TWI881069B - Polycyclic aromatic compound, crystal thereof and method for producing the same - Google Patents

Abstract

A polycyclic aromatic compound represented by the following formula (1), (wherein, Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, _L1 is an alkylene group having 1 to 15 carbon atoms, _R1 is a alkyl group having 1 to 12 carbon atoms, _m1 is an integer of 1 to 5, and _n1 is an integer of 0 to 8).

Description

Polycyclic aromatic compound, crystal thereof and method for producing the same

The present invention relates to a polycyclic aromatic compound, its crystal and a method for producing the same.

In recent years, thermoplastic resin materials such as polycarbonate and polyester, which are made of alcohols with a binaphthyl skeleton, represented by 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl (sometimes abbreviated as BN2EO), have attracted much attention as optical components such as optical lenses or optical sheets due to their excellent optical properties, heat resistance, and formability. For example, Patent Document 1 discloses that the refractive index of a polycarbonate resin made of BN2EO is 1.668. Patent Document 2 discloses that the refractive index of a polycarbonate resin made of 6,6'-diphenyl-2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl is 1.697. However, with the rapid technological innovation in recent years, further improvement of the refractive index is sought. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2014/073496 Specification [Patent Document 2] International Publication No. 2019/043060 Specification

[Problems to be solved by the invention]

The purpose of the present invention is to provide a novel polycyclic aromatic compound with a high refractive index, its crystal and its production method. [Means for solving the problem]

The inventors of the present invention have found that the above-mentioned problem can be solved by the present invention having the following aspects. 《Aspect 1》 A polycyclic aromatic compound represented by the following formula (1),

(wherein, Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, _L1 is an alkylene group having 1 to 15 carbon atoms, _R1 is a alkyl group having 1 to 12 carbon atoms, _m1 is an integer of 1 to 5, and _n1 is an integer of 0 to 8).

《Aspect 2》 A polycyclic aromatic compound as in aspect 1, wherein Z in the aforementioned formula (1) is a phenanthryl group. 《Aspect 3》 A polycyclic aromatic compound as in aspect 1 or 2, wherein the aforementioned polycyclic aromatic compound represented by formula (1) is a polycyclic aromatic compound represented by the following formula (2),

(In the formula, R ₂ and R ₃ are alkyl groups having 1 to 12 carbon atoms, n ₂ and n ₃ are integers of 0 to 4, and L ₁ and m ₁ are the same as those in the above formula (1)).

《Aspect 4》 A polycyclic aromatic compound as in any one of aspects 1 to 3, wherein the polycyclic aromatic compound represented by formula (1) is 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene represented by the following formula (3),

《Aspect 5》 A polycyclic aromatic compound as in any of Aspects 1 to 4, whose HPLC purity is 95% by area or more. 《Aspect 6》 A polycyclic aromatic compound as in any of Aspects 1 to 5, wherein the percentage unit color number (hereinafter also referred to as APHA) of the polycyclic aromatic compound dissolved in a 5% by weight solution of dimethylformamide is 100 or less. 《Aspect 7》 A crystal of a polycyclic aromatic compound as in Aspect 4, which has an endothermic peak in the range of 230-250°C as indicated by differential scanning calorimetry. 《Aspect 8》 A method for producing a polycyclic aromatic compound as in aspect 1, which is a method for producing a polycyclic aromatic compound represented by the above formula (1) by reacting a polycyclic aromatic compound represented by the following formula (4) with ethyl carbonate in the presence of a base, and using a non-protonic polar solvent as a reaction solvent.

(In the formula, Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, _R1 is a alkyl group with 1 to 12 carbon atoms, _{and n1} is an integer from 0 to 8).

《Aspect 9》 A method for producing polycyclic aromatic hydrocarbon compounds as in aspect 8, wherein dimethylformamide is used as a reaction solvent. [Effect of the invention]

According to the present invention, a novel polycyclic aromatic compound having a high refractive index and good hue and purity can be provided. In addition, a novel polycyclic aromatic compound crystal having excellent processability, productivity and handling properties can be obtained.

《Polycyclic Aromatic Compounds》

The novel polycyclic aromatic compound of the present invention is represented by the following formula (1).

