JP2003064038A - Method for producing cyclic aliphatic oxime - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a cyclic aliphatic oxime in high oxime selectivity (generally >=50 and >=80% by selecting a catalyst) by a relatively simple operation without accompanied by dangerous operations as in the case of using a peroxide as an oxidant. SOLUTION: This method for producing the cyclic aliphatic oxime is to oxidize an alicyclic primary amine with molecular oxygen in a gas phase in the presence of a solid catalyst comprising at least one oxide selected from the 5th family and the 6th family of the periodic table and at least one metal oxide selected from the 4th family of the periodic table.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a cycloaliphatic oxime by oxidizing a cycloaliphatic primary amine in a gas phase.

[0002]

Cycloaliphatic oximes are useful compounds as raw materials for medicines and agricultural chemicals in the field of organic chemistry. In particular, when the cycloaliphatic oxime is cyclohexanone oxime, it is a compound useful as an intermediate for ε-caprolactam, which is a raw material for nylon-6. Conventionally, as a method for oxidizing an alicyclic or aliphatic primary amine to obtain an oxime, a method of reacting an amine with hydrogen peroxide in the presence of an inorganic salt catalyst based on molybdenum, tungsten or uranium, It is known to react with organic hydroperoxides in the presence of titanium, molybdenum, tungsten or vanadium based catalysts in organic solvents.

However, when industrially carrying out the method using these hydrogen peroxide or organic hydroperoxide as an oxidizing agent, there are known operational risks associated with the handling of the oxidizing agent. Furthermore, when an organic hydroperoxide is used, the product derived from the reduction of the hydroperoxide is contained in the reaction solution, which causes a problem that the separation and purification operations become complicated.

In order to solve the above problems, the following method using molecular oxygen such as air or oxygen as an oxidant has been proposed. That is, (1) a method in which a water-soluble salt of molybdenum, tungsten or uranium is used and photooxidation is performed using a mercury lamp in the presence of water (method described in German Patent No. 1,021,358), ( 2) A method of reacting in the presence of a tertiary alcohol, preferably ammonia gas, using a catalyst such as tungstic acid, phosphotungstic acid, molybdic acid, selenic acid, selenious acid (Japanese Patent Publication No. 47-253).
No. 24), (3) a method of reacting under liquid phase conditions in the presence of a homogeneous or heterogeneous catalyst based on a metal belonging to Group 4 of the periodic table (European Patent Application Publication No. No. 395,046), (4) a method of reacting under vapor phase conditions in the presence of a solid catalyst based on silica gel or γ-alumina, optionally in combination with tungsten oxide (US Pat. 4,337,358, 4,504,681 and 4,56.
0,797 and 4,624,939).

However, (1), (2) and (3)
Since the method of (1) is a reaction in a liquid phase, the solvent separation step is complicated, and since the methods of (1) and (2) use a homogeneous catalyst, the separation and recovery step of the catalyst component after the reaction is complicated. However, in (3), although a heterogeneous catalyst is used, there is a problem that the oxime selectivity is extremely low at 50% or less. The method (4) is a gas phase reaction, but in the method of US Pat. No. 4,337,358, when silica gel is used as a catalyst and cyclohexylamine is used as a primary aliphatic amine, cyclohexanone oxime is used. Is about 60%. U.S. Pat. No. 4,504,681 describes the use of a catalyst in which a metal oxide is used as a carrier and tungsten containing oxygen is combined, and examples thereof include alumina, magnesium oxide or silica as a carrier. There is a description of a catalyst that combines tungsten oxide.

In this method, when cyclohexylamine is used as the primary aliphatic amine, the selectivity of cyclohexanone oxime is as low as 70% or less. U.S. Pat. No. 4,504,681, 4,
560,797 and 4,624,939
The specification discloses a technique for obtaining a corresponding oxime by oxidation of a saturated aliphatic amine or an alicyclic amine using a catalyst in which γ-alumina and tungsten oxide are combined. However, in order to obtain an oxime with a relatively high selectivity, it is necessary to perform a complicated pretreatment of the catalyst at high temperature for a long time, as shown in the specification of US Pat. No. 4,560,797. There was a problem.

