JP2011105672A - Method for producing 2-hydroxy-6-vinylnaphthalene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially efficiently producing high-purity 2-hydroxy-6-vinylnaphthalene having a small content of impurities such as tar.
The method for producing 2-hydroxy-6-vinylnaphthalene according to the present invention is based on the basicity of 2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds having a molecular weight of 300 to 600 of 1% by weight or less. It reacts with the compound which has the hetero atom which the active hydrogen couple | bonded in presence of a catalyst, and 2-hydroxy-6-vinyl naphthalene is obtained.
[Selection figure] None

Description

  The present invention relates to a method for producing 2-hydroxy-6-vinylnaphthalene which is useful as a raw material for electronic materials, light-related materials and the like.

  2-Hydroxy-6-vinylnaphthalene having a hydroxyl group and a vinyl group in the naphthalene ring is produced by various methods, and is generally produced from a readily available raw material through several steps. However, since this compound has a highly reactive functional group such as a hydroxyl group and a vinyl group in the aromatic ring, various side reactions are liable to occur in the production process. Further, impurities derived from starting materials and intermediate raw materials in the middle are often contained in the reaction liquid in the final process. For this reason, various impurities are mixed in 2-hydroxy-6-vinylnaphthalene obtained in the final step.

  Patent Document 1 proposes a method for precipitating the vinyl naphthalene compound from a water-soluble alcohol solution in which the compound is dissolved, as a method for purifying a vinyl naphthalene compound having a substituent such as a hydroxyl group on the naphthalene ring. According to this method, a naphthalene compound having no vinyl group as an impurity can be removed relatively easily.

JP 2008-143789 A

  However, although the above method can remove impurities having relatively low molecular weight, it is difficult to remove impurities having a large molecular weight such as tar.

  Accordingly, an object of the present invention is to provide a method for industrially efficiently producing high-purity 2-hydroxy-6-vinylnaphthalene having a low content of impurities such as tar.

  As a result of intensive studies to achieve the above object, the present inventors have found that 2-acetoxy-6--6 has a reduced content of an impurity compound having a relatively large molecular weight (for example, an impurity compound having 2 to 3 naphthalene rings). When vinylnaphthalene is used as a raw material and this is reacted with a compound having a heteroatom to which active hydrogen is bonded in the presence of a basic catalyst, the generation of tar content is suppressed, and simple purification reduces the impurity content. It was found that high-purity 2-hydroxy-6-vinylnaphthalene was obtained, and the present invention was completed.

  That is, the present invention has 2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds having a molecular weight of 300 to 600 of 1% by weight or less and having a hetero atom to which active hydrogen is bonded in the presence of a basic catalyst. There is provided a process for producing 2-hydroxy-6-vinylnaphthalene, characterized by reacting with a compound to obtain 2-hydroxy-6-vinylnaphthalene.

In the present invention, 2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds represented by the following formulas (a) to (m) of 1% by weight or less is activated in the presence of a basic catalyst. There is provided a process for producing 2-hydroxy-6-vinylnaphthalene, characterized in that 2-hydroxy-6-vinylnaphthalene is obtained by reacting with a compound having a hetero atom to which hydrogen is bonded.

The present invention further provides 2-acetoxy-6 in which the total content of impurity compounds having a retention time in the range of 8.5 to 25 minutes when analyzed under the following high performance liquid chromatography analysis conditions is 1% by weight or less. 2-hydroxy-6-vinylnaphthalene, characterized in that 2-hydroxy-6-vinylnaphthalene is obtained by reacting vinylnaphthalene with a compound having a heteroatom to which active hydrogen is bonded in the presence of a basic catalyst. Production method.
<High-performance liquid chromatography analysis conditions>
Column: ODS-80Ts (4.6 mm × 15 cm) (manufactured by Tosoh Corporation)
Column temperature: 45 ° C
Eluent: (A) Milli-Q water (ultra pure water), (B) Acetonitrile Gradient conditions: (A) / (B) = 60/40 → 20/80 (gradient 15 minutes), then (A) / (B ) = 20/80 for 5 minutes, then (A) / (B) = 20/80 → 60/40 (gradient 5 minutes)
Detection wavelength: UV280nm
Eluent flow rate: 1.0 mL / min
Sample injection volume: 10 μL

  According to the present invention, 2-acetoxy-6-vinylnaphthalene having a specific impurity compound content of 1% by weight or less is reacted with a compound having a hetero atom to which active hydrogen is bonded in the presence of a basic catalyst. In order to obtain 2-hydroxy-6-vinylnaphthalene, for example, high-purity 2-hydroxy-6-vinylnaphthalene with little tar content is industrially efficient by a simple refining operation without applying activated carbon treatment or the like. Can get well.

