JP2000336054A - Production of hydroxynaphthaldehyde - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a hydroxynaphthaldehyde useful as an intermediate for synthesizing various kinds of chemicals in high yield and high purity by using an inexpensive raw material by oxidizing a hydroxynaphthyl carbinol in the presence of a specific oxidant. SOLUTION: A hydroxynaphthyl carbinol of formula I (e.g. 6-hydroxy-2- naphthalenemethanol) is reacted with manganese dioxide as an oxidant to provide the objective hydroxynaphthaldehyde (e.g. 6-hydroxy-2-naphthaldehyde). The amount of the used manganese dioxide is preferably 0.1-50 mol based on 1 mol compound of formula I, and the reaction is preferably carried out in a solvent (e.g. N,N-dimethylformamide). The compound of formula I can be obtained by reducing a corresponding hydroxynaphthalenecarboxylic acid, for example, by a borane-tetrahydrofuran complex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing hydroxynaphthaldehyde. More specifically, the present invention relates to a method for producing hydroxynaphthaldehyde by oxidizing hydroxynaphthyl carbinol (hereinafter sometimes referred to as hydroquinaphthalenemethanol) with manganese dioxide. Hydroxynaphthaldehyde is useful as a synthetic intermediate for various chemicals such as pharmaceuticals, agricultural chemicals, and dyes.

[0002]

2. Description of the Related Art Various production methods have been proposed for hydroxynaphthaldehyde. For example, with respect to 6-hydroxy-2-naphthaldehyde, there is a method of dealkylating 6-alkoxy-2-naphthaldehyde, and in this case, a method of performing a reaction in the presence of aluminum chloride and potassium iodide (Japanese Unexamined Patent Application Publication No. -25
No. 5613), a method of performing a reaction in a chlorinated solvent (Japanese Patent Application Laid-Open No. 9-255612), and a method of performing a reaction using aluminum iodide (Japanese Patent Application Laid-Open No. 9-59202).
It has been known. Also disclosed is a method of reducing 6-hydroxy-2-naphthonitrile using diisobutylaluminum hydride (JP-A-10-147568). However, in these methods, since the raw material is expensive and the target product has a highly reactive formyl group, a satisfactory yield cannot be obtained.
It is not suitable as an industrial production method.

On the other hand, there is a method of oxidizing an aromatic alcohol to a corresponding aldehyde. For example, a method of oxidizing m-phenoxybenzyl alcohol to m-phenoxybenzyl aldehyde using hypohalous acid and a nitroxyl derivative (Japanese Patent Laid-Open Publication No. No. 310632) has been proposed. However, even if this method is applied to hydroxynaphthalenemethanol having a highly reactive hydroxy group, particularly a hydroxy group and a hydroxymethyl group attached to different rings, the yield is low. It has been found that only the chlorination of the ortho-position of the hydroxy group can hardly obtain the desired aldehyde.

[0004]

As described above, 6-
As a method for producing hydroxy-2-naphthaldehyde,
No industrially satisfactory product has been found so far. An object of the present invention is to provide a method capable of obtaining hydroxynaphthaldehyde in high yield and high purity using inexpensive raw materials.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies in view of the above circumstances, and as a result, have found that the desired aldehyde can be obtained in high yield by oxidizing hydroxynaphthalenemethanol in the presence of manganese dioxide. As a result, the present invention has been completed. That is, the gist of the present invention is a method for producing hydroxynaphthaldehyde represented by the following general formula (II), comprising oxidizing hydroxynaphthyl carbinol represented by the following general formula (I) in the presence of manganese dioxide.

Embedded image (In the formula, the hydroxy group and the hydroxymethyl group are each substituted with a different ring.)

Embedded image (Wherein the hydroxy group and the formyl group are each substituted with a different ring).

Hereinafter, the present invention will be described in detail.

