JP2009214099A - Method for producing amide compound and catalyst to be used therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for promoting an addition reaction of water in high efficiency under a mild condition without producing by-products and a method for producing an amide compound by using the catalyst. <P>SOLUTION: The catalyst is obtained by combining fine particles of palladium, platinum or ruthenium, each of which has 1.0-5.0 nm particle diameter, with an oxygen-containing copper compound. A step of adding water to a nitrile compound is carried out at ≥80°C when the catalyst containing palladium or ruthenium is used or at ≥100°C when the catalyst containing platinum is used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention can be used for the addition reaction of water to an organic compound, particularly the addition reaction of water to a nitrile compound, and the reaction proceeds under mild conditions without generating a by-product. The present invention relates to a catalyst capable of obtaining an amide compound with high yield.

  With respect to the production of the amide compound, for example, a method utilizing an addition reaction of water to a nitrile compound can be mentioned. Many of the amide compounds obtained by such a reaction are industrially useful. For example, acrylamide as a paper strength enhancer and nicotinamide as a component of vitamin B3 are industrially produced as products with a large market scale. Amide compounds are also useful as synthetic intermediates for physiologically active substances such as pharmaceuticals.

  The addition reaction of water to the nitrile compound is an industrially practiced technique, and can be roughly divided into a technique using a microorganism-derived biocatalyst and a technique using an artificial catalyst.

  In general, in a technique using a biocatalyst, water is added to a nitrile compound in the course of microorganism metabolism, and an amide compound is obtained as a product thereof. For example, microorganisms having the action of nitrile hydratase are used as biocatalysts for the synthesis of acrylamide compounds (see, for example, JP-A-5-30982 (Patent Document 1)). However, in the case of a biocatalyst, versatility capable of producing various amide compounds is not necessarily high, and a highly versatile catalyst is desired. Moreover, in the method using a biocatalyst, it is necessary to treat waste water required for maintaining the living body of the catalyst.

  On the other hand, in the method using an artificial catalyst, water is added using an acid / base catalyst, reduced copper, a copper-chromium catalyst, a complex catalyst, etc., but these catalysts are used for limited applications. In addition, the acid / base catalyst requires a high reaction temperature, and there is a problem that a large amount of by-products such as inorganic salts are generated in the neutralization process in the post-treatment stage of the production of the amide compound. . In addition, the reduced copper catalyst requires a high reaction temperature, requires a large amount of water, and requires a concentration operation. Furthermore, the copper-chromium-based catalyst has a problem from the viewpoint of environmental protection because it uses chromium, which is a harmful metal. Furthermore, the complex catalyst method requires a large amount of harmful volatile organic solvent, which is not preferable from the viewpoint of environmental conservation. Therefore, an amide production method that does not discharge a large amount of inorganic salt, does not contain harmful metals, and does not use harmful volatile organic solvents is desired.

  On the other hand, in recent years, research on artificial catalysts focusing on the characteristics of metal fine particles (nanoparticles) is proceeding rapidly. The metal nanoparticles are microcrystalline particles composed of several to several hundred atoms, and an effect not found in a solid catalyst can be obtained. Such an effect is considered to be mainly derived from the high specific surface area and the diversity of the surface structure. Specifically, the metal nanoparticles constituting the cluster exhibit a significantly higher catalytic action than the catalytic action in the bulk phase of a general solid catalyst. Prati et al., Appl. Catal. A: General, 291, 199 (2005) (Non-patent Document 1) reported that polyhydric alcohol can be oxidized with oxygen by using gold nanoparticles originally supported on activated carbon as gold. Yes. In addition, multi-component metal nanoparticle catalysts generally form nuclei of metal nanoparticles (intermetallic compounds) by hydrothermal reaction by reducing a mixed solution in an ionic state. For example, in JP-A-6-300022 (Patent Document 2) and JP-A-7-204511 (Patent Document 3), water to a nitrile compound using an alloy-based nanoparticle obtained by heat treatment as a catalyst. In the examples, only the addition reaction of water to acrylonitrile is reported. Shiraishi et al. Describe the mechanism of the action of alloy-based nanoparticle catalysts in the collection of polymer papers, 57, 346 (2000) (Non-patent Document 2). Palladium interacts with the olefin part of acrylonitrile and water coordinates. It is explained that high activity is exhibited because it plays a role of fixing a nitrile site in the vicinity of the copper.

JP-A-5-30982 JP-A-6-30002 Japanese Patent Laid-Open No. 7-204511

Prati et al. , Appl. Catal. A: General, 291, 199 (2005) Yukihide Shiraishi et al., Polymer Papers, 57, 346 (2000)

  The method for producing an amide compound disclosed in JP-A-6-30002 and JP-A-7-204511 uses palladium and copper alloy nanoparticles as a catalyst. Need to be prepared. Moreover, the preparation method is more complicated than single-component nanoparticles, and it is necessary to set conditions such as controlling the pH during catalyst preparation.

