JPH09132545A - Production of 1,4-dihydroxy-2-naphthoic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily obtain the subject compound useful as an intermediate for dyes, pigments, photographic agents, etc. in high quality and high yield. SOLUTION: 1,4-Dihydroxynaphthalene is reacted with an alkali metal hydroxide (e.g. NaOH) under an inert gas atmosphere (e.g. nitrogen gas) in a propylene- based glycol ether (e.g. dipropylene glycol monomethyl ether) at 110-200 deg.C to provide the alkali metal salt. Successively, carbon dioxide gas is blown into the reaction system so as to carry out carboxylation to provide the objective 1,4-dihydroxy-2-naphthoic acid. The alkali metal hydroxide is used in an amount of 1.5-3mol based on 1mol 1,4-dihydroxynaphthalene. 1,4-dihydroxynaphthalene is obtained by carrying out catalytic reduction of 1,4-naphthoquinone which is a raw material under hydrogen pressure using a catalyst (e.g. palladium carbon).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing 1,4-dihydroxy-2-naphthoic acid.

[0002]

BACKGROUND OF THE INVENTION 1,4-Dihydroxy-2-naphthoic acid is useful as an intermediate for dyes, pigments, photographic agents and the like, and several proposals have been made as industrial production methods thereof.
For example, J. Amer. Chem. Soc., 64 (1942) reports a method for producing phthalic acid and succinic acid ester. In J. Pract. Chem., [2] 62, 30 (1900), 1,4-dihydroxynaphthalene is reacted with alcoholic sodium or potassium hydroxide in an alcohol solvent to form its sodium salt or potassium salt. It is reported that the desired naphthoic acid was synthesized by producing the product, drying it in a hydrogen stream, and then reacting the crystal under pressurized carbon dioxide at 170 ° C. for 20 to 30 hours and salting out with dilute hydrochloric acid.

Recently, JP-A-57-126443 and JP-A-57-128655 disclose 1,4-
A method of carboxylating dihydroxynaphthalene with carbon dioxide gas in the presence of particulate anhydrous potassium carbonate in an organic medium is disclosed in JP-A-59-141537 and JP-A-60-104037. -A method of carboxylating dihydroxynaphthalene with carbon dioxide in the presence of an alkali metal compound and water has been proposed. Further, JP-A-5-194314 discloses a method of forming an alkali metal salt by using a metal alcoholate in an organic medium in which 1,4-dihydroxynaphthalene is dissolved, and subsequently performing carboxylation by using carbon dioxide gas.

As a method for synthesizing 1,4-dihydroxynaphthalene from 1,4-naphthoquinone, Japanese Patent Application 59-59
No. 157608 proposes a method of performing catalytic reduction at 20 to 70 ° C. in a methanol solvent with 5% palladium carbon as a catalyst, filtering the catalyst, and then drying under reduced pressure.

In the method of producing from phthalic acid and succinic acid ester, the process is long and complicated, and the alkali metal salt of 1,4-dihydroxynaphthalene is very unstable, so that many side reaction products are formed and the yield is high. Besides, it is difficult to manufacture industrially. Also, JP-A-57-1264
In the method described in JP-A-43-43655 and JP-A-57-128655, fine particles of anhydrous potassium carbonate having a high hygroscopic property are used, and the reaction is carried out for a long time under a high temperature and high pressure condition with a water content of 0.5% or less. It is necessary to let
The operation of removing 1,4-dihydroxy-2-naphthoic acid from the reaction mixture is also complicated.

Further, in the methods described in JP-A-59-141537 and JP-A-60-104037, the conversion rate is low and it is necessary to recover the raw materials.
The cooling rate after the reaction has an influence and it is necessary to cool rapidly.

