JP3363577B2 - Method for producing α-hydroxyisobutyric acid amide - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing α-hydroxyisobutyric acid amide. More specifically, by reacting acetone cyanohydrin with water in the liquid phase, α
-A method for producing hydroxyisobutyric acid amide.

[0002]

2. Description of the Related Art It is well known that a corresponding amide compound can be produced by reacting a nitrile compound with water, and .alpha.-hydroxyisobutyric acid amide produced by reacting acetone cyanohydrin with water is used for paints and adhesives. It is useful as a precursor of methyl methacrylate, which is a raw material for molding materials and the like. Various catalysts for reacting this nitrile compound with water are known. The manganese oxide disclosed in US Pat. No. 3,366,639 is one of them. Whereas copper-containing catalysts, which are often used for the reaction of nitrile compounds with water, give completely unsatisfactory results for the reaction of α-hydroxynitrile compounds such as acetone cyanohydrin with water, manganese oxide is a West German patent. As disclosed in No. 2,131,813, it has a characteristic of giving a considerable result even to the reaction of an α-hydroxynitrile compound with water.

JP-A-52-222 describes that the yield of α-hydroxyisobutyric acid amide can be increased by adding acetone to a raw material.
As a result of examining an industrial continuous production method of α-hydroxyisobutyric acid amide by reacting acetone cyanohydrin with water using a catalyst suspension bed flow reactor, it was found that the catalytic activity rapidly decreased with time. did.

On the other hand, as a method for extending the life of a manganese dioxide catalyst, a method for improving a manganese dioxide catalyst containing a second component metal is described in JP-A-3-93761 and EP-A-461,850. . Kohei
3-93761 is a co-precipitation method in which a second component metal coexists when preparing manganese dioxide.
Nos. 461 and 850 are a coprecipitation method and an impregnation method in which the second component metal is impregnated and then neutralized with an alkali. However, although the effect is seen in any of these methods, the life of the manganese dioxide catalyst has not reached the stage where it can be industrialized.

As described above, as a result of the industrial reaction of acetone cyanohydrin with water in the liquid phase, α-
In order to produce hydroxyisobutyric acid amide, maintaining the activity of the manganese dioxide catalyst for a long time is the most important issue because the catalyst cost increases if the catalyst replacement becomes frequent due to deterioration or deactivation of the manganese dioxide catalyst. .

[0005]

The inventors of the present invention have completed the present invention as a result of extensive studies to solve the above problems. That is, the present invention adsorbs a vanadium compound on the surface of α-type manganese dioxide during the production of α-hydroxyisobutyric acid amide by reacting acetone cyanohydrin (hereinafter abbreviated as ACH) with water in a liquid phase. It is characterized by reacting the vanadium compound in the presence of α-manganese dioxide adsorbed on the surface of the vanadium compound in the atomic ratio of vanadium element to manganese element of 0.001 to 0.04, which was prepared by a method without treatment with alkali after adsorption. Α-hydroxyisobutyric acid amide (hereinafter, H
Abbreviated as AM. ) Is a manufacturing method.

In the present invention, the adsorption amount of the vanadium compound is the atomic ratio of vanadium element to manganese element,
It is preferably 0.002 to 0.03. Further, in the present invention, α-type manganese dioxide having a vanadium compound adsorbed on its surface has an atomic ratio of 0.005 to 0.06 to the manganese element, or an atomic ratio to the manganese element.
It is preferably α-type manganese dioxide containing 0.005 to 0.06 of an alkaline earth metal element.

