JPH11140013A - Production of oxalacetic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing oxalacetic acid in high efficiency by oxidizing malic acid with molecular oxygen. SOLUTION: Disodium malate is made to react with molecular oxygen as an oxidizing agent in an aqueous solvent in the presence of a catalyst containing a noble metal such as platinum and a base metal such as lead. Oxalacetic acid can be produced in high efficiency by the use of the catalyst of the present invention consisting of a combination of a noble metal with a base metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing oxalic acetic acid, and more particularly to a method for producing oxal acetic acid by oxidizing malic acid with an oxygen-containing gas. Oxalacetic acid obtained by the method of the present invention is used for the production of acridine acid by reacting with a synthetic intermediate for synthesizing various organic compounds, for example, orthoaminobenzaldehyde. Oxalacetic acid is a compound contained in the citric acid cycle in a living body, and is a useful compound used for the synthesis of various physiologically active substances, a substrate for an enzyme reaction, and the like.
Oxalacetic acid has keto-enol tautomers, and in the enol form, cis- and trans-form geometric isomers exist. The cis-form is a structure that can be said to be oxymaleic acid, and has a melting point of 152 ° C., and is converted to trans-form oxyfumaric acid by a strong acid and has a melting point of 184 ° C.

[0002]

2. Description of the Related Art In a method for synthesizing oxalic acetic acid, acetyl halide is reacted with t-butyl alcohol to convert it to t-butyl ester, which is converted to di-t-butyl oxalate in the presence of sodium t-butylate. (J. Am. Chem. Soc. 7)
2 , 4704 (1950)), a method of Claisen condensation of ethyl acetate and diethyl oxalate in the presence of sodium alkoxide (J. Am. Chem. Soc. 74, 2).
418 (1952)). In addition, malic acid is oxidized with potassium permanganate,
A method of oxidizing with hydrogen peroxide in the presence of a multivalent iron salt is also disclosed.

[0003]

As described above, the conventional methods for producing oxalacetic acid require expensive starting materials, require expensive auxiliary materials, require long and complicated production steps, It produces harmful by-products and the like, and all methods have problems in industrially producing oxalacetic acid.

[0004]

The present inventor has conducted various studies on a method for producing oxalacetic acid which does not have the above-mentioned problems. As a result, a reaction formula (1) for oxidizing malic acid, which is easily obtained by a hydration reaction of maleic acid and supplied industrially in a large amount, with an oxygen-containing gas.

[0005]

## STR1 ## represented by _{HOOC-CH 2 CHOH-COOH +} 1/2 O 2 = HOOC-CH 2 CO-COOH + H 2 O (1), discovered an improved method of producing oxalacetate, the present invention It was completed.

That is, according to the present invention, at the time of producing oxalacetic acid by oxidizing malic acid, at least one noble metal selected from the group consisting of palladium, platinum, ruthenium and rhodium and lead, tin, bismuth, molybdenum and tellurium. ,
A method for producing oxalacetic acid, comprising oxidizing malic acid with an oxygen-containing gas in the presence of a catalyst containing at least one element or a compound of elements selected from the group consisting of cerium and antimony.

In the method of the present invention, since the raw materials are malic acid and oxygen-containing gas, the reaction is simple and does not require dangerous raw materials, and does not produce harmful by-products. The method of the present invention is characterized by a catalyst used in carrying out the oxidation reaction. Precious metals such as palladium or platinum, or activated carbon, using a normal catalyst supported on a carrier such as alumina, the target oxalic acetic acid is not obtained at all by the oxidation of malic acid with an oxygen-containing gas, Even if obtained, the yield is very small. By using the catalyst of the present invention in which the noble metal and the base metal or a compound thereof are used, oxalacetic acid can be obtained by oxidation with an oxygen-containing gas for the first time.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The method of the present invention is a method for oxidizing malic acid with an oxygen-containing gas, and is characterized by a catalyst used for the oxidation reaction. The catalyst used in carrying out the method of the present invention comprises one or more selected from the group consisting of palladium, platinum, ruthenium and rhodium as a main component of the catalyst, and further includes lead, tin, bismuth, and co-catalyst components.
One or a combination of one or more elements or compounds thereof selected from the group consisting of molybdenum, tellurium, cerium, and antimony is used. Preferably, the main component of the catalyst is platinum and / or palladium. The catalyst preferably contains a compound of platinum and lead and / or tin; one containing a compound of platinum and bismuth or / and / or molybdenum; and contains a compound of palladium and lead or / and / or antimony. Things. Usually, it is convenient to use the above-mentioned catalyst component supported on a suitable carrier. As the carrier, activated carbon, silica, alumina, silica-alumina, magnesia, titania, zirconia, zeolite, or the like is used.