BEST MODE FOR CARRYING OUT THE INVENTION The hydroxynaphthalenemethanol used as a raw material in the present invention is a compound represented by the formula (I), and specific examples thereof include, for example, 5-hydroxy-2-naphthalenemethanol, 5-hydroxy -1-naphthalenemethanol, 8-hydroxy-2-naphthalenemethanol, 8-hydroxy-1-naphthalenemethanol, 7-hydroxy-1-naphthalenemethanol, 7-hydroxy-2-naphthalenemethanol, 6-
Hydroxy-2-naphthalenemethanol and 6-hydroxy-1-naphthalenemethanol are included. Among them, 5-hydroxy-1-naphthalenemethanol, 8
-Hydroxy-2-naphthalenemethanol, 7-hydroxy-1-naphthalenemethanol, 7-hydroxy-2
-Naphthalenemethanol, 6-hydroxy-2-naphthalenemethanol and 6-hydroxy-1-naphthalenemethanol are new compounds.

[0007] These hydroxynaphthalenemethanols are easily obtained by reducing the corresponding hydroxynaphthalenecarboxylic acid with, for example, borane or aluminum hydride complex compound. The hydroxynaphthalenecarboxylic acid is usually obtained by introducing a carboxyl group into a sodium or potassium salt of α-naphthol or β-naphthol by a Kolbe-Schmidt reaction, followed by isomerization. Since -3-naphthalenecarboxylic acid is commercially produced as an intermediate of a dye and a pigment, and 6-hydroxy-2-naphthalenecarboxylic acid is commercially produced as a raw material for synthesizing a liquid crystal polymer, it is easily available. The derived 6-hydroxy-2-naphthalenemethanol is an important compound also from the viewpoint of the raw material.

Specific examples of borane used for reduction of hydroxynaphthalenecarboxylic acid include, for example, diborane, borane-tetrahydrofuran complex, borane-dimethylsulfide complex, borane-1,4-oxathiane complex, and borane-dimethylaniline complex. Borane-diethylaniline complex, borane-4-phenylmorpholine complex, catechol borane, texyl borane, disiamyl borane, and alkyl borane such as 9-borabicyclo [3.3.1] nonane. Of these, borane-
Preferred are a tetrahydrofuran complex, a borane-dimethylsulfide complex, and a borane-diethylaniline complex. The borane-tetrahydrofuran complex is particularly preferable because it provides the desired 6-hydroxy-2-naphthalenemethanol in high yield. Note that these borane compounds may be used in combination.

As the borane, a commercially available borane can be used as it is, but there is no problem even if a borohydride compound is used and generated in the system. For example, a borane-tetrahydrofuran complex can be easily prepared by reacting a borohydride compound with dimethyl sulfate or boron trifluoride in a tetrahydrofuran solvent. As the borohydride compound, use sodium borohydride, lithium borohydride, calcium borohydride, zinc borohydride, magnesium borohydride, potassium borohydride, beryllium borohydride, barium borohydride, or the like However, sodium borohydride, lithium borohydride, calcium borohydride and the like are preferred mainly from an economic viewpoint. In addition, as a reducing agent, lithium aluminum hydride, lithium diethoxyaluminum hydride, tri-te
Aluminum hydride complex compounds such as rt-butoxyaluminum lithium, diisobutylaluminum hydride, sodium bis (2-methoxyethoxy) aluminum hydride, and the like may be used.

In the present invention, manganese dioxide is used as an oxidizing agent. Manganese dioxide can be easily produced by electrolysis of manganese sulfate solution, heating of manganese oxide in an oxygen stream, and thermal decomposition of manganese nitrate. No problem. In the production method of the present invention, active manganese dioxide can be used. Active manganese dioxide can be produced by: 1) a method of preparing from potassium permanganate, magnesium sulfate and sodium hydroxide, 2) a method of thermally decomposing manganese (II) oxalate or carbonate at 250 ° C., 3) a method of producing activated manganese dioxide. A method of treating manganese with nitric acid, 4) a method of azeotropic dehydration of manganese dioxide using a solvent, and the like are known, and these can be appropriately selected and used according to the substrate, reaction temperature, solvent or reaction time. . In addition, commercially available activated manganese dioxide can be used without any problem.