  Therefore, an object of the present invention is to provide a catalyst that promotes the water addition reaction with high efficiency without generating a by-product by simple catalyst preparation under mild conditions. In particular, the present invention provides a method for producing an amide compound that is useful as a catalyst for producing amides from nitriles and that uses the catalyst.

  As a result of intensive studies to achieve the above object, the present inventors have added an oxygen-containing copper compound to the central palladium, platinum or ruthenium fine particles, thereby being excellent in water addition reaction in the liquid phase. The present inventors have found that a novel catalyst exhibiting catalytic ability can be obtained, and have completed the present invention.

  That is, the catalyst of the present invention is characterized by comprising fine particles of palladium, platinum or ruthenium having a particle diameter in the range of 1.0 nm to 5.0 nm in combination with an oxygen-containing copper compound.

  The catalyst of the present invention can be prepared simply by mixing fine particles of palladium, platinum or ruthenium and an oxygen-containing copper compound, and is characterized by exhibiting catalytic ability for water addition reaction.

  In a preferred example of the catalyst of the present invention, the fine particles of palladium, platinum or ruthenium are clusters.

  In the catalyst of the present invention, the oxygen-containing copper compound is preferably copper sulfate, copper oxide, copper carbonate, copper nitrate and copper bisacetylacetonate.

  The catalyst of the present invention is preferably a fine particle in which the fine particles of palladium, platinum, or ruthenium are present in a monodispersed state by a protective agent made of a water-soluble polymer.

  In the catalyst of the present invention, the molar ratio (Cu / M) of the oxygen-containing copper compound and the palladium, platinum or ruthenium fine particles [wherein M is Pd, Pt or Ru] is 0.1 to 10. preferable. The molar ratio (Cu / M) is the ratio of the number of moles of copper to the number of moles of palladium, platinum, or ruthenium.

  The catalyst of the present invention preferably further contains a protective agent made of a water-soluble polymer. Here, the water-soluble polymer is preferably polyvinylpyrrolidone.

  In another preferred embodiment of the catalyst of the present invention, the fine particles are preferably composed of platinum, and the solvent of the fine particles is preferably pH 6.0 or more.

  The catalyst of the present invention is suitable as a catalyst for producing an amide compound.

  Further, the method for producing an amide compound of the present invention is a step of adding water to a nitrile compound in the presence of the above catalyst in the presence of a catalyst containing palladium or ruthenium at 80 ° C. or higher, or a catalyst containing platinum It is characterized by being carried out at 100 ° C. or higher in the presence of.

  According to the present invention, a novel catalyst that functions under mild conditions by adding an oxygen-containing copper compound to fine particles of palladium, platinum, or ruthenium, and promotes a recyclable hydrolysis reaction and addition reaction. Can be provided. Further, by using such a catalyst, the target amide compound can be easily produced at a high selectivity under mild conditions without preparing a multi-component catalyst dedicated to a specific catalytic reaction system. A water treatment facility required when using a catalyst is also unnecessary.

It is a figure which shows the effect of the oxygen containing copper compound in the addition reaction of water to benzonitrile. It is a figure which shows the effect (80 degreeC) of the addition amount of bisacetylacetonato copper in the addition reaction of water. It is a figure which shows the influence of the reaction temperature in the addition reaction of water to acrylonitrile. It is a figure which shows the influence of the air exposure in the addition reaction of water to acrylonitrile. It is a figure which shows the time-dependent change of the acrylamide yield in the addition reaction of water to acrylonitrile. It is a figure which shows the influence of the water addition amount in the addition reaction of the water to acrylonitrile.

