JP2002363172A - Method for producing 5-alkyloxazolidine-2,4-dione - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple method for producing a 5-alkyloxazolidine-2,4- dione of high purity. SOLUTION: The 5-alkyloxazolidine-2,4-dione can be obtained by reacting 2-hydroxycarboxamide used as a raw material with a carbonic ester in the presence of a metal alcoholate. A solution of a metal salt of the obtained 5- alkyloxazolidine-2,4-dione is subjected to a neutralization precipitation treatment with an acid to obtain the 5-alkyloxazolidine-2,4-dione of high purity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a 5-alkyloxazolidine-2,4-dione useful as a raw material for synthesizing medical and agricultural chemicals or as a raw material for photographic drugs.

[0002]

2. Description of the Related Art As a method for producing an oxazolidine-2,4-dione derivative, a method of synthesizing it by reacting a corresponding ester or amide with urea has been used.
Some derivatives have already been implemented industrially (JA).
m. Chem. Soc. , (1945), 67 , 52
2, JP-A-09-48769).

[0003] However, only a method for producing a 5-alkyloxazolidine-2,4-dione represented by the formula (2) of the present invention is disclosed in JP-A-11-171876.

[0004]

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.) According to JP-A-11-171876, 5-alkyloxazolidine is obtained by reacting a 2-hydroxycarboxylic acid ester that can be produced from a 2-halocarboxylic acid ester with urea. A method for producing -2,4-dione has been proposed.

[0005] In the production method using a 2-halocarboxylic acid ester, there remain problems such as a long process due to treatment of a waste liquid containing organic components generated as the reaction proceeds and purification of an intermediate substance.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide 5-
An object of the present invention is to produce an alkyl oxazolidine-2,4-dione by an industrially advantageous method.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that 2-hydroxycarboxylic acid amide represented by the formula (1) can be converted into a carbonate ester in the presence of a metal alcoholate. The reaction is completed in one step by reacting with a compound, and isolated by a neutralization crystallization method to produce a high-purity 5-alkyloxazolidine-2,4-dione represented by the formula (2). A method was found, and the present invention was completed.

[0008]

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

[0009]

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

That is, the present invention relates to the following items.

[1] A 5-alkyloxazolidine represented by the formula (2), wherein a 2-hydroxycarboxylic acid amide represented by the formula (1) is reacted with a carbonate in the presence of a metal alcoholate. A method for producing 2,4-dione.

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

[2] The 5-alkyloxazolidine-2,4- according to [1], wherein a 2-hydroxycarboxylic acid amide having a water content of 5% by mass or less is used.
Zion production method.

[3] The method for producing a 5-alkyloxazolidine-2,4-dione according to [1] or [2], wherein a crystal of 2-hydroxycarboxylic acid amide is used.

[4] The 5-alkyloxazolidine-2 according to any one of [1] to [3], wherein a 2-hydroxycarboxylic acid amide having an acidic component of 5% by mass or less in terms of sulfuric acid is used. , 4-Dione production method.

[5] The method according to any one of [1] to [4], wherein the metal alcoholate is sodium alcoholate.
-A process for producing alkyloxazolidin-2,4-dione.

[6] The sodium alcoholate is sodium methylate or sodium ethylate [5]
5. The method for producing a 5-alkyloxazolidine-2,4-dione described in 1. above.

[7] The carbonates are dimethyl carbonate,
The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of [1] to [6], which is at least one selected from the group consisting of diethyl carbonate, methyl chlorocarbonate, and ethyl chlorocarbonate.

[8] 2-hydroxycarboxylic acid amide,
The equivalent ratio of carbonates and metal alcoholates is 1:
1.0 to 1.5: The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of [1] to [7], wherein the ratio is 1.0 to 1.5.

[9] The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of [1] to [8], wherein the water content in the raw material solution other than the metal alcoholate is 3% by mass or less.

