JP2015168658A - Method for producing 2,2'-bis(2-hydroxyethoxy)-1,1'-bi-naphthalene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing 2,2'-bis(2-hydroxyethoxy)-1,1'-bi-naphthalene that is suitable as raw material monomer for various resins including optical resin, that is excellent in processability and in productivity, and that is novel.SOLUTION: We have found the problem can be solved by reusing some or all of the mother liquid obtained by crystallizing 2,2'-bis(2-hydroxyethoxy)-1,1'-bi-naphthalene crystal from a solution in which 2'-bis(2-hydroxyethoxy)-1,1'-bi-naphthalene is dissolved, followed by solid-liquid separating the same, as a part of 2,2'-bis(2-hydroxyethoxy)-1,1'-bi-naphthalene crystallization solution.

Description

  The present invention relates to 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene suitable as a monomer for forming a resin (optical resin) constituting an optical member typified by an optical lens or an optical film. The present invention relates to an improvement of a manufacturing method.

Resin materials such as polycarbonates, polyesters, polyacrylates, polyurethanes, epoxies, and the like using binaphthalenes such as 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene as raw materials have optical properties, heat resistance, etc. In recent years, it has attracted attention as a novel optical material such as an optical lens or a sheet because of its superiority.

As a method of obtaining 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene, a method of reacting naphthols with alkylene oxide, halogenoalkanol, or alkylene carbonate is specifically known. In addition, a reaction mixture obtained by reacting 1,1′-bi-2-naphthol with an excess amount of ethylene carbonate in a synthesis example 1 of JP2011-153248A (Patent Document 1) in the presence of a potassium hydroxide catalyst is methylisobutyl. After being dissolved in ketone and washed with water, the solvent was removed at 150 ° C., and 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene was found to have a melting point of 108 by differential scanning calorimetry (DSC) measurement. A method for obtaining a resin at 0 ° C. is disclosed. In Example 1 of JP 2010-187353 (Patent Document 2), a reaction mixture obtained by reacting 1,1′-bi-2-naphthol and an excess amount of ethylene carbonate in a toluene solvent under a potassium carbonate catalyst. Is washed with a 1% aqueous sodium hydroxide solution and water and then desolvated with a rotary evaporator under reduced pressure to obtain 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. Yes. However, in the reaction between 1,1′-bi-2-naphthol and an excess amount of ethylene carbonate, in addition to the target product, a compound in which 1 mol of 1,1′-bi-2-naphthol and 1 mol of ethylene carbonate have reacted. A by-product includes a compound obtained by reacting 1 mol of 1,1′-bi-2-naphthol with 3 mol or more of ethylene carbonate or a compound obtained by polymerizing 2 mol or more of the target compound by a carbonic ester bond. Therefore, the method of obtaining the target product as the concentrated residue by distilling off the solvent from the reaction mixture as described in the above-mentioned patent document is difficult to implement industrially and is difficult to crystallize due to residual by-products. Only a product with insufficient purity and hue was obtained.

As an industrially feasible method, it is conceivable to obtain crystalline 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene by crystallization. For example, as a crystal of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene, a racemic crystal having a melting point of 112 to 113 ° C. and an optically active crystal having a melting point of 133 to 134 ° C. are known. (Non-Patent Document 1). However, the optically active crystal of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene requires an expensive optically active raw material, and the production method described in this document is complicated. Therefore, it is economically problematic to produce 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene by a method described in the literature and use the obtained product as a monomer for resin. .

In addition, the present inventors preliminarily dissolved a reaction mixture obtained by reacting 1,1′-bi-2-naphthol and an excess amount of ethylene carbonate in an alkali catalyst in a solvent, followed by crystallization by a conventional method. As a result, needle-like crystals precipitated all at once in the entire crystallization solution, and stirring became difficult. In order to make it possible to stir, the precipitated crystals absorb the solvent, so it was necessary to add a large amount of solvent, and the filterability and liquid drainage at the time of crystal washing were poor, so the productivity was remarkably bad. It turned out that the purity of the obtained crystal was also bad.

