JP3376419B2 - Synthesis of acetoxyacetic acid using sulfate-supported metal oxide as catalyst - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to acetoxyacetic acid.
The present invention relates to a synthetic method of (acetylglycolic acid).

[0002]

Acetoxyacetic acid is an important compound in the chemical industry because it is used as a synthetic raw material in the production of various chemical products such as agricultural chemicals and surface treatment agents.

As a method for synthesizing acetoxyacetic acid,
Method of heating ethyl glycolate and acetic acid in benzene with a small amount of sulfuric acid to remove water and ethyl acetate produced and synthesize (Beilstein, 3, 233), alkali metal iodide,
There is a method of reacting acetic acid and oxygen gas under high temperature and high pressure in the presence of three components of metal oxide or metal acetate and iodine (JP-A-56-63941).

The former method is not easy to handle and expensive because the starting material, ethyl glycolate, is an irritating and flammable substance. In the latter method, the catalytic activity is not exhibited unless the three components coexist, so the number of reagents used increases, the separation operation between the catalyst and the product becomes complicated, the cost also increases, and the product acetoxy Low yield of acetic acid (yield of acetoxyacetic acid in Examples: 1
%) Etc. Therefore, these methods cannot be said to be industrially excellent methods.

Japanese Unexamined Patent Publication (Kokai) No. 11-147042 discloses that mordenite having an SiO ₂ / Al ₂ O ₃ molar ratio of at least 100 or more is used as a catalyst with an aliphatic aldehyde and carbon monoxide as a catalyst, and is reacted in a reaction medium. A method for producing a hydroxycarboxylic acid derivative, which comprises obtaining a carboxylic acid derivative "is disclosed. The above publication discloses that acetoxyacetic acid can be synthesized as a hydroxycarboxylic acid.

However, in this method, the reaction temperature is 100 to 3
In order to obtain a high yield of 00 ° C, a high temperature of 170 to 200 ° C is particularly required. When a highly toxic gas such as carbon monoxide is used, the reaction conditions are preferably mild.
Furthermore, the high silica type mordenite having a high SiO ₂ / Al ₂ O ₃ molar ratio is very expensive as compared with normal mordenite.

As described above, the method described in the above publication has problems in safety and economy.

As described above, the conventional acetoxyacetic acid synthesis method is
There are problems that it is difficult to separate the catalyst and the target product from the reaction solution, harsh reaction conditions are required, and the raw materials and the catalyst are expensive.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the conventional methods and provides a method for synthesizing acetoxyacetic acid more easily and economically under milder conditions. Is the main purpose.

[0010]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that acetoxyacetic acid can be treated well even under mild reaction conditions by using a specific catalyst which is relatively inexpensive and easy to synthesize. The present invention has been completed by finding a method that can be synthesized in a yield.

That is, the present invention relates to the following method for synthesizing acetoxyacetic acid and a catalyst for synthesizing acetoxyacetic acid. 1. In the method for synthesizing acetoxyacetic acid, in the presence of a metal oxide carrying a sulfate group, formaldehyde and / or a compound which forms formaldehyde under reaction conditions,
A method for synthesizing acetoxyacetic acid, which comprises reacting carbon monoxide with acetic acid and / or acetic anhydride in a reaction medium. 2. Sulfate-supporting metal oxide, sulfate-supporting zirconia,
2. The method for synthesizing acetoxyacetic acid according to 1 above, which is at least one member selected from the group consisting of sulfate-bearing titania and sulfate-bearing tin oxide. 3. 3. The synthesis of acetoxyacetic acid according to 1 or 2 above, wherein the reaction medium is at least one selected from the group consisting of halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons, aliphatic hydrocarbons and aromatic hydrocarbons. Law. 4. A catalyst for synthesizing acetoxyacetic acid comprising at least one selected from the group consisting of sulfate-bearing zirconia, sulfate-bearing titania, and sulfate-bearing tin oxide.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The method for synthesizing acetoxyacetic acid according to the present invention is the method for synthesizing acetoxyacetic acid, wherein, in the presence of a metal oxide carrying a sulfate radical, formaldehyde and / or a compound which forms formaldehyde under reaction conditions, It is characterized in that carbon monoxide is reacted with acetic acid and / or acetic anhydride in a reaction medium.

