KR790000923B1 - Process for producing amid compounds - Google Patents

Abstract

Amides as methacrylamide, nicotinic acid amide, benzamide, propionic acid amide, were prepd. at high conversion rate from nitrile compounds (I; R = alkyl, substituted alkyl, alkenyl, cycloalkyl, aralkyl, aryl, substituted aryl, n = 1,2 ..) by treating with H20 in the presence of active Cu catalysts contg. Na, Ca, Zn or Fe nitrates except Cu(NO3)2 as promoter.

Description

Preparation of Amide Compound

The present invention relates to a method of hydrating a nitrile compound such as acrylonitrile and producing an amide compound such as acrylamide under a metal copper catalyst, which is disclosed in US Patent No. 3,631,104, Known by Belgian patent no. The catalyst used in such a method is a reduction catalyst obtained by various reduction methods, or a large metal copper catalyst having a relatively catalytic surface area such as lane copper and ulman copper.

Although the above-mentioned metal copper catalyst is effective as a hydration catalyst for the amide compound of the nitrile compound, it is required to further improve the catalytic effect on the industrial production scale. In view of the above, the present applicant is a method for improving the conversion rate to an amide compound by a metal copper catalyst, and a copper copper salt of an inorganic acid such as copper nitrate or a copper salt of fatty acid such as copper acetate is used as a metal copper catalyst. Although a method of coexisting as an activator of the above is provided, this is already known as Belgian Patent No.

The method of coexisting an copper salt of an inorganic acid or a copper salt of a fatty acid with the above-mentioned metal copper catalyst as an active adjuvant improves the conversion rate which becomes an amide compound with respect to 50% of non-coexistence like 70% in coexistence, but is industrial manufacture. On the scale, it was necessary to find an active agent that could maintain a longer catalyst life.

It is an object of the present invention to provide a catalyst system useful for a method of hydrating a nitrile compound to produce a corresponding amide compound. Another object of the present invention is to provide a novel activator capable of accelerating the hydration reaction rate of the nitrile compound and maintaining the long catalyst life of the metal copper catalyst, thereby improving the economics of the present invention process.

According to the method of the present invention, nitrile compounds such as acrylonitrile, methacrylonitrile, nicotinonitrile, benzonitrile, propionitrile, and the like may be prepared from metal copper catalysts such as lane copper, reduced copper, woolman copper, and copper powder. Nitrile compounds of activators consisting of nitrates combined with cations such as ammonium, sodium, calcium, zinc, iron, etc., except copper nitrate, as a ratio of the basis weight of nitrogen to the total amount of water, 1-600 ppm better, the presence of actives in the range of 3-200 ppm By reacting with water, the catalyst life is not lowered, and amide compounds such as acrylamide, methacrylamide, nicotinic acid amide, benzamide, and propionate amide can be produced in high yield.

The nitrate useful as the active agent of the present invention is not particularly limited except for copper nitrate, but the cations corresponding to nitrate are ammonium, sodium, potassium, magnesium, calcium, zinc, aluminum, manganese, iron, cobalt, nickel, and the like. Of these, ammonium, sodium, calcium, zinc and iron are commonly used. As such a method of adding nitrate to the reaction system, there are a method of dissolving in raw water or raw nickel, and a method of dissolving in a small amount of water and injecting it into a reactor or a circulation system of the reaction liquid. The amount of such nitrate added is in the range of 1-600 ppm when expressed as the ratio of the amount of nitric acid to the total amount of nitrile compound and water. If the addition amount is less than the above 1 ppm range, the effect is not sufficient, and if it exceeds the 600 ppm range, the temporary catalytic activity can be temporarily improved, but the catalyst activity is remarkably lower than the case where no active aid is added. . As can be understood from the above fact, in order to expect sufficient maintenance of the catalyst life of the present invention, it is preferable to adjust the amount of nitrate in a preferable range of 3-200 ppm as the ratio of the amount of nitrate relative to the total amount of nitrile compound and water. desirable. The metal copper catalyst used for the method of this invention uses metal copper substantially as a catalyst active ingredient, For example, the following are used.

(1) Micro copper strips, such as copper powder and copper wire, made from metal ingots.

(2) A reducing agent obtained by reducing copper compounds such as copper oxide, copper hydroxide and copper salt to 100-500 ° C. with hydrogen or carbon monoxide.

