Crystal of diester compound having binaphthyl skeleton

Abstract

Provided is a crystal of a novel diester compound having a binaphthyl skeleton represented by formula (1). It was found that this compound can be obtained through crystallization more easily than 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl.

Description

Crystals of diester compounds with binaphthyl skeletons

[0001] The present invention relates to a crystal of a novel diester compound having a binaphthyl skeleton.

[0002] In recent years, polyester resins and polyester carbonate resins containing a dicarboxylic acid component having a binaphthyl skeleton as a polymerization component have been expected to be used as raw materials for optical components such as optical disks, transparent conductive substrates, and optical filters, because they have excellent optical properties such as a high refractive index and low birefringence, and also have high heat resistance.

[0003] Resins having a structural unit represented by the formula (I) have attracted attention as resins with excellent optical properties, and such resins are produced, for example, using 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl as a polymerization component (see, for example, Patent Documents 1 to 3). 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl is also produced, for example, by reacting 1,1'-binaphthalene-2,2'-diol with a halogenated acetate such as ethyl chloroacetate (see, for example, Patent Documents 4 and 5).

[0004] JP 2018-002893 A JP 2018-002894 A JP 2018-002895 A JP 2021-017406 A JP 2008-024650 A

[0005] Because raw material monomers for optical resins may adversely affect the optical properties of the resins, they are required to be highly pure. Therefore, when raw material monomers with high boiling points are produced on an industrial scale, purification by crystallization is the norm.

[0006] However, the above-mentioned 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl remains in a liquid state even after purification using silica gel column chromatography (Patent Document 5), and even if crystals are obtained by crystallization, a method that is difficult to implement on an industrial scale is required (specifically, a method in which 1,1'-binaphthalene-2,2'-diol and ethyl chloroacetate are reacted in an acetonitrile solvent, the resulting reaction mixture is washed with water, the acetonitrile is removed, a portion of the resulting residue is added with a 75% aqueous acetone solution, and the mixture is left in a freezer overnight). It has been shown that crude crystals can only be isolated from the reaction mixture by using the seed crystals (Patent Document 4). Thus, because 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl has extremely poor crystallinity or is excessively soluble in solvents, it is difficult to highly purify the compound on an industrial scale, and therefore the compound is not suitable as a raw material monomer for optical resins.

[0007] An object of the present invention is to provide crystals of a novel diester compound having a binaphthyl skeleton that can be more easily obtained by crystallization.

[0008] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a compound represented by the following formula (1), and have thus completed the present invention. Specifically, the present invention includes the following inventions.

[0009] [1] A compound represented by the following formula (1):

[0010] A crystal of the compound represented by the formula:

[0011] [2] A powder X-ray diffraction pattern using Cu-Kα radiation has peaks at diffraction angles 2θ=7.1±0.2°, 7.5±0.2°, 14.1±0.2°, 18.8±0.2°, 19.5±0.2°, and 21.2±0.2°, represented by the following formula (1):

[0012] A crystal of the compound represented by the formula:

[0013] [3] A powder X-ray diffraction pattern using Cu-Kα radiation has peaks at diffraction angles 2θ=7.4±0.2°, 18.7±0.2°, 19.4±0.2°, and 21.1±0.2°, represented by the following formula (1):

[0014] A crystal of the compound represented by the formula:

[0015] [4] A compound represented by the following formula (1): which has a melting endothermic maximum temperature of 173.0°C to 176.9°C in differential scanning calorimetry, and has peaks at diffraction angles 2θ=7.1±0.2°, 7.5±0.2°, 14.1±0.2°, 18.8±0.2°, 19.5±0.2°, and 21.2±0.2° in a powder X-ray diffraction pattern using Cu-Kα radiation:

[0016] A crystal of the compound represented by the formula:

[0017] [5] A compound represented by the following formula (1): which has a melting endothermic maximum temperature of 173.0°C to 176.9°C in differential scanning calorimetry and has peaks at diffraction angles 2θ=7.4±0.2°, 18.7±0.2°, 19.4±0.2°, and 21.1±0.2° in a powder X-ray diffraction pattern using Cu-Kα radiation:

[0018] A crystal of the compound represented by the formula:

[0019] According to the present invention, it is possible to provide crystals of a novel diester compound having a binaphthyl skeleton (i.e., crystals of the compound represented by formula (1) of the present invention having the characteristics described below) that can be obtained by crystallization more easily than 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl. Furthermore, since crystals of the compound represented by formula (1) of the present invention can be crystallized more easily than 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl, they can be recovered in higher yield and purity. Furthermore, crystals of the compound represented by formula (1) of the present invention can be further purified by recrystallization. Therefore, crystals of the compound represented by formula (1) of the present invention are more suitable than 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl as, for example, a raw material monomer for a resin having a structural unit represented by formula (A).