The sulfate group-supporting metal oxide used as a catalyst for synthesizing acetoxyacetic acid is not particularly limited, and examples thereof include sulfate group-supporting zirconia, sulfate group-supporting titania, and sulfate group-supporting tin oxide.

The amount of the sulfate group supported on the sulfate-supporting metal oxide is not particularly limited, but is usually about 0.5 to 10% by weight, preferably about 1 to 5% by weight, in terms of sulfur, based on the metal oxide. .

The specific surface area of the sulfate group-supporting metal oxide is not particularly limited, but is usually 50 to 1 as a value measured by the BET method.
50 m ² / g approximately, and preferably from 80 to 120 ² / g approximately.

As the sulfate group-supporting metal oxide, those prepared by a known method may be used, or commercially available products may be used. Sulfate-supported metal oxides are, for example, Appl. Catal.
It can be prepared using the method described in A, 146 (1996), 3-32. Specifically, it can be prepared by a method in which the starting material is treated with dilute sulfuric acid and baked in an oxidizing atmosphere such as air.

The starting material for the sulfate group-supporting metal oxide can be appropriately selected according to the desired sulfate group-supporting metal oxide. The starting material may be prepared by a known method, or a commercially available product may be used. For example, when preparing sulfate-bearing zirconia, zirconium hydroxide etc. can be illustrated as a starting material. The zirconium hydroxide is not particularly limited, and examples thereof include those prepared from zirconium nitrate dihydrate, zirconium chloride oxide octahydrate and the like. When preparing sulfate-bearing titania, titanium hydroxide etc. can be illustrated as a starting material. The titanium hydroxide is not particularly limited, and examples thereof include those prepared from titanium tetraisopropoxide and the like. When preparing the sulfate-supporting tin oxide, tin hydroxide can be illustrated as a starting material. Examples of tin hydroxide include those prepared from tin tetrachloride pentahydrate, tin octylate, and the like.

The calcination temperature can be appropriately selected according to the desired sulfate-bearing metal oxide. In the case of preparing sulfate-bearing zirconia, the firing temperature is generally about 500 to 700 ° C, preferably about 550 to 650 ° C. When preparing sulfate-bearing titania, the preparation temperature is generally about 450 to 650 ° C, preferably about 500 to 600 ° C. The firing temperature for preparing the sulfate-supported tin oxide is about 450 to 650 ° C, preferably about 500 to 600 ° C.

The preparation method will be described more specifically by taking the case of preparing sulfate-bearing zirconia from zirconium nitrate dihydrate as an example. When concentrated aqueous ammonia is added to the zirconium nitrate dihydrate aqueous solution until the pH becomes about 7 to 8, zirconium hydroxide is precipitated. The obtained zirconium hydroxide may be subjected to treatments such as washing, filtering and drying, if necessary. Zirconium hydroxide is subjected to treatment such as contact with dilute sulfuric acid, immersion, and the like, followed by firing at about 500 to 700 ° C. in an oxidizing atmosphere such as air.

The synthetic raw material used in the synthetic method of the present invention is not particularly limited as long as it is formaldehyde and / or a compound which produces formaldehyde under reaction conditions. Examples of the compound that forms formaldehyde under the reaction conditions include 1,3,5-trioxane, paraformaldehyde, α-polyoxymethylene, and tetraoxane. These compounds may be used alone or in combination of two or more. The amount of the synthetic raw material used in the reaction is not particularly limited, but is usually about 0.5 to 50 mmol, preferably 1 to 5 mmo, in terms of formaldehyde with respect to 1 g of the sulfate group-supporting metal oxide catalyst.
It is about l.