The inventors of the present invention first investigated the state of manganese dioxide, which was used when HAM was produced by reacting ACH with water in a liquid phase and whose activity was lowered, by instrumental analysis. It was found that it was in the state of manganese oxide. As a solution to this, for example, U.S. Pat.
There is some improvement in catalyst life using the method of uniformly adding the second component to the entire manganese dioxide using the co-precipitation method as disclosed in 256 and EP 461,850. Therefore, manganese dioxide uniformly containing vanadium element as the second component was prepared according to the method disclosed in U.S. Pat. No. 4,987,256, and ACH and water were reacted using a suspension bed flow reactor to produce HAM industry. As a result of studying a dynamic continuous production method, it was found that the catalytic activity decreased with time and did not have satisfactory performance as a practical catalyst. It has been found that the reason is that the addition of the V element as the second component during the preparation of manganese dioxide does not result in α-type manganese dioxide having a crystal structure that is originally effective for the reaction between ACH and water. By the way, when HAM is produced by reacting ACH with water in a liquid phase using a manganese dioxide catalyst, the change in the state of the used catalyst to manganese oxide hydroxide is caused by the manganese dioxide exposed to the reaction solution. Since it is considered that the surface of the manganese dioxide progresses from the surface, it was thought that the surface of manganese dioxide should be modified to prevent it. The present inventors have solved this problem by adsorbing a vanadium compound on the surface of manganese dioxide, and developed a catalyst that can be used for a long period of time while maintaining the crystalline structure of α-manganese dioxide that is originally effective. Came to do. At that time, as a method of adsorbing a vanadium compound on the surface of manganese dioxide, it was found that neutralization with an alkali after the adsorption would not be effective due to a decrease in the degree of dispersion of vanadium on the surface of manganese dioxide. It has been found that the adsorption method without summation is optimal.

In the present invention, vanadium compounds to be adsorbed on the surface of α-type manganese dioxide are sodium metavanadate, potassium metavanadate, ammonium metavanadate, vanadates typified by sodium orthovanadate, vanadyl sulfate, vanadyl phosphate, Vanadyl oxalate, vanadyl chloride, vanadyl bromide, vanadyl halides typified by vanadyl fluoride, vanadyl oxalate typified by vanadyl ammonium oxalate, vanadyl typified by vanadyl acetylacetonate-β-
Examples include diketone and vanadyl methoxide, vanadyl ethoxide, vanadyl-n-propoxide, vanadyl isoproxide, vanadyl alkoxide represented by vanadyl-n-butoxide, and the like. The amount of vanadium compound adsorbed on the surface of α-type manganese dioxide is such that the atomic ratio of vanadium element to manganese element is 0.001 to 0.04. If the atomic ratio is lower than 0.001, the amount on the α-type manganese dioxide surface is too small to show a sufficient effect.
When it is higher than 4, the amount on the surface of α-type manganese dioxide is too large to prevent the expression of the activity. Preferably 0.002-
It is 0.03.

Adsorption on the surface of α-type manganese dioxide in the present invention does not need to use a special method. For example, a solution of a vanadium compound to be adsorbed, an α-type manganese dioxide powder, or an α-type manganese dioxide is used as a solvent. A method of mixing the dispersed slurries is used. The temperature at the time of mixing may be room temperature or heating, but if it is 10 ° to 90 ° C, the operation becomes easy. The α-type manganese dioxide having the vanadium compound adsorbed therein can be sufficiently used in the present invention even if it contains the solvent used, but the solvent used is AC.
When the reaction between H and water is adversely affected, the α-manganese dioxide after the adsorption can be dried to remove the solvent.

The α-type manganese dioxide used in the present invention is
It may be either anhydrous or hydrated. The α-type manganese dioxide catalyst is a known method, for example, a method of reacting manganese sulfate and potassium permanganate in an acidic manner (Biochem.
J., 50 , p. 43 (1951), JP-A-3-68447, and JP-A-3-68447.
4-46145), a method of reducing a 7-valent manganese salt with hydrohalic acid (JP-A-63-57535), a method of electrolytically oxidizing an aqueous solution of manganese sulfate, and the like. In particular, α-manganese dioxide obtained by the reaction of permanganate and manganese sulfate under acid is preferable, and further, in order to wash or remove the mineral acid used for acidification, neutralization with ammonia water or the like and You may wash. The permanganate used is, for example, potassium permanganate, sodium permanganate, barium permanganate and strontium permanganate, and depending on the type of permanganate used, α-type dioxide containing an alkali metal element. Α-type manganese dioxide containing manganese or an alkaline earth metal element can be prepared. At this time, the content of the alkali metal element or the alkaline earth metal element is preferably washed with water so that the atomic ratio to the manganese element is 0.005 to 0.06, and more preferably 0.01 to 0.05.