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is (1) when producing a cycloaliphatic oxime by oxidizing a cycloaliphatic primary amine, (1) as an oxidizing agent, there is a problem of danger and complexity of handling. (2) In a gas-phase reaction that does not involve the complicated operation of separating the solvent, it requires molecular oxygen and high temperature conditions, and requires a complicated pretreatment operation of the catalyst for a long time. The purpose of the present invention is to provide (3) a method for efficiently producing an oxime with high selectivity, without carrying out the reaction.

[0008]

Means for Solving the Problems As a result of intensive studies on the catalyst and the reaction conditions for the gas phase oxidation reaction of a cycloaliphatic primary amine, the present inventors have found that, surprisingly, group 5 of the periodic table is used. And a cycloaliphatic primary compound in a gas phase using a composite solid catalyst comprising an oxide of at least one metal selected from Group 6 and an oxide of at least one metal selected from Group 4 of the periodic table. The present inventors have found that cycloaliphatic oximes can be produced with high selectivity by oxidizing amines with molecular oxygen.

That is, according to the present invention, the cycloaliphatic primary amine is selected from oxides of at least one metal selected from groups 5 and 6 of the periodic table and group 4 of the periodic table. A method for producing a cycloaliphatic oxime, which comprises oxidizing in a gas phase using molecular oxygen in the presence of a composite solid catalyst comprising at least one metal oxide. The present invention will be described in detail below. The cycloaliphatic primary amine used in the present invention is preferably a saturated cycloaliphatic primary amine, and examples thereof include cyclohexylamine, cyclooctylamine, cyclopentylamine, cycloheptylamine, cyclododecanylamine and the like. Preference is given to cyclohexylamine. It is also possible to use primary amines in which the cycloaliphatic radical is replaced by a substituent which is inert under the reaction conditions. Examples of such a substituent include an alkyl group. Examples of the cycloaliphatic primary amine substituted with an alkyl group include methylcyclohexylamine.

Cyclohexylamine is, for example, cyclo
Hexen and NH₃Direct amination reaction by
-4948, JP-A-64-75453,
JP-A-9-194438 and JP-A-10-72409.
Those described in Japanese Patent Publication No. 10-291968, etc.
Method), cyclohexanol and NH ₃
Amination reaction (for example, Japanese Examined Patent Publication No. 41-7575)
Publication, JP-B-51-41627 Publication, JP-B-51-3
2601, Japanese Patent Laid-Open No. 6-1758, etc.
Method), aniline, nitrobenze
Well known by hydrogenation of nitrocyclohexane, etc.
What was manufactured by the method etc. can be used.

The purity of cyclohexylamine is not particularly limited, and examples thereof include cyclohexanol, dicyclohexylamine, nitrocyclohexane, N-cyclohexylidene-cyclohexylamine, and the like. It does not matter if it contains a small amount of water. The composite solid catalyst of the present invention contains at least one metal selected from groups 5 and 6 of the periodic table, at least one metal selected from group 4 of the periodic table, and oxygen by elemental analysis. At least a part of them is at least one metal atom selected from groups 5 and 6 of the periodic table and 4 of the periodic table.
It is a structure in which at least one metal atom selected from the group is chemically bonded via an oxygen atom.

This structure has, for example, at least one metal atom selected from Group 4 of the Periodic Table and at least one metal atom selected from Groups 5 and 6 of the Periodic Table as oxygenate ions. Bonded or substituted at least one metal atom of an oxide of at least one metal selected from Group 4 of the Periodic Table with at least one metal atom selected from Groups 5 and 6 of the Periodic Table For example, for a catalyst combining tungsten oxide and zirconia, JOURNAL OFCATAL
YSIS 168, 431-441 (1997), JO
URNALOF THE CHEMICAL SOCI
ETY FARADAY TRANSACTIONS
90 (1), 193-202 (1994) and the like.

