JPH0770020A - Method for producing amide compound - Google Patents

Abstract

(57) [Summary] [Structure] A method for producing an amide compound by reacting a nitrile compound and water in a liquid phase, which is obtained by firing silica powder supporting a manganese compound in the presence of molecular oxygen. Manganese oxide-supporting silica powder is reacted with an aqueous solution of permanganate, and subsequently silica-supporting manganese dioxide produced by acid treatment of the silica powder is used as a catalyst. [Effect] The activity and life of the manganese oxide used for producing an amide compound by reacting a nitrile compound with water in a liquid phase are significantly improved, and the amide compound can be produced industrially advantageously.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an amide compound. More specifically, it relates to a method for producing an amide compound by reacting a nitrile compound and water in a liquid phase.

[0002]

2. Description of the Related Art It is known that a corresponding amide compound can be produced by reacting a nitrile compound with water. For example, α-hydroxyisobutyric acid amide produced by reacting acetone cyanohydrin with water. Is the paint,
It is useful as a precursor of methyl methacrylate, which is a raw material for adhesives and molding materials, and acrylamide produced by reacting acrylonitrile with water is also useful as a raw material for a flocculant, a petroleum recovery agent, 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. In contrast to the copper-containing catalysts frequently used in the reaction of nitrile compounds with water, which give completely unsatisfactory results in the reaction of α-hydroxynitrile compounds such as acetone cyanohydrin with water, manganese oxides are disclosed in US Pat. As disclosed in No. 3,366,639, it has a characteristic of giving a considerable result even to the reaction of α-hydroxynitrile compound with water.

As a method for preparing a manganese oxide for reacting a nitrile compound with water from a divalent manganese compound and permanganate, US Pat. No. 3,366,639 discloses manganese sulfate in the presence of a small excess of caustic soda. JP-A-3-68447 and JP-A-4-46145 propose a method of reacting an aqueous solution of manganese sulfate with potassium permanganate in an acidic manner. However, when manganese dioxide prepared by these methods is used as a suspension bed catalyst, there is a problem that the activity is remarkably reduced due to reduction of specific surface area and reduction due to crystal growth of manganese dioxide over the course of the reaction.
Further, the activity of manganese oxide prepared by these methods is not yet sufficient. As a method for extending the life of the manganese dioxide catalyst, it is disclosed in JP-A-2-196763 that the hydrogen ion concentration (pH) of the raw material liquid supplied to the reactor is set to the range of 4 to 8. EP-A-433,611 discloses the addition of an oxidizing agent to the raw material liquid. 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 another method to solve these problems by increasing the activation by increasing the surface area and suppressing the deterioration due to crystal growth and reduction, manganese dioxide having the same structure as that obtained by the chemical reaction method is added to the surface of the metal oxide support. A method of fixing the dispersion is conceivable.

However, the conventionally known method of producing a supported manganese dioxide by firing a supported divalent manganese salt compound with molecular oxygen does not sufficiently oxidize and the structure cannot be controlled, and the intended manganese dioxide is obtained. I couldn't do that. As a method for solving the problem that the oxidation is not sufficiently promoted by molecular oxygen, for example, in Synthesis 1988, 715, a conventional chemical reaction method is applied to reduce potassium permanganate impregnated in silica with manganese sulfate to obtain silica-supported dioxide. A method of preparing manganese is disclosed. The present inventors prepared silica-supported manganese dioxide according to the preparation method disclosed therein, and observed the structure and dispersion state thereof, and found that the manganese dioxide was mixed with silica powder rather than being fixedly supported on the silica surface. In this state, it was essentially bulk manganese dioxide. Further, its structure is different from that of manganese dioxide obtained by the chemical reaction method, and as described further, it has a high oxidative activity and is easily reduced, so that it has a low activity and is significantly deteriorated. Thus, high-purity manganese dioxide in a highly dispersed state could not be obtained, and manganese dioxide having satisfactory performance in practice could not be obtained even by the supporting method.