The reactor used in the present invention includes a fixed bed flow type reactor and a suspension bed flow type reactor. When the catalyst of the present invention is packed in a fixed bed reactor, it is usually preferable to mold it into a spherical shape or a columnar shape, and it is preferable to mold it into a representative length of 2 to 10 mm. When used in a suspension bed reactor, powder of 16 to 400 mesh is usually preferable. In the suspension bed reactor, the amount of catalyst used is usually such that the catalyst concentration in the reactor is 0.
It is from 01 to 50% by weight, more preferably from 0.1 to 30% by weight. The reactor used in the present invention is preferably a suspension bed flow reactor.

The ACH of the present invention and water are reacted in the liquid phase to produce H
The water used for producing AM is usually 1 mol or more, preferably 5 to 30 mol, per 1 mol of the nitrile compound. Water is usually used as the reaction solvent, but a new solvent inert to the reaction can be used. For example,
Acetone and the like disclosed in JP-A-52-222 are preferably used. The amount of acetone is 0.
It is preferably used in the range of 1 to 3.0 mol.

The reaction temperature in the present invention is in the range of 0 ° to 200 ° C, preferably 30 ° to 150 ° C. If it is lower than 0 ° C, sufficient activity cannot be obtained, and if it is higher than 200 ° C, a side reaction proceeds, which is not preferable. The reaction pressure may be any of reduced pressure, atmospheric pressure or increased pressure as long as it is a pressure sufficient to maintain the liquid phase of the reaction product at the reaction temperature. When a fixed bed flow type reactor is used, the liquid hourly space velocity is usually 0.01 to 40 Hr ^-1 , preferably 0.1 to 20 Hr ^-1 . When a suspension bed flow type reactor is used, the residence time is usually 0.1 to 50 Hr, preferably 0.5 to 30 Hr.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples. Preparation of ACH A glass round-bottomed flask reactor with an internal capacity of 2 liters equipped with a reflux condenser, stirrer, thermometer and liquid introducing section was charged with 580 g of acetone and 10 g of 2% sodium hydroxide aqueous solution, and liquid was maintained at 20 ° C. 284 g of hydrocyanic acid was injected. After the reaction, sulfuric acid was added to adjust the pH of the solution to 3.5. Next, unreacted hydrocyanic acid and acetone were distilled off under reduced pressure to obtain 843 g of 99.8% pure ACH.

Preparation of α-type manganese dioxide (A) Sulfuric acid was added to 2 l of an aqueous manganese sulfate solution (concentration: 395 g / l) to prepare an aqueous manganese sulfate solution having a pH of 1. After adding 557 g of potassium permanganate to this solution and oxidizing it, 1 liter of water was added to this slurry while maintaining the temperature at around 55 ° C.
Was added and aged for 5 hours. The resulting slurry was suction filtered with an aspirator, washed 5 times with 1 l of water, and then dried with a drier at 110 ° C. for 15 hours to obtain 600 g of manganese dioxide. Crush this manganese dioxide to 16-10
520 g was obtained as a 0 mesh pulverized product. The crystal structure of the obtained manganese dioxide was α-type as shown in the powder X-ray diffraction pattern of FIG. Further, when the amount of potassium element contained in the α-type manganese dioxide was analyzed, the atomic ratio to the manganese element was 0.05.

Preparation of α-type manganese dioxide (B) The manganese dioxide before drying obtained above was dispersed in 1 liter of water, and aqueous ammonia was added until the pH reached 7.
The slurry is suction filtered with an aspirator and
After washing 5 times with 1 l of water, it was dried at 110 ° C. for 15 hours in a dryer. The crystal structure of the obtained manganese dioxide was α type, and when the amount of potassium element contained in this α type manganese dioxide was analyzed, the atomic ratio to the manganese element was 0.02.