The amount of the noble metal, which is the main catalyst component, supported on the carrier is usually in the range of 0.1 to 10% by weight, and particularly in the range of 0.5 to 5% by weight. The amount of the above-mentioned promoter component supported on the carrier is 0.1 to 15% by weight, and particularly, the range of 0.5 to 10% by weight is frequently used.

To prepare the catalyst used in the method of the present invention, a noble metal compound such as chloroplatinic acid or palladium acetate is dissolved in a solvent such as water or acetone, and a co-catalyst salt of lead acetate or ammonium molybdate is further added. Melted,
A carrier such as activated carbon or alumina is charged into a solvent in which these catalyst components are dissolved, and the carriers are impregnated with the catalyst components. When the carrier is an activated carbon, the carrier after the impregnation is heat-treated at 300 ° C. or less in an inert gas stream such as nitrogen.
In the following, the catalyst component is supported on a carrier by heat treatment. The supported catalyst component is subjected to an appropriate reduction treatment before it is subjected to the reaction. The reduction treatment of the catalyst is performed in a liquid phase or a gas phase.

In the liquid phase reduction, for example, a catalyst is suspended in an aqueous solution and reduced with a reducing agent such as hydrazine, formalin or hydrogen. At that time, the aqueous solution is appropriately adjusted to basic, neutral or acidic according to the type of the reducing agent used in accordance with a conventional method. In the case of gas phase reduction, hydrogen gas, CO gas, lower alcohol, or the like is used as a reducing agent, but hydrogen gas is often used in general. The hydrogen gas is diluted with an inert gas such as nitrogen, and the operation is performed so that the reduction reaction proceeds rapidly and the catalyst is not excessively locally heated.

A catalyst prepared based on a commercially available supported noble metal catalyst with the addition of the second and third components can also be used in the method of the present invention. For example, 0.5 to 5% by weight
An activated carbon catalyst supporting platinum or an activated carbon catalyst supporting palladium is put into an aqueous solution in which an appropriate amount of the second component compound is dissolved, and the second component is adsorbed and impregnated on the catalyst,
Next, this is filtered and dried to obtain a catalyst. As the second and third components to be used, compounds of the aforementioned elements are used. The form of the compound is not particularly limited, but usually a water-soluble compound such as a nitrate or an organic acid salt is frequently used. The concentration of the aqueous solution of the second or third component is adjusted so that the total amount thereof becomes 0.5 to 5% by weight when the whole amount is adsorbed on the catalyst.

The reaction of the present invention is carried out by dissolving malic acid as a substrate in a suitable solvent. Usually, malic acid as a substrate is used in the form of an alkali metal salt.
Sodium is frequently used as an alkali metal. In the method of the present invention, water is frequently used as a solvent. The concentration of the substrate dissolved in a solvent is often in the range of 1 to 20% by weight. The amount of the catalyst to be used is, for example, in the case where the reaction is carried out batchwise, and is 10 to 2 with respect to the charged malic acid or malate.
The range of 00% by weight is frequently used.

The reaction of the present invention is a method of oxidizing malic acid with an oxygen-containing gas.
A mixed gas such as oxygen and nitrogen or air is frequently used. The pressure of the oxygen-containing gas used is often in the range of atmospheric pressure to 20 kg / cm ² G. However, the reaction may be carried out at atmospheric pressure or lower. The temperature at which the reaction is carried out is in the range of 10 to 100C, and particularly in the range of 20 to 80C. The time required for the reaction varies depending on the amount of the catalyst used and the reaction temperature.
The range is 20 hours. The reaction of the present invention can be carried out batchwise or continuously. The type of the reactor is suitably a suspension bed of a liquid layer, a fixed bed or a trickle bed.