で表される２−ヒドロキシ−６−ビニルナフタレンを、下記式（２）

で表される２−アセトキシ−６−ビニルナフタレンから製造するに際し、該原料２−アセトキシ−６−ビニルナフタレンとして、特定の不純物化合物の含有量が１重量％以下（好ましくは０．５重量％以下、さらに好ましくは０．３重量％以下）である２−アセトキシ−６−ビニルナフタレンを用いることが重要である。 In the production method of the present invention, the following formula (1)

2-hydroxy-6-vinylnaphthalene represented by the following formula (2)

In the production of 2-acetoxy-6-vinylnaphthalene represented by the following formula, the content of the specific impurity compound as the raw material 2-acetoxy-6-vinylnaphthalene is 1% by weight or less (preferably 0.5% by weight or less). It is important to use 2-acetoxy-6-vinylnaphthalene, more preferably 0.3% by weight or less.

  Examples of the impurity compound include compounds having a molecular weight of 300 to 600. Such a compound having a molecular weight in the range of 300 to 600 is 2-acetoxy-6-vinylnaphthalene as a raw material, or 1- (6-acetoxynaphthalen-2-yl) ethanol as a raw material, or a target compound. These compounds are dimers or trimers of 2-hydroxy-6-vinylnaphthalene produced by the reaction of the vinyl group or hydroxyl group, that is, a compound having two or three naphthalene skeletons. When such a compound contains a large amount of impurities in the raw material 2-acetoxy-6-vinylnaphthalene, a compound having a heteroatom in which active hydrogen is bonded to 2-acetoxy-6-vinylnaphthalene in the presence of a basic catalyst When it is reacted with a tar-like (tar-like) substance, and 2-hydroxy-6-vinylnaphthalene, which is the target product, is isolated by crystallization, the 2-hydroxy-6-vinylnaphthalene is isolated. Of 2-hydroxy-6-vinylnaphthalene with high impurity content is obtained. On the other hand, when 2-acetoxy-6-vinylnaphthalene having a total content of compounds having a molecular weight of 300 to 600 as impurities is 1% by weight or less is used as a raw material, the formation of a tar-like substance during the reaction is remarkable. Even if the activated carbon treatment or the like is not applied, it is possible to obtain high-purity 2-hydroxy-6-vinylnaphthalene having no tar-like substance attached by a simple crystallization operation or the like. The purity of 2-acetoxy-6-vinylnaphthalene used as a raw material is preferably 99% by weight or more, more preferably 99.5% by weight, particularly preferably 99.7% by weight. The purity of 2-acetoxy-6-vinylnaphthalene used as a raw material can be determined by high performance liquid chromatography (HPLC). Analysis conditions will be described later.

  Representative examples of the compounds having a molecular weight of 300 to 600 include compounds represented by the formulas (a) to (m). Therefore, the total content of the compounds represented by the formulas (a) to (m) as impurities is 1% by weight or less (preferably 0.5% by weight or less, more preferably 0.3% by weight or less). By using 2-acetoxy-6-vinylnaphthalene as a raw material, high-purity 2-hydroxy-6-vinylnaphthalene free of tar-like substances can be obtained by a simple crystallization operation or the like.

  The molecular weight of each compound represented by the formulas (a) to (m) is as follows. Formula (a): 340, Formula (b): 382, Formula (c): 382, Formula (d): 382, Formula (e): 384, Formula (f): 398, Formula (g): 552, Formula (H): 552, Formula (i): 552, Formula (j): 552, Formula (k): 554, Formula (l): 568, Formula (m): 594.

The content of the compound having a molecular weight of 300 to 600 in 2-acetoxy-6-vinylnaphthalene used as a raw material can be analyzed by high performance liquid chromatography (HPLC). The analysis conditions for high performance liquid chromatography are as follows.
Column: ODS-80Ts (4.6 mm × 15 cm)
Column temperature: 45 ° C
Eluent: (A) Milli-Q water (ultra pure water), (B) Acetonitrile Gradient conditions: (A) / (B) = 60/40 → 20/80 (gradient 15 minutes), then (A) / (B ) = 20/80 for 5 minutes, then (A) / (B) = 20/80 → 60/40 (gradient 5 minutes)
Detection wavelength: UV280nm
Eluent flow rate: 1.0 mL / min
Sample injection volume: 10 μL

The content of the compound having a molecular weight of 300 to 600 contained in the raw material 2-acetoxy-6-vinylnaphthalene is the content of a component having a retention time in the range of 8.5 minutes to 25 minutes in the HPLC analysis. Can be obtained. In the present invention, the total content of impurity compounds having a retention time under the above-mentioned HPLC analysis conditions in the range of 8.5 to 25 minutes is 1% by weight or less (preferably 0.5% by weight or less, more preferably By using 2-acetoxy-6-vinylnaphthalene that is 0.3 wt% or less) as a raw material, high-purity 2-hydroxy-6-vinyl with no tar-like substance attached by a simple crystallization operation or the like Naphthalene can be obtained. The retention time of 2-hydroxy-6-vinylnaphthalene, which is the target product, is 7.3 minutes. The holding time may vary slightly depending on the device.