(3) Reduction copper obtained by reducing copper compounds such as copper oxide, copper hydroxide, copper salt, etc. with borides such as hydrazine or sodium hydride in the liquid phase.

(4) Reduction copper obtained by treating copper compounds such as copper oxide, copper hydroxide, and copper salts in metals with a greater tendency to ionize than copper, such as zinc, aluminum, iron, or tin.

(5) Rane copper obtained by developing a Rane alloy made of aluminum, zinc or magnesium and copper.

(6) Copper obtained by thermal decomposition of copper compounds such as formic acid copper and copper hydroxide in the temperature range of, for example, 100-400 ° C.

(7) When preparing the above-mentioned metal copper catalyst, for example, plural catalysts or carrier adhesion catalysts obtained by coexisting carriers commonly used in the preparation of metals or catalysts such as chromium, zinc, nickel, manganese, molybdenum, and the like.

Even if these catalysts are different from each other, there is no significant difference in the strength of the activity and the selectivity of the reaction. When performing the hydration reaction of acrylonitrile under the usual reaction conditions described below using these catalysts prepared in high purity, The selectivity is 97% or more, and the selectivity of ethylene cyan hydrin is 2% or less.

The amount of metal copper catalyst usually used in the process of the present invention is, for example, when the reaction is carried out in the suspended phase of the metal copper catalyst, the amount of nitrile compound is in the range of 0.01-1,000 g per mole.

The composition of the catalyst system composed of different metal copper salt activating aids and copper catalysts is not limited to any particular composition and has the same effect in any combination. It is generally advantageous to carry out this reaction in the liquid phase, but it can also be carried out in the gas phase, and the ratio of the nitrile compound to water is generally preferred to be excessive in water, and usually in the composition range of 50 to 90% by weight of water. . Moreover, you may add common agent, such as methanol, in order to improve the compatibility of a nitrile compound and water.

Suitable reaction temperatures are in the range of 50-300 ° C. but for example the synthesis of acrylamide from acrylonitrile and especially in the range of 50-150 ° C. is preferred.

As the nitrile compound used in the method of the present invention, the formula R- (CN) n (where R represents alkyl, substituted alkyl, alkenyl, cycloalkyl, aralkyl, aryl, substituted aryl, and n represents 1, 2,...) And alkynyl, such as propylnitrile, substituted alkylnitrile such as chloroacetnitrile, alkenylnitrile such as acrylonitrile methacrylonitrile, cyclohexane, and carbonnitrile. Cycloalkylnitriles such as, aralkylnitriles such as benzyl cyanide, substituted arylnitriles such as benzonitrile, polynitriles such as saxinonitrile, phthalonitrile, and other nitriles such as nicotinonitrile. The aqueous solution of the amide compound obtained by the method of the present invention can be used as an intermediate raw material without purification because the amount of nitrate used is small. Of course, if necessary, each added ion can be removed by a well-known method, for example, use of an ion exchange resin. In addition, in the case of aqueous acrylamide solution, in order to obtain a polymer useful as a paper processing or soil hardener, it can also be used as aqueous solution, and can also be used as acrylamide crystal by a conventional method. In the same way, nicotinic acid amide can be effectively used as agrochemical raw material.

Another advantage of the method of the present invention is that the catalyst life of the metal copper catalyst used for the production of the amide compound from the nitrile compound can be remarkably improved, whereby the production of the amide compound can be performed industrially and efficiently. More specifically, in the case of the combination of a copper salt as an active aid of a conventionally known metal copper catalyst by the combination of a metal copper catalyst of the present invention and a nitrate as an active aid, a decrease in catalyst activity can be significantly prevented. As a result, it is possible to reduce the consumption of the metal cocatalyst, thereby further improving the economics of this method.

An embodiment of the present invention will be described below.

Example 1

Into a reaction tank (material: non-hydrous steel SUS-27) equipped with a 1 liter stirrer with a catalyst separator, 150 g of a Laneige catalyst (denoted the dry weight, which is the same below) described by a conventional method was put in advance. Acrylonitrile and water from which about 90% of dissolved oxygen was removed through the deoxygenation apparatus were continuously supplied at a rate of 300 and 700 g / h, respectively, and reacted at 120 ° C. 39 ppm of sodium nitrate was added to water. (This amount is 20 ppm in terms of the ratio of the amount of the raw material solution, that is, the amount of nitrate to the sum of acrylonitrile and water). This reaction was continued for 14 days, and the resultant solution was analyzed by gas chromatography and expressed as conversion ratio of acrylamide to acrylonitrile. The results are as shown in the following table. Other impurities, in particular acrylic acid, acrylate, and ethylene cyanhydrin And the conversion ratio to β-hydroxypropionamide was 0.5% or less in all. In addition, for comparison purposes, the case where copper sulfate, which is one of the promoters proposed by the inventors of the patent, was added to the raw material solution as the copper ion and 10 ppm was added to the raw material solution for comparison purposes, the results are added and described.

