JP3726315B2 - Purification method of ketonic ester - Google Patents
Purification method of ketonic ester Download PDFInfo
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- JP3726315B2 JP3726315B2 JP17178995A JP17178995A JP3726315B2 JP 3726315 B2 JP3726315 B2 JP 3726315B2 JP 17178995 A JP17178995 A JP 17178995A JP 17178995 A JP17178995 A JP 17178995A JP 3726315 B2 JP3726315 B2 JP 3726315B2
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- ester
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
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Description
【０００１】
【産業上の利用分野】
本発明は、ケトン酸エステルの精製方法に関するものであり、更に詳しくはケトン酸エステルとオキシ酸エステルを含む混合物からケトン酸エステルを精製する方法に関する。
【０００２】
【従来の技術】
ケトン酸エステルは医薬品、農薬、アミノ酸、香料などの原料および中間体として有用な化合物である。
【０００３】
ケトン酸エステルは、相当するオキシ酸エステルの酸化により製造される。
【０００４】
たとえば、乳酸エステルの酸化によるピルビン酸エステルの工業的製法は古くから知られている。例えばバナジウム、モリブデン、リン及び酸素を必須成分として含有する固体触媒に、乳酸エステルおよび酸素を含むガスを接触させる方法（特開昭５２−３９６２４号公報）が挙げられる。
【０００５】
しかしながら、これらの製造方法では生成物のケトン酸エステル中には未反応オキシ酸エステルが含有されている。たとえば、ピルビン酸エステルと乳酸エステルは沸点が近接しており、通常の蒸留精製では高純度のケトン酸エステルを得る事は非常に難しい。
【０００６】
一方、ケトン酸エステルは工業用原料として極めて高純度のものが要求されており、ケトン酸エステルとオキシ酸エステルを分離する試みが多数なされている。例えば、ピルビン酸エステルと乳酸エステルの混合物を水の存在下に蒸留する事により精製する方法（特開昭５９−２２５１４４号公報）が知られている。
【０００７】
【発明が解決しようとする課題】
しかしながら、前記のピルビン酸エステルと乳酸エステルの混合物を水の存在下に蒸留する方法は、充填物を充填した精留塔を装着した精留装置にピルビン酸エステルと乳酸エステルの混合物を仕込み、ピルビン酸エステルを水との共沸混合物として留出させ、一方の乳酸エステルは缶残として残す事により精製するものであるが、留出したピルビン酸エステルは水溶液であり、ピルビン酸エステルを単離するには、改めてピルビン酸エステルと水の共沸混合物から適当な溶媒で抽出するか、或いは水を適当な溶媒との共沸により除去しなければならず、必ずしも有利な方法とはいいがたい。
【０００８】
従って、ケトン酸エステルとオキシ酸エステルの混合物から、高純度のピルビン酸エステルを単離する工業的に有利な方法が望まれていた。
【０００９】
【課題を解決するための手段】
そこで、本発明者らはケトン酸エステルとオキシ酸エステルの混合物からケトン酸エステルを精製する方法について鋭意検討した結果、ケトン酸エステルとオキシ酸エステルを含む混合物を酸共存下に加熱すると、ケトン酸エステルとオキシ酸エステルの分解速度が異なることを見いだし、本発明を完成するに至った。
【００１０】
すなわち、本発明は、ケトン酸エステルおよびオキシ酸エステルを含む混合物を、酸共存下に加熱することを特徴とするケトン酸エステルの精製法である。
【００１１】
以下、本発明を詳細に説明する。
【００１２】
本発明における、ケトン酸エステルとは１分子内にカルボニル基とカルボキシル基を含んでいる酸をアルキルエステルで交換したものであり、ピルビン酸エステル、ベンゾイルギ酸エステル、フェニルピルビン酸エステルなどのα−エステル酸エステル、アセト酢酸エステル、プロピオニル酢酸エステル、ベンゾイル酢酸エステルなどのβ−ケトン酸エステル、レブリン酸エステル、β−ベンゾイルプロピオン酸エステルなどのγ−ケトン酸エステルなどを挙げることができる。
【００１３】
また、オキシ酸エステルとは、１分子内にカルボキシル基と水酸基を含んでいる酸をアルキルエステルで交換したものであり、グリコール酸エステル、乳酸エステル、ヒドロアクリル酸エステル、α−オキシ酪酸エステル、グリセリン酸エステル、リンゴ酸エステル、酒石酸エステル、クエン酸エステルなどの脂肪族オキシ酸エステル、サリチル酸エステル、ｍ−オキシ安息香酸エステル、ｐ−オキシ安息香酸エステル、没食子酸エステル、マンデル酸エステル、トロパ酸エステルなどの芳香族オキシ酸エステルが挙げられるが、本発明では、酸化によりケトン酸になる脂肪族オキシ酸エステルが重要である。
【００１４】