The amount of manganese dioxide used relative to the raw material hydroxynaphthalenemethanol is generally in the range of 0.1 to 50 mol, and preferably in the range of 1 to 30 mol.
In particular, it is preferable to use it in the range of 2 to 30 mol from an economic viewpoint. In this reaction, a solvent that does not react with the starting materials hydroxynaphthalenemethanol and manganese dioxide can be used, if necessary. Specific examples of these solvents include hydrocarbons such as hexane, benzene, and toluene; alcohols such as methanol, ethanol, propanol, and butanol; diols such as ethylene glycol, propylene glycol, butanediol, and hexylene glycol; diethyl. Ethers such as ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, dipropyl ketone and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate, butyrolactone, tricaprylin; dimethylformamide And dimethylacetamide, methylpyrrolidinone and the like; dimethylimidazolidinone, tetramethylurea and the like. Among them, hydrocarbons, ketones, ethers and amides are preferred, and ketones and amides are particularly preferred. This is because the reaction promoting effect and the by-product suppressing effect appear as compared with other solvent systems. Also,
The use amount of these solvents is not particularly limited and is arbitrary.

Although the reaction is sufficient even at room temperature or lower,
In order to further improve the reaction rate, the reaction is usually performed at a temperature of room temperature or higher. The reaction temperature is in the range of -10 to 200C, preferably 0 to 100C. The reaction may be carried out in air or under an atmosphere of an inert gas such as nitrogen or argon. The reaction time depends on the reaction temperature, but is usually 0.1 to 200 hours, preferably 0.5 to 80 hours.
Time range. The resulting hydroxynaphthaldehyde, after filtering off the remaining manganese dioxide, crystallization, extraction,
It can be isolated by means such as column chromatography.

[0013]

The present invention will be described in detail below with reference to Examples, Reference Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist.

REFERENCE EXAMPLE 1 In a nitrogen atmosphere, a sodium borohydride (purity: 92%) 5.4 was placed in a 300 mL four-necked flask equipped with a dropping funnel, a gas inlet tube and a thermometer.
9 g (0.134 mol) and 100 mL of anhydrous tetrahydrofuran are added and stirred. 17.35 g of dimethyl sulfate
(0.135 mol) was added dropwise at 20 ° C. over 30 minutes, and stirring was further continued for 3 hours to confirm that the generation of gas was completed. The resulting borane-tetrahydrofuran complex was kept at 20 ° C., and the supernatant was filtered through a glass filter under a nitrogen atmosphere to separate the monomethyl sulfate formed in the system, and the filtrate was placed in another 500 mL four-necked flask. Transferred. 6-hydroxy-2-naphthalenecarboxylic acid 1
A solution of 2.6 g (0.067 mol) in anhydrous tetrahydrofuran (80 mL) was added dropwise to the prepared borane-tetrahydrofuran complex solution at 0 ° C over 40 minutes using a dropping funnel. The reaction solution was stirred at the same temperature for 15 minutes until the generation of hydrogen was completed, and further stirred under reflux conditions for 4 hours. After the reaction, the reaction solution was cooled, and cooled with ice 8
After adding 0 mL and stirring vigorously at room temperature for 30 minutes, tetrahydrofuran was distilled off under reduced pressure, and then extracted twice with 500 mL of diethyl ether.The obtained organic layer was successively extracted with 150 mL of a saturated aqueous sodium hydrogen carbonate solution. After washing with 150 mL of a saturated saline solution, it was dried with magnesium sulfate. The diethyl ether was removed under reduced pressure, and 6
11.45 g (0.066 mol, yield: 98.1) of -hydroxy-2-naphthalenemethanol as white crystals.
%)Obtained.

Melting point: 181 ° -183 ° C. Elemental analysis: calculated as C ₁₁ H ₁₀ O ₂ (174.20) C: 75.84, H: 5.79 Analytical values: C: 75.90, H: 5.82 ¹ H-NMR (300 MHz, CDCl ₃ + DMSO-
d ⁶ , δ ppm): 9.08 (1H, brs), 7.7
0-7.58 (3H, m), 7.40 (1H, d),
7.10 (2H, q), 4.72 (2H, s), 2.9
1 (1H, brs). ¹³ C-NMR (300 MHz, CDCl ₃ + DMSO-
d ⁶ , δ ppm): 63.28, 108.10, 11
7.79, 124.11, 124.92, 125.2
3, 127.03, 128.20, 133.15, 13
5.57, 154.23.