In the synthetic method of the present invention, acetoxyacetic acid can be synthesized by adding an appropriate amount of acetic acid and / or acetic anhydride to the reaction medium. The amount of acetic acid and / or acetic anhydride to be added is usually from equimolar to 100 times the number of moles of formaldehyde as a synthetic raw material (the number of moles converted to formaldehyde in the case of a compound that produces formaldehyde under the reaction conditions). The amount is about molar, preferably about 5 to 20 times the molar amount.

The reaction medium used in the present invention can be used regardless of whether it is polar or non-polar, but by using a solvent having a certain polarity, acetoxyacetic acid can be obtained in a higher yield. As a reaction medium, for example, chloroform,
Halogenated aliphatic hydrocarbons such as dichloromethane, halogenated aromatic hydrocarbons such as chlorobenzene, hexane,
Examples thereof include aliphatic hydrocarbons such as cyclohexane and methylcyclohexane, aromatic hydrocarbons such as benzene, and the like. Of these, halogenated aliphatic hydrocarbons such as chloroform and dichloromethane are preferable as the reaction medium. As the reaction medium, one type may be used alone, or two or more types may be used in combination.

The reaction pressure in the synthesis method of the present invention is not particularly limited, but it is generally about 10 to 100 kg / cm ² as carbon monoxide partial pressure, and preferably 30 to 60 kg / cm ^2.
It is a degree.

The reaction temperature is not particularly limited, but is generally about 100 to 170 ° C., preferably 130 to 150.
It is about ℃.

The method of the present invention can be carried out, for example, as follows. Formaldehyde, a reaction medium, acetic acid and / or acetic anhydride, and a sulfate group-supporting metal oxide are put into an autoclave, and if necessary, after purging with carbon monoxide, carbon monoxide at a predetermined pressure is introduced. The carbon monoxide introduced may be diluted with an inert gas such as a rare gas or nitrogen. The temperature is raised to a predetermined temperature with stirring, and the reaction is performed for a fixed time, preferably about 1 to 4 hours. After completion of the reaction, the sulfate group-supporting oxide that is the catalyst is filtered off from the reaction mixture to obtain a mixed solution of acetoxyacetic acid and a solvent. Total pressure of the reaction is not particularly limited, usually 10kg / cm ² ~150kg / cm ^2, preferably about 30k
It is about g / cm ^{2 to} 70 kg / cm ² .

The product can be separated from the mixed solution by a known method such as extraction or recrystallization. Specifically, the following procedure can be exemplified. After removing the sulfate group-supporting metal oxide by filtering the reaction mixture, the reaction medium is removed under reduced pressure from the obtained filtrate to obtain an oily substance containing the target substance. The target substance can be separated by subjecting the obtained oily substance to methods such as preparative gas chromatography, preparative high performance liquid chromatography, and vacuum distillation.

In the synthetic method of the present invention, it is considered that acetoxyacetic acid is produced as follows. Formaldehyde is converted to a hydroxymethyl cation by the sulfate-supported metal oxide catalyst, and the reaction of carbon monoxide with acetic acid or acetic anhydride present in the reaction system gives the product acetoxyacetic acid. Formula 1 shows a reaction formula when acetoxyacetic acid is synthesized by reacting formaldehyde with carbon monoxide and acetic acid in the presence of a metal oxide catalyst supporting sulfate.

[0028]

[Formula 1]

[0029]

INDUSTRIAL APPLICABILITY According to the present invention, acetoxyacetic acid can be selectively obtained in a high yield under milder temperature and pressure conditions.

According to the present invention, by using a relatively inexpensive sulfate group-supporting metal oxide that is easy to synthesize as a catalyst, acetoxyacetic acid can be obtained without using a liquid strong acid or an expensive solid acid. Can be obtained selectively and in high yield.

Since the catalyst of the present invention is a solid superacid,
It is easy to separate the catalyst from the product. Therefore, a more economical synthetic method of acetoxyacetic acid can be provided.