The catalyst is separated from the reaction solution after completion of the reaction, and the target oxal acetate is precipitated as a solid by a method such as concentration or by adding an organic solvent such as lower alcohol or acetone to the concentrated solution. To isolate and obtain.

[0016]

The present invention will be described in more detail with reference to the following examples. Example 1 A mixed aqueous solution of palladium acetate and lead acetate was impregnated with activated carbon (Centau) powder manufactured by Calgon, filtered, and dried. This was heated to 200 ° C. in a nitrogen stream and held for 2 hours, and then a nitrogen gas containing 10% hydrogen gas was passed for 2 hours to reduce the catalyst. The obtained catalyst was palladium 5.3.
% And 3.6% lead. A glass reactor having an inner volume of 200 ml and a gas reactor attached thereto was used as a reactor, heated from outside with a hot water bath, and stirred with a magnetic stirrer.
The reaction was performed while suspending the catalyst. 5 in the above reactor
Aqueous solution containing 100% by weight of malic acid disodium salt
Then, 3.5 g of the above-described catalyst supported on palladium-lead activated carbon was charged under a nitrogen atmosphere. 60 reactors
C., the system was replaced with oxygen gas, filled with oxygen at atmospheric pressure, and reacted. The reaction was stopped at this point because the oxygen consumption as measured by gas brew began to drop after 6 hours. After removing the catalyst from the reaction solution by filtration, the concentration of oxalacetic acid in the reaction solution was measured by a conventional method using high performance liquid chromatography.

Example 2 An aqueous solution of chloroplatinic acid and lead acetate was impregnated in a powdered activated carbon centau manufactured by Calgon Co., Ltd., filtered, and then filtered at 250 ° C. in a nitrogen atmosphere.
And dried. Next, a nitrogen gas containing 10% hydrogen gas was passed, and the temperature was raised to 300 ° C. to reduce the catalyst. The resulting catalyst contains 5.1% platinum and 3.5% lead. 5% by weight in the same glass reactor as in Example 1
100 ml of an aqueous solution of disodium malate, platinum-
3.5 g of a lead-supported activated carbon catalyst was charged. After the gas phase was replaced with oxygen gas, oxygen at atmospheric pressure was charged into the gas bottle to perform an oxidation reaction. The outside of the reactor was heated with a water bath to maintain the reaction temperature at 60 ° C., and stirred with a magnetic stirrer to keep the catalyst suspended. After 4.5 hours from the start of the reaction, the amount of oxygen consumed decreased, and the reaction was stopped. After filtering the catalyst from the reaction solution, the amount of oxalacetic acid in the reaction solution was measured by high performance liquid chromatography. As a result, oxalacetic acid was produced in a yield of 73%.

Example 3 A commercially available platinum carbon powder catalyst supporting 2% by weight of platinum (N
E-Chemkyat) impregnated with bismuth nitrate aqueous solution,
After the catalyst was separated by filtration and dried, it was heated to 350 ° C. in a nitrogen stream to prepare a catalyst. The same reactor as in Example 1 was charged with 100 ml of a 5% by weight aqueous solution of disodium malate, and then with 3.5 g of the above catalyst. The gas phase is replaced with oxygen gas, and the gas bottle is filled with oxygen at atmospheric pressure.
The reaction was carried out at ℃. Six hours after the start of the reaction, the amount of oxygen absorbed decreased, so the reaction was terminated, and the catalyst was filtered off from the reaction solution. As a result of analyzing the reaction solution by high performance liquid chromatography, the yield of oxalacetic acid was 72%.

Example 4 A commercially available 5% platinum alumina powder catalyst (manufactured by NE-Chemcat Co.) was impregnated with an aqueous antimony chloride solution, dried and then heated to 300 ° C. in a nitrogen stream. Then hydrogen gas 10
% Under nitrogen gas flow to reduce the catalyst to 350 ° C. to prepare a catalyst. A 5% by weight aqueous solution of malic acid disodium salt 1 was placed in the same apparatus as in Example 1.
Then, 4 g of the above catalyst was charged. The reactor was heated to 60 ° C. from outside with a hot water bath, and the inside of the system was replaced with oxygen gas to cause a reaction. Six hours after the start of the reaction, the amount of oxygen absorbed decreased, so the reaction was stopped and the catalyst was filtered off from the reaction solution. As a result of analyzing the reaction solution by high performance liquid chromatography, a disodium salt of oxalacetic acid was produced in a yield of 67%.