[10] A metal salt of a 5-alkyloxazolidine-2,4-dione represented by the formula (3) obtained in a reaction solution by the production method according to any one of [1] to [9]. Wherein the 5-alkyloxazolidine-2,4-dione represented by the formula (2) is neutralized with a mineral acid and the pH is adjusted when isolating the 5-alkyloxazolidine-2,4-dione from formula (2). Manufacturing method.

Embedded image (R represents an ethyl group, a propyl group, or a butyl group, and M represents an alkali or alkaline earth (1/2) metal.)

[11] The 5-alkyloxazolidine-2,4 described in [10], wherein neutralization with a mineral acid is performed twice or more, and the final hydrogen ion concentration of the solution is adjusted to pH 5 or less. -A process for the production of diones.

[12] Neutralization with mineral acid, pH 6-10
, And then neutralization with a mineral acid to adjust the final hydrogen ion concentration to pH 5 or less, wherein the 5-alkyloxazolidine-2,4 according to [11],
-A process for the production of diones.

[13] The 5-alkyloxazolidine compound according to [12], wherein the alcohol is distilled off, and the alcohol concentration is adjusted to 7% by mass or less.
A method for producing 2,4-dione.

[14] 5-alkyloxazolidine-
The concentration of 2,4-dione in the liquid is 10% by mass to 40% by mass.
[12] or [1]
3] The method for producing a 5-alkyloxazolidine-2,4-dione according to [3].

[15] The 5-alkyloxazolidine-2,4 according to [10], wherein the pH is adjusted to 9 or less by neutralization with a mineral acid, and then the concentration is adjusted and then cooled.
-A process for the production of diones.

[16] The 5-alkyloxazolidine-2,4 described in [15], wherein the alcohol is distilled off to adjust the alcohol concentration to 7% by mass or less.
-A process for the production of diones.

[17] 5-alkyloxazolidine-
The concentration of 2,4-dione in the liquid is 10% by mass to 40% by mass.
[15] or [1]
6] The method for producing a 5-alkyloxazolidine-2,4-dione according to [6].

[18] After pH adjustment by neutralization with a mineral acid,
The concentration of the inorganic salts contained in the liquid is from 10% by mass to 35%.
5-alkyloxazolidine-2,4 according to any one of [10] to [17], wherein
-A process for the production of diones.

[19] A low-purity 5-alkyloxazolidine-2,4-dione is dissolved in an aqueous solution of an alkali metal hydroxide and recrystallized by neutralization to give a high-purity 5-alkyloxazolidine-2,4-dione. Acquire 4-dione 5-
A method for producing an alkyl oxazolidine-2,4-dione.

[20] The purity of the low-purity 5-alkyloxazolidine-2,4-dione is 90.0% by mass or more.
Less than 9.0% by mass, and the purity of the high-purity 5-alkyloxazolidine-2,4-dione is 99.0% by mass.
The method for producing a 5-alkyloxazolidine-2,4-dione according to [19], which is characterized by the above.

[21] 5-alkyloxazolidine-
[19] or [2], wherein the 5-position alkyl group of 2,4-dione is an alkyl group having 1 to 4 carbon atoms.
[0]. A method for producing a 5-alkyloxazolidine-2,4-dione according to [1].

[22] The method for producing a 5-alkyloxazolidine-2,4-dione according to [21], wherein the 5-position alkyl group is an ethyl group, a propyl group or a butyl group.

[23] In the method for producing a 5-alkyloxazolidine-2,4-dione of [1] to [18], the 5-alkyloxazolidine-2,4-dione is dissolved in an aqueous solution of an alkali metal hydroxide. Recrystallized by neutralization to obtain a highly pure 5-alkyloxazolidine-2,
A step of obtaining 4-dione.
A method for producing an alkyl oxazolidine-2,4-dione.

[24] The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of [1] to [18], wherein an organic solvent recoverable from the reaction solution is reused.

