JPH11116528A - Method for producing 1,2,4-butanetricarboxylic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically and industrially obtain the subject compound useful for an intermediate in organic synthesis, alkyd resin, etc., in high yield by reacting a tricyanobutane with an alcohol so as to synthesize the corresponding ester compound and hydrolyzing it in the presence of an acid catalyst. SOLUTION: This objective compound is obtained by reacting 4 to 8 equivalents of an alcohol with 1,2,4-tricyanobutane at 80 to 110 deg.C for 4 to 15 hrs. so as to synthesize the corresponding ester compound and hydrolyzing the resultant ester in the presence of 1 to 50 mol.% of an acid catalyst (e.g. strong acid cation-exchange resin) in terms of exchange capacity based on the aliphatic polyvalent ester at 90 to 110 deg.C for 8 to 30 hrs. Preferably, the ester compound comprises a carboxylic acid-ester compound shown by the formula (R is H or a 1-4C alkyl). The alcohol is pref. a 1-4C aliphatic primary alcohol (e.g. methanol).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing 1,2,4-butanetricarboxylic acid.

[0002]

2. Description of the Related Art Conventionally, as a method for producing 1,2,4-butanetricarboxylic acid, (A) a method for producing 1,2,4-tricyanobutane by hydrolysis using an acid or alkali [Ann. , 572, 83-95 (1951)]. In general, as a method for producing a carboxylic acid by hydrolysis of nitrile, a method using an acid or an alkali is known, and as the acid, a mineral acid such as hydrochloric acid or sulfuric acid is used.
Alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are used as the alkali.

[0003] Further, (B) a method for producing an olefin by an oxidative cleavage reaction using various oxidizing agents is also known. For example, Japanese Patent Publication No. 47-51326,
164135 and French Patent No. 2,218,3
No. 14 (1974) describes a process by nitric acid oxidation, and also French Patent 1,306,556 (19).
62) Specification and EP 513,600 (1
992) The specification describes a method using ozone oxidation.

[0004]

However, when an acid is used in the method (A), separation of the target carboxylic acid from the inorganic salt is difficult because the target carboxylic acid is also highly water-soluble, as a by-product of an inorganic ammonium salt. is there. The inorganic salt and the acid of the catalyst are mixed into the desired carboxylic acid. In addition, in the case of using an alkali, a large amount of ammonia is produced as a by-product, and thus a removal facility is required.Neutralization is required because the target carboxylic acid is an alkali salt. It had drawbacks such as difficulty.

In the method (B), when nitric acid is used, a facility for removing nitric oxide gas generated during the reaction or ozone is used, so that it is necessary to enhance the abatement equipment. Necessary carboxylic acid is by-produced,
It has disadvantages such as difficulty in separating and removing by-product carboxylic acid.

Accordingly, an object of the present invention is to provide a reaction between 1,2,4-tricyanobutane and an alcohol,
By synthesizing the corresponding ester, reliably and easily separating and removing the resulting inorganic salt, and then hydrolyzing the ester in the presence of an acid catalyst, high quality without contamination It is an object of the present invention to provide a method for producing 1,2,4-butanetricarboxylic acid, which can obtain the product in an industrial process, in a high yield, in an industrial process, and economically.

[0007]

According to the present invention, there are provided:
A corresponding ester compound is synthesized by reacting 2,4-tricyanobutane with an alcohol, and then the ester is hydrolyzed in the presence of an acid catalyst to produce 1,2,4-butanetricarboxylic acid. A manufacturing method is provided. In the above method, the corresponding ester is represented by the general formula (1)

Embedded image In the formula, at least one of R is a hydrogen atom, and the other R is an alkyl group having 1 to 4 carbon atoms. Butanetricarboxylic acid can be obtained. As the acid catalyst, a strongly acidic cation exchange resin is particularly desirable.

The production method of the present invention is schematically shown by the following formula (2).

Embedded image In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms.

As a result of intensive studies on the method for producing 1,2,4-butanetricarboxylic acid, generally, the separation and removal of by-produced inorganic salts can be carried out reliably and easily by passing through disadvantageous esters. And then hydrolyzing the ester in the presence of an acid catalyst to find a method for producing 1,2,4-butanetricarboxylic acid of high quality and high yield, which is industrially and economically advantageous. Reached the present invention.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The process of the present invention comprises a step of subjecting 1,2,4-tricyanobtan and an alcohol to an esterification reaction in the presence of water and sulfuric acid; A step of performing a hydrolysis reaction in the presence.

