear that the manufacturing method described in Patent Document 3 for producing compound (1a-1) has significant problems in terms of the efficiency of the reaction step, the operability of the subsequent processing, and the handling of the crystals. In view of these issues, the present invention aims to solve the conventional problems related to biphenanthrene skeleton-containing dihydroxy compounds such as compound (1a-1) and to provide a composition containing a biphenanthrene skeleton-containing dihydroxy compound of superior quality compared to conventional compositions.

[0006] As a result of diligent research to solve the above problems, the inventors have found a method to reduce the amount of metal contained in compositions containing biphenanthrene skeleton-containing dihydroxy compounds such as compound (1a-1), and have completed a composition containing a biphenanthrene skeleton-containing dihydroxy compound with a specific metal content of the present invention that is of superior quality to conventional compositions.

[0007] The present invention is as follows: 1. A composition containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a), wherein the total content of each metal, sodium, potassium, iron, and copper, is 40 ppm or less. (In the formula, R １ Each independently represents an alkylene group with 2 to 4 carbon atoms, R ２) Each independently represents an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a halogen atom, and each independently represents 0 or an integer from 1 to 4. 2. The composition according to 1, wherein the sodium content is 10 ppm or less and the potassium content is 10 ppm or less. 3. The composition according to 1, wherein the copper content is 10 ppm or less and the iron content is 10 ppm or less. 4. The composition according to 1, wherein the biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a) is any of the biphenanthrene skeleton-containing dihydroxy compounds represented by chemical formulas (1a-1) to (1a-3). 5. A method for producing a composition containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a), comprising a washing step of washing a solution containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a) and an aliphatic ketone solvent having 5 to 9 carbon atoms with water. 6. The method for producing a biophatic ketone solvent having 5 to 9 carbon atoms, wherein the aliphatic ketone solvent is at least one selected from methyl isobutyl ketone and cyclohexanone. 7. The method for producing a biophatic ketone solvent according to 5, wherein the biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a) is any of the biphenanthrene skeleton-containing dihydroxy compounds represented by chemical formulas (1a-1) to (1a-3).

[0008] Conventional methods for producing biphenanthrene skeleton-containing dihydroxy compounds often contain large amounts of components resulting from the bases and metals used during or after the reaction. However, the present invention provides a composition containing a high-quality biphenanthrene skeleton-containing dihydroxy compound with a low metal content.

[0009] The composition containing the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) according to the present invention (hereinafter sometimes referred to as "dihydroxy compound (1a)") can be produced, for example, by performing a washing step of washing a solution containing the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) and an aliphatic ketone solvent having 5 to 9 carbon atoms with water and then isolating it. Further, the method for producing a composition containing the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) of the present invention is characterized by including a washing step of washing a solution containing the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) and an aliphatic ketone solvent having 5 to 9 carbon atoms with water.

[0010] <Biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a)> R in the general formula (1a) １ each independently represents an alkylene group having 2 to 4 carbon atoms. Among them, each is preferably an ethylene-1,2 group, a 1-methyl-ethylene-1,2 group or a 2-methyl-ethylene-1,2 group, and both are particularly preferably an ethylene-1,2 group. R in the general formula (1a) １ As, two R １ are preferably the same substituent. R in the general formula (1a) ２ each independently represents an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 18 carbon atoms or a halogen atom. When R ２ is an alkyl group, it is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. When R ２ is an aryl group, it is preferably an aryl group having 6 to 12 carbon atoms, more preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group. Examples of the halogen atom in R ２ include, for example, a chlorine atom, a bromine atom, an iodine atom, and a bromine atom is preferred. R in the general formula (1a) ２Each of these is preferably an alkyl group having 1 to 4 carbon atoms, a naphthyl group, a phenyl group, or a bromine atom; each is more preferably a methyl group, an ethyl group, a naphthyl group, a phenyl group, or a bromine atom; each is even more preferably a phenyl group, a naphthyl group, or a bromine atom; and each is particularly preferably a phenyl group or a bromine atom. In general formula (1a), n is each independently 0 or an integer from 1 to 4. Among these, each is preferably independently 0, 1, or 2; each is more preferably 0 or 1; and 0 is particularly preferred.

[0011] Among the dihydroxy compounds (1a), the compounds represented by chemical formulas (1a-1) to (1a-3) that are preferred are shown below. Of these, the compounds represented by chemical formula (1a-1) or chemical formula (1a-2) are more preferred, and the compound represented by chemical formula (1a-1), 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthryl, is particularly preferred.

[0012] <Method for synthesizing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a)> There are no particular restrictions on the method for obtaining the dihydroxy compound (1a) according to the present invention, but for example, it can be obtained by synthesizing the dihydroxy compound (1a) by a reaction step in which biphenantrols (2a) and a hydroxyalkylene oxidizing agent are reacted in the presence of a basic compound.

[0013] <Biphenantrols represented by general formula (2a) (2a)> R in general formula (2a) ２ And n have the same definition as in general formula (1a), and the preferred embodiment is also the same. Biphenantrols (2a) can be produced, for example, by the manufacturing method described in Japanese Patent Publication No. 2001-039898. Examples of biphenantrols (2a) include 10,10'-dihydroxy-9,9'-biphenanthryl represented by chemical formula (2a-1) (hereinafter sometimes referred to as "compound (2a-1)"). This compound can be produced, for example, by the method described in Japanese Patent Publication No. 60-181043 or the Journal of American Chemical Society, 2008, 130, 6840. Other examples include 10,10'-dihydroxy-6,6'-diphenyl-9,9'-biphenanthryl represented by chemical formula (2a-2) (CAS registration number: 1564249-14-4) and 10,10'-dihydroxy-6,6'-dibromo-9,9'-biphenanthryl represented by chemical formula (2a-3) (CAS registration number: 1564249-12-2), which are described in Tetrahedron, 70, 1786-1793 (2014).

[0014] <Hydroxyalkylene Oxidizing Agent> In the present invention, the hydroxyalkylene oxidizing agent can be glycols containing alkylene groups having 2 to 4 carbon atoms, such as ethylene glycol and propylene glycol; carbonates represented by general formula (3), such as ethylene carbonate and propylene carbonate (hereinafter sometimes referred to as "carbonates (3)"); monohalogenated alcohols having 2 to 4 carbon atoms, such as 2-chloroethanol and 3-chloro-1-propanol; or alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide. Among these, it is preferable to use carbonates (3). R in general formula (3) １ This is the same as the definition of general formula (1a), and the preferred embodiment is also the same. (In the formula, R １ This is the same as the definition in general formula (1a).

[0015] The amount of carbonates (3) used in the reaction step is usually in the range of 2.0 to 5.0 moles, preferably in the range of 2.0 to 4.5 moles, more preferably in the range of 2.0 to 4.0 moles, and particularly preferably in the range of 2.0 to 3.0 moles, per mole of biphenantrols (2a).

[0016] The present invention provides an example of a reaction equation when carbonates (3) are used as the hydroxyalkylene oxidizing agent in a method for producing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a). The following is an example of a reaction equation when compound (2a-1) is used as a biphenantrol (2a) and compound (1a-1) is synthesized as a dihydroxy compound (1a) by performing a hydroxyalkylene oxidization reaction using ethylene carbonate as a hydroxyalkylene oxidizing agent.