[0020] In addition, as will be shown in the Examples section below, the crystals of the compound of the present invention represented by the above formula (1) have a higher melting point (maximum temperature of melting endotherm determined by differential scanning calorimetry) than 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl, and are therefore expected to have better blocking resistance.

[0021] The compound represented by the above formula (1) １ 1 is a H-NMR chart of the compound represented by the formula (1). １３ 1 is a C-NMR chart. FIG. 2 is a diagram showing a differential scanning calorimetry (DSC) curve of the crystal of the compound represented by formula (1) above (crystal of the present invention) obtained in Example 1. FIG. 3 is a diagram showing a powder X-ray diffraction pattern of the crystal of the compound represented by formula (1) above (crystal of the present invention) obtained in Example 1. FIG. 4 is a diagram showing a differential scanning calorimetry (DSC) curve of the crystal of the compound represented by formula (1) above (crystal of the present invention) obtained in Example 2. FIG. 5 is a diagram showing a powder X-ray diffraction pattern of the crystal of the compound represented by formula (1) above (crystal of the present invention) obtained in Example 2.

[0022] The present invention will be described in detail below. In this specification, when a numerical range is expressed as "A to B," it means A or more and B or less.

[0023] The crystals of the compound of the present invention represented by the above formula (1) can be produced by the production method described below, and have a melting point (maximum temperature of melting endotherm determined by differential scanning calorimetry) of 173.0°C to 176.9°C.

[0024] Furthermore, the crystal of the compound of the present invention represented by the above formula (1) has typical peaks at diffraction angles 2θ=7.1±0.2°, 7.5±0.2°, 14.1±0.2°, 18.8±0.2°, 19.5±0.2°, 21.2±0.2°, 26.0±0.2° and 27.1±0.2° in a powder X-ray diffraction pattern using Cu-Kα radiation, due to differences in the production method described below, and in particular, at diffraction angles 2θ=7.1±0.2°, 7.5±0.2°, 14.1±0.2°, 18.8±0.2°, 19.5±0.2°, 21.2±0.2°, 26.0±0.2° and 27.1±0.2°. The pattern has characteristic peaks at diffraction angles 2θ = 7.1 ± 0.2°, 7.5 ± 0.2°, 14.1 ± 0.2°, 18.8 ± 0.2°, 19.5 ± 0.2°, and 21.2 ± 0.2° (hereinafter, this may be referred to as Pattern A), or has characteristic peaks at diffraction angles 2θ = 7.4 ± 0.2°, 18.7 ± 0.2°, 19.4 ± 0.2°, and 21.1 ± 0.2° (hereinafter, this may be referred to as Pattern B).

[0025] The crystal of the compound of the present invention represented by the above formula (1) has a maximum melting endothermic temperature of 173.0°C to 176.9°C in differential scanning calorimetry and / or exhibits the above pattern A in a powder X-ray diffraction pattern using Cu-Kα radiation.

[0026] Furthermore, the crystal of the compound of the present invention represented by the above formula (1) has a maximum melting endothermic temperature of 173.0°C to 176.9°C in differential scanning calorimetry and / or exhibits the above pattern B in a powder X-ray diffraction pattern using Cu-Kα radiation.

[0027] Crystals of the compound of the present invention represented by formula (1) can be produced, for example, by a production method including a step of crystallizing using a mixture of a C7-10 alkylphenyl ether and methanol as a crystallization solvent (hereinafter, this step may be referred to as the crystallization step). Alternatively, for example, the crystals of the compound of the present invention represented by formula (1) produced by the above production method can be used as seed crystals, and crystallization can be carried out using aromatic hydrocarbons as a crystallization solvent. The above "crystallization step" will be described in detail below.