Comparative Example 1 Palladium acetate was impregnated into powdered activated carbon Centau manufactured by Calgon, and then reduced with formalin in an aqueous solution made basic with sodium carbonate to prepare a catalyst. The obtained catalyst was washed with water, separated by filtration, heated to 250 ° C. in a nitrogen stream and dried.
The supported amount of palladium in the catalyst was 5.2%. 4 g of the above catalyst was charged into the same reactor as in Example 1, 100 g of a 5% by weight aqueous solution of disodium malate was charged, and the mixture was externally heated to 60 ° C. in a water bath. The inside of the reactor system was replaced with pure oxygen gas, and the gas vessel was filled with oxygen gas at atmospheric pressure to start the reaction. After 10 hours from the start of the reaction, almost no absorption of oxygen was recognized. At this time, the reaction was stopped, the catalyst was filtered off, and the reaction solution was analyzed by high performance liquid chromatography. As a result, the raw material malate remained unreacted, and the generation of oxal acetate was only a trace amount.

COMPARATIVE EXAMPLE 2 Powdered activated carbon (Centau, Calgon) was impregnated with an aqueous solution of chloroplatinic acid, washed with water, separated by filtration, dried at room temperature, and dried in a nitrogen stream.
The temperature was raised to 0 ° C. and dried. Nitrogen gas containing 10% of hydrogen was passed, the temperature was raised from room temperature to 250 ° C., and reduction was carried out to prepare a catalyst. The platinum content of the resulting catalyst is 5.1%. 4 g of the above catalyst was charged into the same reactor as in Example 1, and a 5% aqueous solution of disodium malate 1
Then, the mixture was heated to 60 ° C. from outside with a hot water bath.
The inside of the reactor system was replaced with oxygen gas, and oxygen at atmospheric pressure was charged into the gas blast to react. Six hours after the start of the reaction, the absorption of oxygen was slight. At this time, the reaction was stopped, the catalyst was separated from the reaction solution by filtration, and the reaction solution was analyzed by high performance liquid chromatography. As a result, the yield of oxalacetic acid was 2.5
% Was over.

Examples 5 to 10 An aqueous solution of disodium malate was oxidized with oxygen using the same reactor as in Example 1 and changing the catalyst used under the same reaction conditions. Table 1 shows the obtained results.

[0023]

Table 1 Table 1 Example No. Catalyst composition Oxal acetate Yield (%) ──────────────────────────────────── 5 Ru-Pb / SiO ₂ 456 Rh-Pb / C 597 Pt-Sn / C 608 Pt-Bi-Mo / C 649 Pt-Te / C 57 10 Pd-Te-Ce / C 56} ──────────────────────── (Note) C stands for activated carbon. The noble metal loading was 5% and the promoter loading was 3%.

[0024]

According to the method of the present invention, oxalacetic acid can be produced without using harmful by-products by using starting materials which are obtained industrially in large quantities at low cost, do not require expensive auxiliary materials, and are free from harmful by-products. .

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C07C 51/235 B01J 23/64 101Z // C07B 61/00 300 103Z

Claims (6)

[Claims] In producing oxalacetic acid by oxidizing malic acid, at least one noble metal selected from the group consisting of palladium, platinum, ruthenium and rhodium and lead, tin, bismuth, molybdenum, tellurium, cerium and antimony A method for producing oxalic acetic acid, comprising oxidizing malic acid with an oxygen-containing gas in the presence of a catalyst containing at least one element or a compound of elements selected from the group consisting of: 2. The method according to claim 1, wherein the noble metal is platinum and / or palladium. 3. The method according to claim 1, wherein the catalyst contains a compound of platinum and lead and / or tin. 4. The method according to claim 1, wherein the catalyst contains a compound of platinum and bismuth and / or molybdenum. 5. The method according to claim 1, wherein the catalyst contains a compound of palladium and lead and / or antimony. 6. The method according to claim 1, wherein the catalyst has a catalyst component supported on a carrier.