ケトン酸エステルおよびオキシ酸エステルを含む混合物は、いかなる混合物でも使用できる。たとえば、オキシ酸エステルの気相酸化によりケトン酸エステルを製造し、未反応のオキシ酸エステルを含む混合物、オキシ酸を酸化してケトン酸を製造し、未反応のオキシ酸を除くことなくエステル化を行なった混合物、さらにグルコース発酵により得たピルビン酸などのケトン酸に不純物として乳酸などのオキシ酸が含まれているものをエステル化して得た混合物などが使用できる。
【００１５】
また、ケトン酸エステルおよびオキシ酸エステルを含む混合物に、反応を阻害しない化合物が共存していても構わない。
【００１６】
さらに、ケトン酸エステルとオキシ酸エステルの混合比は、特に限定されないが、精製の効率を考慮すると、ケトン酸エステルが多く含まれる混合物が好ましい。特に好ましくはケトン酸エステルとオキシ酸エステルの重量比が１０００／１〜５／１である。
【００１７】
また、ここで使用するケトン酸エステルとオキシ酸エステルのエステル残基は、いずれの構造でも構わないが、生産効率を考慮すると低級アルキル残基が好ましい。特に好ましくはメチルエステル残基、エチルエステル残基、プロピルエステル残基、ブチルエステル残基であり、ケトン酸エステルとオキシ酸エステルのエステル残基が同一でも、異なってもよい。また、ケトン酸エステルとオキシ酸エステルのエステル残基が異なる場合には、ケトン酸エステルの方がオキシ酸エステルよりアルキル鎖の長いエステル残基である事が好ましい。
【００１８】
本発明で使用される酸とは、ケトン酸エステルの分解速度を小さく、一方オキシ酸エステルの分解速度を大きくする酸であれば如何なる酸でも使用できる。Ｈ型の陽イオン交換樹脂、例えばナフィオン（デュポン製）、ダイアイオン ＰＫ２０８（三菱化成製）等が挙げられる。また、硫酸や塩酸等の鉱酸類、ベンゼンスルホン酸、トルエンスルホン酸等の芳香族スルホン酸類、メタンスルホン酸等の脂肪族スルホン酸類が挙げられるが、好ましくはＨ型の陽イオン交換樹脂、硫酸、ベンゼンスルホン酸、トルエンスルホン酸等の芳香族スルホン酸類、メタンスルホン酸等の脂肪族スルホン酸類、特に好ましくは硫酸、トルエンスルホン酸である。酸の使用量はケトン酸エステルとオキシ酸エステルの混合物のオキシ酸エステルに対して１モル％〜５００モル％で、好ましくは２０モル％〜２００モル％である。酸中の水の濃度は、ケトン酸エステルの分解を抑え、オキシ酸エステルを選択的に分解させるため、また、その水の除去を考慮し出来るだけ少ない方が望ましい。例えば硫酸の場合は９８もしくは９５％濃度品を、また、スルホン酸類の場合は１水和物品を使用すると良い。
【００１９】
加熱温度は３０〜９０℃が好ましく、さらに好ましくは５０〜８０℃である。温度が低いと分解速度が遅く、生産効率が悪くなる。また、高いとオキシ酸エステルだけでなくケトン酸エステルの分解速度も速くなり、ケトン酸エステルの回収率が低下するので好ましくない。
【００２０】
加熱する際は、実質的にケトン酸エステルとオキシ酸エステルの混合物だけで実施するのが好ましいが、本発明の目的をさまたげない溶媒などを加えて行なっても良い。
【００２１】
加熱する際は、オキシ酸エステルの分解を促進するため、撹拌をするのが好ましい。
【００２２】
酸の共存下に加熱することにより、オキシ酸エステルは加水分解して一般に固体のオキシ酸となるため、容易に分離することができる。
【００２３】
本発明で得られたケトン酸エステルを高濃度に含む混合物から、ケトン酸エステルを単離するには、減圧蒸留法などが採用できる。
【００２４】
以下実施例及び比較例を挙げて本発明を詳細に説明するが、本発明はこれらに限定されるものではない。
【００２５】
実施例１
２００ｍｌ三ッ口フラスコにピルビン酸エチルと乳酸エチルの重量比が９８／２の乳酸エチルが入ったピルビン酸エチル溶液１００ｇと、９５％硫酸１．１５ｇ（硫酸／乳酸エチルのモル比０．５）を仕込み、約７０℃で１時間撹拌した。
【００２６】
この液中のピルビン酸エチルと乳酸エチルをガスクロマトグラムで分析した結果、ピルビン酸エチルと乳酸エチルの重量比が９９．４／０．６であった。
【００２７】
この液に炭酸水素ナトリウム１．８７ｇ（９５％硫酸と当モル量）を加えた後、約６．０ｋＰａ、バス温度約８０℃の条件下で、減圧蒸留し、ピルビン酸エチルと乳酸エチルの重量比が９９．４／０．６の高純度ピルビン酸エチルの留出液９２ｇを得た。
【００２８】
実施例２
２００ｍｌ三ッ口フラスコにピルビン酸エチルと乳酸エチルの重量比が９０／１０の乳酸エチルが入ったピルビン酸エチル溶液１００ｇと、９５％硫酸５．７３ｇ（硫酸／乳酸エチルのモル比０．５）を仕込み、約７０℃で１時間撹拌した。
【００２９】
この液中のピルビン酸エチルと乳酸エチルをガスクロマトグラムで分析した結果、ピルビン酸エチルと乳酸エチルの重量比が９８．５／１．５であった。
【００３０】
実施例３
実施例１の方法において９５％硫酸を、ｐ−トルエンスルホン酸１水和物２．１１ｇ（ｐ−トルエンスルホン酸１水和物／乳酸エチルのモル比０．５）に代えた以外は同様の操作を行なった結果、ピルビン酸エチルと乳酸エチルの重量比が９９／１であった。
【００３１】
比較例１
実施例１の方法において９５％硫酸を、水に代えた以外は同様の操作を行なった結果、ピルビン酸エチルと乳酸エチルの重量比が９８／２であった。
【００３２】
【発明の効果】