Example 1 Ammonium metavanadate (0.22 g) was added to 160 g of water, and the mixture was heated to 60 ° C. and dissolved. 20 g of α-manganese dioxide (A) prepared as described above was dispersed in this,
After stirring at 24 ° C. for 24 hours, the mixture was suction-filtered with an aspirator and dried at 110 ° C. for 15 hours with a drier to prepare a catalyst having a vanadium compound adsorbed on the α-type manganese dioxide surface. The crystal structure of manganese dioxide of the obtained catalyst was α-type as shown in the powder X-ray diffraction pattern of FIG. The atomic ratio of vanadium element and potassium element to manganese element in this catalyst was 0.008 each.
And 0.05.

Next, a vanadium compound prepared as described above was placed in a glass round bottom flask reactor having an inner volume of 0.5 l equipped with a glass stirring rod, a thermometer, a raw material supply port and a liquid outlet with a glass ball filter. After 10 g of the catalyst adsorbed on the α-manganese dioxide surface and 300 g of water were charged,
The internal temperature was raised to 60 ° C and kept at this temperature. Next, 36 ml / mL of the raw material liquid (ACH: acetone: water molar ratio 1: 1.5: 18) consisting of ACH, acetone and water prepared as described above
It was continuously supplied by a metering pump at a flow rate of hr. A continuous reaction was carried out for 90 days while maintaining the temperature in the reactor at 58 ° to 62 ° C. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Example 2 Instead of ammonium metavanadate, vanadyl sulfate
A catalyst was prepared in the same manner as in Example 1 except that 0.265 g was adsorbed. The crystal structure of manganese dioxide in the obtained catalyst was α type, and the atomic ratio of vanadium element and potassium element to manganese element was determined. Are each
It was 0.007 and 0.05. Then, using this catalyst,
A liquid-phase continuous reaction of ACH and water was carried out in the same manner as in Example 1. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Example 3 Instead of ammonium metavanadate, vanadyl sulfate was used.
A catalyst was prepared in the same manner as in Example 1 except that 0.77 g was adsorbed. The crystal structure of manganese dioxide in the obtained catalyst was α type, and the atomic ratio of vanadium element and potassium element to manganese element was determined. Are each
It was 0.02 and 0.05. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Comparative Example 1 Using the α-type manganese dioxide (A) catalyst prepared as described above, a liquid phase continuous reaction of ACH and water was carried out in the same manner as in Example 1. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Comparative Example 2 Sulfuric acid was added to 2 l of an aqueous manganese sulfate solution (concentration: 395 g / l) to prepare an aqueous manganese sulfate solution having a pH of 1, and 40.1 g of ammonium metavanadate was dissolved in this solution. Next, after adding 557 g of potassium permanganate to oxidize, 1 l of water was added to this slurry while maintaining the temperature at around 55 ° C.
Was added and aged for 5 hours. The resulting slurry was suction filtered with an aspirator, washed 5 times with 1 L of water, and then dried with a drier at 110 ° C. for 15 hours to obtain 595 g of vanadium-containing manganese dioxide. This was pulverized to obtain a catalyst of 16-100 mesh pulverized product.

The crystal structure of manganese dioxide of the obtained catalyst was not α-type as shown in the powder X-ray diffraction pattern of FIG. Further, the atomic ratio of vanadium element and potassium element to manganese element of this catalyst was 0.
It was 05 and 0.05. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Comparative Example 3 A solution of 265.6 g of potassium permanganate dissolved in 2.3 l of water was added to an aqueous solution of manganese sulfate (containing 213.5 g of manganese sulfate) 55.
A liquid obtained by mixing 4.8 g, vanadyl sulfate 8.8 g, sulfuric acid 95.6 g, and water 80 g was rapidly added at a temperature of 70 ° C. The resulting slurry was aged at 90 ° C for 3 hours, suction-filtered with an aspirator, washed 4 times with 1 liter of water, and then dried at 110 ° C for 15 hours by a drier to obtain vanadium-containing dioxide. 270 g of manganese was obtained. This was pulverized to obtain a catalyst of 16-100 mesh pulverized product. The crystal structure of manganese dioxide of the obtained catalyst was not α-type as shown in the powder X-ray diffraction pattern of FIG. The atomic ratios of vanadium element and potassium element to manganese element of this catalyst were 0.02 and 0.09, respectively.
Next, using this catalyst, AC was conducted in the same manner as in Example 1.
A liquid phase continuous reaction of H and water was performed. Table 1 shows the daily change of the HAM yield in the obtained HAM-producing solution and the productivity of the catalyst.