JP 2011-153248 A JP 2010-188753 A

J. et al. Org. Chem. , Vol. 42, no. 26, 1977, 4173-4184

  An object of the present invention is to provide a method for producing 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene, which is suitable as a monomer for forming an optical resin, with industrial advantage.

As a result of intensive studies to solve the above problems, the present inventors have re-established the mother liquor obtained by the crystallization operation of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. It was found that 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene can be produced industrially by crystallization by using it, and the present invention was completed.

That is, the present invention includes the following.

[1]
2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystals were crystallized from a crystallization solution containing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. Thereafter, a part or all of the mother liquor obtained by solid-liquid separation is used as a crystallization solution to crystallize 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. And 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene.
[2]
The mother liquor crystallizes 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained by the reaction of 1,1′-bi-2-naphthol and ethylene carbonate, and then the solid solution The production method according to [1], wherein the production method is obtained by separation.
[3]
The production method according to any one of [1] to [2], wherein the organic solvent in the crystallization solution is at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons.

According to the present invention, 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene can be produced by a crystallization method that can be carried out industrially without using a large amount of solvent. Further, by performing crystallization by this method, there is an advantage that the filterability is good at the time of filtration after crystallization. Therefore, the filtration and drying time is shortened, and the obtained 2,2′-bis (2- The effect that hydroxyethoxy) -1,1′-binaphthalene is high quality is exhibited.

Hereinafter, the present invention will be described in detail.
The crystallization solution of the present application means an organic solvent that dissolves a part or all of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene in the crystallization step described later, In addition to a typical organic solvent, it may contain impurities generated by a reaction or the like. (In other words, it indicates a substance other than the desired 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene in the crystallization mass.) The mother liquor in the present application is 2′−. After crystallizing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystals from a crystallization solution containing bis (2-hydroxyethoxy) -1,1′-binaphthalene, solid-liquid separation It shows the liquid obtained.

  The method for synthesizing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene for obtaining the mother liquor in the present invention is not particularly limited, but the effect of the present invention is more easily manifested. Therefore, it is preferably obtained by a reaction between 1,1′-bi-2-naphthol and ethylene carbonate. Hereinafter, a method for synthesizing 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene from 1,1'-bi-2-naphthol and ethylene carbonate will be described.

1,1'-bi-2-naphthol has an optical isomer, but a racemate is usually used. The target 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene is a compound obtained by reacting 1 mol of 1,1′-bi-2-naphthol with 2 mol of ethylene carbonate. 1, 1′-bi-2-naphthol as a side reaction product and 1 mol of ethylene carbonate reacted with 1 mol of ethylene carbonate (hereinafter sometimes referred to as 1 mol adduct), 1,1′-bi-2-naphthol A compound in which 1 mol and 3 mol of ethylene carbonate have reacted (hereinafter may be referred to as a 3-mol adduct), a compound in which 1 mol of 1,1′-bi-2-naphthols and 4 mol or more of ethylene carbonate have reacted (hereinafter, referred to as “3 mol adduct”) 4 mol or more may be described as an adduct), and a compound in which the target product is polymerized by 2 mol or more with a carbonate ester bond (hereinafter may be referred to as a polymer) is produced.

The amount of 1,1′-bi-2-naphthol and ethylene carbonate used is usually 1,1′-bi-2-naphthol / ethylene carbonate (molar ratio) = 1 / 1.9 to 1 / 2.4, preferably Is 1 / 2.0 to 1 / 2.4, more preferably 1 / 2.0 to 1 / 2.3. If the amount of ethylene carbonate used is less than 1 / 1.9, stirring may be difficult and the reaction may not proceed or the reaction may be delayed. Even when the reaction proceeds, there are many side reaction products such as unreacted 1,1'-bi-2-naphthol and 1 mol adduct, and the yield and purity tend to decrease. When the amount of ethylene carbonate used is more than 1 / 2.4, the yield and purity tend to decrease due to an increase in side reaction products such as 3 mol adduct, 4 mol or more adduct and polymer.