The structure of the compounds represented by the formulas (a) to (m) was determined by the following method. That is, 2-acetoxy-6-vinylnaphthalene [crude 2-acetoxy-6-vinylnaphthalene obtained by dehydration reaction of 1- (6-acetoxynaphthalen-2-yl) ethanol] used as a raw material was PTLC (preparative thin layer). Chromatography), fractionated into about 5 fractions (Merck, 1 mm thickness, developing solvent: hexane / ethyl acetate = 3/1 (v / v)), and fractionated samples were subjected to IR, FAB-MS, ¹ It attached | subjected to H-NMR, while analyzing the functional group etc., the said sample was attached | subjected to LC / MS, the mass spectrometry of each component isolate | separated by HPLC was performed, and the structure of each component was determined. The analysis conditions for LC / MS are as follows.

[LC / MS analysis conditions]
(1) Equipment used Mass spectrometer: LCMS-IT-TOF (manufactured by Shimadzu Corporation)
HPLC apparatus: LC-2010 (manufactured by Shimadzu Corporation)
Analysis software: LCsolution
(2) Analysis conditions <MS conditions>
Ion source: ESI, APCIpos, neg (m / z 100-1500)
APCI 400 ° C
<HPLC conditions>
Same as above.

  For the 2-acetoxy-6-vinylnaphthalene having a specific impurity content of 1% by weight or less, for example, crude 2-acetoxy-6-vinylnaphthalene is subjected to column chromatography (for example, silica gel column chromatography). Or purified by crystallization using a mixed solvent of aromatic hydrocarbon and alcohol.

  When crystallization is performed using a mixed solvent of an aromatic hydrocarbon and an alcohol, examples of the aromatic hydrocarbon include benzene, toluene, xylene, and ethylbenzene. These aromatic hydrocarbons can be used alone or in combination of two or more. As the aromatic hydrocarbon, toluene is particularly preferable. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol and the like. These alcohols can be used alone or in combination of two or more. Of these alcohols, ethanol is particularly preferred. As the mixed solvent of aromatic hydrocarbon and alcohol, a mixed solvent of toluene and ethanol is particularly preferable.

  In the mixed solvent of aromatic hydrocarbon and alcohol, the ratio of aromatic hydrocarbon to alcohol is, for example, the former / the latter (weight ratio) = 5/95 to 60/40, preferably the former / the latter (weight ratio) = It is about 8/92 to 40/60. Note that, even when crude 2-acetoxy-6-vinylnaphthalene is crystallized using methanol or a mixed solvent of methanol and water, the content of the specific impurity is 2-acetoxy-6-6 or less. It is difficult to obtain vinyl naphthalene.

  The 2-acetoxy-6-vinylnaphthalene having a low specific impurity content can be obtained by rinsing the crystal obtained by crystallization with a rinsing liquid as necessary and drying. As the rinsing liquid, for example, an alcohol such as methanol or ethanol; water; a mixed solvent thereof is preferably used, and an alcohol (for example, ethanol) is particularly preferably used.

  In the production method of the present invention, 2-acetoxy-6-vinylnaphthalene having a total content of the specific impurities of 1% by weight or less is treated with a compound having a hetero atom to which active hydrogen is bonded in the presence of a basic catalyst. React to produce 2-hydroxy-6-vinylnaphthalene.

  As the basic catalyst, either an organic base or an inorganic base can be used. For example, nitrogen-containing heterocyclic compounds such as pyridine and dimethylaminopyridine; triethylamine, tributylamine, N-methylpiperidine, DBU (diazabicycloundecene) Amines such as sodium methoxide, sodium ethoxide, etc .; alkali metal alkoxides such as sodium acetate; carboxylic acid alkali metal salts such as sodium acetate; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkaline earth metal carbonates such as magnesium carbonate An alkali metal hydrogen carbonate such as sodium hydrogen carbonate; an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide; an alkaline earth metal hydroxide such as magnesium hydroxide; Among these, inorganic bases such as alkali metal carbonates such as sodium carbonate are preferable.

  The usage-amount of a basic catalyst is 0.001-100 mol% with respect to 2-acetoxy-6-vinylnaphthalene, Preferably it is 0.01-50 mol%.

  Examples of the compound having a hetero atom to which active hydrogen is bonded include water, alcohol, thiol, ammonia, primary or secondary amine. These can be used alone or in combination of two or more.