The raw material of the present invention, 1,2,4-tricyanobutane, is, for example, described in Ann. , 572, 83-95
(1951), inexpensively and easily according to a known method described in JP-B-49-36211.

The alcohol used for the esterification reaction in the present invention is an aliphatic alcohol having 1 to 4 carbon atoms.
Primary alcohols are preferred, and methanol is particularly preferred in view of separation, purification and the like. The amount of alcohol used is usually an excess amount, preferably 2 to 10 equivalents, more preferably 4 to 1,2,4-tricyanobutane.
８8 equivalents.

The amount of sulfuric acid used in this esterification reaction is usually 0.5 to 3 with respect to 1,2,4-tricyanobutane.
It is double equivalent, preferably 1-2 equivalent.

The amount of water used in the esterification reaction is usually 0.5 to 0.5% based on 1,2,4-tricyanobutane.
It is 1.5 equivalents, preferably 0.9 to 1.1 equivalents.

[0015] The temperature of the esterification reaction is 60-130.
° C, preferably 80 to 110 ° C. If the temperature is higher than this range, the by-product of ether due to dehydration of alcohol increases, and if the temperature is lower than this range, the reaction rate is unfavorably low. The reaction time is 1 to 20 hours, preferably 4 hours.
~ 15 hours. The reaction pressure is not particularly limited.

In this esterification reaction, acidic ammonium sulfate is formed together with the desired ester, but can be easily separated from the ester by performing a normal extraction operation using a hydrocarbon such as benzene or toluene. Further, the obtained ester can be easily purified by a distillation operation.

Since the hydrolysis reaction in the present invention is an equilibrium reaction, it is usually advantageous to carry out the reaction while distilling off the produced alcohol outside the reaction system.

As the acid catalyst used in the present hydrolysis reaction, a strongly acidic cation exchange resin catalyst is particularly preferable. For example, <Diaion> SK1BH (Mitsubishi Chemical Corporation)
), <Amberlite> IR-120B (manufactured by Rohm and Haas), or a strongly acidic cation such as <Nafion> NR-50 (manufactured by DuPont) such as a fluorinated sulfonic acid. An ion exchange resin catalyst is mentioned. The amount used is usually from 1 to 50 mol% in total exchange capacity with respect to the aliphatic polyester.

The amount of water used in the hydrolysis reaction is usually
It is an excess amount, preferably 2 to 20 equivalents, based on the ester.

The reaction temperature of the hydrolysis reaction is usually 50
To 150 ° C, preferably 90 to 110 ° C. The reaction time varies depending on other reaction conditions, but is usually several hours to several tens of hours, preferably 8 to 30 hours.

1,2,4 obtained by the production method of the present invention
-Butanetricarboxylic acid is used in the fields of powder coatings, polyester fibers and fiber modifiers, etc. for organic synthetic intermediates, alkyd resins, polyamides, polyimides, polyester resins and plasticizer raw materials, and is industrially useful.

According to the production method of the present invention, the Hazen color number is not more than 20% and the mineral acid content (for example, chloro content or SO
₄ minutes) A high-quality product with a high purity of 10 ppm or less and a small amount of coloring and impurities can be obtained, and the yield is not lower than that of the conventional method, and is significant as an industrial and economical production method. .

[0023]

EXAMPLES The present invention will now be described specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Table 1 shows the analytical values and the yields (based on nitriles) of the carboxylic acids obtained in the respective Examples and Comparative Examples.