  A solvent may or may not be used, but the reaction is preferably performed in the presence of a non-reactive organic solvent. The amount of the non-reactive organic solvent used is usually 0.1 to 4 times by weight, preferably 0.5 to 2 times by weight, relative to 1,1'-bi-2-naphthol. If the amount of solvent used is less than 0.1 times by weight, 1,1'-bi-2-naphthol may be difficult to stir depending on other conditions. When the amount of the solvent used is more than 4 times by weight, the production efficiency tends to deteriorate, for example, the reaction time is delayed and the volumetric efficiency is lowered. By reacting with the predetermined amount of ethylene carbonate and a predetermined amount of non-reactive organic solvent, 1,1′-bi-2-naphthol having a high melting point and low solubility in ethylene carbonate or an organic solvent is used as a solution or It is preferable because the reaction can be most efficiently performed in a stirrable slurry state.

The non-reactive organic solvent is not particularly limited as long as it does not inhibit the reaction, aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene, aliphatic hydrocarbons such as pentane, hexane and heptane, Halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, and halogenated aliphatic hydrocarbons such as dichloromethane and 1,2-dichloroethane. Aromatic hydrocarbons and halogenated aromatic hydrocarbons are preferred, and toluene and xylene are particularly preferred.

The catalyst may be either an alkali catalyst or an acid catalyst, but an alkali catalyst is preferred because the reaction proceeds rapidly and impurities are reduced. Examples of the alkali catalyst include potassium hydroxide, sodium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, potassium carbonate and the like. Of these, potassium hydroxide, sodium hydroxide, and potassium carbonate are preferred. The case where an acid catalyst is used is not particularly limited, and examples thereof include sulfuric acid, paratoluenesulfonic acid, methanesulfonic acid and the like. The amount of the catalyst used is not particularly limited, but is usually 0.01 to 0.2 mol, preferably 0.05 to 0.2 mol, relative to 1 mol of 1,1′-bi-2-naphthol. It is. A small amount of catalyst is not preferable because the reaction does not proceed or the reaction is delayed. A large amount of catalyst is not preferable because it causes a decrease in yield and purity due to an increase in by-products such as multimers, and causes coloration.

The reaction temperature is usually 150 ° C. or lower, preferably 140 to 40 ° C., more preferably 130 to 70 ° C., particularly 120 to 90 ° C. If the reaction temperature is too high, it may cause a decrease in yield or a deterioration in hue due to an increase in side reaction products. If the reaction temperature is too low, the reaction may not proceed rapidly.

  Although the reaction can be carried out in the air, it is preferably carried out in an inert gas atmosphere such as nitrogen or argon from the viewpoint of safety. The reaction can be followed by analytical means such as liquid chromatography.

  After the reaction, usually, a solvent is added as necessary to dissolve the reaction mixture, a washing step of washing with an aqueous alkali solution and / or water to decompose and remove unreacted ethylene carbonate and polymer, Further, if necessary, post-treatment steps such as dehydration, filtration and adsorption purification are appropriately performed to obtain a crystallization solution containing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene.

The resulting crystallization solution containing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene was subjected to crystallization operation to produce 2,2′-bis (2-hydroxyethoxy) -1,1′-. After the crystals of binaphthalene are precipitated, solid-liquid separation can be performed by a filtration operation to obtain 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystals and a mother liquor. The mother liquor may contain a solvent used for further washing the crystals separated during solid-liquid separation.

The crystallization operation for obtaining the mother liquor is not particularly limited, but an example of the crystallization conditions will be described below.