Example 1 A 200 mL flask was equipped with a stirrer and 6-hydroxy-2-naphthalenemethanol 1.5.
g (8.61 mmol) and 60 mL of N, N-dimethylformamide were uniformly charged. A commercially available activated manganese dioxide (Aldrich, purity: 85%) 1
5 g (147 mmol) was added, and the mixture was kept at 20 ° C. and stirred vigorously for 12 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 100%, and the yield of 6-hydroxy-2-naphthaldehyde was 94%.
Subsequently, manganese dioxide was filtered from the reaction solution through celite under reduced pressure, and the manganese dioxide was washed with 60 mL of ethyl acetate. The filtrate and the washing solution were combined and the solvent was removed under reduced pressure to obtain an orange solid. 0.1N of the obtained solid
It was dissolved in 100 mL of an aqueous sodium hydroxide solution, and the remaining insolubles were removed by filtration, followed by washing twice with 100 mL of dichloromethane. Dilute hydrochloric acid aqueous solution is added to the aqueous layer to make it neutral (pH = 6),
The resulting white solid was filtered, washed with water until the filtrate became neutral, and dried under reduced pressure at 80 ° C. for 12 hours to give 0.83 g of 6-hydroxy-2-naphthaldehyde.
(4.82 mol, yield 56%) was obtained.

Melting point: 182 ° -183 ° C. ¹ H-NMR (300 MHz, CDCl ₃ , δpp)
m): 10.09 (1H, s), 8.27 (1H,
s), 7.93 (2H, dd), 7.76 (1H,
d), 7.22-7.18 (2H, m), 5.48 (1
H, s). ¹³ C-NMR (300 MHz, CDCl ₃ + DMSO-
d ⁶ , δ ppm): 107.81, 118.28, 12
1.15, 125.24, 125.44, 129.8
0, 129.86, 133.16, 136.70, 15
7.07, 190.23.

Example 2 A stirring bar was placed in a 100 mL flask, and 6-hydroxy-2-naphthalenemethanol 0.3 was added.
5 g (2.01 mmol) and 15 mL of N, N-dimethylformamide were charged and homogenized. Commercially available activated manganese dioxide (Aldrich, purity: 85%)
1.8 g (17.6 mmol) are added and kept at 20 ° C.
Vigorous stirring was performed for 9 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 98.3%,
The yield of hydroxy-2-naphthaldehyde was 93%.

Example 3 A stir bar was placed in a 100 mL flask, and 6-hydroxy-2-naphthalenemethanol 0.3 was added.
5 g (2.01 mmol) and 30 mL of acetone were charged and made uniform. 3.5 g (34.22) of commercially available activated manganese dioxide (Aldrich, purity: 85%) was added thereto.
mmol), and the mixture was kept at 20 ° C. and stirred vigorously for 12 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 96.5%,
The yield of naphthaldehyde was 91%.

Example 4 A stirring bar was placed in a 100 mL flask, and 6-hydroxy-2-naphthalenemethanol 0.3 was added.
5 g (2.01 mmol) and 20 mL of N, N-dimethylformamide were charged and made uniform. In addition to this, electrolytic manganese dioxide (FMH (trade name, manufactured by Tosoh Corporation), purity;
3.5% (36.94 mmol) were added and 20
C. and stirred vigorously for 16 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 92.3%.
And the yield of 6-hydroxy-2-naphthaldehyde was 87%.

Example 5 A stir bar was placed in a 100 mL flask, and 6-hydroxy-2-naphthalenemethanol 0.3 was added.
5 g (2.01 mmol) and 20 mL of N, N-dimethylformamide were charged and made uniform. To this, electrolytic manganese dioxide (HMH [trade name, manufactured by Tosoh Corporation], purity;
3.5% (37.1 mmol) at 20 °
And vigorously stirred for 32 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 94.5%, and the yield of 6-hydroxy-2-naphthaldehyde was 89%.