  Examples of the alcohol include alcohols having 1 to 10 carbon atoms (preferably 1 to 4 carbon atoms) such as methanol, ethanol, propanol, isopropyl alcohol, and butanol. Examples of the thiol include thiols having 1 to 10 carbon atoms (preferably 1 to 4 carbon atoms) such as methyl mercaptan and ethyl mercaptan. Examples of the primary or secondary amine include primary or secondary amines having about 1 to 10 carbon atoms such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, ethanolamine, dimethylamine, and diethylamine. It is done. Among these, water and alcohol are preferable as the compound having a hetero atom to which active hydrogen is bonded.

  The amount of the compound (water, alcohol, etc.) having a hetero atom to which active hydrogen is bonded (the total amount when two or more are used) is usually 0.95 with respect to 1 mol of 2-acetoxy-6-vinylnaphthalene. It is more than mol (for example, about 0.95 mol to 50 mol), preferably more than 1.5 mol (for example, about 1.5 mol to 20 mol).

  A solvent may be used for the reaction. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane and octane; alicyclic hydrocarbons such as cyclohexane; ethers such as diethyl ether, diisopropyl ether, and tetrahydrofuran; Halogenated hydrocarbons such as dichloromethane; Nitriles such as acetonitrile; Aprotic polar solvents such as dimethyl sulfoxide and N, N-dimethylformamide; and mixed solvents thereof.

  In the reaction system, a radical polymerization inhibitor may be present in order to suppress radical polymerization of the raw material and the generated 2-hydroxy-6-vinylnaphthalene. Known radical polymerization inhibitors can be used, and examples include hydroquinone, methoquinone, t-butylcatechol, and phenothiazine.

  The reaction temperature is, for example, −100 ° C. to 200 ° C., preferably 10 ° C. to 100 ° C.

  After completion of the reaction, from the reaction mixture, for example, by using separation and purification means such as filtration, concentration, extraction, washing (water washing, acid or alkali washing, etc.), distillation, crystallization, recrystallization, column chromatography, etc., 2- Hydroxy-6-vinylnaphthalene can be obtained. According to the present invention, since the amount of tar-like substance produced is small, high-purity 2-hydroxy-6-vinylnaphthalene can be easily obtained by crystallization or the like without any particular treatment with activated carbon.

  Crystallization can be performed by cooling the reaction mixture, concentrating to an appropriate amount, or mixing with a poor solvent. You may combine these operation suitably. The cooling temperature in the case of cooling is, for example, about -20 ° C to 20 ° C, preferably about -10 ° C to 10 ° C. The cooling rate is, for example, about 1 to 30 ° C./hr, preferably about 3 to 20 ° C./hr. As the crystallization solvent, it is preferable to use alcohols such as methanol and ethanol; water; a mixed solvent thereof, and it is particularly preferable to use a mixed solvent of alcohol (for example, methanol) and water. When a mixed solvent of alcohol and water is used as the crystallization solvent, the ratio of alcohol (for example, methanol) to water is, for example, the former / the latter (weight ratio) = 1/99 to 99/1, preferably 5/95 to 80/20, more preferably about 20/80 to 45/55.

  Purified 2-hydroxy-6-vinylnaphthalene can be obtained by rinsing the precipitated crystals of 2-hydroxy-6-vinylnaphthalene with a rinsing liquid as necessary and drying. As the rinsing liquid, for example, an alcohol such as methanol and ethanol; water; a mixed solvent thereof is preferably used, and a mixed solvent of alcohol (for example, methanol) and water is particularly preferable. When a mixed solvent of alcohol and water is used as the rinsing liquid, the ratio of alcohol (for example, methanol) to water is, for example, the former / the latter (weight ratio) = 1/99 to 99/1, preferably 5/95 to 80. / 20, more preferably about 20/80 to 45/55.

で表される１−（６−アセトキシナフタレン−２−イル）エタノールを脱水反応に付すことにより製造できる。 2-acetoxy-6-vinylnaphthalene represented by the formula (2) is represented by the following formula (3):

Can be produced by subjecting 1- (6-acetoxynaphthalen-2-yl) ethanol represented by the formula to dehydration reaction.

  The dehydration reaction is usually performed in an organic solvent in the presence of a dehydration catalyst. The organic solvent may be any solvent inert to the reaction, such as aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane and octane; and alicyclic hydrocarbons such as cyclohexane. Ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran; halogenated hydrocarbons such as dichloromethane; nitriles such as acetonitrile; aprotic polar solvents such as dimethyl sulfoxide and N, N-dimethylformamide; and mixed solvents thereof . Among these, aromatic hydrocarbons such as toluene and xylene are preferable.

  Examples of the dehydration catalyst include sulfonic acids such as p-toluenesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, and trifluoromethanesulfonic acid; the sulfonic acids and bases such as pyridine (organic base, Salts (for example, pyridinium p-toluenesulfonic acid); inorganic acids such as phosphoric acid and sulfuric acid; salts of inorganic acids such as potassium hydrogensulfate and ammonium hydrogensulfite; and cation exchange resins.