[25] The invention is characterized in that the 2-hydroxycarboxylic acid amide is 2-hydroxyhexanoic acid amide and the 5-alkyloxazolidine-2,4-dione is 5-butyloxazolidine-2,4-dione. The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of [1] to [18], [23] and [24].

[26] 5-alkyloxazolidine-
2,4-dione is 5-butyloxazolidine-2,4-
5-alkyloxazolidine-2,4 according to any one of [19] to [22], which is a dione.
-A process for the production of diones.

[27] A 5-alkyloxazolidine-2,4-dione having a purity of 99.0% or more, which is produced by the production method according to any one of [1] to [24].

[28] The 5-alkyloxazolidine-2,4-dione according to [27], wherein the content of inorganic salts is 0.2% or less.

[29] 5-butyloxazolidine-2,4-dione having a purity of 99.0% or more, produced by the method of [25] or [26].

[30] The 5-butyloxazolidine-2,4-dione according to [29], wherein the content of inorganic salts is 0.2% or less.

[0041]

DETAILED DESCRIPTION OF THE INVENTION The 5-alkyloxazolidine-2,4-dione intended in the present invention is represented by the formula (2). In particular, 5-butyloxazolidine-2,4-dione is used as a raw material for photographic drugs. preferable.

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

The 2-hydroxycarboxylic acid amide represented by the formula (1), which is a raw material for production, can be produced by amidation of the corresponding ester, introduction of a hydroxy group of a linear amide compound, or hydration of a nitrile form. It is possible.

Embedded image (R represents an ethyl group, a propyl group, or a butyl group.)

The 2-hydroxycarboxylic acid amide is 5-
Quality suitable for use in the production of alkyl oxazolidine-2,4-dione is required. That is, the water content of the 2-hydroxycarboxylic acid amide is preferably 5% by mass or less based on the mass of the crystal. Although a water content of 5% by mass or more can be used, the yield may decrease due to a decrease in yield due to moisture or decomposition of raw materials and products. In this case, the influence of moisture can be suppressed by increasing the molar equivalent number of the metal alcoholate or carbonate, or by adding a dehydrating agent, but this is not an industrially suitable method.

The 2-hydroxycarboxylic acid amide having a water content of 5% by mass or less is prepared by the above-mentioned method.
Washing the hydroxycarboxylic acid amide with alcohol,
Alternatively, it can be produced by drying with a dryer such as a conical dryer.

The raw material 2-hydroxycarboxylic acid amide preferably contains 5% by mass or less, more preferably 1% or less, of an acidic component in terms of sulfuric acid. Such a 2-hydroxycarboxylic acid amide is
It can be manufactured by washing with water using a lens or the like.

After mixing the 2-hydroxycarboxylic acid amide and the carbonic acid ester and then adding a metal alcoholate, the 5-alkyloxazolidine-
2,4-dione can be obtained as a metal salt of a 5-alkyloxazolidine-2,4-dione represented by the formula (3).

[0047]

Embedded image (R represents an ethyl group, a propyl group, or a butyl group, and M represents an alkali or alkaline earth (1/2) metal.) If necessary, an organic solvent which does not participate in the reaction is added. The fluidity and solubility of the liquid can be improved.
In this case, it is preferable to add alcohol.

The water content in the mixture of 2-hydroxycarboxylic acid amide, alcohol and carbonate is preferably 3% by mass or less. This mixed solution may be a solution of 2-hydroxycarboxylic acid amide or a slurry.
After the addition of the metal alcoholate, the temperature of the reaction solution was raised to 50 ° C.
The reaction can be completed by heating to １００100 ° C. Usually, the reaction time is about 3 hours, and the completion of the reaction can be determined by analyzing the concentration of 2-hydroxycarboxylic acid amide or 5-alkyloxazolidine-2,4-dione in the liquid.

The carbonic esters used in the reaction include, for example, dimethyl carbonate, diethyl carbonate, methyl chlorocarbonate,
Carbonylating agents such as ethyl chlorocarbonate, carbonyldiimidazole, and urea can be used.
Two or more types can be mixed and used. These carbonates are suitably used in an amount of 1.0 to 1.5 molar equivalents, preferably 1.0 to 1.3 molar equivalents, based on the number of moles of 2-hydroxyhexanoic acid amide.