本発明の方法により、沸点が近接して蒸留分離が困難なケトン酸エステルとオキシ酸エステルを含む混合物を酸共存下に加熱する事で、高純度のケトン酸エステルを容易に製造する事ができ、製造コストの低減に大きく貢献できる。[0001]
[Industrial application fields]
The present invention relates to a method for purifying a ketone acid ester, and more particularly to a method for purifying a ketone acid ester from a mixture containing a ketone acid ester and an oxyacid ester.
[0002]
[Prior art]
Ketone esters are useful compounds as raw materials and intermediates for pharmaceuticals, agricultural chemicals, amino acids, fragrances and the like.
[0003]
Ketone esters are produced by oxidation of the corresponding oxyacid esters.
[0004]
For example, an industrial process for producing pyruvate by oxidation of lactate has been known for a long time. For example, a method of bringing a gas containing lactic acid ester and oxygen into contact with a solid catalyst containing vanadium, molybdenum, phosphorus and oxygen as essential components (JP-A-52-39624) can be mentioned.
[0005]
However, in these production methods, the unreacted oxyacid ester is contained in the ketone acid ester of the product. For example, pyruvic acid ester and lactic acid ester have close boiling points, and it is very difficult to obtain high-purity ketone acid ester by ordinary distillation purification.
[0006]
On the other hand, ketonic acid esters are required to have extremely high purity as industrial raw materials, and many attempts have been made to separate ketonic acid esters and oxyacid esters. For example, a method of purifying a mixture of pyruvate and lactate by distillation in the presence of water is known (Japanese Patent Laid-Open No. 59-225144).
[0007]
[Problems to be solved by the invention]
However, in the method of distilling the mixture of pyruvate and lactate in the presence of water, a mixture of pyruvate and lactate is charged into a rectifying apparatus equipped with a rectifying column filled with a packing, The acid ester is distilled as an azeotrope with water, and one lactic acid ester is purified by leaving it as a can residue, but the distilled pyruvate is an aqueous solution and the pyruvate is isolated. In this case, it must be newly extracted from the azeotrope of pyruvate and water with a suitable solvent, or water must be removed by azeotropy with a suitable solvent, which is not necessarily an advantageous method.