  The present invention is described in detail below. The catalyst of the present invention is characterized in that palladium, platinum or ruthenium fine particles having a particle diameter in the range of 1.0 nm to 5.0 nm are combined with an oxygen-containing copper compound. As described above, multi-component composite catalysts used for the production of amide compounds are usually complicated to prepare and require strict conditions for their preparation, and it is also necessary to prepare dedicated multi-component catalysts for each reaction system. Therefore, its versatility is low. However, the present inventors have obtained a novel catalyst having excellent catalytic ability for hydrolysis reaction and addition reaction in a solvent simply by mixing oxygen-containing copper compound with general palladium, platinum or ruthenium fine particles. I found out that Surprisingly, in addition to being easy to prepare, such a catalyst can produce an amide compound from a nitrile compound under mild conditions, and it can be seen in the neutralization process in the conventional method for producing an amide compound. An amide compound can be produced in a high yield from a nitrile compound without producing a large amount of by-products such as the obtained inorganic salt. The reason why this catalyst system including metal fine particles (nanoparticles) promotes the water addition reaction is not necessarily clear, but activation of the nitrile compound by coordination of the nitrile group to palladium, platinum or ruthenium, and water It is thought that activation of water occurs due to coordination with copper. That is, the present catalyst system catalyzes the water addition reaction in a dual function form. In Shiroishi et al., 57, 346 (2000) (Non-patent Document 2), the mechanism of action proposed is that the double bond portion of the starting nitrile compound (acrylonitrile) is coordinated to palladium. States that acrylonitrile is fixed in the vicinity of copper. In this catalyst system, water addition reaction proceeds even with hydrocinnamonitrile having no double bond in the vicinity of the nitrile group, which is clearly different from the catalyst system of Shiroishi et al. In this catalyst system, in the addition reaction of water to the nitrile compound, the reaction stops at the amide compound stage, and hydration to the carboxylic acid does not proceed. Further, the dehydration reaction from the amide compound to the nitrile compound, which is a reverse reaction, does not proceed. For this reason, it is the feature of this catalyst system that an amide compound is obtained with a high yield. The high activity of this catalyst system is thought to be derived from the high specific surface area inherent to the nanoparticles. The crystal structure of single crystals of palladium and platinum is a face-centered cubic lattice structure, and these nanoparticles are known to form a cubic octahedron. In the cubic octahedron, about 76% of atoms are located in the outermost shell (outer surface) in the 2-shell structure (55 atoms), and about 63% in the 3-shell structure (147 atoms). Furthermore, since nanoparticles have a higher proportion of steps, kinks, and the like than the bulk phase, there are many surface atoms with high coordination unsaturation. In the case of a solid catalyst, the substrate must first be adsorbed on the surface of the catalyst, which is the reaction field. However, since it is preferentially chemisorbed on surface atoms with high reactivity and coordination unsaturation, Then, it is guessed that the addition reaction of water is accelerated | stimulated because the nitrile compound which is a substrate coordinates at high density. In addition, the catalyst of the present invention is particularly suitable as a catalyst for producing an amide compound, can add water to any nitrile compound, and is not limited to the type of nitrile compound as a substrate.

  Furthermore, since the catalyst of the present invention does not require the use of chromium, which is a harmful metal, and any solvent can be used as described below, it is preferable from the viewpoint of environmental protection.

  The fine particles of palladium, platinum, or ruthenium used in the catalyst of the present invention can be obtained by using a water-soluble polymer such as polyvinylpyrrolidone, naphthalenesulfonic acid condensate, citric acid, polyacrylic acid, or quaternary amine as a protective agent. Fine particles of palladium, platinum or ruthenium can be present in a monodisperse manner. Of these water-soluble polymers, polyvinyl pyrrolidone is particularly preferred. Moreover, as said protective agent, it is not restricted to water-soluble polymer, You may use the organic ligand and surfactant normally used for metal microparticles.

  The fine particles of palladium, platinum or ruthenium used for the catalyst of the present invention are required to have a particle size in the range of 1.0 nm to 5.0 nm. If the particle diameter of the fine particles is within the above specified range, it can act as a catalyst and promote water addition reaction. Therefore, when the particle diameter deviates from the above specified range, the catalytic ability for the water addition reaction is expected to decrease.

The oxygen-containing copper compound used in the catalyst of the present invention is a copper compound containing an oxygen atom in the molecule. Specific examples thereof include copper sulfate (CuSO ₄ ), copper oxide (CuO, Cu ₂ O), copper carbonate (CuCO ₃ · Cu (OH) ₂ ), copper nitrate (Cu (NO) ₂ ), copper acetate, and copper complexes containing oxygen in the ligand. For example, the addition reaction of water to a nitrile compound can be achieved by adding an oxygen-containing copper compound to the catalyst system containing fine particles of palladium, platinum, or ruthenium. This is probably due to the concerted action of the highly active and highly reactive nanoparticle surface active sites and the water activation effect of oxygen-containing copper compounds. In addition, these oxygen containing copper compounds may be used individually by 1 type, and may mix and use 2 or more types. Further, these oxygen-containing copper compounds are not limited to divalent copper compounds, and may be monovalent copper compounds. Furthermore, these oxygen-containing copper compounds may be in the form of hydrates.

Further, as a copper complex containing oxygen in the ligand that can be used in the catalyst of the present invention, specifically, bisacetylacetonato copper (Cu (acac) ₂ ), bis (hexafluoroacetylacetonato) copper Among these, bisacetylacetonato copper is particularly preferable from the viewpoint of economy.

  The catalyst of the present invention preferably has a molar ratio (Cu / M) between the oxygen-containing copper compound and palladium, platinum or ruthenium fine particles (where M is Pd, Pt or Ru) of 0.1 to 10, More preferably, it is more than 0.1 and less than 1.0. When the molar ratio (Cu / M) is less than 0.1 (that is, when the proportion of the oxygen-containing copper compound is reduced), the catalytic ability for the water addition reaction is lowered. On the other hand, when the molar ratio (Cu / M) exceeds 10, (that is, when the proportion of the oxygen-containing copper compound increases), the catalyst efficiency does not increase.