[0028] In the mixture of alkyl phenyl ether having 7 to 10 carbon atoms and methanol, examples of the alkyl phenyl ether having 7 to 10 carbon atoms include methoxybenzene (anisole), ethoxybenzene (phenetole), propoxybenzene, isopropoxybenzene, butoxybenzene, 1-methylpropoxybenzene, 2-methylpropoxybenzene, and tert-butoxybenzene, with methoxybenzene (anisole) and ethoxybenzene (phenetole) being preferred. These alkyl phenyl ethers having 7 to 10 carbon atoms may be used alone or in combination of two or more. In addition, in the mixture of alkyl phenyl ether having 7 to 10 carbon atoms and methanol, the ratio of alkyl phenyl ether having 7 to 10 carbon atoms to methanol is, for example, 1:1 to 20:1 by weight, preferably 5:1 to 15:1.

[0029] The amount of the crystallization solvent used is, for example, 1 to 15 parts by weight relative to 1 part by weight of the compound represented by the above formula (1). When the reaction mixture obtained in the reaction step described below is used as is in the crystallization step, the amount of the compound represented by the above formula (1) contained in the reaction mixture can be measured, for example, by an absolute calibration curve method or an internal standard method using liquid chromatography.

[0030] Examples of methods for crystallizing the compound represented by formula (1) include dissolving the compound represented by formula (1) in a crystallization solvent, cooling the resulting solution to precipitate crystals, and filtering off the precipitated crystals. The temperature at which the compound represented by formula (1) is dissolved in the crystallization solvent may be, for example, 10°C or more higher than the temperature at which the crystals described below are precipitated. The temperature at which the resulting solution is cooled to precipitate crystals is, for example, 20°C to 60°C. Note that seed crystals may be used when precipitating the crystals.

[0031] Thereafter, further cooling may be carried out as necessary. The cooling rate is, for example, 0.1°C / min to 20°C / min, and the cooling end temperature is, for example, 0°C to 25°C. Then, the crystals can be extracted by a conventional method such as filtration or centrifugation. The extracted crystals usually contain a solvent, but the solvent can be removed by drying. Drying can be carried out, for example, by heating under normal pressure or under reduced pressure. The heating temperature is, for example, 70°C to 90°C.

[0032] The thus obtained crystals of the compound represented by the formula (1) can be further purified by recrystallization, distillation, adsorption, column chromatography, or the like.

[0033] In the production method of the present invention, which comprises a step of crystallizing using a crystal of the compound represented by formula (1) as a seed crystal and an aromatic hydrocarbon as a crystallization solvent, examples of the aromatic hydrocarbon used include toluene, xylene, o-xylene, m-xylene, p-xylene, and ethylbenzene. The solution may contain a solvent other than aromatic hydrocarbons, but it is preferable that no other solvent is contained. The amount of solvent used, the crystallization conditions, and the like in this method can be the same as those in the above-described crystallization method, except that the addition of seed crystals is essential. It should be noted that the crystals of the present invention cannot be obtained if seed crystals are not added.

[0034] The compound represented by the above formula (1) used in the present invention can be prepared by reacting a compound represented by the following general formula (2):

[0035] (In the formula, R １ａ , R １ｂand each independently represent an optionally branched alkyl group having 1 to 6 carbon atoms.) can be produced by reacting a compound represented by the formula (I) with diphenyl carbonate or phenyl acetate (hereinafter referred to as the reaction step). It should be noted that, for example, when a general method for producing 2,2'-bis(alkoxycarbonylmethoxy)-1,1'-binaphthyl, typified by the method for producing 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl described in Patent Documents 4 and 5, i.e., a method of reacting a halogenated alkyl acetate with 1,1'-bi-2-naphthol in the presence of a base, is applied as a method for producing a compound represented by formula (I), the reaction mixture after the reaction contains a large amount of by-products, as described in Reference Example 1 below, making it difficult to isolate the compound represented by formula (I) of the present invention. The reaction step is described in detail below. The reaction step is described in detail below.

[0036] R in the above general formula (2) １ａ , R １ｂ The alkyl group having 1 to 6 carbon atoms in the formula (I) may be linear or branched, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0037] The compound represented by the general formula (2) may be one purified by a conventional method (for example, the crystals described in Patent Document 4), or it may be one that is not purified (for example, the compound represented by the general formula (2) contained in a reaction mixture obtained by reacting 1,1'-bi-2-naphthol with a halogenated acetate). In particular, since the crystals of the compound represented by formula (1) of the present invention have low solubility in commonly used organic solvents such as aromatic hydrocarbons, even if the unpurified compound represented by the general formula (2) is used as a raw material, impurities contained in the previous step can be easily removed by crystallization after the reaction.