  The usage-amount of a dehydration catalyst is 0.01-20 mol% with respect to 1- (6-acetoxynaphthalen-2-yl) ethanol, Preferably it is about 0.1-10 mol%.

  In the reaction system, a radical polymerization inhibitor may be present in order to suppress the radical polymerization of the generated 2-acetoxy-6-vinylnaphthalene. As the radical polymerization inhibitor, those described above can be used.

  The reaction temperature is, for example, 50 to 200 ° C, preferably 80 to 150 ° C. The dehydration reaction may be carried out while distilling off by-product water. In this case, an organic solvent azeotroped with water may be used as a reaction solvent, and the distilled water may be discharged out of the system while the organic solvent and water are azeotroped.

  After completion of the reaction, from the reaction mixture, for example, by using separation and purification means such as filtration, concentration, extraction, washing (water washing, acid or alkali washing, etc.), distillation, crystallization, recrystallization, column chromatography, etc., 2- Acetoxy-6-vinylnaphthalene can be obtained.

で表される１−（６−ヒドロキシナフタレン−２−イル）エタノール［＝１−（６−ヒドロキシ−２−ナフチル）エタノール］をアセチル化剤と反応させることにより製造できる。アセチル化剤としては、例えば、酢酸クロリド、酢酸ブロミド、無水酢酸などを使用できる。アセチル化剤の使用量は、１−（６−ヒドロキシナフタレン−２−イル）エタノール１モルに対して、通常０．９５〜２．０モル、好ましくは１．０〜１．３モル程度である。なお、これより多い量のアセチル化剤を用いることもできる。 1- (6-acetoxynaphthalen-2-yl) ethanol represented by the formula (3) is represented by the following formula (4):

Can be produced by reacting 1- (6-hydroxynaphthalen-2-yl) ethanol [= 1- (6-hydroxy-2-naphthyl) ethanol] represented by the formula: As the acetylating agent, for example, acetic acid chloride, acetic acid bromide, acetic anhydride and the like can be used. The amount of the acetylating agent used is usually 0.95 to 2.0 mol, preferably about 1.0 to 1.3 mol, with respect to 1 mol of 1- (6-hydroxynaphthalen-2-yl) ethanol. . A larger amount of acetylating agent can be used.

  The reaction between 1- (6-hydroxynaphthalen-2-yl) ethanol and an acetylating agent is usually performed in an organic solvent. The organic solvent may be any solvent inert to the reaction, such as aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane and octane; and alicyclic hydrocarbons such as cyclohexane. Ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran (THF); halogenated hydrocarbons such as dichloromethane; nitriles such as acetonitrile; aprotic polar solvents such as dimethyl sulfoxide and N, N-dimethylformamide; mixed solvents thereof Is mentioned. Among these, ethers such as tetrahydrofuran (THF), aromatic hydrocarbons such as toluene, and mixed solvents thereof are preferable.

  The above reaction is usually performed in the presence of a base. As the base, any of organic bases and inorganic bases can be used, for example, nitrogen-containing heterocyclic compounds such as pyridine and dimethylaminopyridine; triethylamine, tributylamine, N-methylpiperidine, DBU (diazabicycloundecene) and the like. Amines; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; carboxylic acid alkali metal salts such as sodium acetate; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkaline earth metal carbonates such as magnesium carbonate; Examples thereof include alkali metal hydrogen carbonates such as sodium hydrogen; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as magnesium hydroxide. Among these, inorganic bases such as alkali metal carbonates such as sodium carbonate are preferable. The amount of the base used is usually 0.95 to 20 mol, preferably 1.0 to 10 mol, more preferably 1.5 to 8 mol, relative to 1 mol of 1- (6-hydroxynaphthalen-2-yl) ethanol. Is a mole. A large excess of base can also be used.

  The reaction temperature in the above reaction is, for example, −100 ° C. to 200 ° C., preferably 10 ° C. to 150 ° C.

  After completion of the reaction, from the reaction mixture, for example, by using separation and purification means such as filtration, concentration, extraction, washing (water washing, acid or alkali washing, etc.), distillation, crystallization, recrystallization, column chromatography, etc., 1- (6-Acetoxynaphthalen-2-yl) ethanol can be obtained.

で表される６−ヒドロキシ−２−ナフトアルデヒドと、下記式（６）
ＣＨ₃ＭｇＸ （６）
（式中、Ｘはハロゲン原子を示す）
で表されるグリニヤール試薬とを反応させることにより得ることができる。 1- (6-Hydroxynaphthalen-2-yl) ethanol represented by the formula (4) is represented by the following formula (5):

6-hydroxy-2-naphthaldehyde represented by the following formula (6)
CH ₃ MgX (6)
(Wherein X represents a halogen atom)
It can obtain by making it react with the Grignard reagent represented by these.