  Moreover, the manufacturing method of the amide compound of this invention is characterized by including the process of adding water to a nitrile compound on heating conditions in presence of the above-mentioned catalyst. Here, when palladium fine particles or ruthenium fine particles are selected as the metal fine particles constituting the catalyst, heating at 80 ° C. or higher is required, and it is preferably performed in the range of 80 to 180 ° C. On the other hand, when platinum fine particles are selected as the metal fine particles constituting the catalyst, it is necessary to perform heating at 100 ° C. or higher, and it is preferable to carry out in the range of 180 to 250 ° C. According to the present invention, by using the above catalyst, the target amide compound can be produced in a high yield without generating a by-product. In addition, various amide compounds such as aromatic amides, hetero-substituted aromatic amides, aliphatic amides and the like can be produced and have wide versatility. In the method for producing an amide compound of the present invention, the fine particles of palladium, platinum or ruthenium constituting the catalyst are preferably clusters. In this case, polyvinylpyrrolidone, naphthalenesulfonic acid condensate, citric acid, By using a water-soluble polymer such as polyacrylic acid or quaternary amine as a protective agent, the fine particles constituting the catalyst can be present in a monodisperse form. Thereby, the yield of an amide compound can be improved significantly.

  As described above, the catalyst used in the method for producing an amide compound of the present invention can be prepared simply by mixing fine particles of palladium, platinum or ruthenium and an oxygen-containing copper compound. There is no problem of generating by-products. In addition, the catalytic ability for the addition reaction is exhibited by performing the heat treatment in the specified temperature range. Therefore, there is no need to prepare a catalyst by previously reacting fine particles of palladium, platinum or ruthenium with an oxygen-containing copper compound. For example, when preparing a catalyst, a nitrile is added together with fine particles of palladium, platinum or ruthenium and an oxygen-containing copper compound. A compound, water, solvent and the like can be added simultaneously.

  The nitrile compound used in the method for producing the amide compound of the present invention is not particularly limited. For example, monovalent aliphatic nitriles such as acetonitrile, propionitrile, butyronitrile, hydrocinnamonitrile, mandelonitrile, phenoxyacetonitrile, etc. Polyvalent aliphatic nitriles such as malononitrile, succinonitrile, adiponitrile, polyacrylonitrile, unsaturated aliphatic nitriles such as acrylonitrile, methacrylonitrile, allyl cyanide, benzonitrile, p-methoxybenzonitrile, p-chlorobenzo Examples thereof include aromatic nitriles such as nitrile, p-bromobenzonitrile, p-iodobenzonitrile, p-cyanobenzaldehyde, 3-cyanopyridine, 4-cyanopyridine, and phthalonitrile. In addition, according to the present invention, a corresponding amide compound can be produced in a high yield even when a low-reactivity nitrile compound such as p-methoxybenzonitrile or hydrocinnamonitrile is used. Further, according to the present invention, 3-cyanopyridine containing a nitrogen atom can also be efficiently converted into industrially important nicotinamide. Furthermore, industrially important acrylamide can also be produced.

Moreover, the catalyst used for the manufacturing method of the amide compound of this invention can contain a solvent.
As a solvent that can be used for the catalyst, that is, a solvent that can be used for the addition reaction of water to the nitrile compound, for example, dimethoxyethane, diethyl ether, anisole, tetrahydrofuran, ethylene glycol dimethyl ether, Ethers such as ethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dioxane and cyclopentyl methyl ether; alcohols such as methanol, ethanol, n-butanol, benzyl alcohol, ethylene glycol and diethylene glycol; phenols such as phenol; formic acid, acetic acid and propion Acids, carboxylic acids such as toluic acid; esters such as methyl acetate, butyl acetate, benzyl benzoate; benzene, toluene, ethylbenzene, tetralin Aromatic hydrocarbons such as n-hexane, n-octane and cyclohexane; halogenated hydrocarbons such as dichloromethane, trichloroethane and chlorobenzene; nitro compounds such as nitromethane and nitrobenzene; N, N-dimethylformamide; Carboxylic acid amides such as N, N-dimethylacetamide and N-methylpyrrolidone; Other amide compounds such as hexamethylphosphoric triamide; Ureas such as N, N-dimethylimidazolidinone; Sulfones such as dimethylsulfone; Dimethyl sulfoxide Sulfoxides such as lactones; lactones such as gamma butyrolactone and caprolactone; carbonates such as dimethyl carbonate and ethylene carbonate; and polyethers such as triglyme and tetraglyme. Further, a nitrile compound itself such as acrylonitrile, acetonitrile, benzonitrile, 3-cyanopyridine, polyacrylonitrile or the like as a raw material may be used as a solvent. These may be used alone or in combination of two or more.