Further, in JP-A-5-194314, an alkali metal alcoholate, which is industrially expensive, is used in the reaction for producing an alkali metal salt, and the unstable starting material 1,4-dihydroxy compound is used. Uses naphthalene. As described above, various methods have been proposed as a method for producing 1,4-dihydroxy-2-naphthoic acid, which is useful as an intermediate for various products, but all of them are not necessarily industrially advantageous methods. At present, there is a strong demand for the development of an industrially advantageous manufacturing method.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an industrially advantageous method for producing 1,4-dihydroxy-2-naphthoic acid.

[0009]

Means for Solving the Problems The present inventors have made 1,4-
As a result of various studies to find a method for easily and advantageously producing dihydroxy-2-naphthoic acid industrially, 1,4-dihydroxynaphthalene was treated with an alkali metal hydroxide in a specific organic medium. 1,4-dihydroxy-2-naphthoic acid can be produced in high yield by treating with a metal salt and then with carbon dioxide gas, and 1,4-naphthoquinone, which is a stable compound alone, is selected as a raw material, In a specific organic medium, it is first subjected to catalytic reduction, then to treatment with an alkali metal hydroxide, and finally to treatment with carbon dioxide gas, followed by isolation to make it industrially easy. It has been discovered that high quality 1,4-dihydroxy-2-naphthoic acid can be produced with high and consistent yields. The present invention has been completed by further research based on such findings.

That is, the gist of the present invention is (1) 1,4-
Dihydroxynaphthalene is treated with an alkali metal hydroxide at 110 ° C. to 200 ° C. in a propylene glycol ether under an inert gas atmosphere to form an alkali metal salt thereof, which is subsequently carboxylated with carbon dioxide gas. A method for producing 1,4-dihydroxy-2-naphthoic acid, characterized in that (2) 1,4-dihydroxynaphthalene inactivates a catalytic reduction product of 1,4-naphthoquinone in a propylene glycol ether. The method according to (1) above, which is in the form of a solution obtained after filtration in a gas atmosphere.
(3) Propylene glycol ether is propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol methyl ether. Acetate, propylene glycol Diacetate, propylene glycol
(4) The method according to (1) or (2) above, which is one or more selected from the group consisting of phenyl ethers.
The production method according to (1) above, wherein the alkali metal hydroxide is sodium hydroxide or potassium hydroxide, (5) 1 mole of the alkali metal hydroxide relative to 1 mol of 1,4-dihydroxynaphthalene as a raw material. 0.5 mol to 3 mol is used, and (6) the production process according to (1) above, and (6) the production according to (2) above, wherein the catalytic reduction uses a Raney nickel, platinum carbon or palladium carbon catalyst. About the method.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. The first feature of the present invention is that, when deriving 1,4-dihydroxynaphthalene in propylene glycol ether into its metal salt, an inexpensive alkali metal hydroxide is used instead of an expensive metal alcoholate. is there. Compared with the most excellent method using a metal alcoholate as a conventional method, it is extremely inexpensive and industrially extremely advantageous.

Alkali metal hydroxides used in the metal salt formation reaction of 1,4-dihydroxynaphthalene include
Industrially, sodium hydroxide or potassium hydroxide can be mentioned, but sodium hydroxide is preferable. The amount used is twice the theoretical amount, but usually 1,4
-1.5 to 3 times the molar amount of dihydroxynaphthalene. Even if used in a large excess, the yield is not improved correspondingly, which is economically disadvantageous. The amount is preferably 2 to 3 times, and more preferably 2.0 to 2.4 times. The alkali metal salt formation reaction is carried out in an inert gas atmosphere, the reaction temperature is usually 110 ° C to 200 ° C, and the reaction time is 3 to 9 hours. As the inert gas, nitrogen gas is preferable from the economical point of view.

As the organic medium used for the metal salt formation reaction of 1,4-dihydroxynaphthalene, propylene glycol ether, particularly propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n- Butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol methyl ether acetate, propylene glycol diacetate and propylene glycol phenyl ether are preferred. In particular, it is necessary that the boiling point be higher than the reaction temperature of the metal salt forming reaction. If methanol or ethanol is used, the reaction yield will be extremely low even if the reaction is carried out under pressure.