[0017] (Basic Compounds) The reaction step to obtain the dihydroxy compound (1a) is carried out in the presence of a basic compound. As the basic compound, basic compounds commonly used in hydroxyalkoxylation reactions can be used, specifically, for example, triorganophosphine compounds, nitrogen-containing heterocyclic basic compounds, alkali metal compounds, and alkaline earth metal compounds. Examples of triorganophosphine compounds include triphenylphosphine and tributylphosphine. Examples of nitrogen-containing heterocyclic basic compounds include 1-methylimidazole. Examples of alkali metal compounds include alkali metal carbonates such as potassium carbonate, calcium carbonate, and magnesium carbonate; alkali metal hydroxides such as magnesium hydroxide, calcium hydroxide, and sodium hydroxide; alkali metal bicarbonates such as sodium bicarbonate; and alkali metal salts of hydrocarbon hydroxy compounds such as sodium methoxy and sodium phenoxy. Examples of alkaline earth metal compounds include calcium hydroxide and barium hydroxide. Among these basic compounds, alkali metal compounds are preferred, alkali metal carbonates, alkali metal hydroxides, or alkali metal bicarbonates are more preferred, alkali metal carbonates or alkali metal hydroxides are even more preferred, and alkali metal carbonates are particularly preferred. The alkali metal in these alkali metal compounds is preferably sodium or potassium, and more preferably potassium. That is, at least one selected from sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium bicarbonate, and potassium bicarbonate is preferred, at least one selected from sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide is more preferred, potassium carbonate or potassium hydroxide is even more preferred, and potassium carbonate is particularly preferred. These basic compounds may be used alone or in combination of two or more. The amount of this basic compound used is preferably in the range of 0.001 to 10% by weight of biphenantrols (2a), more preferably in the range of 0.01 to 5% by weight, and even more preferably in the range of 0.1 to 5% by weight.

[0018] (Reaction Solvent) The reaction step to obtain the dihydroxy compound (1a) is preferably carried out in the presence of an organic solvent. A non-protic organic solvent is preferred. Specifically, examples of such non-protic organic solvents include aprotic nonpolar organic solvents such as aromatic hydrocarbon organic solvents having 6 to 9 carbon atoms, aliphatic hydrocarbon organic solvents, and ether organic solvents, as well as aprotic polar organic solvents such as amide organic solvents, ester organic solvents, carbonate organic solvents, and aliphatic ketone organic solvents. Specific examples of aromatic hydrocarbon organic solvents having 6 to 9 carbon atoms include benzene, toluene, orthoxylene, metaxylene, paraxylene, mixed xylene, and mesitylene, with at least one of these being preferred, at least one of toluene, orthoxylene, metaxylene, and paraxylene being more preferred, and toluene being particularly preferred. Specific examples of aliphatic hydrocarbon organic solvents include hexane, heptane, and octane. Specific examples of ether organic solvents include diethyl ether, tetrahydrofuran, and dioxane. Specific examples of amide organic solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Specific examples of ester organic solvents include γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, butyl acetate, ethyl acetate, and isobutyl acetate. Specific examples of carbonate organic solvents include ethylene carbonate and propylene carbonate. Specific examples of aliphatic ketone organic solvents include acetone (3 carbon atoms), methyl ethyl ketone (4 carbon atoms), diethyl ketone, cyclopentanone (5 carbon atoms), methyl isobutyl ketone, cyclohexanone (6 carbon atoms), methyl amyl ketone, cycloheptanone (7 carbon atoms), methylhexyl ketone, and cyclooctanone (8 carbon atoms).Among aprotic organic solvents, at least one aprotic organic solvent selected from aromatic hydrocarbon organic solvents having 6 to 9 carbon atoms, amide organic solvents, and aliphatic ketone solvents is preferred, at least one aprotic organic solvent selected from aromatic hydrocarbon organic solvents having 6 to 9 carbon atoms, amide organic solvents, and aliphatic ketone solvents having 5 to 9 carbon atoms is more preferred, aliphatic ketone organic solvents having 6 to 8 carbon atoms are even more preferred, aliphatic ketone organic solvents having 6 or 7 carbon atoms are even more preferred, and aliphatic ketone organic solvents having 6 carbon atoms are particularly preferred. Specific examples of preferred aliphatic ketone solvents include at least one of diethyl ketone, cyclopentanone, methyl isobutyl ketone, cyclohexanone, methyl amyl ketone, cycloheptanone, methylhexyl ketone, and cyclooctanone, with methyl isobutyl ketone or cyclohexanone being particularly preferred. There are no particular restrictions on the amount of organic solvent used, but it is preferably in the range of 1 to 20 times the weight of biphenantrols (2a), more preferably in the range of 2 to 15 times, even more preferably in the range of 2 to 10 times, and particularly preferably in the range of 2 to 8 times.

[0019] (Phase Transfer Catalyst) In the reaction step to obtain the dihydroxy compound (1a), it is preferable to use a phase transfer catalyst. Specific examples of the phase transfer catalyst include quaternary ammonium salts or quaternary phosphonium salts, which are preferred, with quaternary ammonium salts being more preferred. Specific examples of quaternary ammonium salts include tetraalkylammonium halides, specifically tetrabutylammonium chloride, tetrabutylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetramethylammonium chloride, and tetramethylammonium bromide, which are tetraalkylammonium halides in which the alkyl group has 1 to 4 carbon atoms. Among quaternary ammonium salts, tetraalkylammonium halides are preferred, tetraalkylammonium halides in which the alkyl group has 1 to 4 carbon atoms are more preferred, and it is even more preferable that at least one is selected from the compounds of the specific examples above, with tetrabutylammonium bromide being particularly preferred. Specific examples of quaternary phosphonium salts include tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, and tetraphenylphosphonium bromide, and it is preferable that at least one is selected from these compounds. These phase transfer catalysts may be used individually or in combination of two or more types. The amount of the phase transfer catalyst used is preferably in the range of 0.001 to 10% by weight of biphenantrols (2a), more preferably in the range of 0.01 to 5% by weight, and even more preferably in the range of 0.1 to 5% by weight.

[0020] (Reaction Conditions) The reaction temperature in the reaction step to obtain the dihydroxy compound (1a) is not particularly limited as long as the reaction proceeds at a temperature, but it is usually carried out under heating. Depending on the type of solvent used, it is in the range of 50 to 250°C, preferably in the range of 70 to 200°C, and more preferably in the range of 100 to 180°C. It is even more preferable that the reaction be carried out at a temperature under reflux of the solvent. The reaction time depends on the reaction temperature, the amount and type of biphenantrols (2a), hydroxyalkylene oxidizing agent, basic compound, organic solvent and phase transfer catalyst used, etc., but it is usually carried out for about 3 to 48 hours. When carbonates (3) are used as the hydroxyalkylene oxidizing agent, the point at which carbon dioxide generation is no longer observed can be used as an indicator of the end of the reaction.

[0021] <Neutralization Step> It is preferable to perform a neutralization step in which the dihydroxy compound (1a) obtained in the reaction step is neutralized by adding an acid (for example, hydrochloric acid, sulfuric acid, acetic acid, propionic acid, etc.) or an aqueous solution of an acid to neutralize the basic compound contained in the reaction solution. This neutralization step may also be performed after the hydrolysis step described later.