  The catalyst is preferably a solution having a pH of 6.0 or more when the fine particles are platinum. If the pH of the solution is less than 6.0, the yield of the amide compound may decrease, which is not preferable from the viewpoint of securing the yield of the target amide compound.

  In the addition reaction of water to the nitrile compound, the amount of water used is preferably in the range of 0.1 to 1000 molar equivalents and more preferably in the range of 0.5 to 1000 molar equivalents per mole of nitrile group of the nitrile compound from the viewpoint of yield. The range of 1.0 to 1000 molar equivalents is more preferred, and the range of 10 to 1000 molar equivalents is particularly preferred. If the amount of water used is less than 0.1 molar equivalent per mole of nitrile group, the yield of the amide compound is greatly reduced. On the other hand, if the amount of water used exceeds 1000 molar equivalents per mole of nitrile group, the catalyst of the nitrile compound In some cases, the yield of the amide compound may be reduced because contact with the water is suppressed.

  In the addition reaction of water to the nitrile compound, the amount of fine particles of palladium, platinum or ruthenium contained in the catalyst is preferably in the range of 0.00001 to 1.0 times mol, 0.001 to 0.5 times the nitrile group of the nitrile compound. A molar range is more preferred. When the amount of the fine particles used is less than 0.00001 times mol, the reaction rate is lowered and industrially disadvantageous. On the other hand, when the amount exceeds 1.0 times mol, the economic efficiency is lowered.

  The addition reaction is preferably performed at a pressure sufficient to keep the reaction system substantially in a liquid phase. Here, the addition reaction is preferably performed in an atmosphere of an inert gas, preferably nitrogen gas or argon gas, but is not particularly limited, and may be performed in air. The reaction format is not particularly limited, and may be batch or continuous. The amide compound obtained by the production method of the present invention can be recovered by methods such as distillation and crystallization. The catalyst after recovering the amide compound can be used again for the reaction.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Catalyst Preparation Example 1)
Commercially available palladium fine particle (nanoparticle) solution (manufactured by Nanocube Japan, palladium average particle size 1.8 nm, palladium concentration 5.0 mol% (based on nitrile group), water: ethanol = 1: 1 (v / v), protection Polyvinylpyrrolidone containing agent) was used as it was as a solution in the form of a catalyst.

(Catalyst Preparation Example 2)
Commercially available platinum fine particle (nanoparticle) solution (manufactured by Nanocube Japan, platinum average particle size 1.5 nm, platinum concentration 5.0 mol% (based on nitrile group), water: ethanol = 1: 1 (v / v), protection Polyvinylpyrrolidone containing agent) was used as it was as a solution in the form of a catalyst.

(Preparation Example 3 of the catalyst of the present invention)
Bisacetylacetonato copper (Cu (acac) ₂ ) was added to the catalyst solution prepared in Preparation Example 1 at room temperature just before the start of the reaction to prepare a catalyst A for amide synthesis. The molar ratio (Cu / Pd) between bisacetylacetonato copper and palladium fine particles was 2.

(Preparation Example 4 of the catalyst of the present invention)
Bisacetylacetonato copper (Cu (acac) ₂ ) was added to the catalyst solution prepared in Preparation Example 2 at room temperature just before the start of the reaction to obtain an amide synthesis catalyst B (pH = 1.5). The molar ratio (Cu / Pt) of copper bisacetylacetonate to platinum fine particles was 2.

<Catalyst effect due to difference in metal fine particles>
A typical experimental example using the amide synthesis catalyst A is shown. Under an argon atmosphere, 0.5 mL of the catalyst solution was added to a screw-type test tube (palladium amount 1.1 mg, bisacetylacetonato copper 5.6 mg), and benzonitrile (0.02 mL, 0.2 mmol) was added. After sealing the test tube, it was set in a heat block heated to 100 ° C. and heated for 8 hours. After cooling to room temperature, the reaction solution was quantified with a gas chromatograph, and the benzamide concentration and the benzonitrile concentration were determined. Table 1 shows the benzamide yield of the addition reaction of water to benzonitrile after 8 hours at 100 ° C. The formula for calculating the yield of benzamide is shown below.
Benzamide yield (%) = [benzamide concentration (product)] / [benzonitrile initial concentration (substrate)] × 100
In both palladium and platinum, catalytic activity at 100 ° C. was hardly observed with metal fine particles alone, but by adding bisacetylacetonato copper, which is an oxygen-containing copper compound, the yield of benzamide in catalysts based on palladium was increased. Dramatically improved.

  Next, water was added to benzonitrile under the same conditions as those shown in Table 1 except that the temperature of the heat treatment was changed to 180 ° C., and the benzamide yield was determined. The results are shown in Table 2. In the catalyst system in which bisacetylacetonato copper was added to fine palladium particles, the yield was improved to 100%. A catalyst system in which bisacetylacetonate copper was added to platinum fine particles also improved the yield to 7%. In the catalyst system in which bisacetylacetonato copper was added to the palladium fine particles, the yield reached 100% within 1 hour. That is, even at 180 ° C., the catalytic function is clearly improved by adding bisacetylacetonato copper, which is an oxygen-containing copper compound.