Comparative Example 4 Manganese dioxide was prepared in the same manner as in Comparative Example 3 except that vanadyl sulfate was not mixed. Then vanadyl sulfate
2.27 g was added to 160 g water and heated to 60 ° C. to dissolve. 20 g of the manganese dioxide prepared as described above was dispersed in this, stirred at 60 ° C for 24 hours, suction filtered with an aspirator, and dried at 110 ° C for 15 hours with a dryer to obtain a catalyst with a vanadium compound adsorbed on the surface. Was prepared. The crystal structure of the obtained catalyst manganese dioxide is shown in FIG.
It was α type as shown in the powder X-ray diffraction pattern.
The atomic ratios of vanadium element and potassium element to manganese element of this catalyst were 0.06 and 0.09, respectively.
Met. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Obtained H
Table 1 shows the daily change of the HAM yield in the AM product solution and the productivity of the catalyst.

Examples 4 to 5 Instead of 0.22 g of ammonium metavanadate, 0.109 g of ammonium metavanadate or 0.1 of vanadyl sulfate.
By the same method as in Example 1 except that 52 g was adsorbed,
A catalyst was prepared by adsorbing a vanadium compound on the surface of α-type manganese dioxide. Then, using these catalysts, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Atomic ratio of vanadium element and potassium element to manganese element of catalyst, HA in the obtained HAM product liquid
Table 2 shows the change in M yield over time and the productivity of the catalyst.

Example 6 A surface of α-type manganese dioxide was prepared in the same manner as in Example 1 except that 0.185 g of vanadyl acetylacetonate was adsorbed on a catalyst in a toluene solvent and the catalyst after adsorption was washed with toluene. A catalyst having a vanadium compound adsorbed on was prepared. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Table 2 shows the atomic ratios of vanadium element and potassium element to the manganese element of the catalyst, the change with time of HAM yield in the obtained HAM production liquid, and the productivity of the catalyst.

Comparative Example 5 Instead of ammonium metavanadate, vanadyl sulfate was used.
A catalyst was prepared in the same manner as in Comparative Example 2 except that 4.47 g was added. The crystal structure of manganese dioxide of the obtained catalyst was not α type. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Atomic ratio of vanadium element and potassium element to manganese element of catalyst, HA in the obtained HAM product liquid
Table 2 shows the change in M yield over time and the productivity of the catalyst.

Example 7 Manganese sulfate aqueous solution having pH = 1 was prepared by adding sulfuric acid to 2 l of manganese sulfate aqueous solution (concentration: 395 g / l). After adding 500 g of sodium permanganate to this solution and oxidizing it, 1 liter of water was added to this slurry while maintaining the temperature at around 55 ° C.
Was added and aged for 5 hours. The resulting slurry was suction filtered with an aspirator and washed 5 times with 1 l of water. This was dispersed in 1 liter of water, and aqueous ammonia was added until the pH reached 7. The slurry was suction filtered with an aspirator, washed 5 times with 1 liter of water, and then dried with a drier at 110 ° C. for 15 hours.
I got 0g. This was pulverized to obtain a catalyst of 16-100 mesh pulverized product. The crystal structure of manganese dioxide of the obtained catalyst was α type. Next, 0.255 g of sodium metavanadate
Was added to 160 g of water and heated to 60 ° C. to dissolve it. 20 g of α-type manganese dioxide prepared as described above was dispersed in this, stirred at 60 ° C for 24 hours, suction-filtered with an aspirator, and dried at 110 ° C for 15 hours with a drier to convert the vanadium compound to α-type. A catalyst adsorbed on the surface of manganese dioxide was prepared. Using this catalyst, a liquid phase continuous reaction of ACH and water was carried out in the same manner as in Example 1. Table 3 shows the atomic ratio of vanadium element and potassium element to the manganese element of the catalyst, the change with time of HAM yield in the obtained HAM production liquid, and the productivity of the catalyst.