Example 1 (1) Esterification Step 100 equipped with a stirrer, thermometer, cooler and dropping funnel
In a 0 ml glass reactor, 66.6 g (0.5 mol) of 1,2,4-tricyanobutane and 19 ml of methanol were added.
2.3 g (6.0 mol) was charged and kept at 60 ° C. with stirring, and 245.2 g of 90% sulfuric acid (2.
(25 mol, water 1.36 mol). With the drop, the temperature rises from 60 ° C. to 90 ° C.
The reaction was carried out at 90 ° C. for another 12 hours. After the completion of the reaction, toluene was added to perform extraction and liquid separation. Thereafter, toluene was concentrated and distilled off from the extract, and 101.2 g of 1,2,4-butanetricarboxylic acid trimethyl ester was obtained by distillation under reduced pressure. Analysis by gas chromatography revealed a purity of 9
The yield was 9.9% and the yield was 87.0 mol% (based on nitrile). (2) Hydrolysis step 3 equipped with a stirrer, thermometer and Vigreux fractionating tube
In a 00 ml glass reactor, 46.5 g (0.2 mol) of 1,2,4-butanetricarboxylic acid trimethyl ester 75.7 g (4.2 mol) of water and an ion exchange resin <Diaion> SK1BH (Mitsubishi Chemical) 16.0 g of a styrene-based sulfonic acid type strongly acidic cation exchange resin (manufactured by Incorporated), total exchange capacity 2.4 meq./g) was charged, and the mixture was reacted at a reaction temperature of 100 ° C to 105 ° C for 13 hours with stirring. During that time, by-produced methanol was distilled off. After separating the ion exchange resin from the reaction solution, water was concentrated and distilled off, acetonitrile was added, and the mixture was cooled to 5 ° C. The precipitated crystals were separated and dried to obtain 35.3 g of white crystals. As a result of purity analysis by liquid chromatography, 1, 2, 4
-Butanetricarboxylic acid purity 99.8%, yield 9
2.6 mol% (based on ester), melting point 123.4 ° C., Hazen color number 10 (30% by weight aqueous solution), chloro content 1 pp
m.

Example 2 (1) Esterification Step In the same manner as in Example 1, the reaction and extraction were carried out.
Toluene was concentrated and distilled off from the extract, and 108.6 g of a residue was obtained.
I got The residue was analyzed by gas chromatography. As a result, 94.1% of 1,2,4-butanetricarboxylic acid trimethyl ester (based on the yield of 88.0 mol% nitrile),
Butane monocarboxylic acid dimethyl ester 2.0% (based on 2.0 mol% nitrile), butane dicarboxylic acid monomethyl ester 0.3% (based on 0.3 mol% nitrile), toluene 3.5% A mixture having the following composition: (2) Hydrolysis step 3 equipped with a stirrer, thermometer and Vigreux fractionating tube
A mixture of the above composition was placed in a 00 ml glass reactor.
3 g (0.2 mol of 1,2,4-butanetricarboxylic acid trimethyl ester, 0.004 mol of butanemonocarboxylic acid dimethyl ester, 0.001 mol of butanedicarboxylic acid monomethyl ester, total of 0.205 mol), water 162 0.8 g (9.0 mol) and ion exchange resin <N
afion> NR-50 (fluorine-based strongly acidic cation exchange resin manufactured by DuPont, total exchange capacity 0.8 meq./
g) 8.0 g was charged and the reaction temperature was 96 ° C. while stirring.
To 103 ° C. for 15 hours. During that time, by-produced methanol was distilled off. Thereafter, the same post-treatment as in Example 1 was performed to obtain 36.0 g of white crystals. As a result of analysis by liquid chromatography, the purity of 1,2,4-butanetricarboxylic acid was 99.5%, the yield was 91.4% (based on ester), the melting point was 123.4 ° C., and the color number of Hazen was 5 (30% by weight aqueous solution). ), The chloro content was 1 ppm.

Comparative Example 1 50 equipped with a stirrer, thermometer, cooler and dropping funnel
182.3 g of 36% hydrochloric acid in a 0 ml glass reactor
(1.8 mol), kept at 70 ° C. with stirring, and melted from a dropping funnel to 1,2,4-tricyanobutane.
7 g (0.2 mol) was gradually added dropwise while maintaining the reaction temperature at 70 ° C. After completion of the reaction, the temperature was raised to 110 ° C., and the reaction was further performed for 5 hours. After the completion of the reaction, the reaction solution was cooled to 10 ° C., and the precipitated crystal was separated and dried. Crystal 2
As a result of analyzing 8.7 g, 6.6% (yield 5.0 mol%) of 1,2,4-butanetricarboxylic acid, 91.3% of ammonium chloride, 1.6% of water and 0.5% of hydrogen chloride were obtained. A mixture having the following composition: Next, hydrochloric acid and water were concentrated and distilled off from the mother liquor from which the above crystals were separated, and acetone 35 was removed.
After adding 0 g, the mixture was heated to 50 ° C. to separate and remove insoluble crystals. Further, the separated solution was concentrated and cooled to 5 ° C., and the precipitated crystals were separated and dried to obtain 29.3 g of pale yellow-brown crystals. As a result of analysis by liquid chromatography,
The purity of 1,2,4-butanetricarboxylic acid is 98.5.
%, Yield 75.9 mol% (based on nitrile), melting point 12
1.5 ° C, Hazen color number 80 or more (30% by weight aqueous solution)
, And contamination of 0.5% of ammonium chloride was observed.