* 1 The catalyst described in Preparation Example 1 or Preparation Example 2 was used.
* 2 The amide synthesis catalyst A or B described in Preparation Example 3 or Preparation Example 4 was used.

  From the results in Tables 1 and 2, the formation of benzamide from benzonitrile was observed only when the catalyst of the present invention was used. Although not shown in Tables 1 and 2, even when bisacetylacetonato copper was used alone, the reaction of adding water to benzonitrile did not proceed at all.

<Catalyst effect due to different additives>
Using the catalyst described in Preparation Example 1, the effect of the difference in the additive on the benzamide yield was examined. The results are shown in FIG.

  From the results shown in FIG. 1, the formation of benzamide from benzonitrile was observed when a catalyst to which an oxygen-containing copper compound was added was used. In particular, the yield of amide compound when using bisacetylacetonato copper (yield 88%), copper sulfate (yield 98%), copper carbonate (yield 96%) or copper oxide (yield 73%) It turned out to be expensive. That is, it has been clarified that the combination of palladium fine particles and an appropriate copper compound is effective as one of novel catalyst systems for catalyzing the addition reaction of water to a nitrile compound.

[ＰｈＣＯＮＨ₂]はベンズアミドのモル濃度であり、［Ｐｄ］はパラジウムのモル濃度であり、［Ｃｕ(acac)₂］は銅錯体（Ｃｕ(acac)₂）のモル濃度である。 <Effect of addition amount of oxygen-containing copper compound on catalytic performance>
In the synthesis of benzamide from benzonitrile, the amide synthesis obtained by the same method as in Preparation Example 3 except that the molar ratio (Cu / Pd) was changed by changing the amount of oxygen-containing copper compound (Cu (acac) ₂ ) The effect of the addition amount of the copper compound on the catalytic performance was evaluated using the catalyst for catalyst. A typical experimental example is shown. Under an argon atmosphere, 0.5 mL of the catalyst solution was added to a screw-type test tube (palladium amount 1.1 mg, bisacetylacetonate copper 5.6 mg), and benzonitrile (0.02 mL, 0.2 mmol) was added. After sealing the test tube, it was set in a heat block heated to 80 ° C. and heated for 16 hours. After cooling to room temperature, the reaction solution was quantified with a gas chromatograph, and the benzamide concentration and the benzonitrile concentration were determined.
The catalyst efficiency (TON, 16 hours) was calculated by the following formula.

[PhCONH ₂ ] is the molar concentration of benzamide, [Pd] is the molar concentration of palladium, and [Cu (acac) ₂ ] is the molar concentration of the copper complex (Cu (acac) ₂ ).

The result calculated from the above equation is shown in FIG. FIG. 2B is a logarithmic representation of (a). Here, [Cu (acac) ₂ ] is the molar concentration of the copper complex, and [Pd fine particles] is the molar concentration of palladium.

  As is apparent from the results of FIG. 2, the effect of adding the oxygen-containing copper compound is widely confirmed from a very low ratio to a high ratio of the oxygen-containing copper compound added, and the TON value has a molar ratio (Cu / Pd). The highest value was obtained at about 0.2. From this, it was found that the molar ratio (Cu / Pd) of the oxygen-containing copper compound to the palladium fine particles in the amide synthesis catalyst is preferably in the range of more than 0.1 and less than 1.0 from the viewpoint of the addition efficiency.

<Influence of pH>
The influence of the pH of the amide synthesis catalyst B described in Preparation Example 4 was evaluated. The pH of the catalyst B solution was adjusted by adding 0.1 M NaOH dropwise. In the experiment, 0.5 mL of the catalyst solution was added to a screw-type test tube in an argon atmosphere, and benzonitrile (0.02 mL, 0.2 mmol) was added. The test tube was sealed and heated at a reaction temperature of 100 ° C. for 16 hours. The results are shown in Table 3. The catalyst system in which bisacetylacetonatocopper was added to platinum fine particles only had a yield of 1% or less. However, the catalyst system in which the pH of the solution was adjusted to neutral (6.9) had a yield of 96%. Improved. That is, it was found that the catalyst function can be improved by adjusting the pH in the platinum catalyst system. Under neutral conditions (pH = 6.9), the reaction did not proceed with only platinum fine particles.