The second feature of the present invention is that when producing 1,4-dihydroxy-2-naphthoic acid, 1,4-naphthoquinone, which is a stable compound, is selected as a starting compound,
First, 1,4-dihydroxynaphthalene is induced by catalytic reduction, which is the first reaction, and is not isolated, but treated with alkali metal hydroxide, which is the second reaction, in the same solvent under an inert gas atmosphere. To give 1,4-dihydroxynaphthalene metal salt, and further subjected to a treatment with carbon dioxide gas in the same solvent to undergo a carboxylation reaction to produce the desired 1,4-dihydroxy-2-naphthoic acid, Finally, it is a so-called one-pot reaction for isolating 1,4-dihydroxy-2-naphthoic acid from the reaction solution. Therefore, according to the method of the present invention, unstable 1
Since 4-dihydroxynaphthalene can be subjected to the next reaction in a reducing atmosphere without isolation, it is extremely advantageous in yield and operation compared with the conventional method.

Therefore, as the organic medium used in the present invention, the above-mentioned catalytic reduction reaction, alkali metal salt formation reaction,
And a solvent suitable for all of the carboxylation reactions. Such an organic medium needs to have the following properties. That is,
First, 1,4-naphthoquinone, which is a raw material for the catalytic reduction reaction, is well dissolved, and 1,4-dihydroxynaphthalene, which is a product thereof, which is a raw material for the alkali metal salt formation reaction, is well dissolved. It is necessary that the product, which is an alkali metal salt, also be well dissolved. Further, as the organic medium used in the present invention, those which are stable with no change with time due to heat and do not cause side reactions such as esterification are preferable from the viewpoint of recycling and the like.

Examples of the organic medium include propylene glycol ether, particularly propylene glycol methyl ether, dipropylene glycol methyl ether,
Examples thereof include tripropylene glycol methyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol methyl ether acetate, propylene glycol diacetate, and propylene glycol phenyl ether.

Of these, those having a boiling point of 170 ° C. or higher and a solubility parameter δ of 11 or less are preferable. This is because the carboxylation reaction, which is the third reaction, may be performed at 170 ° C to 180 ° C.
Also, the solubility parameter δ lower than 11 is 1,4
-It has been found that the production rate of dihydroxy-2-naphthoic acid is good. Here, the solubility parameter δ is J.
A material constant proposed by H. Hildebrand that depends only on temperature. When the heat of vaporization of the liquid is ΔH: V is the molar volume, δ = (ΔH / V) ^0.5 is defined. The amount of organic medium used is 1,4-naphthoquinone, or 1,4
-It is 3 to 20 times by weight, preferably 3 to 10 times by weight, that of dihydroxynaphthalene.

The catalyst for catalytic reduction used in the present invention is not particularly limited as long as it is an ordinary metal catalyst for catalytic reduction. Among them, Raney nickel, platinum carbon,
And palladium carbon etc. are preferable. Industrially recoverable and economical palladium carbon or platinum carbon is particularly preferred. The catalytic reduction method is carried out under hydrogen pressure according to a known method.

In the method of the present invention, 1,4-naphthoquinone is catalytically reduced to 1,4-dihydroxynaphthalene, which is made into an alkali metal salt without isolation, and subsequently carbon dioxide gas is introduced into the reaction system. Blow in to carry out carboxylation. The alkali metal salt formation reaction is 1,4-
Similar to the above-mentioned conditions when dihydroxynaphthalene is used as a raw material, usually 1.
It is carried out using 5 to 3 times mol, preferably 2 to 3 times mol, and more preferably 2 to 2.4 times mol of alkali metal hydroxide. The amount of carbon dioxide gas blown in may be a stoichiometric amount, but is usually slightly excessive. The reaction temperature for carboxylation is
Considering the stability and reaction rate of the product, the range of 50 to 180 ° C is preferable, and 90 to 130 ° C is more preferable. The carboxylation can be carried out under normal pressure, but it can also be carried out under pressure. When the reaction is carried out under pressure, the pressure may be about 10 kg / cm ² or less.