[0006]

As described above, in order to industrially react a nitrile compound and water in a liquid phase to produce an amide compound, catalyst replacement due to deterioration or deactivation of the manganese dioxide catalyst is frequently performed. Since the catalyst cost will increase, it is necessary to maintain the activity of the manganese dioxide catalyst for a long time.
The establishment of a method for producing a catalyst having activity that can be used on an industrial scale has become a major issue.

[0007]

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, in the method for producing an amide compound by reacting a nitrile compound and water in a liquid phase, the first step of firing silica powder carrying a manganese compound in the presence of molecular oxygen, obtained The reaction is carried out in the presence of silica-supported manganese dioxide produced by the method comprising the second step of reacting the manganese oxide-supporting silica powder with an aqueous solution of permanganate and the third step of acid-treating the silica powder. A method for producing a characteristic amide compound.

That is, the present inventors have made detailed investigations on the oxidation conditions of the manganese compound supported on silica and the phase change of the resulting silica-supported manganese dioxide. As a result, the silica-supported manganese compound was tested in the presence of molecular oxygen. Then, after firing, further oxidize with permanganate, and then further age phase change in acidic aqueous solution to fix manganese dioxide with the same structure as that obtained by the conventional chemical reaction method on the silica surface in a highly dispersed state And the activity of manganese dioxide supported on silica obtained in this way is higher than that of conventional manganese oxides which are active in the reaction of nitrile compounds and water, and produces amide compounds in high yield. It was found that the deterioration due to crystal growth and reduction was significantly suppressed, and the present invention was completed.

The manganese compounds used in the present invention are divalent manganese salt compounds such as manganese nitrate, manganese sulfate, manganese chloride, manganese carbonate, manganese phosphate and manganese acetate, and manganese carbonyl. Of course, the manganese salt compound may be used as an anhydrous salt or a hydrate, and two or more kinds of these manganese salts may be used in combination. Also,
The method for supporting a divalent manganese compound on silica is usually an impregnation method or an ion exchange method, and when manganese carbonyl is used, a gas phase adsorption method can also be used.

The molecular oxygen used when calcining the silica powder supporting the manganese compound of the present invention is oxygen diluted with any gas represented by oxygen or air, and calcining the silica supporting the manganese compound. Temperature is 150-500
C., more preferably 200 to 400.degree. Although any silica can be used as a carrier, for example, a gel obtained by extruding a gel of Aerosil silica, which is calcined at 200 to 600 ° C. for 1 to 20 hours, can be used. Permanganate used in the present invention is sodium permanganate, potassium permanganate, barium permanganate, etc., the concentration of their aqueous solution is usually
0.1 to 1.0 mol / l, and the amount used is based on the reaction formula (1)

[0011]

## STR1 ## 2MnO ₄ ^- a ----- (1) Normal 1.0-1.5 times the amount of computation that is calculated based on the ^{_{- + 3Mn 2 O 3 + H}} 2 O → 8MnO 2 + 2OH.

In the present invention, the oxidation temperature of the manganese oxide-supporting silica slurry by permanganate is usually 40 to 15
The temperature is 0 ° C, preferably 60 to 90 ° C. If the temperature is low, it may take a long time to oxidize, and the oxidization may not proceed sufficiently.
The oxidation time is 0.1 to 20 hours in the above temperature range, although it depends on the temperature. Examples of the acid used in the acid treatment of the present invention include sulfuric acid, nitric acid and hydrochloric acid. The pH of the acid-treated aqueous solution is 2 or less, preferably 1 or less. The acid treatment temperature is not particularly limited, but is preferably 50 to 90 ° C. Further, the aging time is usually 10 minutes to 48 hours, preferably 30
Minutes to 24 hours. In the present invention, the acid-treated manganese dioxide-supported silica is sufficiently usable for reacting a nitrile compound with water to produce an amide compound, but after filtering the acid-treated manganese dioxide-supported silica slurry, water is added again. In addition, a slurry may be neutralized with aqueous ammonia, filtered, washed with water, and dried.