<Evaluation of versatility for various nitrile compounds>
In the same manner as the catalyst A for amide synthesis described in Preparation Example 3, a catalyst is prepared using copper sulfate, copper oxide or copper bisacetylacetonate, and water is added to a nitrile compound other than benzonitrile. It was. Table 4 summarizes the experimental results including the results (none) of using the catalyst of Preparation Example 1 that does not use an oxygen-containing copper compound as an additive. A typical experimental example is shown. Under an argon atmosphere, 0.5 mL of a catalyst solution was added to a screw-type test tube (palladium amount 1.1 mg, bisacetylacetonato copper 5.6 mg), and a nitrile compound (0.2 mmol) was added. After sealing the test tube, it was set in a heat block heated to 100 ° C. and heated for 16 hours. After cooling to room temperature, the reaction solution was quantified with a gas chromatograph and the amide concentration and nitrile concentration were determined.

  From the results of Table 4, according to the present invention, a low-reactivity nitrile compound such as p-methoxybenzonitrile or an aliphatic nitrile which is a benzonitrile derivative in which a methoxy group which is an electron-donating substituent is bonded to the para-position. It has been found that the corresponding amide compound can be synthesized in a yield equivalent to or higher than that of benzonitrile even when a certain hydrocinnamonitrile is used. This is a feature not found in conventional artificial catalysts. By-products could not be confirmed at all with a gas chromatograph apparatus. In any nitrile compound, the addition reaction of water does not proceed with only the palladium fine particles (none), and the oxygen-containing copper compound is essential.

Next, under the conditions shown in the following reaction formula, a catalyst is prepared using copper oxide (CuO) in place of bisacetylacetonate copper in the same manner as the amide synthesis catalyst A described in Preparation Example 3, When water was added to acrylonitrile, the corresponding acrylamide could be synthesized in high yield.

(Preparation Example 5 of the catalyst of the present invention)
Commercially available palladium fine particle (nanoparticle) solution (manufactured by Nanocube Japan, palladium average particle size 1.8 nm, palladium concentration 0.8 mol% (based on nitrile group), water: ethanol = 1: 1 (v / v), protection A transition metal compound as an additive was added at room temperature immediately before the start of the reaction to obtain an amide synthesis catalyst. The molar ratio of the transition metal compound to the palladium fine particles (transition metal compound / Pd) was 2.

<Application to acrylonitrile (1)>
Catalytic effect due to difference in additive In the catalyst for amide synthesis described in Preparation Example 5, bisacetylacetonato copper (Cu (acac) ₂ ), copper acetate (Cu (OAc) ₂ ), copper (II) oxide as additives (CuO), copper oxide (I) (Cu ₂ O), copper sulfide (II) (CuS), copper chloride (II) (CuCl), copper chloride (I) (CuCl ₂ ), copper carbonate (CuCO ₃ · Cu A catalyst was prepared using (OH) ₂ ), acetylacetonato zinc (Zn (acac) ₂ ) or silver oxide (Ag ₂ O), and water was added to acrylonitrile. The experiment was performed in an argon atmosphere, and 0.5 mL of the catalyst solution and acrylonitrile (0.066 mL, 1.0 mmol) were added to the screw-type test tube. After sealing the test tube, it was set in a heat block heated to 100 ° C. and heated for 16 hours.

From the results in Table 5, it was confirmed that acrylamide was formed from acrylonitrile when Cu (acac) ₂ , Cu (OAc) ₂ , CuO, Cu ₂ O, or CuCO ₃ .Cu (OH) ₂ was used as an additive. In particular, it was found that the yield of acrylamide was high when CuO or Cu ₂ O was used. Similarly to the result of benzonitrile, the addition reaction of water did not proceed with only the palladium fine particles.

<Application to acrylonitrile (2)>
Catalytic effect due to difference in metal particles In the catalyst for amide synthesis described in Preparation Example 5, ruthenium fine particles (average particle size 2 nm) or silver fine particles (average particle size 10 to 20 nm) instead of commercially available palladium fine particles (both Tanaka Kikinzoku Kogyo) A catalyst was prepared using copper (II) oxide (CuO) as an additive under the same conditions as in Preparation Example 5 except that the product was subjected to an addition reaction of water to acrylonitrile. In the experiment, 0.5 mL of the catalyst solution was added to a screw-type test tube under an argon atmosphere, and acrylonitrile (0.066 mL, 1.0 mmol) was added. The test tube was sealed and heated at a reaction temperature of 100 ° C. for 16 hours.

  From the results in Table 6, acrylamide formation was observed when ruthenium fine particles were used. On the other hand, the catalytic activity of silver fine particles was hardly recognized. In addition, the addition reaction of water did not proceed with only the fine particles (numbers 3 and 4 in Table 6).

<Application to acrylonitrile (3)>
Influence of reaction temperature In the catalyst for amide synthesis described in Preparation Example 5, a catalyst was prepared using copper (II) oxide (CuO) as an additive, and water was added to acrylonitrile. In the experiment, 0.5 mL of the catalyst solution was added to a screw-type test tube under an argon atmosphere, and acrylonitrile (0.066 mL, 1.0 mmol) was added. The test tube was sealed and heated for 16 hours. The results are shown in FIG.