[0022] <Hydrolysis Step> In the reaction step described above, the dihydroxy compound (1a) obtained using carbonates (3) as a hydroxyalkylene oxidizing agent has an excess amount of carbonates (3) added, so carbonates (3) remain in the reaction solution even after the reaction is complete. If heating or other treatment is performed in this state, side reactions may proceed, potentially reducing the purity and yield of the dihydroxy compound (1a). Therefore, it is preferable to mix water with the obtained reaction solution and perform a hydrolysis step of carbonates (3). The amount of water used is in the range of 1 to 10 molar times the amount of carbonates (3) used in the above reaction. The temperature should be below the boiling point of the reaction solution, but is usually in the range from room temperature to below the boiling point of the reaction solution. Specifically, the lower limit of the temperature is 10°C or higher, preferably 20°C or higher, more preferably 40°C or higher, and even more preferably 60°C or higher. The upper limit of the temperature depends on the boiling point of the solvent used, but is preferably 150°C or lower.

[0023] <Alkali Treatment Step> In the reaction step described above, when carbonates (3) are used as the hydroxyalkylene oxidizing agent, a by-product is produced in which carbonates (3) are added in excess to the dihydroxy compound (1a). To reduce this by-product, it is preferable to mix a basic compound with the reaction solution obtained in the reaction step and perform an alkaline treatment. In the alkaline treatment step, a basic compound of the same type as the basic compound used in the reaction step, and water (which may be an aqueous solution of the basic compound) are mixed as needed. Among the basic compounds used in the alkaline treatment step, sodium hydroxide or potassium hydroxide is preferred. In order to efficiently reduce excess reaction products, the amount of basic compound used is usually 0.4 moles or more, preferably in the range of 0.4 to 20 moles, and more preferably in the range of 0.5 to 10 moles, per mole of dihydroxy compound (1a).

[0024] <Example of a method for producing a composition containing the dihydroxy compound (1a) of the present invention: Washing step> As an example of a method for producing a composition containing the dihydroxy compound (1a) of the present invention, it can be produced by preparing a solution containing the dihydroxy compound (1a) and an aliphatic ketone solvent having 5 to 9 carbon atoms, and then carrying out a washing step of washing with water. The solution can be prepared by using the dihydroxy compound (1a) obtained by the above reaction step, or, if necessary, by using the dihydroxy compound (1a) isolated through the above neutralization step, hydrolysis step, alkali treatment step, and separation step by crystallization, filtration, distillation, column chromatography, etc., and dissolving it in an aliphatic ketone solvent having 5 to 9 carbon atoms. Furthermore, if the dihydroxy compound (1a) obtained in the reaction step using the aliphatic ketone solvent having 5 to 9 carbon atoms according to the production method of the present invention is uniformly dissolved in the reaction solution, the reaction solution can be used as is, or, if necessary, the solution can be used after undergoing the above neutralization step, hydrolysis step, alkali treatment step.

[0025] Among the aliphatic ketone solvents having 5 to 9 carbon atoms used in the washing process, those having 6 to 9 carbon atoms are preferred, more preferably 6 to 8, even more preferably 6 or 7, and particularly preferred to have 6 carbon atoms. Specific examples of aliphatic ketone solvents to be used include diethyl ketone, cyclopentanone, methyl isobutyl ketone, cyclohexanone, methyl amyl ketone, cycloheptanone, methylhexyl ketone, and cyclooctanone, of which at least one is preferred, and methyl isobutyl ketone or cyclohexanone is particularly preferred. The amount of aliphatic ketone solvent having 5 to 9 carbon atoms used relative to the dihydroxy compound (1a) can be adjusted as appropriate in light of the solubility of the aliphatic ketone solvent used, but is preferably in the range of 3 to 30 times by weight, more preferably in the range of 4 to 25 times by weight, and even more preferably in the range of 4 to 20 times by weight. The solution used in the washing step may contain organic solvents such as the reaction solvent used in the process of obtaining the dihydroxy compound (1a), as long as it does not hinder the effects of the present invention. However, the total amount of dihydroxy compound (1a) and the aliphatic ketone solvent having 5 to 9 carbon atoms in the solution is preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 95% by weight or more, based on the total weight of the solution. It is particularly preferable to prepare the solution of dihydroxy compound (1a) and the aliphatic ketone solvent having 5 to 9 carbon atoms by using the aliphatic ketone solvent having 5 to 9 carbon atoms alone. The amount of water used in the washing step is not particularly limited, but is preferably in the range of 0.05 to 5.0 times by weight, more preferably 0.1 to 3.0 times by weight, and even more preferably 0.1 to 1.5 times by weight, based on the solution containing the dihydroxy compound (1a) and the aliphatic ketone solvent having 5 to 9 carbon atoms. The temperature of the solution during the washing process is not particularly limited as long as the dihydroxy compound (1a) dissolves and separates well from water. However, the upper limit of the temperature that can be heated is limited by the boiling point of the solvent used and the temperature at which it forms an azeotrope with water. The range is preferably 30 to 150°C, more preferably 40 to 140°C, even more preferably 60 to 130°C, and particularly preferably 70 to 120°C.In the washing process, there are no particular restrictions on the number of times the solution is washed with water, as long as water-soluble impurities are sufficiently removed. An appropriate number of washes can be set, whether it is once or multiple times.

[0026] <Method for Isolating a Composition Containing Dihydroxy Compound (1a)> The composition containing dihydroxy compound (1a) of the present invention is obtained by isolating dihydroxy compound (1a) from the solution after the washing step. As a method of isolation, it is preferable to perform a crystallization step to precipitate crystals from the solution and obtain them as crystals. Other isolation methods include, for example, a method of distilling off the solvent from the solution using a device such as a spray dryer. When precipitating crystals from such a solution, in view of the solubility of dihydroxy compound (1a), if necessary, the amount of aliphatic ketone solvent having 5 to 9 carbon atoms may be adjusted in advance by distilling off or adding an aliphatic ketone solvent having 5 to 9 carbon atoms in relation to the amount of dihydroxy compound (1a). Also, if a solvent other than an aliphatic ketone solvent having 5 to 9 carbon atoms was used in the reaction step or post-treatment step, if necessary, a part or all of it may be distilled off in advance. Then, as a method for precipitating crystals, methods such as cooling crystallization, poor solvent addition crystallization, and solvent distillation crystallization may be used. In the case of cooling crystallization, the crystallization solution is heated to a temperature where the upper limit is the boiling point and the lower limit is 80°C, preferably 90°C, more preferably 100°C, and even more preferably 110°C, and then cooled to a range of 0 to 40°C, preferably 10 to 40°C, more preferably 15 to 40°C, and even more preferably 15 to 35°C. In poor solvent-added crystallization, the poor solvent refers to a solvent in which the solubility of the dihydroxy compound (1a) is lower than that of the aliphatic ketone solvent with 5 to 9 carbon atoms used, and crystals are precipitated by reducing the solubility by mixing in a poor solvent. Examples of poor solvents include solvents other than aliphatic ketone solvents with 5 to 9 carbon atoms, such as lower alcohol solvents such as methanol, ethanol, isopropanol, and 1-butanol; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and octane; and other aliphatic ketone solvents that are poor solvents compared to the aliphatic ketone solvent already used to dissolve the dihydroxy compound (1a). Solvent-removed crystallization is a method of precipitating crystals by removing the organic solvent contained in the crystallization solution through distillation.These crystallization methods may be carried out not by using only one method, but by combining multiple methods. For example, crystallization methods include cooling crystallization and poor solvent addition crystallization, crystallization methods by solvent distillation crystallization and cooling crystallization, and methods combining cooling crystallization, poor solvent addition crystallization, and solvent distillation crystallization. Among these, cooling crystallization or cooling crystallization and poor solvent addition crystallization are preferred as methods for precipitating crystals. The crystals of the composition containing the dihydroxy compound (1a) obtained by the above crystallization can be filtered, washed with a solvent if necessary, and dried in a drying step in which the adhering solvent is evaporated to dry the crystals and obtain the dihydroxy compound (1a). The crystals of the composition obtained by the above method are easy to handle, such as being easy to filter, dry, and transport, and the fact that industrial production can be carried out efficiently is one of the effects of the present invention. To further increase the purity, further purification by distillation, recrystallization, or column chromatography may be performed in accordance with conventional methods.