[0008]
Therefore, an industrially advantageous method for isolating high-purity pyruvate from a mixture of a ketone ester and an oxyacid ester has been desired.
[0009]
[Means for Solving the Problems]
Therefore, the present inventors have intensively studied a method for purifying a ketone acid ester from a mixture of a ketone acid ester and an oxyacid ester. As a result, when a mixture containing a ketone acid ester and an oxyacid ester is heated in the presence of an acid, The inventors found that the decomposition rates of the ester and the oxyacid ester are different, and completed the present invention.
[0010]
That is, the present invention is a method for purifying a ketone acid ester characterized by heating a mixture containing a ketone acid ester and an oxyacid ester in the presence of an acid.
[0011]
Hereinafter, the present invention will be described in detail.
[0012]
In the present invention, the ketone acid ester is an acid having a carbonyl group and a carboxyl group in one molecule exchanged with an alkyl ester, and an α-ester such as pyruvate, benzoylformate or phenylpyruvate. Examples thereof include β-ketone acid esters such as acid esters, acetoacetate esters, propionyl acetate esters, and benzoyl acetate esters, and γ-ketone acid esters such as levulinate esters and β-benzoylpropionate esters.
[0013]
In addition, an oxyacid ester is an acid obtained by exchanging an acid containing a carboxyl group and a hydroxyl group in one molecule with an alkyl ester. Glycolic acid ester, lactic acid ester, hydroacrylic acid ester, α-oxybutyric acid ester, glycerin Aliphatic oxyacid esters such as acid esters, malic acid esters, tartaric acid esters, and citric acid esters, salicylic acid esters, m-oxybenzoic acid esters, p-oxybenzoic acid esters, gallic acid esters, mandelic acid esters, tropic acid esters, etc. In the present invention, an aliphatic oxyacid ester that becomes a ketone acid by oxidation is important.
[0014]
The mixture containing the ketonic acid ester and the oxy acid ester can be used in any mixture. For example, a ketone acid ester is produced by gas phase oxidation of an oxyacid ester, a mixture containing an unreacted oxyacid ester, an oxyacid is oxidized to produce a ketone acid, and esterified without removing the unreacted oxyacid. In addition, a mixture obtained by esterifying a ketonic acid such as pyruvic acid obtained by glucose fermentation and containing an oxyacid such as lactic acid as an impurity can be used.
[0015]
Moreover, the compound which does not inhibit reaction may coexist in the mixture containing a ketone acid ester and an oxy acid ester.
[0016]
Furthermore, the mixing ratio of the ketone acid ester and the oxyacid ester is not particularly limited, but considering the efficiency of purification, a mixture containing a large amount of the ketone acid ester is preferable. Particularly preferably, the weight ratio of ketone acid ester to oxyacid ester is 1000/1 to 5/1.
[0017]
In addition, the ester residue of the ketone acid ester and the oxy acid ester used here may have any structure, but considering the production efficiency, a lower alkyl residue is preferable. Particularly preferred are a methyl ester residue, an ethyl ester residue, a propyl ester residue, and a butyl ester residue, and the ester residues of the ketone acid ester and the oxy acid ester may be the same or different. Moreover, when the ester residues of the ketone acid ester and the oxy acid ester are different, the ketone acid ester is preferably an ester residue having a longer alkyl chain than the oxy acid ester.
[0018]
As the acid used in the present invention, any acid can be used as long as it reduces the decomposition rate of the ketone ester while increasing the decomposition rate of the oxyacid ester. Examples include H-type cation exchange resins such as Nafion (manufactured by DuPont) and Diaion PK208 (manufactured by Mitsubishi Kasei). In addition, mineral acids such as sulfuric acid and hydrochloric acid, aromatic sulfonic acids such as benzenesulfonic acid and toluenesulfonic acid, and aliphatic sulfonic acids such as methanesulfonic acid, preferably H-type cation exchange resin, sulfuric acid, Aromatic sulfonic acids such as benzenesulfonic acid and toluenesulfonic acid, and aliphatic sulfonic acids such as methanesulfonic acid, particularly preferably sulfuric acid and toluenesulfonic acid. The amount of the acid used is 1 mol% to 500 mol%, preferably 20 mol% to 200 mol%, based on the oxyacid ester of the mixture of ketone acid ester and oxyacid ester. It is desirable that the concentration of water in the acid is as low as possible in order to suppress decomposition of the ketone ester and selectively decompose the oxyester, and to consider the removal of the water. For example, a 98% or 95% concentration product is used in the case of sulfuric acid, and a monohydrate article is preferably used in the case of sulfonic acids.