(wherein, Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, _L1 is an alkylene group having 1 to 15 carbon atoms, _R1 is a alkyl group having 1 to 12 carbon atoms, _m1 is an integer of 1 to 5, and _n1 is an integer of 0 to 8).

In formula (1), Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, more preferably anthracene, phenanthrene, phenalene, and even more preferably phenanthrene.

In formula (1), _L1 is an alkylene group having 1 to 15 carbon atoms, preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and particularly preferably an ethylene group.

In formula (1), _R1 is a alkyl group having 1 to 12 carbon atoms, and examples of the alkyl group include alkyl, cycloalkyl, aryl, naphthyl, aralkyl, etc. Specific examples of the alkyl group include preferably _C1-6 alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, etc., more preferably _C1-4 alkyl groups, and even more preferably _C1-3 alkyl groups, among which methyl and ethyl groups are particularly preferred.

Specific examples of the cycloalkyl group include preferably C _5-8 cycloalkyl groups such as cyclopentyl and cyclohexyl, and more preferably C _5-6 cycloalkyl groups.

Specific examples of the aryl group include preferably a phenyl group, an alkylphenyl group (mono- or dimethylphenyl group, tolyl group, 2-methylphenyl group, xylyl group, etc.), and a naphthyl group, and more preferably a phenyl group.

Moreover, specific examples of the aralkyl group preferably include C _6-10 aryl-C _1-4 alkyl groups such as benzyl and phenethyl.

In formula (1), _m1 is an integer of 1 to 5, preferably an integer of 1 to 2, and more preferably 1.

In formula (1), _n1 is an integer between 0 and 8, preferably an integer between 0 and 4, and more preferably 0.

Among the polycyclic aromatic compounds represented by the formula (1), the biphenanthrene compound represented by the following formula (2) is preferred.

(In the formula, R ₂ and R ₃ are alkyl groups having 1 to 12 carbon atoms, n ₂ and n ₃ are integers of 0 to 4, and L ₁ and m ₁ are the same as those in the above formula (1)).

R ₂ and R ₃ in formula (2) are alkyl groups having 1 to 12 carbon atoms, and their specific examples are the same as those of R ₁ in formula (1).

In formula (2), n ₂ and n ₃ are integers of 0 to 4, preferably integers of 0 to 2, and more preferably 0.

L ₁ and m ₁ in formula (2) are the same as L ₁ and m ₁ in the above formula (1).

Specific examples of the biphenanthrene compound represented by formula (2) are preferably 2,2'-bis(2-hydroxyethoxy)-1,1'-biphenanthrene, 3,3'-bis(2-hydroxyethoxy)-4,4'-biphenanthrene, and 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene, and particularly preferably 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene represented by the following formula (3).

The HPLC purity of the polycyclic aromatic compound of the present invention measured by HPLC is preferably 95% by volume or more, more preferably 97% by volume or more, and even more preferably 98% by volume or more.

The APHA of the polycyclic aromatic compound of the present invention when the compound is dissolved in a 5 wt% solution of dimethylformamide is preferably 100 or less, more preferably 70 or less, and even more preferably 50 or less. When the APHA is 100 or less, the color of the compound becomes good and is preferred.

《Crystallization of polycyclic aromatic compounds》 The crystals of the compound represented by the above formula (3) obtained by the present invention preferably have an endothermic peak in the range of 230-250°C as shown by differential scanning calorimetry, more preferably have an endothermic peak in the range of 235-250°C, more preferably have an endothermic peak in the range of 240-248°C, and particularly preferably have an endothermic peak in the range of 243-246°C. The crystals of the compound represented by the above formula (3) obtained by the present invention have excellent processability, productivity, and handling properties, and are good in color and purity.

"Method for producing polycyclic aromatic compounds" The polycyclic aromatic compounds of the present invention can be produced by reacting a polycyclic aromatic compound represented by the following formula (4) with ethyl carbonate in the presence of a non-protonic polar solvent and a base.

(In the formula, Z is a polycyclic aromatic hydrocarbon formed by three benzene ring bonds, _R1 is a alkyl group with 1 to 12 carbon atoms, _{and n1} is an integer from 0 to 8).