  In the formula (6), examples of the halogen atom represented by X include chlorine, bromine and iodine atoms.

  The Grignard reaction is usually performed in an organic solvent. The organic solvent may be any solvent inert to the reaction, such as aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane and octane; and alicyclic hydrocarbons such as cyclohexane. Ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran (THF); and mixed solvents thereof. Of these, ethers such as tetrahydrofuran (THF) are preferred.

  The amount of the Grignard reagent represented by the formula (6) is, for example, 0.95 to 10 mol, preferably 1.0, per 1 mol of 6-hydroxy-2-naphthaldehyde represented by the formula (5). About 5 mol. The reaction temperature is, for example, -100 ° C to 100 ° C, preferably 0 ° C to 80 ° C.

  After completion of the reaction, for example, quenching with an aqueous solution containing acid, etc., and using separation and purification means such as filtration, concentration, extraction, washing (water washing, acid or alkali washing, etc.), distillation, crystallization, recrystallization, column chromatography, etc. Thus, 1- (6-hydroxynaphthalen-2-yl) ethanol represented by the formula (4) can be obtained.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

  The purity analysis of 2-acetoxy-6-vinylnaphthalene (ACVN) used as a raw material was performed by HPLC (high performance liquid chromatography). The analysis conditions are the same as described above.

Synthesis example 1
Under a nitrogen atmosphere, a solution prepared by dissolving 2-hydroxy-6-naphthaldehyde (49.97 g, 0.29 mol) in dehydrated THF (water content of 20 ppm or less, 406 g) was added with 1.0 mol / L of methylmagnesium bromide. The temperature was maintained at 10 ° C. or lower in a THF solution (753.51 g, 0.75 mol), and the mixture was added dropwise over 85 minutes while stirring. After completion of the dropping, stirring was continued at 20 ° C. for 47 hours. Thereafter, a mixed solution of 12N hydrochloric acid (70 mL) and water (210 mL) was added dropwise while stirring at 20 ° C. or lower. After completion of dropping, the upper layer and the lower layer were separated. The separatory funnel was washed with 200 mL of water and 500 mL of toluene, and the aqueous layer and the organic layer were all transferred to a 3 L flask. 6N hydrochloric acid (first time, 20 g, second time, 5 g, third time, 5 g, fourth time, 10 g) was sequentially added to the combined liquid mixture, and the addition of hydrochloric acid was finished when the pH of the lower layer became 1. . Thereafter, the organic layer was washed successively with 500 mL of saturated aqueous sodium bicarbonate and 500 mL of saturated brine. About 200 g of low-boiling components were distilled from the resulting solution (THF / toluene solution, total 1747 g) (distillation temperature 64 ° C., normal pressure), and crude 1- (6-hydroxy-2-naphthyl) ethanol (crude diol). (1534 g, the yield of the desired product (crude diol) in this crude liquid was 55.14 g (0.29 mol), yield 100%). When the water concentration in the organic solvent containing this crude 1- (6-hydroxy-2-naphthyl) ethanol was measured with a Karl Fischer (water analyzer), it was 2.3% by weight.

Synthesis example 2
To the crude diol obtained in Synthesis Example 1, dry THF (water content of 20 ppm or less, 500 g) and sodium carbonate (153 g, 1.44 mol) were added, and the temperature was raised to 52 ° C. with stirring in a nitrogen atmosphere. Acetic acid (35.35 g, 0.346 mol) was added dropwise. After completion of the dropping, stirring was continued for 2 hours while maintaining 53 to 55 ° C. When the reaction solution was analyzed by HPLC (high performance liquid chromatography), it was confirmed that the raw material (diol) remained, and acetic anhydride (2.98 g, 0.0292 mol) was further added dropwise. Stirring was performed for 1 hour after the dropping, and the raw material was analyzed by HPLC. As a result, the content of the raw material (diol) was less than 0.1% by weight. In order to stop the reaction, after adding 403 g of toluene, the whole vessel was cooled with ice water, and 961 g of 3N hydrochloric acid was slowly added dropwise so that the internal temperature could be maintained at 14-17 ° C. After separating the organic layer and the aqueous layer, the organic layer is washed with distilled water, the organic layer is concentrated to dryness with an evaporator, and crude 1- (6-acetoxynaphthalen-2-yl) ethanol (crude acetate) 65.0 g (Yield 97%).