[0027] A composition containing the dihydroxy compound (1a) obtained by the above manufacturing method can be cleaned to remove water-soluble impurities contained in the dihydroxy compound (1a) or its solution. In particular, it is possible to reduce metals such as basic compounds used in the reaction and post-treatment steps, salts produced in the neutralization step, and metal impurities originating from the raw materials used, thereby enabling the production of a composition containing the dihydroxy compound (1a) of the present invention. The composition containing the dihydroxy compound (1a) of the present invention has a total content of sodium, potassium, iron, and copper of 40 ppm or less, preferably 20 ppm or less, more preferably 12 ppm or less, even more preferably 5 ppm or less, even more preferably 3 ppm or less, and particularly preferably 1 ppm or less. Since lower content is preferable, there is no lower limit, but it may be 0.001 ppm or more, or 0.01 ppm or more. The sodium content of the composition is preferably 10 ppm or less, more preferably 5 ppm or less, even more preferably 3 ppm or less, even more preferably 1 ppm or less, and particularly preferably 0.5 ppm or less. Since a lower content is preferable, there is no lower limit, but it may be 0.001 ppm or more, or 0.01 ppm or more. The potassium content of the composition is preferably 10 ppm or less, more preferably 5 ppm or less, even more preferably 3 ppm or less, even more preferably 1 ppm or less, and particularly preferably 0.5 ppm or less. Since a lower content is preferable, there is no lower limit, but it may be 0.001 ppm or more, or 0.01 ppm or more. The iron content of the composition is preferably 10 ppm or less, more preferably 5 ppm or less, even more preferably 3 ppm or less, even more preferably 1 ppm or less, and particularly preferably 0.5 ppm or less. Since a lower content is preferable, there is no lower limit, but it may be 0.001 ppm or more, or 0.01 ppm or more.The copper content of the composition is preferably 10 ppm or less, more preferably 5 ppm or less, even more preferably 3 ppm or less, even more preferably 1 ppm or less, and particularly preferably 0.5 ppm or less. Since a lower content is preferable, there is no lower limit, but it may be 0.001 ppm or more, or 0.01 ppm or more. An example of an analytical method for the metal content contained in a composition containing the dihydroxy compound (1a) is the method described in the examples below.

[0028] The reason why compositions containing dihydroxy compound (1a) contain sodium and potassium is due to the use of basic compounds containing sodium and potassium, such as potassium carbonate, during the reaction, and the use of basic compounds containing sodium and potassium, such as added sodium hydroxide, during the alkali treatment after the reaction. The reason why compositions containing dihydroxy compound (1a) contain iron and copper is that biphenantrols (2a), such as compound (2a-1) used as a raw material, have conventionally used compounds containing metals such as copper and iron during their manufacture, and these are contained in the biphenantrols (2a), and may remain present even after the production of dihydroxy compound (1a) without being removed. It has become clear that conventionally known methods for synthesizing dihydroxy compound (1a) have a problem in that the product contains a large amount of metal. However, the compositions containing dihydroxy compound (1a) of the present invention can solve this problem and are therefore very useful.

[0029] The composition containing the dihydroxy compound (1a) of the present invention preferably has an average particle diameter in the range of 20 to 150 μm in the volume-based cumulative particle size distribution measured using a wet laser diffraction particle size distribution measuring device. The lower limit value of such an average particle diameter is more preferably 30 μm or more, and further preferably 80 μm or more. The upper limit value of such an average particle diameter is more preferably 130 μm or less, and further preferably 110 μm or less. The composition containing the dihydroxy compound (1a) having such an average particle diameter can be obtained by performing the crystallization operation in the aforementioned crystallization step.

[0030] The purity of the composition containing the dihydroxy compound (1a) of the present invention is preferably such that the ratio of the peak area of the dihydroxy compound (1a) to the peak areas of all components detected at a wavelength of 280 nm in high performance liquid chromatography (HPLC) analysis is 90.0% or more, more preferably 93.0% or more, further preferably 95.0% or more, still more preferably 98.0% or more, and particularly preferably 99.0% or more. The HPLC analysis method for the purity of the composition containing the dihydroxy compound (1a) of the present invention is a method according to the HPLC analysis for purity analysis in the analysis method of the following examples.

[0031] The composition containing the dihydroxy compound (1a) of the present invention preferably has a hue of 400 APHA or less when it is a 10 wt% cyclohexanone solution. The APHA value of such a hue is more preferably 300 or less, further preferably 200 or less, and particularly preferably 100 or less. The numerical value indicating the hue of the cyclohexanone solution can be treated as the numerical value obtained by rounding off the units digit of the hue analysis result value, and it is preferable that the numerical value is within the above range.

[0032] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. The analysis method is as follows. <Analysis Method> 1. Reaction selectivity analysis, purity analysis When analyzing the target compound and the reaction solution obtained under the following apparatus and conditions, the area percentage of the target compound was taken as the purity and the reaction selectivity. Apparatus: Prominence UFLC (liquid chromatography) manufactured by Shimadzu Corporation Pump: LC-20AD Column oven: CTO-20A Detector: SPD-20A Column: HALO C18 (inner diameter 3 mm, length 75 mm) Oven temperature: 50 °C Flow rate: 0.7 mL / min. Mobile phase: (A) 0.2% by volume acetic acid aqueous solution, (B) methanol Gradient conditions: (B) volume % 0-7 min., 50% → 70% 7-13 min., 70% 13-20 min., 70% → 100% 20-23 min., 100% Sample injection volume: 5 μL Detection wavelength: 280 nm

[0033] 2. Melting point measurement: Differential scanning calorimetry (DSC) The crystal was precisely weighed into an aluminum pan and measured under the following operating conditions using a differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation: DSC-7020) with aluminum oxide as a control. (Operating conditions) Heating rate: 10 °C / min. Measurement temperature range: 30 to 400 °C Measurement atmosphere: open, nitrogen 50 mL / min. Sample amount: 2 to 3 mg

[0034] 3. Hue evaluation The sample was dissolved in cyclohexanone to prepare a 10% by weight solution. After calibrating the following measuring instrument with cyclohexanone, the dissolved color of the prepared 10% by weight solution was measured. Measuring instrument: TZ 6000 manufactured by Nippon Denshoku Industries Co., Ltd.