The organic solvent in the crystallization solution is not particularly limited, and examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene, and aliphatic hydrocarbons such as pentane, hexane, and heptane. Aromatic hydrocarbons and aliphatic hydrocarbons are preferred from the standpoint of the development of the above, and toluene and xylene are most preferred. These solvents can be used as a mixture of two or more. The amount of the organic solvent used is usually 3 to 20 times by weight, preferably 5 to 12 times by weight, relative to 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene in the crystallization solution. is there. When the amount of the solvent is more than 20 times by weight, economical efficiency and productivity are deteriorated. On the other hand, if the amount of the solvent is less than 3 times by weight, a sufficient purification effect cannot be obtained, the impurities are increased, and the effect of the present application may not be exhibited. These solvents can be newly added, or the solvent used in the reaction or purification step can be used as it is without being newly added.

It is preferable to completely heat and dissolve the crystals before crystallization. Although the temperature at the time of melt | dissolution is not specifically limited, Usually, it is 65 degreeC or more and below the boiling point of a solvent, Preferably it is 80 to 110 degreeC. If this temperature is low, the effects of the present application may not be exhibited. The dissolution time is not particularly limited, but is usually 0.5 to 5 hours, preferably 1 to 3 hours under stirring.

Although the cooling rate is not particularly limited, it is usually 0.05 to 1 ° C per minute, preferably 0.1 to 0.5 ° C per minute, particularly 0.1 to 0.3 ° C per minute. is there. If the cooling rate is too slow, the effect of the present application may not be exhibited, which is not preferable. If the cooling rate is too high, impurities are likely to be incorporated into the crystal, which causes a decrease in purity.

The mixture may be further cooled after crystal precipitation. The temperature at the end of cooling is not particularly limited, but is usually −10 to 40 ° C., preferably 0 to 30 ° C., and more preferably 10 to 30 ° C. If this temperature is low, the purity tends to decrease. If this temperature is high, the amount of loss to the solvent increases, resulting in poor economic efficiency and productivity.

The mother liquor and the crystal are separated by separating the crystallization solution containing the crystal with a solid-liquid separator. As a solid-liquid separator, for example, it can be separated into 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystal and mother liquor by a centrifuge, filter press, Nutsche, etc., but industrially A centrifuge is preferred.

Subsequently, the mother liquor is reused to crystallize 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene, and 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene is crystallized. A method for obtaining the crystals will be described.

  The amount of the mother liquor to be reused is usually 10% by weight or more of the obtained mother liquor, preferably 25% by weight or more, more preferably 40% by weight or more, particularly 50% by weight or more of the reaction for obtaining the mother liquor. It is reused for crystallization of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene produced by the reaction of the same scale (the same amount of 1,1′-bi-2-naphthol used). When the scale of the reaction for obtaining the mother liquor and the reaction for reusing the mother liquor are different, the amount of the mother liquor to be reused may be adjusted according to the amount used. If the amount of the mother liquor to be reused is less than 10% by weight, the effects of the present invention may not be exhibited. Moreover, the total amount of the organic solvent contained in the crystallization solution when the mother liquor is reused is usually based on 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene in the crystallization solution. The amount of the solvent in the crystallization solvent after the mother liquor is added (the sum of the amount of the solvent contained in the mother liquor and the amount of the newly added solvent) may be adjusted so as to be 3 to 20 times, preferably 5 to 12 times . The mother liquid to be reused may be one that has never been reused, or may be a mother liquid that has been reused multiple times. Moreover, the mother liquor to be reused may be added when performing the crystallization operation, and may be added in the crystallization step or may be added in the previous step.

The crystallization conditions when reusing the mother liquor are not particularly limited, but it is preferable to completely dissolve the crystals by heating before crystallization. Although the temperature at the time of melt | dissolution is not specifically limited, Usually, it is 65 degreeC or more and below the boiling point of a solvent, Preferably it is 80 to 110 degreeC. If this temperature is low, the effects of the present application may not be exhibited. The dissolution time is not particularly limited, but is usually 0.5 to 5 hours, preferably 1 to 3 hours under stirring.