Examples of aprotic polar solvents used in the production method of the present invention include N-methylpyrrolidone, dichloromethane, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, ethyl carbonate, propyl carbonate, etc., preferably dimethylformamide.

The amount of the aprotic polar solvent used in the production method of the present invention is preferably 0.1 to 10 times by weight, more preferably 0.3 to 7 times by weight, and even more preferably 0.5 to 5 times by weight relative to the polycyclic aromatic compound represented by formula (4). If the amount of the solvent used is less than 0.1 times by weight, it may be difficult to stir the polycyclic aromatic compound represented by formula (4) or the generated polycyclic aromatic compound represented by formula (1). If the amount of the solvent used is more than 10 times by weight, the reaction time may be delayed or the volumetric efficiency may be reduced, which may deteriorate the production efficiency and be disadvantageous to the economy. In addition, long-term heating operation may increase the amount of side reactants or cause coloration.

In the production method of the present invention, the usage amount (molar ratio) of the polycyclic aromatic compound represented by formula (4) and ethyl carbonate is preferably 1:1.9 to 1:2.9, more preferably 1:2 to 1:2.7, and even more preferably 1:2.1 to 1:2.5. If the usage amount of ethyl carbonate is less than 1:1.9, the reaction time may be prolonged. In addition, the polycyclic aromatic compound represented by formula (4) may remain in an unreacted state, or the by-products obtained by the reaction of 1 mol of the polycyclic aromatic compound represented by formula (4) with 1 mol of ethyl carbonate may increase, thereby reducing the yield or purity. If the amount of ethyl carbonate used is more than 1:2.9, the by-products obtained by the reaction of 1 mol of the polycyclic aromatic compound represented by formula (4) with 3 mol or more of ethyl carbonate increase, and the yield or purity may decrease.

In the production method of the present invention, the reaction temperature is not particularly limited, but is preferably 150°C or less, more preferably 140-40°C, and even more preferably 130-70°C. When the reaction temperature is too high, the yield may decrease or the color may deteriorate due to an increase in side reactions. When the reaction temperature is too low, the reaction may not proceed quickly.

Examples of the base used in the production method of the present invention include potassium hydroxide, sodium hydroxide, barium hydroxide, magnesium oxide, sodium carbonate, potassium carbonate, etc., preferably potassium hydroxide, sodium hydroxide, potassium carbonate, and more preferably potassium carbonate.

The amount of alkali used in the production method of the present invention is not particularly limited, but is preferably 0.01 to 0.5 mol, and more preferably 0.05 to 0.3 mol, relative to 1 mol of the polycyclic aromatic compound represented by formula (4). When the amount of alkali used is small, the reaction may not proceed or the reaction may be delayed. When the amount used is large, the yield or purity may decrease due to the increase in by-products, which may cause coloring. [Example]

The present invention is described in more detail below with reference to the embodiments, but the present invention is not limited to the following embodiments unless the gist thereof is exceeded.

In the examples, various measurements were performed as follows. (1) HPLC measurement The measurement was performed using a Hitachi high-speed liquid chromatograph L-2350 under the measurement conditions shown in Table 1 below. Unless otherwise specified in the examples, the area percentage values are corrected by excluding the solvent in HPLC.

(2) NMR measurement The compound obtained in Example was dissolved in CDCl ₃ and measured using JNM-AL400 (400 MHz) manufactured by JEOL Ltd. Solvent: CDCl ₃ (3) Differential scanning calorimetry (DSC) The measurement was performed using Discovery DSC25 manufactured by TA Instruments under a nitrogen flow at a heating rate of 20°C/min.

(4) Refractive index (nD) The compound obtained in Example was dissolved in dimethyl sulfoxide to prepare a solution of a specific concentration. The refractive index of the solution of each concentration was measured at 25°C using a DR-M2 Abe refractometer manufactured by ATAGO. The refractive index (nD) of the compound obtained in Example was obtained by extrapolating the measured results of each concentration to the value of 100% concentration.