[0035] 4. NMR analysis Using Fourier transform nuclear magnetic resonance AVANCE III HD 400 (manufactured by BRUKER), the 1H-NMR spectrum of the sample was measured in deuterated chloroform (CDCl ３ ) １

[0036] ​5. Refractive Index The compound to be measured was dissolved in N,N-dimethylformamide to prepare solutions with concentrations of 30% by weight, 20% by weight, and 10% by weight. The refractive index was measured using the refractometer described below. From the obtained results, the relationship between concentration and refractive index was derived, and the value at a concentration of 100% by weight was calculated by extrapolation. This value was defined as the refractive index of the compound. Equipment: Refractometer (Kyoto Electronics Manufacturing Co., Ltd.: RA-500)

[0037] 6. Powder X-ray Diffraction (XRD) 0.1 g of the obtained solid was filled into the material-filled section of a glass test plate and measured using the following equipment and conditions. Equipment: Rigaku Corporation: SmartLab (powder X-ray diffractometer) X-ray source: CuKα Scan axis: 2θ / θ Mode: Continuous Measurement range: 2θ = 5° to 90° Step: 0.01° Speed ​​measurement time: 2θ = 33.9° / min. IS: 2 / 3 RS: 20.00 mm Output: 40 kV, 30 mA

[0038] 7. Analysis of Metal Content: After dry ashing of 1 g of the sample, acid dissolution was performed. The amounts of sodium and potassium were analyzed by atomic absorption spectrometry, and the amounts of iron and copper were analyzed by inductively coupled plasma mass spectrometry. In this analysis, if the measurement result for sodium and potassium was less than 0.1 ppm (not undetectable), it was indicated as "less than 0.1 ppm." Similarly, if the measurement result for iron and copper was less than 0.01 ppm (not undetectable), it was indicated as "less than 0.01 ppm." These values ​​were not added together when summing the contents of each metal.

[0039] <Comparative Example 1> Compound (1a-1) was synthesized based on the description in Example 1 of Patent Document 3. 10.03 g of 10,10'-dihydroxy-9,9'-biphenanthrene:compound (2a-1) (metal content: iron 2.4 ppm, copper 3.8 ppm, sodium 1.3 ppm, potassium 0.1 ppm), 5.24 g of ethylene carbonate, 0.37 g of potassium carbonate, and 20 mL of dimethylformamide (DMF) were added to a 100 mL four-necked flask. Nitrogen was blown into the flask to replace the air with nitrogen, and the mixture was heated to 120°C and stirred for 5 hours while maintaining the temperature. After the reaction, the reaction solution was cooled to room temperature, and then 14.16 g of DMF and 2.18 g of 10% NaOH aqueous solution were added. The solution was then heated to 110°C and stirred for 2 hours while maintaining the temperature to perform alkali treatment. The reaction solution was then cooled to 40°C. 102.97 g of water was placed in a 200 mL Erlenmeyer flask, and while stirring the water with a magnetic stirrer, the alkali-treated reaction solution was added dropwise to the water using a pipette. The water immediately became cloudy upon addition of the reaction solution, and after the entire volume of the reaction solution had been added, a pale yellow slurry was obtained. This slurry was filtered by suction using a Kiriyama funnel (filter paper No. 5C) to obtain 40.78 g of a pale yellow paste. 40.78 g of the filtered paste and 89.97 g of water were added to a 200 mL Erlenmeyer flask and stirred with a magnetic stirrer at room temperature for 1 hour. The slurry in the Erlenmeyer flask was filtered to separate the solids using a Kiriyama funnel (filter paper No. 5C) to obtain a pale yellow paste containing 35.19 g of solvent. Next, the obtained paste was transferred to a 100 mL round-bottom flask, and the solvent was removed by evaporation for 7.5 hours using an evaporator (internal pressure 0.9–1 MPa, bath temperature 100°C). 11.93 g of a milky white, lumpy solid of compound (1a-1) was obtained. The purity of the obtained compound (1a-1) was low at 92.9%, and a large amount of by-products resulting from the excess reaction of ethylene carbonate (1.6%) were present (area percentage determined by high-performance liquid chromatography). In addition, residual 10,10'-dihydroxy-9,9'-biphenanthrene from the starting material and many other unidentifiable impurities were observed.The color evaluation result of the solid containing the obtained compound (1a-1) was APHA 500 or higher. The solid containing the obtained compound (1a-1) contained 3.1 ppm of iron, 4.9 ppm of copper, 44.4 ppm of sodium, and 44.0 ppm of potassium, with a total content of 96.4 ppm for each metal.

[0040] The composition containing compound (1a-1) obtained in Comparative Example 1 had low purity due to a large amount of residual raw materials, by-products resulting from the excessive reaction of ethylene carbonate, and other impurities. Furthermore, the hue value of the composition containing compound (1a-1) was very high, indicating strong coloration. The composition containing compound (1a-1) was found to contain a large amount of sodium and potassium resulting from the potassium carbonate used during the reaction and the sodium hydroxide added after the reaction, as well as iron and copper contained in the raw material compound (2a-1).

[0041] <Comparative Example 2> Using a solid containing the compound (1a-1) obtained in Comparative Example 1, an experiment to recrystallize compound (1a-1) was conducted based on the description in Example 2 of Patent Document 3. 6.04 g of the solid containing compound (1a-1) obtained in Comparative Example 1 and 8.44 g (5.9 mL) of chloroform were added to a 100 mL round-bottom flask, but no change was observed, and the dissolution of the solid could not be observed. In other words, it was confirmed that the recrystallization operation based on the description in Example 2 of Patent Document 3 could not be performed. Furthermore, an additional 75.85 g of chloroform was added (total 84.29 g), but the solid still did not dissolve. In an attempt to further increase the solubility, the solid-liquid mixture was heated and stirred in a water bath at 50-60°C for more than 2 hours, but the solid of compound (1a-1) still did not dissolve. Therefore, the solubility of compound (1a-1) in chloroform was measured, and the results were 0.6% by weight at 25°C, 1.2% by weight at 45°C, and 2.3% by weight at 60°C.

[0042] In light of the experimental procedure for recrystallization and the solubility measurement results of Comparative Example 2, it was concluded that the method described in Example 2 of Patent Document 3 cannot purify a solid containing compound (1a-1) by recrystallization. Although Patent Document 3 describes an example of a purification method for compound (1a-1) by recrystallization, it was concluded that there is still no practical purification method.