[0038] Examples of organic titanium compounds include alkoxy titanium catalysts. Examples of alkoxy titanium catalysts include tetramethyl ester, tetra-n-propyl ester, tetraisopropyl ester, tetra-n-butyl ester, tetraisobutyl ester, tetra-tert-butyl ester, tetra-2-ethylhexyl ester, tetraoctyl ester, tetraphenyl ester, tetrabenzyl ester, and tetratolyl ester of titanic acid. These organic titanium compounds may be used alone or in combination of two or more.

[0039] The amount of the organotitanium compound used is, for example, 0.025 to 0.10 moles per mole of the compound represented by the general formula (2).

[0040] The amount of diphenyl carbonate or phenyl acetate used is, for example, 4 to 25 moles per mole of the compound represented by the above general formula (2).

[0041] The reaction of the compound represented by the general formula (2) with diphenyl carbonate or phenyl acetate may be carried out using diphenyl carbonate or phenyl acetate as a solvent, or may be carried out in the presence of an organic solvent other than diphenyl carbonate or phenyl acetate. Examples of the organic solvent include aromatic hydrocarbons. Examples of the aromatic hydrocarbon include toluene, xylene, and mesitylene. When the organic solvent is used, the amount used is, for example, 0.05 to 5.0 parts by weight per 1 part by weight of the compound represented by the general formula (2). These organic solvents may be used alone or in combination of two or more.

[0042] The reaction of the compound represented by the general formula (2) with diphenyl carbonate or phenyl acetate can be carried out, for example, at 130°C to 170°C. If necessary, the reaction may be carried out under normal pressure or reduced pressure while removing by-products. When the reaction is carried out under reduced pressure, the internal pressure is, for example, 0.67 kPa to 6.7 kPa.

[0043] After the reaction step is carried out, the resulting reaction mixture may be used in the crystallization step as is, or may be used in the crystallization step after, as necessary, post-treatments such as neutralization and washing with water, concentration, etc. Alternatively, the compound represented by formula (1) may be isolated from the resulting reaction mixture by crystallization, column chromatography, etc., and used in the crystallization step. Alternatively, the isolated compound represented by formula (1) may be purified by recrystallization, distillation, adsorption, column chromatography, etc., as necessary, before being used in the crystallization step.

[0044] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Various measurements and tests in the examples were carried out by the methods described below. Furthermore, the "purity" described in the examples is an HPLC area percentage value measured under the following conditions.

[0045] [1] HPLC Measurement Apparatus: Shimadzu LC-2030 Column: XBridge Phenyl (3.5 μm, 4.6 mmφ×150 mm) Column temperature: 40° C. Detection wavelength: UV 254 nm Mobile phase: Solution A = ultrapure water containing 0.1% formic acid, Solution B = acetonitrile containing 0.1% formic acid (Note: Analysis was performed by changing the concentration of Solution B as follows.) Solution B concentration: 40% (5 min hold) → 30 min → 70% (10 min hold) → 5 min → 100% (10 min) Mobile phase flow rate: 1.0 ml / min Sample injection volume: 5 μL

[0046] [2] NMR measurement １ H-NMR and １３ C-NMR was performed using tetramethylsilane as an internal standard and deuterated chloroform (CDCl) as a solvent. ３ ) were recorded on a JEOL-ESC400 spectrometer.

[0047] [3] LC-MS Measurement Apparatus: Xevo G2 Q-Tof manufactured by Waters Column: L-Column 2 ODS (2 μm, 2.1 mmφ×100 mm) Column temperature: 40° C. Detection wavelength: UV 200-500 nm Mobile phase: Solution A = 10 mM ammonium acetate methanol water, Solution B = methanol (Note: Analysis was performed by changing the concentration of Solution B as follows.) Solution B concentration: 60% (1 min hold) → 7 min → 90% (2 min hold) Mobile phase flow rate: 0.35 ml / min Detection method: Q-Tof Ionization method: ESI (+) method Ion Source: Voltage (+) 2.0 kV, temperature 120° C. Sampling Cone: Voltage 10V, gas flow 50 L / h Desolvation Gas: temperature 400°C, gas flow 1000 L / h

[0048] [4] Differential Scanning Calorimetry (DSC) 5 mg of crystals of the compound represented by formula (1) were precisely weighed into an aluminum pan and measured using a differential scanning calorimeter (DSC7020, manufactured by SII Nanotechnology Inc.) under the following operating conditions with aluminum oxide as a control: (Operating conditions) Heating rate: 10°C / min, Measurement range: 30-300°C, Atmosphere: open, nitrogen 40 ml / min.