After completion of the reaction, the obtained 1,4-dihydroxy-2-naphthoic acid may be isolated by any method. For example, if necessary, the reaction solution is cooled and diluted with water, After neutralizing with an acid and filtering if necessary, the filtrate is made acidic, and the precipitated crystals are filtered off and washed with water to obtain highly pure 1,4-dihydroxy-2-naphthoic acid. it can. Examples of the acid used for neutralization and acidification include organic acids such as acetic acid, mineral acids such as hydrochloric acid and sulfuric acid, and these acids may be used alone,
It can also be used together. The pH during neutralization is preferably 8
˜5, more preferably 7.5 to 5.5, and the pH during crystallization is preferably around 1.

To isolate 1,4-dihydroxy-2-naphthoic acid, it is preferable to neutralize the reaction solution and then dilute it with water.
This is for improving the stirring property of the reaction liquid after crystallization. The amount of water used for dilution is preferably an equivalent amount to 10 times by weight, and more preferably 3 to 5 times the organic medium used for the reaction.
Weight times. After diluting with water, crystallization is performed by acid precipitation. In this way, highly pure 1,4-dihydroxy-
2-Naphthoic acid can be obtained industrially and advantageously in high yields.

The thus obtained 1,4-dihydroxy-
2-naphthoic acid is useful as an intermediate for dyes, pigments, photographic agents and the like.

[0023]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples, parts and% represent parts by weight and% by weight, respectively.

Example 1 A reaction vessel equipped with a stirrer was added to 189 parts of dipropylene glycol monomethyl ether at room temperature under a nitrogen atmosphere and 1,4-
Naphthoquinone (47.4 parts) was added, and 5% palladium carbon (0.05 parts) was further added. The temperature was raised to 80 ° C. while blowing hydrogen and maintained at the same temperature. After completion of hydrogen absorption, the catalyst was filtered under a nitrogen gas atmosphere and cooled to room temperature. The solvent was added in an amount of 7.5 times the weight of the raw material, and then 25.7 parts of sodium hydroxide was added while blowing nitrogen gas and the temperature was raised and kept at 190 ° C. for 2 hours. After the metal salt was formed, it was cooled to 100 ° C. and carbon dioxide gas was blown into the liquid. Bubbling was continued for another hour after gas absorption was no longer observed.

Then, the mixture was cooled to 60 ° C. and 35% acetic acid 5
7.1 parts was added dropwise for neutralization. This reaction solution was poured into 366.5 parts of warm water prepared in advance. pH is 8
After confirming that the amount was less than the above, the generated side reaction product was filtered off, and 35% hydrochloric acid was added dropwise to the filtrate to adjust the pH to 1.0.
The resulting precipitate is cooled, filtered, washed with water, and then air dried at 50 ° C.,
51.8 parts of 1,4-dihydroxy-2-naphthoic acid were obtained. As a result of composition analysis by HPLC of this product, 1,4
-The purity of dihydroxy-2-naphthoic acid is 98.6%
And the yield was 84.6%. The purity was measured by a carboxylic acid neutralization titration method. The decomposition point is 19
It was 0 ° C or higher.

Example 2 The reaction was carried out under the same conditions as in Example 1 except that 1.2 parts of Raney nickel was used as the catalyst. As a result, 1,4-
51.1 parts of crystals of dihydroxy-2-naphthoic acid were obtained. The purity of this crystal is 99.1%, and the yield is 82.8%.
Met.

Example 3 The reaction was carried out under the same conditions as in Example 1 except that 0.05 part of platinum carbon was used as the catalyst. as a result,
Crystals of 1,4-dihydroxy-2-naphthoic acid 52.2
Got a part. The purity of this crystal is 99.0%, and the yield is 8
It was 4.5%.