The composite solid catalyst of the present invention comprises an oxide of at least one metal selected from Groups 5 and 6 of the Periodic Table and at least one selected from Group 4 of the Periodic Table formed separately therefrom. It is presumed that it has different acid properties than the mere physical mixture of the metal oxide with. Examples of oxides of at least one metal selected from Groups 5 and 6 of the periodic table contained in the composite solid catalyst of the present invention include oxides of V, Nb, Ta, Mo, W and the like. ,
Preferred are oxides of Nb, Ta and W, and more preferred are oxides of W. The chemical species of these oxides are not limited to any particular valence state and may be present in the solid catalyst at any positive oxidation value that the chemical species may have.

Metal oxides belonging to Group 4 of the periodic table contained in the composite solid catalyst of the present invention include Ti, Zr and Hf.
Oxides such as TiO ₂ , ZrO ₂ ,
And TiO ₂ -ZrO ₂ and the like as a composite oxide. Ratio of total metal atoms of groups 5 and 6 of the periodic table to total metal atoms of group 4 of the periodic table contained in the composite solid catalyst used in the present invention [(metal atoms of group 5 and 6) / (4
The group metal atom / atom ratio] can be arbitrarily selected in accordance with the combination of metal oxides, the preparation method and the conditions, but is preferably in the range of 0.01 to 1.0, and 0.015 to 1.05.
The range of 0.5 is more preferable, and the range of 0.02 to 0.3 is the most preferable.

The method for preparing the composite solid catalyst of the present invention is not limited, and a method known as a known catalyst preparation method can be used. Below, Nb, Ta, and W are shown as typical metals of Groups 5 and 6 of the periodic table.
The method for preparing the catalyst of the present invention will be described by taking Ti and Zr as representative metals of Group 4 as an example. With respect to other metals, the catalyst of the present invention can be prepared in accordance with this. 1) Catalyst preparation by impregnation method or adsorption method As a precursor of metal oxide of Nb, Ta or W, oxide hydrate complex of at least one of these metals with oxalic acid or tartaric acid, or ammonium salt or halide of said acid , Oxyhalide, alkoxide, nitrate, hydroxide, carboxylate, sulfate, oxide carbonate and the like are used.

This precursor is dissolved in an appropriate solution of water, alcohol, etc., and solid oxides of Ti and Zr, oxide sols, hydroxides, etc. are mixed alone or in a predetermined ratio. Or TiO prepared in advance
_{The 2-} ZrO ₂ composite oxide solid is dipped in the solution of the above-mentioned precursor, and Nb, Ta, and Ta by a known method such as an impregnation method (for example, evaporation dryness method) and an adsorption method (for example, equilibrium adsorption method). At least one metal component selected from W is supported on an oxide of at least one metal selected from Ti and Zr. Then, in the temperature range of room temperature to about 150 ° C., if necessary, depressurizing operation is performed to dry to remove the solvent. Subsequently, the composite solid catalyst of the present invention is prepared by baking in a gas phase in a stream of pure oxygen, air, an oxygen-containing gas or the like at a high temperature of about 300 to 700 ° C.
When supporting two or more kinds of metal components selected from Groups 5 and 6 of the Periodic Table, a preparation method in which these compounds are supported simultaneously or sequentially can be used.

In the supporting method described above, the metal oxide of Group 4 of the periodic table in the solid catalyst is, for example, TiO ₂
When selecting ZrO ₂ , preferably anatase-type crystalline form having a large specific surface area, amorphous TiO ₂ or titanium hydroxide, and when selecting ZrO ₂ , a monoclinic system having a large specific surface area, tetragonal Crystalline ZrO ₂ or zirconium hydroxide represented by the general formula ZrO (OH) ₂ or Zr (OH) ₄ is used.

2) Preparation of catalyst by coprecipitation method As a precursor of metal oxides such as Nb, Ta and W, soluble salts of at least one of these metals, preferably soluble compounds soluble in an aqueous medium, for example, Ammonium salt, halide, oxyhalide, nitrate,
Carboxylates, sulfates, carbonates and the like are used.
As a raw material of the oxide such as TiO ₂ , ZrO ₂ or TiO ₂ —ZrO ₂ , a soluble metal compound which is soluble in an aqueous medium is preferably used. For example, when selecting TiO ₂ , titanium tetrachloride, titanium sulfate, titanium oxalate, or the like can be used. When selecting ZrO ₂ , zirconium tetrachloride, zirconium oxychloride, etc. may be mentioned.