Comparative Example 2 3 equipped with a stirrer, thermometer and Vigreux fractionating tube
In a 00 ml glass reactor, 1
2,4-butanetricarboxylic acid trimethyl ester 4
6.5 g (0.2 mol), 133.8 g of 18% hydrochloric acid
(0.66 mol), and the reaction temperature was 1 while stirring.
The reaction was performed from 00 ° C to 107 ° C for 3 hours. During that time, methanol produced as a by-product was distilled off together with hydrochloric acid and water. After completion of the reaction, water and hydrochloric acid were concentrated and distilled off, and acetonitrile was added, followed by cooling to 5 ° C. Separating precipitated crystals,
Drying yielded 33.9 g of pale yellow crystals. As a result of analysis by liquid chromatography, the purity of 1,2,4-butanetricarboxylic acid was 98.8%, and the yield was 88.1 mol%.
(Based on ester), melting point 121.3 ° C, Hazen color number 8
0 (30% by weight aqueous solution) and the chloro content was 400 ppm.

Comparative Example 3 A sample equipped with a stirrer, a thermometer and a Vigreux fractionating tube was prepared.
In a 00 ml glass reactor, 1
2,4-butanetricarboxylic acid trimethyl ester 4
6.5 g (0.2 mol), water 75.7 g (4.2 mol)
And 4.0 g (0.04 mol) of 98% sulfuric acid,
The reaction was carried out from 100 ° C. to 108 ° C. for 15 hours with stirring. During that time, by-produced methanol was distilled off. After completion of the reaction, water was concentrated and distilled off, and acetonitrile was added, followed by cooling to 5 ° C. The precipitated crystals were separated and dried to obtain 33.6 g of light brown crystals. As a result of analysis by liquid chromatography, the purity of 1,2,4-butanetricarboxylic acid was 98.5%, the yield was 87.0 mol% (based on ester), the melting point was 121.0 ° C., and the Hazen color number was 70 (3).
0 wt% aqueous solution), and the SO ₄ content was 320 ppm.

[0029]

[Table 1] (Note 1) SO ₄ minutes

[0030]

According to the present invention, a corresponding ester is synthesized by reacting 1,2,4-tricyanobtan with a lower alcohol, and then the ester is hydrolyzed in the presence of an acid catalyst. High quality 1,2,4-
Butanetricarboxylic acid can be produced by an industrial method in good yield and economically.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C07C 69/34 C07C 69/34 // C07B 61/00 300 C07B 61/00 300 (72) Inventor Riji Kita Sakaide, Kagawa Prefecture 1729-5 Ejiri-cho (72) Shuji Hara 582-2 Nakamura-cho, Zentsuji-shi, Kagawa Prefecture (72) Toshiaki Shiramine 79, Sanjo-cho, Marugame-shi, Kagawa

Claims (5)

[Claims] 1. The method according to claim 1, wherein the corresponding ester is synthesized by reacting 1,2,4-tricyanobutane with an alcohol, and the ester is hydrolyzed in the presence of an acid catalyst. For producing 4,4-butanetricarboxylic acid. 2. The corresponding ester is represented by the following formula (1): The method according to claim 1, wherein in the formula, at least one of Rs is a hydrogen atom, and the other Rs are an alkyl group having 1 to 4 carbon atoms. 3. The method according to claim 1, wherein the alcohol is a primary aliphatic alcohol having 1 to 4 carbon atoms. 4. The method according to claim 1, wherein the primary aliphatic alcohol is methanol. 5. The method according to claim 1, wherein the acid catalyst is a strongly acidic cation exchange resin.