Examples 4 to 6 The catalytic reduction reaction temperature is 60 ° C., 90 ° C., or 100.
The reaction was carried out under the same conditions as in Example 1 except that the reaction was carried out at 0 ° C. Table 1 shows the results.

[0029]

[Table 1]

Example 7 The reaction was carried out under the same conditions as in Example 1 except that potassium hydroxide was used in the alkali metal salt formation reaction. as a result,
Crystals of 1,4-dihydroxy-2-naphthoic acid 51.9
Got a part. The crystal has a purity of 98.9% and a yield of 8
It was 3.9%.

Example 8 The reaction was carried out under the same conditions as in Example 1 except that the reaction was carried out using propylene glycol diacetate as the organic medium. As a result, 52.0 parts of crystals of 1,4-dihydroxy-2-naphthoic acid were obtained. The purity of this crystal is 9
The yield was 9.0% and the yield was 84.1%.

Example 9 In a reaction vessel equipped with a stirrer, under a nitrogen atmosphere, at room temperature, 173 parts of dipropylene glycol monomethyl ether was added and 1,4-
25.6 parts of dihydroxynaphthalene and 13.4 parts of sodium hydroxide were added and the temperature was raised and kept at 189 ° C. for 2 hours. After the metal salt was formed, it was cooled to 100 ° C. and carbon dioxide gas was blown into the liquid. After no gas absorption was observed, carbon dioxide gas was blown in for another hour.
Next, the mixture was cooled to 70 ° C., and 57 parts of 35% acetic acid was added dropwise for neutralization. This reaction solution was poured into 193 parts of warm water prepared in advance. The resulting side reaction product was filtered off, and 35% hydrochloric acid was added dropwise to the filtrate to adjust the pH to 1.0. The resulting precipitate was cooled, collected by filtration, washed with water, and air-dried at 50 ° C.
30.4 parts of 4-dihydroxy-2-naphthoic acid were obtained.
As a result of composition analysis by HPLC, the purity of 1,4-dihydroxy-2-naphthoic acid was 98.8% and the yield was 83.0%. The purity was measured by the carboxylic acid neutralization titration method. The decomposition point was 190 ° C or higher.

[0033]

Industrial Applicability According to the method of the present invention, 1,4-dihydroxy-2-naphthoic acid, which is useful as an intermediate for dyes and the like, can be industrially advantageously produced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 37/68 9155-4H C07C 37/68 39/225 9155-4H 39/225 65/11 2115- 4H 65/11 // C07B 61/00 300 C07B 61/00 300

Claims (6)

[Claims] 1. 1,4-Dihydroxynaphthalene is treated with an alkali metal hydroxide at 110 ° C. to 200 ° C. in a propylene glycol ether under an inert gas atmosphere to form an alkali metal salt thereof, and subsequently, A method for producing 1,4-dihydroxy-2-naphthoic acid, which comprises carboxylating using carbon dioxide gas. 2. The 1,4-dihydroxynaphthalene is a solution obtained after filtering the catalytic reduction product of 1,4-naphthoquinone in propylene glycol ether under an inert gas atmosphere. The manufacturing method according to claim 1, which is characterized in that. 3. A propylene glycol ether is propylene glycol methyl ether, dipropylene glycol methyl ether or tripropylene glycol.
Methyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether,
The production method according to claim 1 or 2, which is one or more selected from the group consisting of propylene glycol methyl ether acetate, propylene glycol diacetate, and propylene glycol phenyl ether. 4. The method according to claim 1, wherein the alkali metal hydroxide is sodium hydroxide or potassium hydroxide. 5. An alkali metal hydroxide is added to 1. mol of 1,4-dihydroxynaphthalene as a raw material in an amount of 1.
The method according to claim 1, wherein 5 to 3 mol is used. 6. The method according to claim 2, wherein the catalytic reduction uses a Raney nickel, platinum carbon or palladium carbon catalyst.