A precursor of an oxide component of at least one metal selected from the above-mentioned Nb, Ta and W, and Ti
An aqueous solution prepared by dissolving at least one metal oxide precursor raw material selected from O ₂ and ZrO ₂ in an aqueous medium at an arbitrary ratio is stirred preferably while maintaining the temperature at 60 ° C. or lower to obtain an aqueous liquid. An aqueous solution in which a basic compound is dissolved is added to obtain a precipitate so that the final pH is in the range of 5 to 11. As the basic compound used for neutralization to precipitation, ammonia, sodium hydroxide, potassium hydroxide,
Examples thereof include sodium carbonate and potassium carbonate, and among these, an aqueous solution of ammonia (ammonia water) is preferably used because of easy handling of the coprecipitate slurry.
When the aqueous solution of at least one metal component selected from Nb, Ta and W is basic, the aqueous solution containing them is mixed with ammonia water at the same time as TiO ₂ and Zr.
It is also possible to add at least one metal oxide precursor raw material selected from O ₂ to an aqueous solution in which the precursor raw material is dissolved to cause precipitation.

After separating the precipitate obtained by the above operation from the precipitate slurry, it is washed thoroughly and then at room temperature to about 150 ° C.
In the temperature range of 1, the drying process is performed by performing a depressurizing operation as needed. Then, the composite solid catalyst of the present invention is prepared by heating and firing in a gas phase in a stream of pure oxygen, air, an oxygen-containing gas or the like at a high temperature of about 300 to 700 ° C. 3) Preparation of catalyst by sol-gel method Mixing at least one metal alkoxide selected from Nb, Ta and W and at least one metal alkoxide selected from Ti and Zr in a desired ratio,
In a non-aqueous solvent such as a lower alcohol, heating is performed as necessary to prepare a uniform solution. The types of ligands (alkoxy groups) of at least one metal alkoxide selected from Nb, Ta and W and the alkoxide of at least one metal selected from Ti and Zr used may be the same or different from each other. Types of metal alkoxide ligands include methoxide, ethoxide, n
-Propoxide, iso-propoxide, sec-butoxide and the like can be mentioned. The solubilities of a plurality of different metal alkoxides differ depending on the ligand species and the solvent species. Therefore, a combination that can provide a uniform solution may be arbitrarily selected according to the metal species used.

After the uniform solution is prepared, deionized water for hydrolysis or an aqueous solution diluted with monoalcohol as necessary is added to the solution and stirred for a while to hydrolyze a plurality of metal alkoxides. Usually, hydrolysis is completed in several hours at room temperature, but the reaction system may be heated to shorten the decomposition time. In order to improve the hydrolysis rate, a catalytic amount of acid or base such as nitric acid or aqueous ammonia may be used. Then, the produced gel-like substance is taken out, and in order to remove the alcohol, solvent and excess water corresponding to the hydrolyzed ligand, it is dried at a temperature range of room temperature to about 150 ° C, if necessary, under reduced pressure. Perform processing. Then, the catalyst of the present invention is prepared by heating and calcining at a high temperature of about 300 to 700 ° C.

It is also possible to use a method for preparing a solid gel directly by hydrolyzing the mixed metal alkoxide without using a non-aqueous solvent. For example, Nb, Ta and W
At least one metal alkoxide selected from the above and at least one metal alkoxide selected from Ti and Zr are mixed at a desired ratio in a dry gas phase atmosphere, and a particularly large amount of non-aqueous solvent is used. Prepare a homogeneous solution without. Next, about 2 times or more equivalent amount of demineralized water with respect to the total alkoxy groups of the mixed metal alkoxide is added to the mixed solution of the mixed metal alkoxide with vigorous stirring and heat removal. The alkoxide hydrolyzes almost instantly to give a cake-like solid gel. Then
In the temperature range of room temperature to about 150 ° C., the gel is dried by optionally performing a depressurization operation to remove water and alcohol. Then, the composite solid catalyst of the present invention is prepared by heating and calcining at a high temperature of about 300 to 700 ° C.