From these results, it was found that the nitrate root as an accelerator was more improved than copper ions.

Example 2

The same reaction as in Example 1 was carried out using ammonium nitrate instead of sodium nitrate for 6 days in different amounts of addition. As in Example 1, the conversion rate from acrylonitrile to acrylamide was collectively obtained. In addition, the amount of ammonium nitrate was expressed by the quantity of the root nitrate with respect to the sum total of a raw material liquid, ie, acrylonitrile and water.

(Note) The result of * is quoted in Example 1.

Example 3

The same reaction as in Example 1 was carried out using various copper acid salts for six days, respectively, and the results were shown in the conversion ratio from acrylonitrile to acrylamide as in Example 1, and the results shown in the following table were obtained. The amount of nitrate was 20 ppm as the nitrate relative to the total amount of the raw material liquid, that is, acrylonitrile and water.

Example 4

A 300 g metal reaction tube was charged with 300 g of refined copper oxide, which was then sufficiently reduced to 200-250 ° C. using hydrogen gas diluted to 2% with nitrogen to reduce copper. The acrylonitrile and water which removed about 90% of dissolved oxygen by passing through a deoxidation apparatus were continuously supplied at the speed | rate of 300 and 700 g / h, respectively, and it reacted at 120 degreeC. In water, 39 ppm of sodium zalate was added and used beforehand. (If this amount is expressed as the ratio of the amount of nitric acid to the total amount of the raw material, i.e. acrylonitrile and water, the amount is 20 ppm). The result of continuing this reaction for 6 days is shown as a conversion ratio from acrylonitrile to acrylamide, and it is as follows. Moreover, the result of having performed the experiment when no sodium acetate was added for comparison was added and described.

The same experiments were carried out on the hydrogen reduction copper chromium oxide catalyst and the catalyst obtained by reducing the copper salt with hydrazine.

Example 5

5 kg of copper powder for reagents was placed in a reaction tank (material: non-steel SUS-27) equipped with a 10 liter stirrer equipped with a catalyst separator, and the acryl was removed from the dissolved oxygen by about 90% through a deoxygenation device. Onitrile and water were continuously fed at a rate of 300,700 g / h and reacted at 120 ° C. 39 ppm of sodium nitrate was added to water. (If this amount is expressed as the ratio of the amount of the nitric acid to the total of the raw material liquid, that is, acrylonitrile and water, the amount is 20 ppm). When the result of the reaction for 6 days is expressed as the conversion rate from acrylonitrile to acrylamide, the conversion rate to other impurities, particularly acrylic acid, acrylate, ethylene cyanhydrin and β-hydroxypropionamide, is as follows. Was less than 0.5%. In addition, the results of the experiment when no sodium nitrate was added for comparison are described as follows.

Example 6

When the same reaction as in Example 1 was carried out using methacronitrile and benzonitrile for 6 days instead of acrylonitrile, the conversion rate from each nitrile compound to the corresponding amide compound as in Example 1 was expressed as follows. Same as In addition, the amount of sodium nitrate was added to the following table as described in Example 1 by using 20 ppm of nitrate as the nitrate root for the total of the raw material solution, that is, each nitrile compound and water. .

Example 7

The same reaction as in Example 1 was carried out using propionitrile and nicotinonitrile (3-cyanopyridine) for 14 days instead of acrylonitrile, and the results were as follows. When expressed as conversion rate, it is as follows. The amount of sodium nitrate added was 20 ppm as the nitrate root for the total amount of the raw material solution, that is, each nitrile compound and water as in Example 1, and the experiment without addition of the nitrate root for comparison was also performed. It added to and described.

Claims (1)

A method for preparing an amide compound by reaction of a nitrile compound with water in the presence of a metal copper catalyst and an activator for the catalyst, wherein the ratio of the nitric acid radical to the total amount of the nitrile compound and water is in the range of 1-600 ppm. A method for producing an amide compound using nitrates other than copper nitrate as an activator.