Examples 8-9 Instead of 0.22 g ammonium metavanadate 0.20 g ammonium metavanadate or vanadyl sulphate 0.75
A catalyst in which a vanadium compound was adsorbed on the surface of α-type manganese dioxide was prepared in the same manner as in Example 1 except that 6 g was adsorbed on α-type manganese dioxide (B). Next, in the same manner as in Example 1 using these catalysts, A
A liquid phase continuous reaction of CH and water was performed. Atomic ratio of vanadium element and potassium element to manganese element of the catalyst,
Table 3 shows the daily change of the HAM yield in the obtained HAM product solution and the productivity of the catalyst.

Comparative Example 6 Manganese sulfate aqueous solution (pH = 1) was prepared by adding sulfuric acid to 2 l of manganese sulfate aqueous solution (concentration: 395 g / l), and 22.2 g of vanadyl sulfate was dissolved in this solution. Next, after adding and oxidizing 557 g of potassium permanganate, 1 liter of water was added to this slurry while maintaining the temperature at around 55 ° C., and aged for 5 hours. The resulting slurry was suction filtered with an aspirator and washed 5 times with 1 l of water. This was dispersed in 1 liter of water, and aqueous ammonia was added until the pH reached 7.
The slurry is suction filtered with an aspirator and
After washing 5 times with 1 l of water, dry it at 110 ° C for 15
Manganese dioxide containing vanadium after drying for 59 hours
I got 0g. This was pulverized to obtain a catalyst of 16-100 mesh pulverized product. The crystal structure of manganese dioxide of the obtained catalyst was not α type. Next, using this catalyst, Example 1
A liquid-phase continuous reaction of ACH and water was carried out in the same manner as in. Table 3 shows the atomic ratio of vanadium element and potassium element to the manganese element of the catalyst, the change with time of HAM yield in the obtained HAM production liquid, and the productivity of the catalyst.

Examples 10-11 Instead of 0.22 g ammonium metavanadate, 0.109 g ammonium metavanadate or 0.1 g vanadyl sulfate.
A catalyst having a vanadium compound adsorbed on the surface of α-type manganese dioxide was prepared in the same manner as in Example 1 except that 14 g of α-type manganese dioxide (B) was adsorbed. Next, in the same manner as in Example 1 using these catalysts, A
A liquid phase continuous reaction of CH and water was performed. Atomic ratio of vanadium element and potassium element to manganese element of the catalyst,
Table 4 shows the change over time in the HAM yield and the productivity of the catalyst in the obtained HAM product solution.

Comparative Example 7 Instead of 22.2 g of vanadyl sulfate, 4.43 g of vanadyl sulfate
A catalyst was prepared in the same manner as in Comparative Example 6 except that was added. The crystal structure of the obtained catalyst manganese dioxide is α
It was not a mold. Next, using this catalyst, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Table 4 shows the atomic ratios of vanadium element and potassium element to the manganese element of the catalyst, the change with time of HAM yield in the obtained HAM production liquid, and the productivity of the catalyst.

Example 12 Manganese sulfate aqueous solution having pH = 1 was prepared by adding sulfuric acid to 2 l of manganese sulfate aqueous solution (concentration: 395 g / l). After adding 662 g of barium permanganate to this solution and oxidizing it,
While maintaining the temperature at around 55 ° C., 1 liter of water was added to this slurry and aged for 5 hours. The resulting slurry was suction filtered with an aspirator and washed 5 times with 1 l of water. This was dispersed in 1 liter of water, and aqueous ammonia was added until the pH reached 7. The slurry was suction filtered with an aspirator, washed 5 times with 1 l of water, and then dried with a drier at 110 ° C. for 15 hours to obtain 590 g of manganese dioxide. This was pulverized to obtain a catalyst of 16-100 mesh pulverized product. The crystal structure of manganese dioxide of the obtained catalyst was α type.