[0032]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 200 g of zirconium nitrate dihydrate was dissolved in 5 L of water to obtain a pH of 8.
25% aqueous ammonia solution was added until. The precipitated solid was washed with 3 L of water (warm water at 50 to 60 ° C.), the solid was filtered off, and dried at 100 ° C. for 24 hours to obtain 115 g of zirconium hydroxide. 2 g of zirconium hydroxide was brought into contact with 30 ml of 1N sulfuric acid on a filter paper, and then air dried overnight. This was placed in a glass sample tube, calcined at 600 ° C. for 3 hours, and then sealed while heated to obtain a sulfate group-supporting zirconia.

In the autoclave, zirconium hydroxide 2
Sulfonate-supported zirconia prepared from g, 1,3,5-trioxane (5 mmol), dichloromethane (50 ml) and acetic acid (50 mmol) were added, and after purging with carbon monoxide, 50 kg / cm ² carbon monoxide was introduced. The glass tube sealed with sulfate-bearing zirconia ruptured at this pressure. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After completion of the reaction, the reaction mixture and the catalyst were separated by filtration. The filtrate was distilled under reduced pressure and concentrated. A part of this concentrated solution diluted with a solvent was used for the following analysis. Gas chromatography (GC), gas chromatography mass (GC-MS)
Analysis and NMR measurements were performed. As a result, the main product was identified as acetoxyacetic acid. The acetoxyacetic acid was quantified by GC analysis using n-heptadecane as the internal standard substance, and the yield was confirmed to be 60%.

Example 2 As a catalyst, zirconia carrying sulfate radical prepared in the same manner as in Example 1 was used. Zirconium hydroxide in autoclave
Sulfonate-supporting zirconia prepared from 2 g, 1,3,5-trioxane (5 mmol), dichloromethane (50 ml) and acetic acid (50 mmol) were added, and after purging with carbon monoxide, 50 kg / cm ² of carbon monoxide was introduced. While stirring, the temperature was raised to 110 ° C. and the reaction was carried out for 3 hours.

After the reaction was completed, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 13%.

Example 3 As the catalyst, sulfate group-supporting zirconia prepared in the same manner as in Example 1 was used. Zirconium hydroxide in autoclave
After adding sulfate group-supporting zirconia prepared from 2 g, 1.7 mmol of 1,3,5-trioxane, 50 ml of cyclohexane and 50 mmol of acetic acid and purging with carbon monoxide, 50 kg / cm ² carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After the reaction was completed, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 3.5%.

Example 4 As the catalyst, sulfate group-supporting zirconia prepared in the same manner as in Example 1 was used. Zirconium hydroxide in autoclave
Sulfate-supported zirconia prepared from 2 g, 1,3,5-trioxane 1.7 mmol, benzene 50 ml and acetic acid 50 mmol,
After purging with carbon monoxide, 50 kg / cm ² of carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After the reaction was completed, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 3.0%.

Example 5 As the catalyst, sulfate group-supported zirconia prepared in the same manner as in Example 1 was used. Zirconium hydroxide in autoclave
Sulfate-supported zirconia prepared from 2 g, 1.7 mmol of 1,3,5-trioxane, 50 ml of chlorobenzene and 50 mmol of acetic acid were added, and after purging with carbon monoxide, 50 kg / cm ² carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After the reaction was completed, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 13%.

Example 6 As a catalyst, zirconia carrying sulfate radical prepared in the same manner as in Example 1 was used. Zirconium hydroxide in autoclave
Sulfonate-supporting zirconia prepared from 2 g, 1,3,5-trioxane 5 mmol, dichloromethane 50 ml and acetic anhydride 5 mmol were added, and after purging with carbon monoxide, 50 kg / cm ² carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After completion of the reaction, the reaction mixture and the catalyst were separated by filtration. As a result of the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 33%.

Example 7 Sulfuric acid-bearing zirconia prepared in the same manner as in Example 1 was used as the catalyst. Zirconium hydroxide in autoclave
Sulfonate-supporting zirconia prepared from 2 g and paraformaldehyde were added in an amount of 5 mmol in terms of formaldehyde, 50 ml of dichloromethane and 50 mmol of acetic acid, and after purging with carbon monoxide, 50 kg / cm ² of carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After completion of the reaction, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 32%.