The metal alcoholate is preferably a methylate or ethylate of an alkali or alkaline earth metal such as sodium, potassium or magnesium, and particularly preferably sodium methylate or sodium ethylate. These metal alcoholates can be used in solid form,
The corresponding alcohol solution is excellent in handling. The metal alcoholate is suitably used in an amount of 1.0 to 1.5 molar equivalents, and preferably 1.0 to 1.3 molar equivalents, based on the number of moles of 2-hydroxycarboxylic acid amide. 2
5-alkyloxazolidine-2, which is obtained by using -hydroxycarboxylic acid amide and carbonic acid ester, metal alcoholate.
In the production of the 4-dione metal salt, the order of adding the raw materials is not particularly limited, and the production can be performed from any of the raw materials.
Either batch addition or split addition of these raw materials may be used. Further, when the conversion of 2-hydroxycarboxylic acid amide is not sufficient, one or both of carbonates and metal alcoholates can be added in an appropriate amount.

High performance liquid chromatography (HPLC)
The solvent is distilled off under reduced pressure from the reaction solution for which the completion of the reaction has been confirmed. About 80% or more of the alcohol contained in the reaction solution is distilled off. The alcohol distilled off at this time can be reused in the reaction. After completion of the distillation, water is added, and the pH is adjusted to 6 to 10 with a mineral acid. The water added at this time is added so that the concentration of the 5-alkyloxazolidine-2,4-dione metal salt in the liquid is 10 to 30% by mass. The mineral acid used for neutralization may be any of hydrochloric acid, nitric acid and sulfuric acid. Regarding the concentration of the mineral acid, either a dilute mineral acid or a concentrated mineral acid can be used.

When the pH is adjusted to pH 6 or less, 5-
Alkyl oxazolidine-2,4-dione crystals may precipitate, and the crystals can be collected by a centrifuge or the like, but the alcohol remaining in the liquid causes a reduction in the recovery rate. In some cases, the 5-alkyloxazolidine-2,4-dione may be oily. This oily substance often contains impurities and has a low content.

The reaction solution whose pH has been adjusted is distilled off under reduced pressure to reduce the alcohol concentration in the solution to 7% by mass or less. Water is added to this solution, and 5-alkyloxazolidine-2,4-
The concentration is adjusted such that the concentration of the metal salt of dione in the liquid is 10% by mass to 40% by mass. Using the concentration adjusting solution for crystallization, 5
-Alkyloxazolidine-2,4-dione Crystallized mother liquor

Mineral acid is gradually added dropwise to the mother liquor under stirring conditions to lower the pH, particularly to pH 5 or less, so that pale yellow to white crystals of 5-alkyloxazolidine-2,4-dione can be obtained. Can be obtained. The crystallization temperature is
The temperature is preferably 70 ° C. or lower, and above this, the precipitated crystals are dissolved. When crystals are difficult to precipitate, the crystals can be started by adding 5-alkyloxazolidine-2,4-dione crystals as seed crystals.

When the pH of the crystallized mother liquor is 9 or less, preferably 6 or more and 9 or less, crystallization by cooling to 20 ° C. or less is effective instead of adding a mineral acid to lower the pH.

The obtained crystals can be obtained by a device such as centrifugation. Washing of the crystals with an organic solvent or water is preferred for reducing impurities. When the obtained crystals are dried with a conical drier or the like, crystals having a purity of 5-alkyloxazolidine-2,4-dione of 99.0% by mass or more can be obtained. In the crystal obtained by this method, the content of the inorganic salt in the crystal is 1.0% by mass or less.