Synthesis example 3
Crude acetate obtained in Synthesis Example 2 (65.0 g, 0.282 mol), p-toluenesulfonic acid monohydrate (2.69 g, 0.0141 mol), and pyridine (0.5584 g, 0.0071) Mol) was placed in a flask and toluene (1230 g) was added. While stirring this mixture, the temperature was raised until toluene began to distill. The reaction was continued for 5 hours, and it was confirmed by HPLC analysis that the raw material had completely disappeared. The reaction mixture was cooled to room temperature and separated, and the organic layer was washed successively with 5% aqueous sodium hydrogen carbonate (520 g) and distilled water (520 g). The organic layer was concentrated to obtain a toluene solution containing 49% by weight of 2-acetoxy-6-vinylnaphthalene (ACVN).

Example 1
The toluene solution of 2-acetoxy-6-vinylnaphthalene (ACVN) obtained by the method of Synthesis Example 3 was concentrated under reduced pressure, and the resulting concentrate (crude ACVN) was subjected to silica gel column chromatography (developing solvent: ethyl acetate / hexane). ) And purified. When the obtained ACVN was analyzed by HPLC, the purity was 99% by weight and the total content of impurity components having a retention time in the range of 8.5 to 25 minutes (represented by the above formulas (a) to (m)). The total content of the compounds having a molecular weight of 300 to 600) was 1% by weight.
1.0 g (0.0047 mol) of the obtained ACVN was dissolved in 18.5 g of methanol, 0.25 g (0.0024 mol) of sodium carbonate was added and reacted at 30 ° C. After confirming the disappearance of ACVN, it was neutralized with 4.7 mL of 1N hydrochloric acid, and 0.04 g of t-butylcatechol (5 mol% vs. ACVN) was added.
Next, when 32 g of water was added, no precipitation of a brown tar-like substance was observed. Further, no tar-like substance was generated even when heated to 57 ° C. The heating was stopped, the mixture was cooled to 0-5 ° C. at a cooling rate of 10 ° C./hr, the precipitated crystals were collected by filtration, rinsed with 2 g of methanol / water = 1/2 (wt / wt), and dried. As a result, 0.7 g (purity 95% by weight, yield 83%) of 2-hydroxy-6-vinylnaphthalene (HVN) was obtained.

Example 2
A toluene solution of 2-acetoxy-6-vinylnaphthalene (ACVN) obtained by the method of Synthesis Example 3 was concentrated under reduced pressure, and 2.0 g of the resulting concentrate (crude ACVN; purity 74% by weight) and toluene 2. After mixing 0 g and 10 g of ethanol, heating to 53 ° C. and confirming dissolution, the mixture was cooled to around 40 ° C. at a cooling rate of 10 ° C./hr, and seed crystals were added. Then, it cooled to 0-5 degreeC with the cooling rate of 10 degreeC / hr. The precipitated crystals were filtered, rinsed with 2.0 g of cold ethanol and dried to obtain ACVN (0.91 g, 62% yield). When the obtained ACVN was analyzed by HPLC, the purity was 99.9% by weight, and the total content of impurity components having a retention time in the range of 8.5 minutes to 25 minutes (in the above formulas (a) to (m)) The total content of the compounds represented, the total content of the compounds having a molecular weight of 300 to 600) was 0.1% by weight.
0.83 g (0.0039 mol) of the obtained ACVN was dissolved in 4.2 g of methanol, 0.21 g (0.0020 mol) of sodium carbonate was added and reacted at 30 ° C. After confirming the disappearance of ACVN, the mixture was neutralized with 0.69 g of 6N hydrochloric acid, and 0.03 g of t-butylcatechol (5 mol% vs. ACVN) was added.
Next, when 7.6 g of water was added, no precipitation of brown tar-like material was observed. The mixture was stirred at room temperature (25 ° C.) for 1 hour. The precipitated crystals were collected by filtration, rinsed with 1.6 g of methanol / water = 1/2 (wt / wt), and dried to give 0.58 g of 2-hydroxy-6-vinylnaphthalene (HVN) (purity 92. 4% by weight, yield 81%).

Comparative Example 1
A toluene solution of 2-acetoxy-6-vinylnaphthalene (ACVN) obtained by the same method as in Synthesis Example 3 was concentrated under reduced pressure, and 1.0 g (0. 0%) of the resulting concentrate (crude ACVN; purity 70% by weight) was obtained. 0033 mol) was dissolved in 18.5 g of methanol, 0.18 g (0.0017 mol) of sodium carbonate was added and reacted at 30 ° C. After confirming the disappearance of ACVN, it was neutralized with 1N hydrochloric acid, and 0.03 g of t-butylcatechol (5 mol% vs. ACVN) was added.
Next, when 35 g of water was added, a brown tar-like substance was deposited. When heated to 50 ° C. and HVN was dissolved, the tar-like substance became oily.