(5) APHA measurement 0.5 g of the test sample was dissolved in 10 ml of dimethylformamide and placed in a φ25 mm test tube. The test was performed using a TZ6000 manufactured by Nippon Denshoku Industries Co., Ltd.

[Example 1] In a nitrogen environment, 10.00 g of 10,10'-dihydroxy-9,9'-biphenylene, 5.24 g of ethyl carbonate, 0.36 g of potassium carbonate and 20 ml of dimethylformamide were added to a flask equipped with a stirrer, a cooler and a thermometer, and reacted at 120°C for 5 hours. After the reaction liquid was cooled, 15 ml of dimethylformamide and 2 ml of a 10% NaOH aqueous solution were added, and alkalization treatment was performed at 110°C for 3 hours. After the reaction liquid was cooled, the reaction liquid was dripped into distilled water while stirring, and the resulting crystals were recovered. After the recovered crystals were washed with distilled water, the recovered crystals were dried to obtain 10.3 g (yield 84%) of white crystals of 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene. The purity of the obtained crystals was 97.27%, APHA was 70, the endothermic peak of differential scanning calorimetry was 237°C, and the refractive index was 1.713. The NMR spectrum of the obtained 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene is shown in Figure 1, and the differential scanning calorimetry results are shown in Figure 2.

[Example 2] 10.3 g of the crystals obtained in Example 1 were dissolved in 10 ml of chloroform, and then 100 ml of hexane was added for recrystallization. The crystals were recovered and dried to obtain 8.4 g of white crystals of 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene. The purity of the obtained crystals was 98.96%, the APHA was 50, and the endothermic peak of the differential scanning calorimetry analysis was 245°C. The obtained differential scanning calorimetry analysis results are shown in Figure 3.

[Comparative Example 1] Except that the 20 ml of dimethylformamide in Example 1 was replaced with 70 ml of toluene and the reaction temperature was changed from 120°C to 110°C, the reaction was carried out in the same manner as in Example 1. When the reaction liquid was subjected to HPLC analysis after 7 hours of reaction, the target product 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene was about 4%, and the raw material 10,10'-dihydroxy-9,9'-biphenanthrene remained about 90%. The reaction rate was significantly slower and the target product could not be obtained.

[Comparative Example 2] As described in International Publication No. 2019/043060, 2,2'-bis(2-hydroxyethoxy)-6,6'-diphenyl-1,1'-binaphthyl was synthesized, and the refractive index of the compound was measured to be 1.694. [Industrial Applicability]

The novel polycyclic aromatic compound obtained in the present invention has a high refractive index and is therefore suitable as a monomer for forming a resin constituting an optical component represented by an optical lens or an optical film.

[Figure 1] is a diagram showing the NMR spectrum of the 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene compound obtained in Example 1. [Figure 2] is a diagram showing the differential scanning calorimetry (DSC) curve of the 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene compound obtained in Example 1. [Figure 3] is a diagram showing the differential scanning calorimetry (DSC) curve of the 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene compound obtained in Example 2.

Claims (6)

A polycyclic aromatic compound represented by the following formula (3) is 10,10'-bis(2-hydroxyethoxy)-9,9'-biphenanthrene, . For example, the polycyclic aromatic compound of claim 1 has a HPLC purity of 95% by volume or more. The polycyclic aromatic compound of claim 1 or 2, wherein the APHA of the polycyclic aromatic compound dissolved in a 5 wt% solution of dimethylformamide is less than 100. A crystal of a polycyclic aromatic compound as claimed in claim 1 or 2, which has an endothermic peak in the range of 230-250°C as shown in differential scanning calorimetry. A method for producing a polycyclic aromatic compound as claimed in claim 1, wherein a polycyclic aromatic compound represented by the following formula (4) is reacted with ethyl carbonate in the presence of a base to produce a polycyclic aromatic compound represented by the above formula (3), and an aprotic polar solvent is used as a reaction solvent. (wherein Z is a phenanthryl group, _R1 is a alkyl group having 1 to 12 carbon atoms, and _n1 is 0). A method for producing polycyclic aromatic compounds as claimed in claim 5, wherein dimethylformamide is used as a reaction solvent.