Apart from the above, a coordination chemical sol-gel method known as a kind of sol-gel method can also be used. This method is characterized by forming a cross-linking complex in which different metal atoms are bonded to each other through a diol in a homogeneous solution, and the different metal elements are present in the vicinity of one of the metal elements. Is known as a method for obtaining a composite oxide having low crystallinity. For example, an alkoxide of at least one metal selected from Nb, Ta, and W and an alkoxide of at least one metal selected from Ti and Zr are mixed in a desired ratio, and a diol is added in order to perform the above-mentioned complex formation. Add a solvent to prepare a homogeneous solution. The diols used as the crosslinking ligand are
It is preferable that two or more methylene groups are bound between two hydroxyl groups and that they do not form an insoluble complex by binding to any of Nb, Ta, W, Ti and Zr atoms. Specifically, pinacol, hexylene glycol, etc. are used as a suitable diol solvent.

To replace the ligand of at least one metal alkoxide selected from Nb, Ta and W and the alkoxide of at least one metal selected from Ti and Zr with diols, a plurality of desired metal alkoxides can be used. Approximately 60 parts of a homogeneous solution containing diol
Heat and stir to a temperature of ~ 150 ° C. In order to improve the rate of complex formation, a method of continuously distilling and removing the monoalcohol corresponding to the liberated ligand or a method of adding a small amount of an acid ester such as dimethylsulfate as a catalyst is selected. be able to.

After preparing the complex formation reaction solution, about 70 to 10
While stirring the solution at 0 ° C., deionized water for hydrolysis or an aqueous solution diluted with a monoalcohol or a diol used as a solvent as needed was added thereto to give a plurality of complexed metal alkoxides. Hydrolyze. Then, the gel produced under a temperature condition of about 100 ° C. or lower is sufficiently aged. Then, the produced gel-like substance is taken out, dried under reduced pressure in a temperature range of about 100 to 150 ° C., and the dried gel is heated and calcined at a high temperature of about 500 to 700 ° C. to obtain the composite solid of the present invention. Prepare the catalyst.

In addition, as a method of using a metal alkoxide as a raw material, the following preparation method can be used. For example, using an aqueous solution containing at least one of soluble salts of Nb, Ta and W, the alkoxides of at least one metal selected from Ti and Zr are instantly hydrolyzed with stirring, and then the mixture is heated at room temperature to about In the temperature range of 150 ° C., if necessary, decompression operation is performed to dry the product, and water and alcohol are removed. Then, the obtained gel-like compound is heated and calcined in a gas phase in a stream of pure oxygen, air, an oxygen-containing gas or the like at a high temperature of about 400 ° C. or higher to prepare a composite solid catalyst of the present invention. .

According to the method of the present invention, a cycloaliphatic oxime is obtained by contacting a cycloaliphatic primary amine with molecular oxygen in a gas phase with a composite solid catalyst. The gas phase reaction in the present invention is carried out in a temperature range in which the cycloaliphatic amine can maintain a gas phase, preferably 50 ° C to 250 ° C.
C., more preferably 120.degree. C. to 220.degree. C., most preferably 135.degree. C. to 180.degree. Reaction temperature is 250
If the temperature exceeds 50 ° C, the decomposition reaction of the produced oxime is promoted, and if the reaction temperature is lower than 50 ° C, the reaction rate decreases. The pressure may be atmospheric pressure, and if necessary, the reaction may be carried out under pressure or under reduced pressure.

The concentration of the amine supplied is preferably 0.5 to 20% by volume, more preferably 2 to 10% by volume, based on the total amount of gas supplied. The cycloaliphatic amine may be used directly, or may be diluted with a gas such as nitrogen or helium that does not affect the reaction. Oxygen is preferably diluted with an inert gas mixture such as N ₂ or He that does not affect the reaction and used in a concentration range of 2 to 23%, more preferably 3 to 11%. However, the oxygen concentration is preferably within a range such that the reaction system does not have an explosive composition. Strict concentration control of cycloaliphatic amine, oxygen and inert gas can avoid the formation of explosive composition, but it is possible to use a mixed gas of oxygen and inert gas that is adjusted to below the limit oxygen concentration in advance. .