The 5-alkyloxazolidine-2,4-dione which has become oily by the neutralization after the reaction and the purity is less than 99.0% by mass, particularly 90.0% by mass or more and 99.0% by mass.
Less than 5% by weight of 5-alkyloxazolidine-2,4-dione can be re-purified by dissolving in an aqueous solution of an alkali metal hydroxide and then neutralizing with a mineral acid, whereby the content after drying is 99.0. It is possible to obtain crystals of not less than mass%.

[0058]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

In this example, high performance liquid chromatography analysis (hereinafter referred to as HPLC analysis) is performed. The analysis conditions are as follows. Column: Shodex DM-, manufactured by Showa Denko KK
614 (length 15 cm, inner diameter 0.6 cm) Column temperature condition: 40 ° C. Eluent: 0.1% H ₃ PO ₄ aqueous solution Flow rate: 1.0 ml / min Detection: RI, UV (detection wavelength 210 nm)

The acid content in the 2-hydroxycarboxylic acid amide was measured by the following method. Analysis: After dissolving 2-hydroxycarboxylic acid amide in a 50% by mass aqueous methyl alcohol solution, 0.1 mol / L-N
Titration with an automatic titrator using an aOH aqueous solution. Acid content is
It was calculated by the following equation. Acid content% by mass (sulfuric acid equivalent) = (Titration (ml) x 0.1 (mo
1 / L) × factor × 4.904) ÷ Sample mass (g) Factor: NaOH concentration correction coefficient

<Example 1> A cooling tube, a stirring blade, a thermometer, and a dropping funnel were set in a 2000 mL four-necked flask.
2-hydroxyhexanoic acid amide (267 g, 2.04
mol, water content 0.7 mass%, acidic component (sulfuric acid conversion)
0.3% by mass), 267 g of methyl alcohol and 239 g of dimethyl carbonate (2.65 mol). 30% by mass sodium methylate (477 g, 2.65 mol)
Was added from the dropping funnel at a rate of 10 mol / hr. After the addition was completed, the mixture was stirred for 2 hours so that the temperature of the reaction solution was 60 to 70 ° C. A part of the solution after 2 hours was sampled, and the components of the reaction solution were analyzed by HPLC. As a result, 2-hydroxyhexanoic acid amide as a raw material was not recognized, and the target product, 5-butyloxazolidin-2,4- The dione sodium salt concentration was 28.0% by mass. From the above analytical values, 5-butyloxazolidine-2,
The yield in terms of 4-dione was 96%. After the reaction was completed, 85% of methyl alcohol in the reaction solution was distilled off under reduced pressure. 1158 g of purified water was added to the liquid after the distillation to give a concentration of the metal salt of 5-butyloxazolidine-2,4-dione in the liquid of 20% by mass. While stirring this solution, concentrated sulfuric acid was added dropwise so that the solution pH became 8.0. The liquid after the pH adjustment was distilled off under reduced pressure until the methyl alcohol concentration in the liquid became 1% by mass or less. Purified water was added to the liquid after distillation to give a concentration of 5-butyloxazolidine-2,4-dione metal salt in the liquid of 20% by mass, and this concentration-adjusted liquid was used as a crystallization mother liquor. By gradually adding concentrated sulfuric acid to the mother liquor at about 40 ° C., crystals of 5-butyloxazolidine-2,4-dione are precipitated. When the crystallization was completed, the hydrogen ion concentration of the crystallized solution was pH3. The precipitated crystals were collected by a centrifugal separator to obtain 293.5 g of 5-butyloxazolidine-2,4-dione crystals. When the crystals were analyzed, the purity of 5-butyloxazolidine-2,4-dione was 99.5% by mass, and that of the inorganic salt was 0.1% by mass.