[0043] <Example 1> In a 500 mL four-necked flask equipped with a refluxer, stirrer, and thermometer, 29.5 g (0.076 mol) of compound (2a-1), 20.2 g (0.229 mol) of ethylene carbonate, 1.7 g (0.031 mol) of potassium hydroxide, 1.3 g (0.004 mol) of tetrabutylammonium bromide, and 150 g of toluene were charged. The mixture was heated to 110°C under a nitrogen atmosphere and stirred for 21 hours. The reaction solution after this reaction was measured by high-performance liquid chromatography, and the selectivity for compound (1a-1) was 87.3%. The reaction solution after the reaction was a slurry containing crystals of compound (1a-1). After the reaction was complete, in order to remove the remaining ethylene carbonate, 4.4 g (0.243 mol) of pure water was added to the reaction solution. Furthermore, a Dean-Stark tube was attached to the flask, and the internal temperature was heated to 110°C to hydrolyze the remaining ethylene carbonate. After cooling the reaction mixture to room temperature, water (61.0 g) was added, and the mixture was filtered to recover the crystals of compound (1a-1). The purity of the obtained compound (1a-1) crystals was 91.3% by liquid chromatography analysis. In a 2 L four-necked flask equipped with a refluxer, stirrer, and thermometer, the obtained compound (1a-1) crystals, methyl isobutyl ketone (641.9 g), water (117.5 g), and 1.88 g (0.031 mol) of acetic acid were added and heated to 88°C, stirring under reflux to completely dissolve the crystals. After stirring for 1 hour, the potassium hydroxide remaining in the obtained crystals was neutralized, and the aqueous layer was separated. After adding water to the obtained oil layer and stirring, the washing operation to separate the aqueous layer was repeated four times to remove the potassium acetate generated by neutralization. The oil layer was then filtered while hot at a temperature of 80°C. After filtration, the oil layer was heated to 90°C, then cooled. When the liquid temperature was 70°C, heptane (214.0 g) was added and the mixture was cooled to room temperature. By filtering off the precipitated crystals, pale yellow crystals of compound (1a-1) were obtained. １ ¹H-NMR analysis confirmed that the obtained crystals contained compound (1a-1). １¹H-NMR: 1.86 (t, 2H), 3.36–3.44 (m, 2H), 3.47–3.52 (m, 2H), 3.65–3.70 (m, 2H), 3.98–4.04 (m, 2H), 7.35–7.36 (m, 2H), 7.59–7.63 (m, 2H), 7.71–7.75 (m, 2H), 7.79–7.83 (m, 2H), 8.41–8.43 (dd, 2H), 8.80 (d, 2H), 8.86 (d, 2H). The yield of compound (1a-1) relative to the starting compound (2a-1) was 57 mol%. The purity of the crystalline composition containing the obtained compound (1a-1) was 96.6% by high-performance liquid chromatography. Differential scanning calorimetry analysis of the crystals of the composition containing the obtained compound (1a-1) revealed that the crystals had an endothermic peak top temperature (melting point) of 249°C. Weight loss measured by a differential thermogravimetric analyzer was 0.1% at 249°C and 0.2% at 280°C, confirming that there was almost no weight loss near the melting point. The boiling points of both methyl isobutyl ketone (boiling point 116°C) and heptane (boiling point 98°C) used in crystallization are lower than the melting point of the obtained compound (1a-1) (249°C). Furthermore, since the crystals of the composition containing the obtained compound (1a-1) showed almost no weight loss after melting, as described above, they are not adduct crystals. The refractive index (nD20) of the composition containing compound (1a-1) measured by the above analytical method was 1.686. The composition containing the obtained compound (1a-1) contained 0.7 ppm of sodium, less than 0.1 ppm of potassium, 3.6 ppm of iron, and 0.11 ppm of copper, with a total content of 4.4 ppm for each metal. Table 1 shows the main diffraction peaks (those with a relative intensity greater than 5%) obtained by powder X-ray diffraction (PXRD) of the crystals of the composition containing the obtained compound (1a-1).

[0044]

[0045] <Example 2> In a 1 L four-necked flask equipped with a refluxer, stirrer, and thermometer, 123.7 g (0.32 mol) of compound (2a-1) (metal content: iron 2.4 ppm, copper 4.4 ppm, sodium 0.2 ppm, potassium 0.1 ppm), 84.5 g (0.96 mol) of ethylene carbonate, 7.2 g (0.13 mol) of potassium hydroxide, 5.2 g (0.009 mol) of tetrabutylammonium bromide, and 375.1 g of methyl isobutyl ketone were charged and dissolved. The flask was heated to 120°C under a nitrogen atmosphere and stirred for 6.5 hours. When the reaction solution after this reaction was measured by high-performance liquid chromatography, all of the starting compound (2a-1) was consumed, and the selectivity of compound (1a-1) was 86.0%. The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, 84.6 g (4.7 mol) of pure water and 13.0 g of 36% hydrochloric acid were added to the reaction solution to remove the remaining ethylene carbonate and neutralize the remaining potassium hydroxide. The mixture was then heated under reflux for 1 hour to hydrolyze the remaining ethylene carbonate. After the reaction solution was cooled to room temperature, it was filtered to recover crystals containing compound (1a-1). The purity of the obtained crystals of the composition containing compound (1a-1) was 94.4% by liquid chromatography analysis. The yield of crystals containing compound (1a-1) relative to the starting compound (2a-1) was 84 mol%. In a 5 L four-necked flask equipped with a refluxer, stirrer, and thermometer, the crystals of the composition containing compound (1a-1) obtained above, methyl isobutyl ketone (2742.3 g), pure water (318.9 g), and 36% hydrochloric acid (6.4 g) were added, and the mixture was heated to 88°C and stirred under reflux to completely dissolve the crystals. The mixture was stirred for one hour to neutralize the potassium hydroxide remaining in the resulting crystals, and the aqueous layer was separated. Water was added to the resulting oil layer and stirred, and the washing operation to separate the aqueous layer was repeated four times to remove the potassium chloride generated by neutralization. Then, the solution temperature was set to 80°C, and hot filtration was performed. The filtered liquid was heated to 119°C, and the solvent (1850.6 g) containing methyl isobutyl ketone and water was removed by distillation, with crystals precipitation occurring during the process, and then the mixture was cooled to room temperature.The precipitated crystals were filtered off to obtain crystals of a composition containing the pale yellow compound (1a-1). The yield of compound (1a-1) relative to the starting compound (2a-1) was 74 mol%. The purity of the obtained crystals of the composition containing compound (1a-1) was 98.1% by high-performance liquid chromatography. The endothermic peak top temperature (melting point) of the obtained crystals of the composition containing compound (1a-1) was 248°C by differential scanning calorimetry. The obtained composition containing compound (1a-1) contained 0.3 ppm of sodium, less than 0.1 ppm of potassium, 0.02 ppm of iron, and 0.34 ppm of copper, with a total content of 0.66 ppm for each metal.