[0049] [5] Powder X-ray Diffraction 150 mg of crystals of the compound represented by formula (1) were filled into the sample filling section of a glass test plate, and measured using a powder X-ray diffractometer (Spectris: X'PertPRO) under the following conditions: X-ray source: CuKα, output: 1.8 kW (45 kV-40 mA), measurement range: 2θ = 5° to 70°, scan rate: 2θ = 2° / min, slit: DS = 1°, mask = 15 mm, RS = variable (from 0.1 mm).

[0050] <Production Example 1> Production example of a compound represented by the above formula (1) (hereinafter, sometimes referred to as "compound of formula (1)") 50 g (0.18 mol) of 1,1'-bi-2-naphthol, 150 g of acetonitrile, 55.5 g (0.40 mol) of potassium carbonate, and 5 g of potassium iodide were charged into a glass reactor equipped with a stirrer, a heater / cooler, and a thermometer, and the internal temperature was raised to 80°C and stirred at the same temperature for 1 hour. Next, 59.9 g (0.49 mol) of ethyl chloroacetate was added dropwise while maintaining the temperature of the reaction solution at 70°C to 80°C. After stirring at the same temperature for 24 hours, 125 g of ion-exchanged water was added dropwise to the reaction solution to dissolve the inorganic salts, and then the aqueous layer was separated. Next, the obtained organic layer was concentrated to distill off water and a portion of the acetonitrile, and then 150 g of toluene was added and the organic layer was washed with water. The resulting organic layer was then concentrated to distill off water and a portion of the toluene, yielding 111.4 g of a toluene solution of 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl (containing 25.1 wt% toluene). 187 g (0.87 mol) of diphenyl carbonate was charged to the toluene solution at 25°C, and the internal temperature was raised to 80°C to dissolve the diphenyl carbonate. Next, 1.3 g (0.0046 mol) of tetraisopropyl orthotitanate was charged, and after reducing the internal pressure to 1.3 kPa, the internal temperature was raised to 150°C. The reaction was carried out for 8 hours at the same temperature while distilling off toluene and by-products. Thereafter, crystals precipitated when the internal temperature was cooled to 100°C; therefore, 150 g of toluene was charged, and the internal temperature was raised to 110°C to redissolve the precipitated crystals. Next, the internal temperature was cooled to 85° C. to precipitate crystals without adding seed crystals, and then the internal temperature was cooled to 5° C. at a cooling rate of 10° C. / hour. Subsequently, the precipitated crystals at the same temperature were filtered off, and the obtained crystals were dried under reduced pressure at 1.3 kPa for 11 hours while being heated in a water bath at 90° C., thereby obtaining 73.2 g of the compound represented by the above formula (1) as crystals.

[0051] Furthermore, the obtained compound represented by the above formula (1) was subjected to NMR measurement and LC-MS measurement according to the above measurement methods. １ H-NMR, １３ The C-NMR and LC-MS spectral values ​​are shown below. １ H-NMR,１３ The C-NMR measurement chart is shown.

[0052] [ １ H-NMR (CDCl ３ )] δ (ppm) = 4.78 (4H, s), 6.92 (4H, d), 7.17-7.22 (6H, m), 7.29-7.34 (6H, m), 7.44 (2H, d), 7.88 (2H, d), 7.99 (2H, d).

[0053] [ １３ C-NMR (CDCl ３ )] δ (ppm) = 67.08, 115.44, 120.46, 121.23, 124.30, 125.66, 126.01, 126. 68, 127.96, 129.39, 129.85, 129.93, 133.99, 150.06, 153.57, 167.84.

[0054] [LC-MS] Mass spectrometry value ([M+NH ４ ] ＋ ): 572.20650 (calculated molecular weight of the compound represented by the above formula (1) (ESI +; [C ３６ H ２６ O ６ +NH ４ ] ＋ ): 572.20676).

[0055] Example 1 A glass reactor equipped with a stirrer, heater / cooler, and thermometer was charged with 10.0 g of the crystals of the compound of formula (1) obtained as in Production Example 1, 45.5 g of anisole, and 4.5 g of methanol (anisole:methanol = 10:1). The internal temperature was raised to 70°C to dissolve the compound of formula (1), and the mixture was then cooled to an internal temperature of 0°C at a cooling rate of 12°C per hour and maintained at that temperature for 3 hours. During cooling, precipitation of crystals was confirmed at an internal temperature of 52°C. The precipitated crystals were filtered and then dried under reduced pressure to obtain 4.8 g of crystals of the compound of formula (1). The DSC chart of the obtained crystals of the compound of formula (1) is shown in Figure 3, the X-ray diffraction pattern is shown in Figure 4, and the main X-ray diffraction peaks (those with a relative intensity of more than 5%) obtained by powder X-ray diffraction are shown in Table 1. The maximum melting endotherm temperature of the obtained crystals of the compound of formula (1) measured by DSC was 176.9°C.