Example 2 2-hydroxyhexanoic acid amide (267 g, 2.04 mol, water content 1.0% by mass, acidic component (sulfuric acid equivalent) 0.6% by mass), methyl alcohol 267 g, dimethyl carbonate (239 g) , 2.65m
ol) was added. 30% by mass sodium methylate (4
(77 g, 2.65 mol) in the same manner as in Example 1. After the completion of the reaction, methyl alcohol was distilled off under reduced pressure to remove 85% of the methyl alcohol in the reaction solution. 1158 g of purified water was added to the liquid after the distillation to give a concentration of the metal salt of 5-butyloxazolidine-2,4-dione in the liquid of 20% by mass. When this solution was stirred, concentrated sulfuric acid was added dropwise so that the solution had a pH of 3, and the oil was in a dispersed state. The yellow crystals obtained by centrifuging the crystals obtained by cooling the oil dispersion were dried, and then the purity of 5-butyloxazolidine-2,4-dione in the crystals was measured to be 95.2% by mass. .

Example 3 2-hydroxyhexanoic acid amide (267 g, 2.04 mol, water content 0.7 mass%, acidic component (sulfuric acid equivalent) 0.3 mass%), methyl alcohol 267 g, dimethyl carbonate (165 g) , 1.84m
ol) was added. 30 mass% sodium methylate (3
Example 1 except that 31 g (1.84 mol) was used.
It carried out according to. A part of the reaction solution is sampled and HP
When the components of the reaction solution were analyzed by LC,
-Hydroxyhexanoic acid amide concentration in the liquid was 3.6% by mass, and the target product, 5-butyloxazolidine-2,
The concentration of the sodium salt of 4-dione in the liquid was 30.4% by mass. From the above analysis values, 2-hydroxyhexanoic acid amide conversion rate 86%, 5-butyloxazolidine-2,4
-The yield in terms of dione was 85.5%. To this solution was added dimethyl carbonate (74 g, 0.82 mol), 30%
After adding sodium methylate (147 g, 0.82 mol) additionally and reacting at 60-70 ° C. for 2 hours, a part of the reaction solution was sampled, and the components of the reaction solution were analyzed by HPLC. The concentration of the acid amide in the liquid was 0% by mass, and the concentration of the target product, sodium salt of 5-butyloxazolidine-2,4-dione, was 27.5% by mass. From the above analysis values, the conversion of 2-hydroxyhexanoic acid amide was 100%, and the yield in terms of 5-butyloxazolidine-2,4-dione was 94.1%.
Met.

Example 4 Moisture content in crystal of 10% by mass
2-hydroxyhexanoic acid amide (267 g,
2.04 mol, acidic component (sulfuric acid conversion 1.2 mass%), methyl alcohol 267 g, dimethyl carbonate (23
9g, 2.65 mol). It carried out according to Example 1 except having used 30 mass% sodium methylate (477 g, 2.65 mol). A part of the reaction solution was sampled, and the components of the reaction solution were analyzed by HPLC. 4-dione sodium salt in liquid 2
It was 4.0% by mass and the concentration of 2-hydroxyhexanoic acid in the liquid was 2.3% by mass. From the above analytical values, the conversion ratio of 2-hydroxyhexanoic acid amide was 92.6%, and the yield in terms of 5-butyloxazolidine-2,4-dione was 82.1%.
Met.

Example 5 2-hydroxyhexanoic acid amide (267 g, 5.5% by mass of the acidic component in the crystal)
2.04 mol, water content 0.9 mass%, methyl alcohol 267 g, dimethyl carbonate (239 g, 2.65 m)
ol) was added. 30% by mass sodium methylate (4
Example 1 except that 77 g (2.65 mol) was used.
It carried out according to. A part of the reaction solution is sampled and HP
When the components of the reaction solution were analyzed by LC,
-Hydroxyhexanoic acid amide in the liquid at a concentration of 1.3% by mass, and the target product, 5-butyloxazolidine-2,
The concentration of 4-dione sodium salt in the liquid was 25.9% by mass. From the above analysis values, the conversion of 2-hydroxyhexanoic acid amide was 93.8%, and 5-butyloxazolidine-
The yield in terms of 2,4-dione was 88.7%.