In the present invention, the type of reactor is not limited, and various reactors can be used.
For example, a flow type fixed bed reactor or a fluidized bed reactor can be used. The amine exists as a gas in the reactor,
In the case of a vertical flow type reactor with respect to the flow of oxygen, any of an ascending cocurrent system, a descending cocurrent system and a countercurrent system can be selected. These reactors may have a single catalyst bed or multiple catalyst beds. Also, a plurality of reactors in parallel or in series may be used.

The shape of the solid catalyst is not limited, and powdered, crushed, particulate or columnar shaped ones can be used depending on the reaction form. The amount of the solid catalyst used is the reaction system to be carried out, the reaction form, the reaction temperature, the type of solvent used, the oxide of at least one metal selected from Groups 5 and 6 of the periodic table in the solid catalyst, and the periodic rule. Table 4
It can be arbitrarily selected depending on the combination of the oxides of at least one metal selected from the group and the content ratio.

According to the method of the present invention, the conversion rate of the cycloaliphatic amine is preferably 50% or less, more preferably 40%.
%, Most preferably 30% or less, a high cyclic alicyclic oxime selectivity can be obtained. The cycloaliphatic oxime formed is recovered from the product mixture by conventional means such as distillation or extraction. Generally, unreacted cycloaliphatic primary amines can be recycled, preferably recycled to the reactor. Considering the reuse of unreacted cycloaliphatic amine,
In industrially carrying out the oxidation reaction of the present invention, improving the reaction selectivity of the target product cycloaliphatic oxime is extremely important as compared with the improvement of the conversion rate of the substrate amine, and is effective. Becomes

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described with reference to Examples.

[0033]

Example 1 1) Preparation of solid catalyst Ammonium metatungstate hydrate was dissolved in 200 g of water, and then 30 g of commercially available zirconia (RC-100 (trademark) manufactured by Daiichi Rare Element Chemical Industry) was added. This was a suspension slurry. This suspension slurry was placed in a round-bottomed flask, incorporated into a rotary evaporator, and stirred and mixed under normal pressure at an oil bath temperature of 90 ° C. for 1.5 hours at low speed. In addition, set the oil bath temperature to 120
The temperature in the system was gradually lowered to 20 kPa at 0 ° C, and the contents were concentrated to dryness. Then, the obtained solid matter is added to 1
Vacuum dry overnight at 20 ° C., pulverize and mix,
The particle size was 75 μm or less. Then, the crushed mixture was put into a glass annular furnace and subjected to a calcination treatment at 500 ° C. for 4 hours while supplying atmospheric pressure air to obtain a zirconia solid catalyst supporting tungsten oxide (W / Zr atomic ratio = 0.09). It was After the catalyst is compression molded and crushed, 1.0 mm ~
It was sieved to a particle size of 1.4 mm and used for the reaction.

2) Oxidation reaction of cyclohexylamine Introducing cyclohexylamine and oxygen respectively
Introducing a pipe to measure the temperature of the catalyst layer inside
Incorporate the pod tube for inserting the thermocouple of
Filler layer made of SUS316 for vaporizing xylamine
With outer diameter 12.7 mm, inner diameter 9.0 mm, total length 1
Prepared above in a 00 mm SUS316 reactor
2.0 g of the prepared solid catalyst was charged and incorporated into a heating furnace.
After purging the reactor with nitrogen, heat to 160 ° C.,
The composition has a cyclohexylamine concentration of 6.0% by volume and oxygen
The reaction gas having a concentration of 7.0% by volume has a space velocity of 350.
h ^-1The reaction was carried out by supplying under the following conditions. Automatically rear
The reaction gas is sampled from the reactor and the composition is determined by GC.
Was analyzed. When the reaction reached a steady state, cyclohexyl
Min conversion is 2.9%, cyclohexanone oxime
Selectivity (hereinafter based on converted cyclohexylamine
The calculated value is 82.7%.

[0035]

Example 2 Using the catalyst of Example 1, the reaction temperature was set to 180.
When the reaction was carried out under the same experimental conditions as in the method of Example 1 except that the temperature was changed to ° C, the conversion of cyclohexylamine was 8.5% and the selectivity of cyclohexanone oxime was 86.
It was 3%.