The catalyst used in the present invention may be either a hydrous material or a dried material. The reactor used in the present invention is not particularly limited, but usually a fixed bed reactor or a suspension bed reactor is used. When the catalyst is packed in a fixed bed reactor, it is usually preferable to mold it into a spherical shape or a cylindrical shape, and it is preferable to mold it into a representative length of 2 to 10 mm. When used in a suspension bed tank reactor, a powder of 16 to 400 mesh is usually preferable. The amount of catalyst used is such that the catalyst concentration in the reactor is 0.01 ~
It is 50% by weight, more preferably 0.1 to 30% by weight.

The nitrile compound used for preparing the amide compound by reacting the nitrile compound of the present invention with water in a liquid phase is represented by the general formula R-CN (wherein R is alkyl, cycloalkyl, alkenyl, cycloalkenyl). , Aryl, alkaryl, aralkyl or heterocyclic,
Each of them may further have halogen, alkoxy, nitro, ester, ketone or hydroxyl group as a substituent,
Alternatively, it may not have. ). Polynitriles are also used in the present invention.

On the other hand, the water used in the present invention 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 when the nitrile compound is a hydrophobic substance, lower alcohols such as methyl alcohol and ethyl alcohol, and 1,4-dioxane are used in order to enhance the compatibility with water. , Ethers such as tetrahydrofuran, ketones such as acetone, dimethyl sulfoxide, N, N-dimethylamide,
N, N-dimethylacetamide, N-methylpyrrolidone and the like are used. In particular, when ketone cyanohydrin is used as the nitrile compound, in order to suppress the decomposition of the ketone cyanohydrin, the constituent ketone of the nitrile compound is added to the reaction solvent in an amount of 0.1 to 3.0 mol per mol of the nitrile compound. It is recommended to exist in the range of. For example, in the reaction of an α-hydroxynitrile compound such as acetone cyanohydrin, it is preferable to add acetone as a reaction solvent as disclosed in JP-A-52-222.

The amide compound is a nitrile compound RC
N (in the formula, R is an alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, alkaryl, aralkyl or heterocyclic group, each of which further has halogen, alkoxy, nitro, ester, ketone or hydroxyl group as a substituent. Which may or may not have a general formula RCO-
NH ₂ (wherein R is an alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, alkaryl, aralkyl or heterocyclic group, and is a substituent such as halogen, alkoxy, nitro, ester, ketone or hydroxyl group, respectively. May or may not be included.).

The reaction temperature 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. 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 using a fixed bed flow type reactor, the liquid hourly space velocity is usually 0.01 to 40 Hr ^-1 , preferably 0.1 to 20 Hr.
^-1 . When using a suspended bed flow reactor,
The residence time is 0.1 to 50 hours, preferably 0.5 to 30 hours.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 Preparation of Catalyst A silica (Aerosil 380, specific surface area 340 m ² / g (manufactured by Nippon Aerosil)) slurry was extruded and molded at 400 ° C. for 3 days.
Bake for hours. This is crushed (specific surface area 320 m ² /
g) To 150.0 g, 150 ml of a 1.2 mol / l manganese acetate aqueous solution was added at room temperature under reduced pressure of 40 mmHg, and the mixture was allowed to stand at room temperature under normal pressure for 1 hour and then evaporated to dryness at 40 ° C. and 40 mmHg. 110 ° C
After drying for 10 hours in air, it was calcined at 200 ° C. for 15 hours under air flow to prepare manganese oxide supported on silica. Continue this
The mixture was added to 150 ml of a 0.6 mol / l potassium permanganate aqueous solution and reacted at 80 ° C. for 15 hours. This is filtered, washed and re-watered.
180 ml was added to make a slurry and the pH of the solution was adjusted to 0.5 with sulfuric acid, followed by aging at 70 ° C for 1 hour. This was filtered once and water was added again to form a slurry, which was neutralized by adding aqueous ammonia, filtered, and dried at 110 ° C. for 10 hours. The supported amount and average valence of MnO ₂ were measured by a chemical analysis method, and were 11.6 wt% and 3.93, respectively. Hydration Reaction of Nitrile In a 500 ml glass round-bottomed flask reactor with a glass stirring bar, reflux condenser and thermometer, 35 g of supported manganese dioxide (4.0 g as manganese dioxide) and acetone were prepared. 300 g of a raw material consisting of cyanohydrin, acetone and water was added at a molar ratio of 1: 0.9: 11, and the mixture was reacted at 70 ° C. for 5 hours while stirring. When the catalyst was filtered off from the reaction solution and analyzed by high performance liquid chromatography, the conversion of acetone cyanohydrin was 97% and the selectivity of α-hydroxyisobutyric acid amide was 96%.