<Example 6> After the reaction in the same manner as in Example 1, p
After adjusting to H8, the methanol concentration was distilled off to about 1% by mass, and the crystallization mother liquor (28.5 ° C.) whose concentration was adjusted with purified water was 1%.
The temperature was gradually cooled to 9.0 ° C or lower. Colorless crystals produced by cooling were collected by centrifugation to obtain 284.3 g of 5-butyloxazolidine-2,4-dione crystals. When the crystals were analyzed, 5-butyloxazolidine-
The purity of 2,4-dione is 99.4% by mass, and that of the inorganic salt is 0.1%.
It was 05% by mass.

Example 7 A 1000 mL four-necked flask equipped with a stirring blade, a thermometer, and a dropping funnel was charged with 5-butyloxazolidine-2,4-dione having a purity of 9 in the crystal.
165 g of 5.2% by mass crystals and 700 g of purified water were added,
Under stirring conditions, 48% sodium hydroxide was added to dissolve. The hydrogen ion concentration in the liquid at that time was pH 9. This solution was used as a crystallization mother liquor, and neutralized and crystallized with sulfuric acid in the same manner as in Example 1. The purity of the obtained crystals after drying was measured by HPLC and found to be 99.7% by mass, and the recovery based on the re-dissolved 5-butyloxazolidine-2,4-dione was 96.5%.

[0068]

Industrial Applicability According to the present invention, 5-alkyloxazolidine-2,4-dione can be synthesized with high purity in a short step using 2-hydroxycarboxylic acid amide as a raw material. These can be widely used as raw materials for photographic drugs, industrial materials, and intermediates for medical and agricultural chemicals.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiaki Miyoda, Inventor No. 2-3 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Showa Denko KK (72) Inventor Norihito Nishimura 2-3-3 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. Showa Denko KK (72) Inventor Shin Saito 2-3-3 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture F-term (reference) 4C056 AA01 AB01 AC02 AD01 AE03 AF01 BA03 BB08 BC01 4H039 CA42 CH10

Claims (30)