Next, 0.109 g of ammonium metavanadate
Was added to 160 g of water and heated to 60 ° C. to dissolve it. 20 g of α-type manganese dioxide prepared as described above was dispersed in this, stirred at 60 ° C for 24 hours, suction-filtered with an aspirator, and dried at 110 ° C for 15 hours with a drier to convert the vanadium compound to α-type. A catalyst adsorbed on the surface of manganese dioxide was prepared. Using this catalyst, a liquid phase continuous reaction of ACH and water was carried out in the same manner as in Example 1. Table 5 shows the atomic ratios of vanadium element and barium element to the manganese element of the catalyst, the change with time of HAM yield in the obtained HAM production liquid, and the productivity of the catalyst.

Examples 13-14 Instead of 662 g barium permanganate, 575 g strontium permanganate or magnesium permanganate 46
A catalyst in which a vanadium compound was adsorbed on the surface of α-type manganese dioxide was prepared in the same manner as in Example 12 except that 3 g was added and oxidation was performed. Then, using these catalysts, a liquid phase continuous reaction of ACH and water was performed in the same manner as in Example 1. Atomic ratio of vanadium element and alkaline earth metal element to manganese element of catalyst, HAM obtained
Table 5 shows the daily change of the HAM yield in the product solution and the productivity of the catalyst.

[0037]

[Table 1] * 1: HAM production per unit amount of catalyst (g-HAM / g-ca
talyst)

[0038]

[Table 2] * 1: HAM production per unit amount of catalyst (g-HAM / g-ca
talyst)

[0039]

[Table 3] * 1: HAM production per unit amount of catalyst (g-HAM / g-ca
talyst)

[0040]

[Table 4] * 1: HAM production per unit amount of catalyst (g-HAM / g-ca
talyst)

[0041]

[Table 5] * 1: HAM production per unit amount of catalyst (g-HAM / g-ca
talyst)

[0042]

According to the method of the present invention, the catalyst life of manganese dioxide used in the production of α-hydroxyisobutyric acid amide by reacting acetone cyanohydrin with water in a liquid phase is such that the vanadium compound is adsorbed. It is significantly improved by using α-type manganese dioxide, which is industrially advantageous in α-
Hydroxyisobutyric acid amide can be produced and is of great industrial value.

[Brief description of drawings]

FIG. 1 is a powder X-ray diffraction pattern of α-type manganese dioxide (A).

2 is a powder X-ray diffraction diagram in Example 1. FIG.

FIG. 3 is a powder X-ray diffraction diagram in Comparative Example 2.

4 is a powder X-ray diffraction diagram in Comparative Example 3. FIG.

5 is a powder X-ray diffraction diagram in Comparative Example 4. FIG.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadaaki Yamamoto 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (56) Reference JP-A-3-93761 (JP, A) JP-A-4 -282352 (JP, A) JP 4-46145 (JP, A) JP 6-340602 (JP, A) JP 5-170720 (JP, A) (58) Fields investigated (Int.Cl) . ⁷ , DB name) C07C 235/06 C07C 231/06 C07B 61/00 300

Claims (5)

(57) [Claims] 1. When a reaction of acetone cyanohydrin with water in a liquid phase to produce α-hydroxyisobutyric acid amide, a vanadium compound is adsorbed on the surface of α-type manganese dioxide and no treatment with alkali is carried out after the adsorption. A method for producing an α-hydroxyisobutyric acid amide, characterized by reacting a vanadium compound prepared by the method described above in the presence of α-type manganese dioxide adsorbed on the surface at an atomic ratio of vanadium element to manganese element of 0.001 to 0.04. . 2. The adsorption amount of vanadium compound is 0.002 to 0.03 in terms of atomic ratio of vanadium element to manganese element.
The manufacturing method according to claim 1, wherein 3. An α having a vanadium compound adsorbed on its surface
Type manganese dioxide in atomic ratio to elemental manganese
The method according to claim 1 or 2, which contains 0.005 to 0.06 of an alkali metal element. 4. An α having a vanadium compound adsorbed on its surface
Type manganese dioxide in atomic ratio to elemental manganese
3. The method according to claim 1, which contains 0.005 to 0.06 of an alkaline earth metal element. 5. The production method according to claim 1, 2, 3 or 4, wherein the reactor for reacting acetone cyanohydrin and water in a liquid phase is a suspension bed flow reactor.