[0019]
The heating temperature is preferably 30 to 90 ° C, more preferably 50 to 80 ° C. When the temperature is low, the decomposition rate is slow and the production efficiency is deteriorated. On the other hand, if it is high, the decomposition rate of not only the oxyacid ester but also the ketone acid ester is increased, and the recovery rate of the ketone acid ester is decreased.
[0020]
When heating, it is preferable to carry out substantially only with a mixture of a ketone acid ester and an oxyacid ester, but it may be carried out by adding a solvent that does not obscure the object of the present invention.
[0021]
When heating, it is preferable to stir to promote decomposition of the oxyester.
[0022]
By heating in the presence of an acid, the oxyacid ester is hydrolyzed into a generally solid oxyacid, and therefore can be easily separated.
[0023]
In order to isolate the ketone ester from the mixture containing the ketone ester obtained in the present invention at a high concentration, a vacuum distillation method or the like can be employed.
[0024]
EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these.
[0025]
Example 1
100 g of ethyl pyruvate solution containing ethyl lactate having a weight ratio of 98/2 ethyl pyruvate to ethyl lactate in a 200 ml three-necked flask, 1.15 g of 95% sulfuric acid (molar ratio of sulfuric acid / ethyl lactate 0.5) And stirred at about 70 ° C. for 1 hour.
[0026]
As a result of gas chromatogram analysis of ethyl pyruvate and ethyl lactate in this solution, the weight ratio of ethyl pyruvate to ethyl lactate was 99.4 / 0.6.
[0027]
After adding 1.87 g of sodium hydrogen carbonate (95% sulfuric acid and equimolar amount) to this solution, it was distilled under reduced pressure under the condition of about 6.0 kPa and bath temperature of about 80 ° C., and the weight of ethyl pyruvate and ethyl lactate 92 g of distillate of high-purity ethyl pyruvate having a ratio of 99.4 / 0.6 was obtained.
[0028]
Example 2
100 g of ethyl pyruvate solution containing ethyl lactate having a weight ratio of 90/10 of ethyl pyruvate to ethyl lactate in a 200 ml three-necked flask and 5.73 g of 95% sulfuric acid (0.5 molar ratio of sulfuric acid / ethyl lactate) And stirred at about 70 ° C. for 1 hour.
[0029]
As a result of analyzing the ethyl pyruvate and ethyl lactate in this liquid by gas chromatogram, the weight ratio of ethyl pyruvate to ethyl lactate was 98.5 / 1.5.
[0030]
Example 3
The same procedure as in Example 1 except that 95% sulfuric acid was replaced with 2.11 g of p-toluenesulfonic acid monohydrate (p-toluenesulfonic acid monohydrate / ethyl lactate molar ratio 0.5). As a result of the operation, the weight ratio of ethyl pyruvate to ethyl lactate was 99/1.
[0031]
Comparative Example 1
As a result of performing the same operation except that 95% sulfuric acid was replaced with water in the method of Example 1, the weight ratio of ethyl pyruvate to ethyl lactate was 98/2.
[0032]
【The invention's effect】
According to the method of the present invention, a high-purity ketonic acid ester can be easily produced by heating a mixture containing a ketonic acid ester and an oxyester that are close to the boiling point and difficult to separate by distillation in the presence of an acid. Can greatly contribute to the reduction of manufacturing costs.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17178995A JP3726315B2 (en) | 1995-07-07 | 1995-07-07 | Purification method of ketonic ester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17178995A JP3726315B2 (en) | 1995-07-07 | 1995-07-07 | Purification method of ketonic ester |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0920723A JPH0920723A (en) | 1997-01-21 |
| JP3726315B2 true JP3726315B2 (en) | 2005-12-14 |
Family
ID=15929728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17178995A Expired - Lifetime JP3726315B2 (en) | 1995-07-07 | 1995-07-07 | Purification method of ketonic ester |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3726315B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6348617B1 (en) | 1996-10-09 | 2002-02-19 | Sumitomo Chemical Company, Limited | Method for purifying pyruvic acid compounds |
| JP2011516590A (en) * | 2008-04-14 | 2011-05-26 | ロンザ リミテッド | Purification method of α-ketoester |
-
1995
- 1995-07-07 JP JP17178995A patent/JP3726315B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0920723A (en) | 1997-01-21 |
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