[0056]

[0057] Example 2 A glass reactor equipped with a stirrer, heater / cooler, and thermometer was charged with 10.0 g of the crystals of the compound of formula (1) obtained as in Production Example 1 and 55.0 g of toluene. The internal temperature was raised to 110 ° C. to dissolve the compound of formula (1), and then the internal temperature was cooled to 90 ° C. Thereafter, 0.03 g of the crystals of the present invention obtained in Example 1 was added as seed crystals, and the mixture was maintained at the same temperature for 1 hour, confirming the precipitation of crystals. The mixture was further cooled to 0 ° C. at a cooling rate of 10 ° C. per hour and maintained at the same temperature for 3 hours. The precipitated crystals were then filtered off, and the filtered crystals were dried under reduced pressure to obtain 8.6 g of crystals of the compound of formula (1). The DSC chart of the obtained crystals of the compound of formula (1) is shown in FIG. 5, the X-ray diffraction pattern is shown in FIG. 6, and the main X-ray diffraction peaks (those with a relative intensity of more than 5%) obtained by powder X-ray diffraction are shown in Table 2. The maximum melting endothermic temperature of the obtained crystals of the compound of formula (1) was 176.8°C as measured by DSC.

[0058]

[0059] Comparative Example 1 Crude crystals of 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl were produced in the same manner as in the method described in Synthesis Example of Patent Document 4. Using the obtained crude crystals, crystals of 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl were obtained in the same manner as in Example 1 of Patent Document 4. The maximum melting endotherm temperature of the obtained crystals measured by DSC was 110.5°C.

[0060] Reference Example 1 A glass reactor equipped with a stirrer, a heater / cooler, and a thermometer was charged with 0.5 g (0.0018 mol) of 1,1'-bi-2-naphthol, 1.5 g of 4-methyltetrahydropyran, 1.0 g (0.0072 mol) of potassium carbonate, and 0.05 g of potassium iodide, and the mixture was heated to 120°C and stirred at the same temperature for 1 hour. Next, 0.94 g (0.0044 mol) of phenyl bromoacetate was added dropwise while maintaining the temperature of the reaction solution at 100°C to 120°C. After stirring for 1 hour, the reaction mixture was subjected to HPLC analysis, which revealed that a complex mixture containing a large amount of by-products had been produced, and the compound represented by formula (1) could not be isolated.

Claims

1. A compound represented by the following formula (1): A crystal of the compound represented by the formula:

2. A powder X-ray diffraction pattern using Cu-Kα radiation has peaks at diffraction angles 2θ = 7.1 ± 0.2°, 7.5 ± 0.2°, 14.1 ± 0.2°, 18.8 ± 0.2°, 19.5 ± 0.2°, and 21.2 ± 0.2°, which is represented by the following formula (1): A crystal of the compound represented by the formula:

3. A powder X-ray diffraction pattern using Cu-Kα radiation has peaks at diffraction angles 2θ=7.4±0.2°, 18.7±0.2°, 19.4±0.2°, and 21.1±0.2°, which is represented by the following formula (1): A crystal of the compound represented by the formula:

4. A compound represented by the following formula (1): wherein the maximum melting endothermic temperature measured by differential scanning calorimetry is 173.0°C to 176.9°C, and the powder X-ray diffraction pattern measured by Cu-Kα radiation has peaks at diffraction angles 2θ=7.1±0.2°, 7.5±0.2°, 14.1±0.2°, 18.8±0.2°, 19.5±0.2°, and 21.2±0.2°: A crystal of the compound represented by the formula:

5. A compound represented by the following formula (1): wherein the maximum melting endothermic temperature measured by differential scanning calorimetry is 173.0°C to 176.9°C, and the powder X-ray diffraction pattern measured by Cu-Kα radiation has peaks at diffraction angles 2θ=7.4±0.2°, 18.7±0.2°, 19.4±0.2°, and 21.1±0.2°: A crystal of the compound represented by the formula:

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