Although the cooling rate is not particularly limited, it is usually 0.05 to 1 ° C per minute, preferably 0.1 to 0.5 ° C per minute, particularly 0.1 to 0.3 ° C per minute. is there. If the cooling rate is too slow, the effect of the present application may not be exhibited, which is not preferable. If the cooling rate is too high, impurities are likely to be incorporated into the crystal, which causes a decrease in purity.

In the course of cooling, 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystals were added as seed crystals at a temperature of 60 to 50 ° C., preferably 58 to 52 ° C. It is preferable to precipitate the crystals because the effects of the present invention are more manifested. Furthermore, after adding a seed crystal, it is good to stir at the temperature of 50 degreeC or more for a fixed time (for example, 1-5 hours, Preferably it is 1-3 hours).

The mixture may be further cooled after crystal precipitation. The temperature at the end of cooling is not particularly limited, but is usually −10 to 40 ° C., preferably 0 to 30 ° C., and more preferably 10 to 30 ° C. If this temperature is low, the purity tends to decrease. If this temperature is high, the amount of loss to the solvent increases, resulting in poor economic efficiency and productivity.

Thereafter, the mother liquor and the crystals are separated by separating the crystallization solution containing the crystals with a solid-liquid separator. As a solid-liquid separator, for example, it can be separated into 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystal and mother liquor by a centrifuge, filter press, Nutsche, etc., but industrially A centrifuge is preferred. Thereafter, the obtained crystal may be washed using the solvent or the like used for the crystallization, or may be dried. The crystal purity of 2,2'-bis (2-hydroxyethoxy) -1,1'-binaphthalene thus obtained is usually 95% or more. The obtained crystal may be subjected to repurification such as adsorption and recrystallization. Moreover, you may reuse the obtained mother liquid to the reuse process mentioned above.

EXAMPLES The present invention will be specifically described below with reference to examples and test examples, but the present invention is not limited to these. In the examples, various measurements were carried out by the following methods. The yields in the following Examples and Comparative Examples are (RS) -2,2′-bis (2-hydroxy) relative to (RS) -1,1′-bi-2-naphthol used in the reaction unless otherwise specified. It is the solid yield of ethoxy) -1,1′-binaphthalene, and the HPLC purity is the area percentage of HPLC measured under the following conditions.
<HPLC purity>
Equipment: Shimadzu LC-2010A
Column: SUMPAX ODS A-211 (5 μm, 4.6 mmφ × 250 mm)
Mobile phase: pure water / acetonitrile (acetonitrile 30% → 100%)
Flow rate: 1.0 ml / min, column temperature: 40 ° C., detection wavelength: UV 254 nm
<YI value>
Each crystal of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene was dissolved in N, N-dimethylformamide so that the resulting solution would be 28.6% by mass, and the following conditions were satisfied. The YI value of the N, N-dimethylformamide solution obtained in (1) was measured.
Device: Color difference meter (Nippon Denshoku Industries, SE6000)
Cell used: Optical path length 33mm Quartz cell

<Comparative Example 1>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 1300 g of toluene, and the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. When this crystallization solution was cooled, crystals precipitated at 63 ° C. all at once, making stirring difficult. Toluene (1200 g) was added to make it possible to stir, and then cooled to 30 ° C. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with 200 g of toluene, and separated into crystals containing a solvent and mother liquor. This filtration operation took 40 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 50% by weight, and the crystal was poor in filterability. The mother liquor separated by filtration was 2630 g. Next, the crystals containing the solvent obtained by solid-liquid separation were dried to obtain 198 g of pale yellow crystals of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene (yield). Rate 84.1%, HPLC purity 99.1%, YI value: 11).