Comparative Example 1 An attempt was made to synthesize acetoxyacetic acid without using a reaction medium. As a catalyst, sulfate group-supported zirconia prepared in the same manner as in Example 1 was used. Zirconium hydroxide 2g in autoclave
Sulfonate-supporting zirconia prepared from the above, 1,3,5-trioxane (5 mmol) and acetic acid (50 mmol) were added, and after purging with carbon monoxide, 50 kg / cm ² carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After completion of the reaction, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that acetoxyacetic acid was not generated at all.

Example 8 145 ml of titanium tetraisopropoxide was added to 2 L of water,
Subsequently, 125 ml of 60% nitric acid was added. A 25% aqueous ammonia solution was added until the pH reached 8, and the precipitated solid was washed with 5 L of water. The solid obtained was dried at 100 ° C. for 24 hours to obtain 43 g of titanium hydroxide. After contacting 2 g of titanium hydroxide with 30 ml of 1N sulfuric acid on a filter paper, it was air dried overnight. After putting this in a glass tube and firing at 550 ° C for 3 hours,
By sealing the tube, sulfate-bearing titania was obtained.

In an autoclave, 1.7 m of 1,3,5-trioxane, titania containing sulfate prepared from 2 g of titanium hydroxide.
After adding mol, 50 ml of dichloromethane and 50 mmol of acetic acid and purging with carbon monoxide, 50 kg / cm ² of carbon monoxide was introduced. The glass sample tube sealed with sulfate-bearing titania is
It burst by this pressure. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After the reaction was completed, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 31%.

Example 9 50 g of tin tetrachloride pentahydrate was dissolved in 1 L of water and adjusted to pH 9.5-10.
25% aqueous ammonia solution was added until. After washing the precipitated solid with 5 L of water, the solid was filtered off and dried at 100 ° C. for 24 hours to obtain 13 g of tin hydroxide. 2 g of tin hydroxide and 30 ml of 6N sulfuric acid were stirred in a beaker and immersed for 30 minutes. The solid was filtered off, dried overnight, put in a glass tube, baked at 550 ° C. for 3 hours, and sealed to obtain a sulfate-bearing tin oxide.

In an autoclave, sulfate-supported tin oxide prepared from 2 g of tin hydroxide, 1,3,5-trioxane 1.7 mmo
l, 50 ml of dichloromethane and 50 mmol of acetic acid were added, and after purging with carbon monoxide, 50 kg / cm ² of carbon monoxide was introduced. While stirring, the temperature was raised to 150 ° C. and the reaction was performed for 3 hours.

After completion of the reaction, the reaction mixture and the catalyst were separated by filtration. As a result of performing the same analysis as in Example 1, it was confirmed that the yield of acetoxyacetic acid as a main product was 48%.

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Claims (4)

(57) [Claims] 1. In a method for synthesizing acetoxyacetic acid, carbon monoxide and acetic acid and / or acetic anhydride are reacted with formaldehyde and / or a compound which produces formaldehyde under reaction conditions in the presence of a metal oxide carrying a sulfate group. A method for synthesizing acetoxyacetic acid, which comprises reacting in a medium. 2. The synthesis of acetoxyacetic acid according to claim 1, wherein the sulfate-bearing metal oxide is at least one selected from the group consisting of sulfate-bearing zirconia, sulfate-bearing titania and sulfate-bearing tin oxide. Law. 3. The reaction medium is a halogenated aliphatic hydrocarbon,
The method for synthesizing acetoxyacetic acid according to claim 1 or 2, which is at least one selected from the group consisting of halogenated aromatic hydrocarbons, aliphatic hydrocarbons, and aromatic hydrocarbons. 4. A catalyst for the synthesis of acetoxyacetic acid comprising at least one selected from the group consisting of sulfate-bearing zirconia, sulfate-bearing titania and sulfate-bearing tin oxide.