Example 2 A silica (Aerosil 380, specific surface area 340 m ² / g (manufactured by Nippon Aerosil)) slurry was extruded and molded at 400 ° C. for 3 days.
Bake for hours. This is crushed (specific surface area 320 m ² /
g) To leave 100g manganese carbonyl _{(Mn 2 (CO) 10)} 2 hours while stirring the 14g at room temperature to close the vacuum after valve mixed ^{10-2 2} torr in a valved glass flask. Then, the obtained powder was transferred to a quartz reaction tube, and the temperature was maintained at 200 ° C for 10
Oxidized over time to prepare silica-supported manganese oxide. This is followed by 100 ml of 0.36 mol / L potassium permanganate aqueous solution.
And was reacted at 90 ° C. for 12 hours. This is filtered, washed until the color of potassium permanganate is no longer observed in the filtrate, and 120 ml of water is added again to make a slurry.
The mixture was added until the pH reached 0.5 and then aged at 70 ° C for 30 minutes. This was filtered once and water was added again to make a slurry, which was neutralized by adding aqueous ammonia, filtered, and dried at 110 ° C. for 15 hours. The supported amount of MnO ₂ and the average valence thereof were measured by a chemical analysis method to be 7.1 wt% and 3.94, respectively. Next, using 56 g of this catalyst (4 g as manganese dioxide), the reaction between acetone cyanohydrin and water was carried out in the same manner as in Example 1. The conversion of acetone cyanohydrin is 96% and the selectivity of α-hydroxyisobutyric acid amide is 95%.
%Met.

Example 3 Silica-supported manganese dioxide was prepared in the same manner as in Example 1 except that sodium permanganate was used as the permanganate. The supported amount and average valence of MnO ₂ were measured by a chemical analysis method, and found to be 12.1 wt% and 3.95, respectively.
Met. Hydration Reaction of Nitrile Next, 33 g of this catalyst (4 g as manganese dioxide) was used to carry out a reaction of acetone cyanohydrin and water in the same manner as in Example 1. The conversion rate of acetone cyanohydrin is
The selectivity of α-hydroxyisobutyric acid amide was 94% and that of 97%.

Comparative Example 1 Except that no aging phase change was performed using an aqueous sulfuric acid solution,
Silica-supported manganese dioxide was prepared in the same manner as in Example 1. Next, 35 g of this catalyst (4 as manganese dioxide)
g) was used to react acetone cyanohydrin with water in the same manner as in Example 1. The conversion of acetone cyanohydrin was 32% and the selectivity of α-hydroxyisobutyric acid amide was 78%.

Comparative Example 2 Manganese sulfate aqueous solution having pH = 1 was prepared by adding sulfuric acid to 1 liter of manganese sulfate aqueous solution (concentration 395 g / L). After 279 g of potassium permanganate was added to this solution for oxidation, 0.5 l of water was added to this slurry while maintaining the temperature at around 55 ° C., and the mixture was aged for 5 hours. The resulting slurry is suction filtered with an aspirator and washed 5 times with 1 l of water,
Manganese dioxide dried at 110 ° C for 15 hours in a dryer
I got 300g. Next, using 4 g of this catalyst, the reaction of acetone cyanohydrin and water was carried out in the same manner as in Example 1. The conversion of acetone cyanohydrin was 87% and the selectivity of α-hydroxyisobutyric acid amide was 85%.