<Example 1>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. 200 g of toluene and 1100 g of the mother liquor obtained in Comparative Example 1 were added to the reaction mixture for dilution, and then the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. When this crystallization solution was cooled to 30 ° C. over 8 hours, crystals were precipitated at 39 ° C. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with 200 g of toluene, and separated into crystals containing a solvent and mother liquor. This filtration operation took 10 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 15% by weight, and it was a crystal with good filterability. The mother liquor separated by filtration was 1603 g. Next, the crystals containing the solvent obtained by solid-liquid separation were dried to obtain 211 g of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene white crystals (yield) 89.5%, HPLC purity 99.7%, YI value: 4)

<Example 2>
A crystallization solution was obtained in the same manner as in Example 1 except that 900 g of the mother liquor obtained in Example 1 was added instead of 900 g of the mother liquor obtained in Comparative Example 1. When this crystallization solution was cooled to 30 ° C. over 10 hours, crystals were precipitated at 36 ° C. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with 200 g of toluene, and separated into crystals containing a solvent and mother liquor. This filtration operation took 10 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 14.5% by weight, and it was a crystal with good filterability. The mother liquor separated by filtration was 1610 g. Next, the crystal containing the solvent obtained by solid-liquid separation was dried to obtain 212 g of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene white crystals (yield) 90.0%, HPLC purity 99.8%, YI value: 3).

<Example 3>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. After diluting the reaction mixture with 760 g of toluene and 410 g of the mother liquor obtained in Example 2, the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. The crystallization solution was cooled to 55 ° C. over 5 hours. At the same temperature, 0.085 g of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained in Example 2 was added as a seed crystal and stirred at the same temperature for 2 hours to obtain crystals. After precipitation, it was cooled to 30 ° C. over 3 hours. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with 200 g of toluene, and separated into crystals containing a solvent and mother liquor. This filtration operation took 10 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 14% by weight, and it was a crystal with good filterability. The mother liquor separated by filtration was 1510 g. Next, the crystals containing the solvent obtained by solid-liquid separation were dried to obtain 211 g of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene white crystals (yield) 89.7%, HPLC purity 99.7%, YI value: 2).

<Example 4>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 270 g (0.943 mol) of (RS) -1,1′-bi-2-naphthol, 190 g (2.158 mol) of ethylene carbonate, potassium carbonate 13.5 g and 270 g of toluene were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 1080 g of toluene and 1350 g of the mother liquor obtained in Example 3, and then the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. The crystallization solution was cooled to 55 ° C. over 5 hours. At the same temperature, 0.270 g of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained in Example 3 was added as a seed crystal and stirred at the same temperature for 2 hours to obtain crystals. After precipitation, it was cooled to 30 ° C. at 0.1 ° C./min for 4 hours. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with 300 g of toluene, and separated into crystals containing a solvent and mother liquor. This filtration operation took 15 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 15% by weight, and it was a crystal with good filterability. The mother liquor separated by filtration was 2990 g. Next, the crystals containing the solvent obtained by solid-liquid separation were dried to obtain 315 g of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene white crystals (yield) 89.2%, HPLC purity 99.8%, YI value: 2).

<Example 5>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and xylene 180 g were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 670 g of xylene and 500 g of the mother liquor obtained in Example 4, and the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. The crystallization solution was cooled to 55 ° C. over 5 hours. At the same temperature, 0.900 g of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained in Example 4 was added as a seed crystal and stirred at the same temperature for 2 hours to obtain crystals. After precipitation, it was cooled to 30 ° C. over 4 hours. This was filtered under reduced pressure with a Nutsche, and the crystals were further washed with 200 g of xylene to separate into crystals containing a solvent and a mother liquor. This filtration operation took 10 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 18% by weight, and it was a crystal with good filterability. The mother liquor separated by filtration was 1541 g. Next, the crystal containing the solvent obtained by solid-liquid separation was dried to obtain 208 g of white crystals of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene (yield) 88.5%, HPLC purity 99.8%, YI value: 3).

<Comparative Example 2>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 1300 g of toluene, and the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic layer was concentrated to remove toluene, and then 540 g of acetone was added to the residue and dissolved by heating at 56 ° C. Next, when this solution was cooled to 30 ° C. over 3 hours, crystals were precipitated at 35 ° C. This was filtered under reduced pressure with a Nutsche to separate into crystals containing the solvent and mother liquor. This filtration operation took 30 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 48% by weight, and the crystal was poor in filterability. Next, the crystals containing the solvent obtained by solid-liquid separation were dried to obtain 110 g of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene white crystals (yield). 46.7%, HPLC purity 99.5%, YI value: 7).