[Claims] 1. A 5-alkyloxazolidine represented by the formula (2), wherein a 2-hydroxycarboxylic acid amide represented by the formula (1) is reacted with a carbonate in the presence of a metal alcoholate. A method for producing 2,4-dione. Embedded image (R represents an ethyl group, a propyl group, or a butyl group.) (R represents an ethyl group, a propyl group, or a butyl group.) 2. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein a 2-hydroxycarboxylic acid amide having a water content of 5% by mass or less is used. 3. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein crystals of 2-hydroxycarboxylic acid amide are used. 4. The 5-alkyloxazolidin-2,4- according to any one of claims 1 to 3, wherein a 2-hydroxycarboxylic acid amide having an acidic component of 5% by mass or less in terms of sulfuric acid is used. Zion production method. 5. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein the metal alcoholate is sodium alcoholate. 6. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 5, wherein the sodium alcoholate is sodium methylate or sodium ethylate. 7. The 5-alkyloxazolidine- according to claim 1, wherein the carbonate ester is at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, methyl chlorocarbonate, and ethyl chlorocarbonate.
A method for producing 2,4-dione. 8. An equivalent ratio of 2-hydroxycarboxylic acid amide, carbonates and metal alcoholate of 1: 1.
The 5-alkyloxazolidine-2,4- according to any one of claims 1 to 7, wherein 0 to 1.5: 1.0 to 1.5.
Zion production method. 9. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein the water content in the raw material solution other than the metal alcoholate is 3% by mass or less. 10. The 5-method represented by the formula (3) obtained in the reaction solution by the production method according to claim 1.
From the metal salt of alkyl oxazolidin-2,4-dione, 5-alkyloxazolidine-2,
When isolating 4-dione, it is neutralized with a mineral acid and p
A method for producing a 5-alkyloxazolidine-2,4-dione, wherein H is adjusted. Embedded image (R represents an ethyl group, a propyl group, or a butyl group, and M represents an alkali or alkaline earth (1/2) metal.) 11. The 5-alkyloxazolidine-2,4-claim according to claim 10, wherein the neutralization with a mineral acid is performed twice or more, and the final hydrogen ion concentration of the solution is adjusted to pH 5 or less. Zion production method. 12. The method according to claim 11, wherein the final hydrogen ion concentration is adjusted to pH 5 or less by neutralizing with a mineral acid to adjust the pH to 6 to 10, then adjusting the concentration, and then neutralizing with a mineral acid. The described 5-alkyloxazolidine-2,4-
Zion production method. 13. The 5-alkyloxazolidin-2 according to claim 12, wherein the alcohol is distilled off, and the alcohol concentration is adjusted to 7% by mass or less.
A method for producing 4-dione. 14. A 5-alkyloxazolidine-2,4
The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 12 or 13, wherein the concentration of -dione in the liquid is adjusted from 10% by mass to 40% by mass. 15. Neutralization with a mineral acid to pH 9 or less,
The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 10, wherein cooling is performed after the concentration is adjusted. 16. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 15, wherein the alcohol is distilled off to adjust the alcohol concentration to 7% by mass or less. 17. A 5-alkyloxazolidine-2,4
The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 15 or 16, wherein the concentration of -dione in the liquid is adjusted from 10% by mass to 40% by mass. 18. The method according to claim 10, wherein after the pH is adjusted by neutralization with a mineral acid, the concentration of the inorganic salts contained in the solution is adjusted to 10% by mass to 35% by mass. A method for producing the described 5-alkyloxazolidine-2,4-dione. 19. A highly pure 5-alkyloxazolidine-2,4-dione is dissolved in an aqueous solution of an alkali metal hydroxide and recrystallized by neutralization to give a highly pure 5-alkyloxazolidine-2,4. -A method for producing 5-alkyloxazolidine-2,4-dione which yields dione. 20. A low-purity 5-alkyloxazolidine-2,4-dione having a purity of 90.0% by mass or more.
20. The 5-alkyloxazolidine-2,4 according to claim 19, wherein the purity of the 5-alkyloxazolidine-2,4-dione having a purity of less than 0% by mass is 99.0% by mass or more. -A process for the production of diones. 21. 5-alkyloxazolidine-2,4
The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 19 or 20, wherein the alkyl group at the 5-position of -dione is an alkyl group having 1 to 4 carbon atoms. 22. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 21, wherein the alkyl group at the 5-position is an ethyl group, a propyl group, or a butyl group. 23. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein
Alkyl oxazolidine-2,4-dione is dissolved in an aqueous solution of an alkali metal hydroxide and recrystallized by neutralization.
A method for producing 5-alkyloxazolidine-2,4-dione, comprising a step of obtaining 5-alkyloxazolidine-2,4-dione having high purity. 24. The method for producing a 5-alkyloxazolidine-2,4-dione according to claim 1, wherein an organic solvent recoverable from the reaction solution is reused. 25. The method according to claim 25, wherein the 2-hydroxycarboxylic acid amide is 2
2. Hydroxyhexanoic acid amide, wherein the 5-alkyloxazolidine-2,4-dione is 5-butyloxazolidine-2,4-dione.
25. The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of claims 18, 23 and 24. 26. 5-alkyloxazolidine-2,4
The method for producing a 5-alkyloxazolidine-2,4-dione according to any one of claims 19 to 22, wherein -dione is 5-butyloxazolidine-2,4-dione. 27. A 5-alkyloxazolidine-2,4-dione having a purity of 99.0% or more, produced by the production method according to any one of claims 1 to 24. 28. The 5-alkyloxazolidine-2,4-dione according to claim 27, wherein the content of the inorganic salt is 0.2% or less. 29. 5-Butyloxazolidine-2,4-dione having a purity of 99.0% or more, which is produced by the production method according to claim 25 or 26. 30. The 5-butyloxazolidine-2,4-dione according to claim 29, wherein the content of the inorganic salts is 0.2% or less.