Example 4 A glass round bottom flask reactor having an inner volume of 200 ml equipped with a glass stir bar, a reflux condenser and a thermometer, had 35 g of supported manganese dioxide prepared in Example 1 (4 g as manganese dioxide) and acrylonitrile. And a raw material consisting of water 1: 3
73 g was added at a molar ratio of 9, and the mixture was reacted at 70 ° C. for 5 hours while stirring. When the catalyst was filtered off from the reaction solution and analyzed by high performance liquid chromatography, the conversion rate of acrylonitrile was 75.
%, The selectivity of acrylamide was 82%.

Comparative Example 3 35 g of the catalyst prepared in Comparative Example 1 (as manganese dioxide 4
g) was used to react acrylonitrile with water in the same manner as in Example 4. Acrylonitrile conversion is 15
%, The selectivity of acrylamide was 67%. Comparative Example 4 Using 4 g of the catalyst prepared in Comparative Example 2, acrylonitrile and water were reacted in the same manner as in Example 4. Acrylonitrile conversion is 20%, acrylamide selectivity is
It was 70%. Example 5 A glass-made round-bottomed flask reactor having an internal capacity of 500 ml equipped with a glass stirring rod, a thermometer, a raw material supply port, and a liquid outlet equipped with a glass ball filter was placed in a glass-bottomed flask reactor made of Example 1 (86 g of supported manganese dioxide). As 10g) and water 300g
After charging, the internal temperature was raised to 60 ° C. and kept at this temperature. Next, a raw material solution consisting of acetone cyanohydrin, acetone and water (acetone cyanohydrin: acetone: water molar ratio 1: 1.2: 15) was continuously supplied by a metering pump at a flow rate of 34 ml / hr. While maintaining the temperature in the reactor at 58 ° to 62 ° C, continuous reaction was carried out for 30 days. Table 1 shows the change with time of the yield of α-hydroxyisobutyric acid amide in the resulting α-hydroxyisobutyric acid amide production liquid.

Comparative Example 5 86 g of the catalyst prepared in Comparative Example 1 (as manganese dioxide 10
g) was used to carry out a continuous reaction with acetone cyanohydrin and water in the same manner as in Example 5. Table 1 shows the change with time of the yield of α-hydroxyisobutyric acid amide in the resulting α-hydroxyisobutyric acid amide production liquid.

Comparative Example 6 Acetone cyanohydrin and water were continuously reacted in the same manner as in Example 5 using 10 g of the catalyst prepared in Comparative Example 2. Table 1 shows the change with time of the yield of α-hydroxyisobutyric acid amide in the resulting α-hydroxyisobutyric acid amide production liquid.

[0027]

[Table 1]

[0028]

INDUSTRIAL APPLICABILITY According to the present invention, the activity and life of the manganese oxide used when the nitrile compound and water are reacted in the liquid phase to produce the amide compound are such that the silica powder supporting the manganese compound has a molecular oxygen content. Calcination in the presence of, and reacting the resulting manganese oxide-supporting silica powder with an aqueous solution of permanganate, using silica-supported manganese dioxide produced by acid treatment of this silica powder greatly improves In addition, the amide compound can be produced industrially advantageously, and is extremely valuable in the industry.

(72) Inventor Keiichi Ikeda 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Masahiro Tokuman 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chem., Ltd.

Claims (1)

[Claims] 1. A method for producing an amide compound by reacting a nitrile compound and water in a liquid phase, the first step of calcining a silica powder carrying a manganese compound in the presence of molecular oxygen, the resulting oxidation. Characterized by reacting manganese-supported silica powder in the presence of silica-supported manganese dioxide produced by a method comprising a second step of reacting an aqueous solution of permanganate and a third step of treating the silica powder with an acid. And a method for producing an amide compound.