<Comparative Example 3>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 1300 g of toluene, and the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic layer was concentrated to remove toluene, and then 540 g of methanol was added to the residue and dissolved by heating at 64 ° C. Subsequently, when this solution was cooled to 30 ° C. over 3 hours, crystals were precipitated at 32 ° C. This was filtered under reduced pressure with a Nutsche to separate into crystals containing the solvent and mother liquor. This filtration operation took 30 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 45% by weight, and the crystal was poor in filterability. Next, the crystal containing the solvent obtained by solid-liquid separation was dried to obtain 125 g of pale yellow crystals of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene (yield). Rate 53%, HPLC purity 99.3%, YI value: 8).

<Comparative Example 4>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and 180 g of toluene were charged and stirred at 110 ° C. for 10 hours. The reaction mixture was diluted with 1300 g of toluene, and the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux. When 400 g of toluene and 800 g of hexane were added to this and cooled, crystals were deposited at 65 ° C. at once. This was cooled to 30 ° C. over 4 hours and filtered under reduced pressure with a Nutsche, and the crystals were further washed with a mixed solvent of toluene / hexane = 140 g / 60 g to separate the crystals containing the solvent into the mother liquor. This filtration operation took 40 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 52% by weight, and the crystal was poor in filterability. Crystals containing the solvent obtained by solid-liquid separation were dried to obtain 197 g of pale yellow crystals of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene (yield 83). 9%, HPLC purity 98.2%, YI value: 13).

<Example 6>
In a glass reactor equipped with a stirrer, a cooler, and a thermometer, 180 g (0.629 mol) of (RS) -1,1′-bi-2-naphthol, 127 g (1.439 mol) of ethylene carbonate, potassium carbonate 9.0 g and xylene 180 g were charged and stirred at 110 ° C. for 10 hours. After diluting the reaction mixture with 200 g of octane and 1200 g of the mother liquor obtained in Example 5, the organic solvent layer containing the reaction mixture was kept at 80 ° C. and washed with an aqueous sodium hydroxide solution. Next, this organic solvent layer was washed with water until the washing water became neutral. The obtained organic solvent layer was dehydrated under reflux to obtain a crystallization solution. The crystallization solution was cooled to 55 ° C. over 5 hours. At the same temperature, 0.900 g of 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained in Example 5 was added as a seed crystal and stirred at the same temperature for 2 hours to obtain crystals. After precipitation, it was cooled to 30 ° C. over 4 hours. After this was filtered under reduced pressure with Nutsche, the crystals were further washed with xylene / octane = 180 g / 30 g to separate into crystals containing a solvent and mother liquor. This filtration operation took 16 minutes. Further, when a part of the obtained crystal was collected and analyzed, the solvent content in the crystal was 25% by weight, and the crystal was relatively good in filterability. The mother liquor separated by filtration was 1530 g. Next, the crystal containing the solvent obtained by solid-liquid separation was dried to obtain 208 g of white crystals of (RS) -2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene (yield) 88.5%, HPLC purity 99.6%, YI value: 5).

Claims (3)

2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene crystals were crystallized from a crystallization solution containing 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. Thereafter, a part or all of the mother liquor obtained by solid-liquid separation is used as a crystallization solution to crystallize 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. And 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene. The mother liquor crystallizes 2,2′-bis (2-hydroxyethoxy) -1,1′-binaphthalene obtained by the reaction of 1,1′-bi-2-naphthol and ethylene carbonate, and then the solid solution The production method according to claim 1, wherein the production method is obtained by separation. The production method according to claim 1, wherein the organic solvent in the crystallization solution is at least one selected from the group consisting of aromatic hydrocarbons and aliphatic hydrocarbons.