[0046] <Example 3> In a 100 mL four-necked flask equipped with a refluxer, stirrer, and thermometer, 15.0 g (0.039 mol) of compound (2a-1), 8.5 g (0.097 mol) of ethylene carbonate, 0.87 g (0.016 mol) of potassium hydroxide, 0.63 g (0.002 mol) of tetrabutylammonium bromide, and 47.5 g of methyl isobutyl ketone were charged and dissolved. The flask was heated to 118°C under a nitrogen atmosphere and stirred for 13 hours. The reaction solution after this reaction was measured by high-performance liquid chromatography, and the selectivity of compound (1a-1) was 86.1%. The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, in order to remove the remaining ethylene carbonate, 7.9 g (0.438 mol) of water and 1.6 g (0.016 mol) of concentrated hydrochloric acid were added to the reaction solution to neutralize the remaining potassium hydroxide. The liquid was then heated to 92°C to hydrolyze the remaining ethylene carbonate. After cooling the reaction solution to room temperature, it was filtered to recover crystals of the composition containing compound (1a-1). The purity of the obtained crystals of the composition containing compound (1a-1) was 95.2% by liquid chromatography analysis. The yield of compound (1a-1) relative to the starting compound (2a-1) was 70.1 mol%. The average particle size in the volume-based cumulative particle size distribution of the obtained crystals of the composition containing compound (1a-1), measured using a wet laser diffraction particle size distribution analyzer, was 103 μm. In a 100 mL four-necked flask equipped with a refluxer, stirrer, and thermometer, 12.5 g of crystals of the composition containing the obtained compound (1a-1) described above (including the solvent used during filtration), 43.9 g of cyclohexanone, 25.1 g of pure water, and 0.6 g (0.0078 mol) of concentrated hydrochloric acid were added. The solution was heated to 84°C and stirred to completely dissolve the crystals. After stirring for 1 hour, the potassium hydroxide remaining in the obtained compound (1a-1) crystals was neutralized and the aqueous layer was separated. Water was added to the obtained oil layer and stirred, and the washing operation to separate the aqueous layer was repeated four times to remove the potassium chloride generated by neutralization. The solution was then cooled, and methyl isobutyl ketone (43.9 g) was added when the solution temperature was 60°C and the solution was cooled to room temperature.By filtering off the precipitated crystals, crystals of a composition containing the pale yellow compound (1a-1) were obtained. The purity of the obtained crystals of the composition containing compound (1a-1), measured by high-performance liquid chromatography, was 98.4%. The yield of compound (1a-1) relative to the starting compound (2a-1) used was 62.6 mol%. The average particle size in the volume-based cumulative particle size distribution of the obtained crystals of the composition containing compound (1a-1), measured using a wet laser diffraction particle size distribution analyzer, was 39 μm.

[0047] <Example 4> In a reaction vessel equipped with a refluxer, stirrer, and thermometer, 12 parts by weight of compound (2a-1) (metal content: iron 2.4 ppm, copper 3.8 ppm, sodium 1.3 ppm, potassium less than 0.1 ppm), 6.8 parts by weight of ethylene carbonate, 0.7 parts by weight of potassium hydroxide, 0.5 parts by weight of tetrabutylammonium bromide, and 33.8 parts by weight of methyl isobutyl ketone were charged and dissolved. The reaction vessel was heated to 118°C under a nitrogen atmosphere and stirred for 10 hours. When the reaction solution after this reaction was measured by high-performance liquid chromatography, the selectivity of compound (1a-1) was 92.3%. The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, 16.7 parts by weight of methyl isobutyl ketone was mixed in while maintaining the liquid temperature at 80°C. Then, 1.2 parts by weight of water was added to the reaction solution to remove the remaining ethylene carbonate, and 6.2 parts by weight of water and 0.8 parts by weight of acetic acid were mixed in to neutralize the remaining potassium hydroxide. After the reaction solution was cooled from 80°C to room temperature, the crystallized slurry was filtered. The filtered crystals were washed with methyl isobutyl ketone and water to recover the crystals of compound (1a-1). The solvent content of the recovered crystals was 7% by weight of water and 3% by weight of methyl isobutyl ketone. The purity of the crystals of the composition containing the obtained compound (1a-1) was 96.1% by liquid chromatography analysis. The yield of compound (1a-1) relative to the starting compound (2a-1) was 91.8 mol%. The average particle size in the volume-based cumulative particle size distribution of the crystals of the composition containing the obtained compound (1a-1), measured using a wet laser diffraction particle size distribution analyzer, was 82 μm. In a reactor equipped with a refluxer, a stirrer, and a thermometer, 5 parts by weight of the crystals of the composition containing the obtained compound (1a-1) (including the solvent used during filtration), 103.1 parts by weight of methyl isobutyl ketone, and 11.8 parts by weight of pure water were added. The mixture was heated to 85°C and stirred to completely dissolve the crystals. After stirring for 0.5 hours, the aqueous layer was separated. Water was added to the obtained oil layer and stirred, and the washing operation to separate the aqueous layer was repeated. Then, the mixture was heated to 115°C under atmospheric pressure and distilled at atmospheric pressure, distilling off 66.8 parts by weight of a solvent containing water. The mixture was then cooled to 25°C.Crystals were obtained by filtering off the precipitated crystals. The filtered crystals were dried by heating to 75°C under reduced pressure. The purity of the crystals of the composition containing the obtained compound (1a-1) was 98.4% by high-performance liquid chromatography. The yield of compound (1a-1) relative to the starting compound (2a-1) used was 75.8 mol%. The hue of the crystals of the composition containing the obtained compound (1a-1) when prepared as a 10 wt% cyclohexanone solution was APHA 30. The average particle size in the volume-based cumulative particle size distribution of the crystals of the composition containing the obtained compound (1a-1), measured using a wet laser diffraction particle size distribution analyzer, was 73 μm. The crystals of the composition containing the obtained compound (1a-1) contained 0.04 wt% methyl isobutyl ketone and 0.05 wt% water. The composition containing the obtained compound (1a-1) contained less than 0.1 ppm of sodium, 1.5 ppm of potassium, 0.46 ppm of iron, and 0.24 ppm of copper, with a total content of 2.2 ppm for each metal.

[0048] <Example 5> 5.0 g (0.013 mol) of compound (2a-1), 2.9 g (0.032 mol) of ethylene carbonate, 0.29 g (0.0052 mol) of potassium hydroxide, 0.21 g (0.00065 mol) of tetrabutylammonium bromide, and 20.0 g of cyclohexanone were charged into a 100 mL test tube. The mixture was heated to 120°C under a nitrogen atmosphere and stirred for 6 hours. The reaction solution after this reaction was measured by high-performance liquid chromatography, and the selectivity for compound (1a-1) was 92.8%. The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, 7.5 g of cyclohexanone and, in order to remove the remaining ethylene carbonate, 2.9 g (0.15 mol) of water and 0.52 g (0.0052 mol) of concentrated hydrochloric acid were added to the reaction solution. The solution was further heated to 85°C to hydrolyze the remaining ethylene carbonate, and the aqueous layer was separated. Next, 6.5 g (0.013 mol) of an 8% sodium hydroxide aqueous solution was added, and the mixture was heated to 85°C for alkaline treatment. After standing at 85°C, the aqueous layer was separated, neutralized with acid, and the washing operation was repeated by adding water and separating the aqueous layer. The solution was then cooled, and methyl isobutyl ketone was added when the liquid temperature reached 60°C, and the mixture was cooled to room temperature. The precipitated crystals were recovered by filtration. The purity of the crystals of the composition containing the obtained compound (1a-1) was 98.7% by liquid chromatography analysis. The yield of compound (1a-1) relative to the starting compound (2a-1) was 53.0 mol%.