Comparative Example 2
90.9 g of methanol was added to 36.9 g of a 49 wt% toluene solution of 2-acetoxy-6-vinylnaphthalene (ACVN) obtained by the method of Synthesis Example 3, and the solution was completely dissolved by heating. The temperature at this time was 47 ° C. The heating was stopped, the mixture was cooled to around 40 ° C. at a cooling rate of 10 ° C./hr, and seed crystals were added. Then, it cooled to 0-5 degreeC with the cooling rate of 10 degreeC / hr. The precipitated crystals were filtered, rinsed with 2.0 g of cold ethanol, and dried to obtain ACVN (14.5 g, yield 74.6%). When the obtained ACVN was analyzed by HPLC, the purity was 93.8% by weight, and the total content of impurity components having a retention time in the range of 8.5 minutes to 25 minutes (in the above formulas (a) to (m)). The total content of the compounds represented, the total content of the compounds having a molecular weight of 300 to 600) was 5% by weight or more.
14.41 g of the obtained ACVN (purity 93.8% by weight, 0.0623 mol) and 6.68 g (0.0630 mol) of sodium carbonate were mixed with 267.9 g of methanol and reacted at 30 ° C. The disappearance of ACVN was confirmed 3 hours after the start of the reaction. The mixture was neutralized with 1N hydrochloric acid and 12N hydrochloric acid, and 0.52 g of t-butylcatechol (5 mol% vs. ACVN) was added.
When 187 g of the obtained crude HVN solution was taken and 222 g of water (methanol / water ratio in the liquid was reduced to 1/2) was added thereto, a brown tar-like substance was precipitated. When heated to 52 ° C. and HVN was dissolved, the tar-like substance became oily.

Comparative Example 3
The toluene solution of 2-acetoxy-6-vinylnaphthalene (ACVN) obtained by the method of Synthesis Example 3 was concentrated under reduced pressure, and the resulting concentrate (crude ACVN; purity 74% by weight) 52.0 g (0.181 mol) To this, 250 g of methanol was added and heated to 55 ° C. for complete dissolution. The mixture was cooled to around 40 ° C. at a cooling rate of 10 ° C./hr, and seed crystals were added. Then, it cooled to 0-5 degreeC with the cooling rate of 10 degreeC / hr. The precipitated crystals were filtered, rinsed with 50 g of cold methanol, and dried to obtain ACVN (27.2 g, yield 59.9%). When the obtained ACVN was analyzed by HPLC, the purity was 84.5% by weight, and the total content of impurity components having a retention time in the range of 8.5 minutes to 25 minutes (in the above formulas (a) to (m)) The total content of the compounds represented, the total content of the compounds having a molecular weight of 300 to 600) was 10% by weight or more.
26.8 g of the obtained ACVN (purity 84.5% by weight, 0.107 mol) and 6.68 g (0.0630 mol) of sodium carbonate were mixed with 508 g of methanol and reacted at 30 ° C. The disappearance of ACVN was confirmed 3 hours after the start of the reaction. Neutralized with 126 g of 1N hydrochloric acid.
When 223 g of the obtained crude HVN solution was taken and 297 g of water (methanol / water ratio in the liquid was halved) was added thereto, a brown tar-like substance was precipitated. When heated to 52 ° C. and HVN was dissolved, the tar-like substance became oily.

Claims (3)

  2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds having a molecular weight of 300 to 600 of 1% by weight or less is reacted with a compound having a hetero atom to which active hydrogen is bonded in the presence of a basic catalyst. A process for producing 2-hydroxy-6-vinylnaphthalene, which comprises obtaining hydroxy-6-vinylnaphthalene. 2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds represented by the following formulas (a) to (m) of 1% by weight or less, in the presence of a basic catalyst, a heteroatom bonded with active hydrogen A process for producing 2-hydroxy-6-vinylnaphthalene, which is obtained by reacting with a compound having an acid.

2-acetoxy-6-vinylnaphthalene having a total content of impurity compounds having a retention time in the range of 8.5 to 25 minutes when analyzed under the following high performance liquid chromatography analysis conditions is 1% by weight or less, A process for producing 2-hydroxy-6-vinylnaphthalene, which comprises reacting with a compound having a hetero atom to which active hydrogen is bonded in the presence of a catalytic catalyst to obtain 2-hydroxy-6-vinylnaphthalene.
<High-performance liquid chromatography analysis conditions>
Column: ODS-80Ts (4.6 mm × 15 cm)
Column temperature: 45 ° C
Eluent: (A) Milli-Q water (ultra pure water), (B) Acetonitrile Gradient conditions: (A) / (B) = 60/40 → 20/80 (gradient 15 minutes), then (A) / (B ) = 20/80 for 5 minutes, then (A) / (B) = 20/80 → 60/40 (gradient 5 minutes)
Detection wavelength: UV280nm
Eluent flow rate: 1.0 mL / min
Sample injection volume: 10 μL