JPS5950665B2 - Production method of unsaturated amide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention deals with the hydration of unsaturated nitriles to produce corresponding products, specifically, composite oxides containing titanium, zinc and nickel, composite oxides containing titanium, zinc and lanthanum, and titanium, cadmium. The present invention relates to a method for producing a corresponding unsaturated amide by reacting an unsaturated nitrile with water using any one kind of complex oxide selected from the group consisting of complex oxides containing lanthanum and lanthanum as a catalyst.

Various composite oxides have been proposed as catalysts for the catalytic hydration reaction of nitriles.

For example, in Japanese Patent Publication No. 48-23716, a composite oxide catalyst containing iron and zinc,
No. 39426 proposes a composite oxide catalyst containing nickel and chromium.

These known composite oxides have low activity and require a high temperature of 100°C or more or a reaction time of several hours to increase the reaction rate of nitrile, causing side reactions and reducing the yield of amide. It has the following drawback. The present inventors have conducted intensive research to solve the above problems and provide an industrially advantageous manufacturing method, and as a result, a composite oxide that combines titanium oxide and a specific metal oxide has been developed. was discovered to be a catalyst with excellent activity and selectivity.

That is, composite oxides containing titanium, zinc and nickel, composite oxides containing titanium, zinc and lanthanum, and composite oxides containing titanium, cadmium and lanthanum have high activity and selectivity in the hydration reaction of unsaturated nitriles. The present invention was completed based on this discovery.

The term "complex oxide" as used herein includes binary oxides, ternary oxides, quaternary oxides and higher multi-component oxides, as well as solid solutions and non-stoichiometric oxides.

This also includes physical mixtures of single oxides, such as titanium dioxide and zinc oxide. The term "oxide" is also defined to include those in an at least partially hydrated state. The composite oxide catalyst used in the present invention can be prepared in any convenient manner that can be adopted for preparing this type of catalyst.

As a preparation method, a precipitation method can be preferably employed. That is, solutions of two or more salts of the above-mentioned specific metals, such as sulfates, nitrates, oxyacids, halogenates, organic acid salts, etc., especially aqueous solutions, include aqueous ammonia, alkali hydroxides, alkali carbonates, organic amines as alkaline substances. A commonly used method is to add a solution, especially an aqueous solution, to form a precipitate of the corresponding metal hydroxide or hydrated oxide, and to sinter the resulting precipitate to an appropriate concentration. It is also possible to combine each metal in stages. For example, it is possible to first prepare an oxide and then add an alkali to an aqueous solution of a salt of another metal in its presence to precipitate a hydroxide or hydrous oxide. Methods that do not involve hydroxide or hydrous oxide precipitation include precipitation at a temperature sufficiently high for the oxide to form a mechanical mixture of one or more salts as described above. A method of obtaining the corresponding oxide by heating to thermal decomposition is also adopted. A mechanochemical method may be used, which consists of mixing the various oxides already obtained and sufficiently pulverizing the mixture using a ball mill or the like. In this case, it will be even better if you add water and perform ball milling in a wet state. Effective. The composite oxide catalyst thus obtained is preferably calcined at a high temperature to stabilize the catalyst structure.

The firing temperature in this case may be appropriately selected depending on the type of metal used or the combination thereof.

The firing temperature of the catalyst is particularly preferably in the range of 400°C to 600°C.

The heating atmosphere should generally avoid reducing properties. Such a composite oxide catalyst can be used by being supported on a carrier, as is commonly used for this type of catalyst.

Therefore, suitable supports such as silica, alumina, silica/alumina, diatomaceous earth, alundum, corundum, activated carbon, naturally occurring silicates, etc. can be supported on the metal compound at any stage of the catalyst preparation process described above. . The hydration reaction of nitrile according to the method of the present invention is usually carried out at a temperature of room temperature to 300°C using the above-mentioned catalyst.
From the viewpoint of increasing the reaction rate and suppressing side reactions, it is particularly preferable to carry out the reaction at a temperature of 40°C to 150°C. In the hydration reaction of nitrile, it is necessary that at least a stoichiometric amount of water to the nitrile be present in the reaction system. This water may be not only free water but also hydration water when the composite oxide catalyst is at least partially hydrated. Although the reaction can be carried out in either a gas phase or a liquid phase, it is usually carried out in a liquid phase. It is also possible to carry out the reaction under pressure. In order to inhibit polymerization during the reaction, suitable polymerization inhibitors such as hydroquinone, phenothiazine, P-
Tert-butylcatechol and the like can be added as necessary.

It is also possible to suppress polymerization by dissolving oxygen in the reaction feed solution. In carrying out the method of the present invention, a stable solvent that can withstand use at the reaction temperature can also be used together with water.

Solvents used in the present invention include alcohols, ketones, amides, sulfoxides, and specific examples include methanol, ethanol, isopropanol, acetone, dimethylformamide, dimethylsulfoxide, formamide, acetamide, and the like. Typical examples of unsaturated nitriles applicable to the present invention include acrylonitrile,
Methacrylonitrile, crotonitrile, β-phenylacrylonitrile, 2-cyano-2-butene, 1-
Examples include cyano-1-octene, 10-undecenonitrile, maleate nitrile, and fumarate nitrile.

The catalyst of the present invention has high activity and selectivity in the amidation reaction, and even if dissolved oxygen is contained in the reaction feed solution, the catalyst activity and selectivity are not adversely affected. The present invention provides an excellent method for producing unsaturated amides, which is both economical and economical.

Next, the present invention will be explained using Examples, but these Examples do not limit the present invention.

'Example 1 Titanium tetrachloride TiCl.

38Og, zinc nitrate Zn(NO,)2 ・6H201
4.9g, Ni nitrate (NO3)2 6H2
Dissolve 05.8 g in 31 water.

While stirring vigorously, add 28% ammonia water (Sml) to this.
Add until it reaches 7. The formed precipitate is filtered by suction and washed with a large amount of water. Dry at 110°C and bake in air at 500°C for 6 hours.

5 g of the catalyst prepared by the above method was crushed and placed in a 100 ml flask equipped with a Liebig condenser together with 23 g of a 6.8% (by weight) aqueous solution of acrylic resin, and heated under reflux for 5 hours with stirring under atmospheric pressure. (The reaction temperature is approximately 7
0℃).

After the reaction, the reaction mixture was filtered to remove the catalyst and analyzed by gas chromatography, and it was confirmed that 0.65 g of acrylamide (yield: 31.1 mol%) was contained in each filtrate.

No other by-products were detected. Comparative Examples 1 to 12 and Examples 2 to 4 Preparation 1 was carried out in the same manner as in Example 1 except that the catalyst components were changed.
A catalyst having the catalyst composition shown in Table 1 was prepared, and a catalytic reaction was carried out under the same reaction conditions as in Example 1.

The results were as shown in Table 1. In all cases, by-products were not detected or were present in very small amounts.
2 Comparative Example 13-1
8 A catalyst having the catalyst composition listed in Table 2 was prepared by the same method as in Example 1 except that the catalyst components were changed to two components, and Example 1
The catalytic reaction was carried out under the same reaction conditions.

The results were as shown in Table 2.

Claims (1)

[Claims] 1 Any type of composite oxide selected from the group consisting of a composite oxide containing titanium, zinc and nickel, a composite oxide containing titanium, zinc and lanthanum, and a composite oxide containing titanium, cadmium and lanthanum. A method for producing an unsaturated amide, which comprises reacting an unsaturated nitrile with water using as a catalyst.