[0049] <Example 6> In a 300 mL four-necked flask equipped with a refluxer, stirrer, and thermometer, 25.0 g (0.065 mol) of compound (2a-1), 14.2 g (0.162 mol) of ethylene carbonate, 1.45 g (0.026 mol) of potassium hydroxide, 1.0 g (0.0032 mol) of tetrabutylammonium bromide, and 100.0 g of cyclohexanone were charged. The mixture was heated to 120°C under a nitrogen atmosphere and stirred for 5.5 hours. High-performance liquid chromatography analysis of the reaction solution after the reaction showed a selectivity of 93.4% for compound (1a-1). The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, 32.4 g of 8% sodium hydroxide aqueous solution was added, the liquid temperature was heated to 85°C, and the mixture was stirred for 1 hour for alkali treatment. 25.0 g of cyclohexanone and 25.0 g of water were mixed, stirring was stopped, and the mixture was allowed to stand at a liquid temperature of 85°C. The mixture separated into three layers from top to bottom: an oil layer, a slurry layer, and an aqueous layer. The lower aqueous layer was removed. After neutralization with acetic acid, 67.5 g of pure water was added, and the crystals in the intermediate slurry layer dissolved. The liquid was allowed to stand at a temperature of 85°C to remove the aqueous layer, and then the washing of the oil layer was repeated. Subsequently, the filtrate was obtained by hot filtration using a Kiriyama funnel (filter paper No. 5C). To remove a portion of the cyclohexanone contained in the filtrate, the mixture was heated to 80°C and 9 kPa and then subjected to vacuum distillation. After that, 70.0 g of methyl isobutyl ketone was mixed in, and when cooled to room temperature, crystals precipitated. The precipitated crystals were filtered off, and the crystals were washed with 25.0 g of methyl isobutyl ketone to recover the crystals of compound (1a-1). The purity of the crystals of the composition containing the obtained compound (1a-1), measured by high-performance liquid chromatography, was 99.1%. The yield of compound (1a-1) relative to the starting compound (2a-1) was 94.6 mol%. The color of the crystals of the composition containing the obtained compound (1a-1) when prepared as a 10 wt% cyclohexanone solution was APHA 290. 25.0 g of the crystals of the composition containing the obtained compound (1a-1) and 75.0 g of methyl isobutyl ketone were charged into a 300 mL four-necked flask equipped with a refluxer, stirrer, and thermometer. The mixture was heated to 85°C under a nitrogen atmosphere and stirred for 1 hour in a slurry state.Subsequently, the mixture was cooled to 25°C, the crystals were filtered off, and the crystals were washed with 25.0 g of methyl isobutyl ketone to recover the crystals containing the solvent. The recovered crystals were dried under reduced pressure at 80°C to obtain a powder of compound (1a-1). The purity of the crystals of the composition containing the obtained compound (1a-1) was 99.3% by high-performance liquid chromatography. The endothermic peak top temperature (melting point) of the crystals of the composition containing the obtained compound (1a-1) was 248.6°C by differential scanning calorimetry. The hue of the crystals of the composition containing the obtained compound (1a-1) when prepared as a 10 wt% cyclohexanone solution was APHA230. The crystals of the composition containing the obtained compound (1a-1) contained 1.8 ppm of sodium, 0.4 ppm of potassium, 0.2 ppm of iron, and less than 0.01 ppm of copper, with a total content of 2.2 ppm for each metal.

[0050] <Example 7> In a 300 mL four-necked flask equipped with a refluxer, stirrer, and thermometer, 10.0 g (0.026 mol) of compound (2a-1), 5.7 g (0.065 mol) of ethylene carbonate, 0.58 g (0.01 mol) of potassium hydroxide, 0.42 g (0.001 mol) of tetrabutylammonium bromide, and 40.0 g of cyclohexanone were charged. The mixture was heated to 120°C under a nitrogen atmosphere and stirred for 5 hours. High-performance liquid chromatography analysis of the reaction solution after the reaction showed a selectivity of 93.1% for compound (1a-1). The reaction solution after the reaction was a slurry containing crystals. After the reaction was complete, 20.0 g of water was added to the reaction solution to remove the remaining ethylene carbonate. Then, 2.2 g of 48% sodium hydroxide aqueous solution was added, the solution was heated to 85°C, and stirred for 1 hour to perform alkali treatment. 5.0 g of methyl isobutyl ketone was mixed, stirring was stopped, and the mixture was allowed to stand at a temperature of 85°C. After separating the aqueous layer, the mixture was neutralized with acetic acid, and the washing operation was repeated by adding pure water and separating the aqueous layer. Then, the mixture was filtered hot using a Kiriyama funnel (filter paper No. 5C), and the filtrate was heated to 90°C to redissolve all the precipitated crystals. The solution was then cooled, and 68.5 g of methyl isobutyl ketone was mixed in the middle of the process. When the mixture cooled to room temperature, crystals precipitated. The precipitated crystals were filtered off, washed with 20.0 g of methyl isobutyl ketone, and the crystals were recovered. The purity of the crystals of the composition containing the obtained compound (1a-1), measured by high-performance liquid chromatography, was 98.9%. The yield of compound (1a-1) relative to the starting compound (2a-1) was 69.1 mol%. The color of the crystalline composition containing the obtained compound (1a-1) when it was prepared as a 10% by weight cyclohexanone solution was APHA270.

[0051] The method in Example 1 used toluene as the reaction solvent, and in Examples 2 to 4 used methyl isobutyl ketone as the solvent to synthesize and isolate compound (1a-1). This method allowed for the dissolution of the compound in an aliphatic ketone solvent and subsequent washing with water, demonstrating that a composition containing the highly pure compound (1a-1) of the present invention could be produced. The compositions containing compound (1a-1) obtained in Examples 2 and 4 showed significantly reduced metal content and higher purity compared to the composition containing compound (1a-1) obtained in Comparative Example 1. The methods in Examples 5 to 7, by using cyclohexanone as the reaction solvent, allowed for post-treatment steps (hydrolysis, neutralization, and alkali treatment) in addition to washing with water after the reaction, demonstrating that a composition containing the highly pure compound (1a-1) could be produced. The composition containing compound (1a-1) obtained in Example 5 showed significantly reduced metal content and higher purity compared to the composition containing compound (1a-1) obtained in Comparative Example 1. From the above, we found that compositions containing biphenanthrene skeleton-containing dihydroxy compounds obtained by conventionally known methods for producing biphenanthrene skeleton-containing dihydroxy compounds contain large amounts of components due to the bases and metals used during or after the reaction, and these could not be purified by washing with water or recrystallization. It has become clear that the method of the present invention makes it possible to produce compositions containing high-quality biphenanthrene skeleton-containing dihydroxy compounds with low metal content, thereby solving the above problem.

Claims

1. A composition containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a), wherein the total content of each metal, sodium, potassium, iron, and copper, is 40 ppm or less. (In the formula, R １ Each independently represents an alkylene group with 2 to 4 carbon atoms, R ２ Each of these independently represents an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a halogen atom, and each of these independently represents 0 or an integer from 1 to 4.

2. The composition according to claim 1, wherein the sodium content is 10 ppm or less, and the potassium content is 10 ppm or less.

3. The composition according to claim 1, wherein the copper content is 10 ppm or less, and the iron content is 10 ppm or less.

4. The composition according to claim 1, wherein the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) is any one of the biphenanthrene skeleton-containing dihydroxy compounds represented by chemical formulas (1a-1) to (1a-3).

5. A method for producing a composition containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a), comprising a washing step of washing a solution containing a biphenanthrene skeleton-containing dihydroxy compound represented by general formula (1a) and an aliphatic ketone solvent having 5 to 9 carbon atoms with water.

6. The manufacturing method according to claim 5, wherein the aliphatic ketone solvent having 5 to 9 carbon atoms is at least one selected from methyl isobutyl ketone and cyclohexanone.

7. The manufacturing method according to claim 5, wherein the biphenanthrene skeleton-containing dihydroxy compound represented by the general formula (1a) is any of the biphenanthrene skeleton-containing dihydroxy compounds represented by chemical formulas (1a-1) to (1a-3).

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