[0036]

Example 3 Using the catalyst of Example 1, the reaction temperature was set to 200.
When the reaction was carried out under the same experimental conditions as in the method of Example 1 except that the temperature was changed to ° C, the conversion of cyclohexylamine was 14.3% and the selectivity of cyclohexanone oxime was 8%.
It was 8.9%.

[0037]

Comparative Example 1 1) Preparation of catalyst Commercially available aluminum-secondary-butoxide 1
0.0 g was placed in a beaker, and an aqueous solution of ammonium metatungstate (commercial ammonium metatungstate 0.31 g was dissolved in 5.0 g of water to obtain an aqueous solution) was added dropwise little by little with vigorous stirring with a glass rod. . The produced gel product was dried at room temperature for 1 hour and then vacuum dried at 120 ° C. overnight. Then, the dried product was calcined at 400 ° C. for 4 hours in a normal pressure air stream to obtain an alumina catalyst combined with tungsten oxide. When analyzed by fluorescent X-ray, tungsten was found to be 9.
It contained 7 mass%. After compression molding the catalyst and crushing it,
It was sieved to a particle size of 1.0 mm to 1.4 mm and used for the reaction.

2) Oxidation reaction of cyclohexylamine When a reaction was carried out under the same experimental conditions as in the method of Example 1 except that the catalyst prepared in Comparative Example 1 was used, the conversion of cyclohexylamine was 6.7%. The selectivity of cyclohexanone oxime was 68.6%.

[0039]

Comparative Example 2 The catalyst of Comparative Example 1 was used, and the reaction temperature was 180.
When the reaction was performed under the same experimental conditions as in the method of Example 1 except that the temperature was changed to 0 ° C, the conversion of cyclohexylamine was 9.9% and the selectivity of cyclohexanone oxime was 71.
It was 2%.

[0040]

Comparative Example 3 The catalyst of Comparative Example 1 was used, and the reaction temperature was 200.
When the reaction was carried out under the same experimental conditions as in the method of Example 1 except that the temperature was changed to 0 ° C, the conversion of cyclohexylamine was 14.5% and the selectivity of cyclohexanone oxime was 6%.
It was 1.9%.

[0041]

According to the present invention, when a cycloaliphatic primary amine and molecular oxygen are reacted in the gas phase to produce a cycloaliphatic oxime, a high oxime selectivity (usually 50%) is obtained.
As described above, it is possible to produce an oxime at 80% or more by selecting a catalyst. Further, since a peroxide is not used as an oxidizing agent, it is possible to avoid the operational risk associated with handling the oxidizing agent, and it is possible to industrially produce a cycloaliphatic oxime with a relatively simple operation. . In addition, the reaction can be carried out in the gas phase without the complexity of solvent separation, and the reaction can be carried out at high temperature without requiring a complicated pretreatment of the catalyst for a long time.

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Claims (5)

[Claims] 1. A cyclic aliphatic primary amine, an oxide of at least one metal selected from groups 5 and 6 of the periodic table, and at least one metal selected from group 4 of the periodic table. A process for producing a cycloaliphatic oxime, which comprises oxidizing the compound in the gas phase with molecular oxygen in the presence of a composite solid catalyst comprising the above oxide. 2. The method for producing a cycloaliphatic oxime according to claim 1, wherein the cycloaliphatic primary amine is cyclohexylamine. 3. The composite solid catalyst comprises an oxide of at least one metal selected from Nb, Ta and W, and TiO _2.
The method for producing a cycloaliphatic oxime according to claim 1 or 2, comprising an oxide of at least one metal selected from ZrO ₂ . 4. The method for producing a cycloaliphatic oxime according to claim 1, 2 or 3, wherein the composite solid catalyst comprises an oxide of W and ZrO ₂ . 5. A ratio of total metal atoms of Group 5 and Group 6 of the Periodic Table to total metal atoms of Group 4 of the Periodic Table contained in the composite solid catalyst [(Group 5 and Group 6 metal atoms) / (Group 4) The metal atom / atomic ratio] is in the range of 0.01 to 1.0.