  From the results of FIG. 3, the formation of acrylamide was observed at a reaction temperature of 80 ° C. or higher.

<Application to acrylonitrile (4)>
Influence of air exposure In the catalyst for amide synthesis described in Preparation Example 5, a catalyst was prepared using copper (II) oxide (CuO) as an additive, and water was added to acrylonitrile. In the experiment, 0.5 mL of the catalyst solution was added to a screw test tube in the atmosphere, and acrylonitrile (0.066 mL, 1.0 mmol) was added. The test tube was sealed and heated at a reaction temperature of 100 ° C. for 16 hours. The results are shown in FIG.

  From the results in FIG. 4, it was confirmed that acrylamide was produced even under atmospheric exposure (in the presence of air). Therefore, it is clear that there is no need to be in an argon atmosphere when producing acrylamide.

<Application to acrylonitrile (5)>
Changes in acrylamide yield over time In the catalyst for amide synthesis described in Preparation Example 5, a catalyst was prepared using copper (II) oxide (CuO) as an additive, and water was added to acrylonitrile. In the experiment, 0.5 mL of a catalyst solution was added to a screw-type test tube under an argon atmosphere, and acrylonitrile (0.066 mL, 1.0 mmol) was added. After sealing the test tube, it was set in a heat block heated to 100 ° C., and the change in acrylamide yield was measured. The results are shown in FIG.

  From the results of FIG. 5, the acrylamide yield continued to increase until approximately 16 hours after the start of the experiment. Acrylamide was produced immediately after the start of the reaction, and it was confirmed that this catalyst system had no induction period.

(Preparation Example 6 of the catalyst of the present invention)
Commercially available palladium fine particle (nanoparticle) solution (manufactured by Nanocube Japan, palladium average particle size 1.8 nm, palladium concentration 0.8 mol% (based on nitrile group), water: ethanol = 1: 1 (v / v), protection The solvent of polyvinylpyrrolidone as an agent) was once distilled off under reduced pressure and redissolved with a solution in which the mixing ratio of water: ethanol was changed. Thereafter, copper (II) oxide (CuO) as an additive was added at room temperature immediately before the start of the reaction to obtain an amide synthesis catalyst. The molar ratio (Cu / Pd) of copper (II) oxide (CuO) and fine palladium particles was 2.

<Application to acrylonitrile (7)>
Effect of water addition amount In the catalyst for amide synthesis described in Preparation Example 6, added to a fine particle solution adjusted so that the ratio of substrate (acrylonitrile) to water ([H ₂ O] / [substrate]) is 5 to 100 A catalyst was prepared using copper (II) oxide (CuO) as a product, and water was added to acrylonitrile. In the experiment, 0.5 mL of the catalyst solution was added to a screw-type test tube under an argon atmosphere, and acrylonitrile (0.066 mL, 1.0 mmol) was added. After sealing the test tube, it was set in a heat block heated to 100 ° C., and the transition of acrylamide yield was measured with a gas chromatograph. The results are shown in FIG. [H ₂ O] is the molar concentration of water, and [Substrate] is the molar concentration of the substrate (acrylonitrile).

  From the results shown in FIG. 6, acrylamide was produced even when the excess amount of water required for the addition reaction was a small excess 5 relative to acrylonitrile. Acrylamide was produced even when there was 100 times more water than acrylonitrile.

Claims (10)

  A catalyst comprising a combination of fine particles of palladium, platinum or ruthenium having a particle diameter in the range of 1.0 nm to 5.0 nm with an oxygen-containing copper compound.   2. The catalyst according to claim 1, wherein the fine particles of palladium, platinum or ruthenium are clusters.   The catalyst according to claim 1 or 2, wherein the oxygen-containing copper compound includes at least one selected from the group consisting of copper sulfate, copper oxide, copper carbonate, copper nitrate, and bisacetylacetonato copper. .   3. The catalyst according to claim 2, wherein the fine particles of palladium, platinum, or ruthenium are fine particles that are monodispersed by a protective agent made of a water-soluble polymer.   The molar ratio (Cu / M) between the oxygen-containing copper compound and the palladium, platinum, or ruthenium fine particles (where M is Pd, Pt, or Ru) is 0.1 to 10. The catalyst according to 1.   The catalyst according to claim 2, further comprising a protective agent comprising a water-soluble polymer.   The catalyst according to claim 6, wherein the water-soluble polymer is polyvinylpyrrolidone.   The catalyst according to claim 1, wherein the fine particles are made of platinum, and the solvent of the fine particles has a pH of 6.0 or more.   The catalyst according to claim 1, which is a catalyst for producing an amide compound.   The step of adding water to the nitrile compound in the presence of the catalyst according to claim 9 is performed at 80 ° C or higher in the presence of a catalyst containing palladium or ruthenium, or at 100 ° C or higher in the presence of a catalyst containing platinum. The manufacturing method of the amide compound characterized by performing.

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