Example 6 A stirring bar was placed in a 100 mL flask, and 6-hydroxy-2-naphthalenemethanol 0.3 was added.
5 g (2.01 mmol) and 20 mL of N, N-dimethylformamide were charged and made uniform. This was mixed with electrolytic manganese dioxide (HH (trade name, manufactured by Tosoh Corporation), purity: 92.1).
8%) 3.5 g (37.11 mmol), and the mixture was added at 20 ° C.
And vigorously stirred for 32 hours. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 89.2%, and the yield of 6-hydroxy-2-naphthaldehyde was 84%.

Comparative Example 1 A stirring bar was placed in a 50 mL flask.
0.71 g of 6-hydroxy-2-naphthalenemethanol
(4.08 mmol), 0.21 g of sodium hydroxide
(5.25 mmol) and 50 mL of water at 20 ° C. for 30 minutes.
For a minute. 9 mL of a 5% by weight aqueous solution of sodium hypochlorite (pH> 11) was added dropwise thereto over 5 minutes under ice-cooling, and stirring was further continued for 30 minutes under ice-cooling. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 100%. Subsequently, 30 mL of a saturated aqueous sodium thiosulfate solution was added to the reaction solution, and the mixture was further extracted twice with 100 mL of ethyl acetate. The obtained organic layer was washed with 50 mL of a saturated saline solution and dried over magnesium sulfate. The ethyl acetate was removed under reduced pressure, and the residue was analyzed. As a result, 0.62 g (2.97 mmol, yield: 72.8%) of 5-chloro-6-hydroxy-2-naphthylenemethanol was produced as an orange solid. As a result, the desired 6-hydroxy-2-naphthaldehyde was not obtained at all.

Comparative Example 2 A stirring bar was placed in a 50 mL flask.
0.71 g of 6-hydroxy-2-naphthalenemethanol
(4.08 mmol), 0.032 g of 2,2,6,6-tetramethylpiperidine-1-oxyl (0.20 mm
ol), 30 mL of ethyl acetate and 0.05 of potassium bromide
g (0.42 mmol) aqueous solution (10 mL) was charged. 5% by weight aqueous sodium hypochlorite solution (p
H> 10) After dropping 8 mL over 5 minutes, stirring was further continued for 2 hours under ice cooling. As a result of analyzing the reaction solution using liquid chromatography, the conversion of 6-hydroxy-2-naphthalenemethanol was 55.20%, and 5-chloro-6-hydroxy-2-naphthalenemethanol (yield 25.6%). ) And a number of by-products. Also,
No desired trace amount of 6-hydroxy-2-naphthaldehyde was formed.

[0025]

According to the present invention, hydroxynaphthaldehyde, which is useful as an intermediate for the synthesis of various chemicals such as pharmaceuticals, agricultural chemicals and dyes, can be industrially advantageously produced inexpensively, in high yield, with high purity, and easily. Can be manufactured.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Iwane 3-1-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Pref. Mitsubishi Chemical Corporation Tsukuba Research Laboratory F-term (reference) BJ50 BQ30 FC54

Claims (4)

[Claims] 1. A method for producing hydroxynaphthaldehyde represented by the following general formula (II), comprising oxidizing hydroxynaphthyl carbinol represented by the following general formula (I) in the presence of manganese dioxide. Embedded image (In the formula, the hydroxy group and the hydroxymethyl group are each substituted by a different ring.) (In the formula, the hydroxy group and the formyl group are each substituted with a different ring.) 2. The raw material is 6-hydroxy-2-naphthyl carbinol and the product is 6-hydroxy-2-naphthyl carbinol.
The method for producing hydroxynaphthaldehyde according to claim 1, which is naphthaldehyde. 3. The method for producing hydroxynaphthaldehyde according to claim 2, wherein the 6-hydroxy-2-naphthyl carbinol is obtained by reducing 6-hydroxy-2-naphthalene carboxylic acid. 4. The method for producing hydroxynaphthaldehyde according to claim 1, wherein the manganese dioxide is activated manganese dioxide.