JP2001342174A - Method for producing amide compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing an amide compound by a rearrangement of an oxime compound by which the selectivity for the objective amide compound is extremely improved and further the reaction rate is improved. SOLUTION: This method for obtaining the amide compound by rearranging the oxime compound in the presence of a rhenium compound and a solvent in a liquid phase is characterized in that the water content in the solution obtained by dissolving the oxime compound in the solvent is <=100 ppm. Preferably, the method for producing the amides is characterized in that the oxime compound and the solvent used in the reaction are used after drying them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an amide compound by rearrangement of an oxime compound.

[0002]

2. Description of the Related Art A rearrangement reaction of an oxime compound to an amide compound is known as a Beckmann rearrangement reaction. For example, in an industrial production method of ε-caprolactam by rearrangement of cyclohexanone oxime, fuming sulfuric acid is used as a rearrangement agent. The reaction used has been performed. in this way,
It is necessary to neutralize with amide to separate and recover amide compounds, and there are parts that produce a large amount of ammonium sulfate as a by-product and corrosion of equipment, which causes problems in the process, and the development of an efficient catalytic reaction system is expected. Have been. Above all, as the Beckmann rearrangement reaction in the liquid phase under relatively mild reaction conditions, a method using a Vilsmeier complex (Egypt. J. Ch.
em, 16.55 (1990)), a method using a reaction accelerator comprising an N, N'-disubstituted formamide and an alkylating agent (Patent 264)
0583), a method using a strong acid or a derivative thereof and a perrhenate as a catalyst (JP-A-5-51366).
A method using a specific rhenium compound as a catalyst (JP-A-8-143544) A method using a specific rhenium compound in combination with another compound (JP-A-8-151362, JP-A-9-301951, JP-A-9-301952) and the like It has been known.

[0003]

However, according to the study of the present inventors, these methods are still insufficient for industrial implementation, and further improvements are desired. Known rearrangement methods are insufficient in the selectivity and reaction rate of amides, and the present invention aims to provide a method for producing amides suitable for industrial implementation.

[0004]

That is, the gist of the first invention of the present invention is to provide a method for obtaining an amide compound by rearranging an oxime compound in a liquid phase in the presence of a rhenium compound and a solvent, wherein the oxime compound is dissolved in the solvent. The method for producing amides, characterized in that the amount of water in the solution thus obtained is 100 ppm or less, and the gist of the second invention is to rearrange an oxime compound in a liquid phase in the presence of a rhenium compound and a solvent to form an amide. The present invention relates to a method for producing an amide, which comprises drying and using an oxime compound and a solvent used in the reaction.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail.
As the Re compound used as a catalyst in the present invention, those represented by the following general formulas (I) and / or (II) are preferable.

## STR3 ## _{Re m X n ··· (I)} ( wherein, X represents an oxygen atom, a halogen atom, a hydrogen atom, an optionally substituted alkyl group, an aryl group, an alkenyl group, a carbonyl group, phosphine Represents at least one member selected from the group consisting of a ligand and a nitrogen-containing ligand, wherein m represents a number of 1 to 5, and n represents a number of 1 to 40.)

Embedded image ReO_Three-OY (II) (where Y is ReO_Three-May have a group or a substituent
An alkyl group, an aryl group, an optionally substituted
Alkylcarbonyl group, arylcarbonyl group, Z _Three-S
i-group (Z is an alkyl group which may have a substituent or
Aryl group). In the general formula (I), X represents
Has an oxygen atom, a halogen atom, a hydrogen atom and a substituent
Alkyl group, aryl group, alkenyl group,
Consisting of a bonyl group, a phosphine ligand and a nitrogen-containing ligand.
Represents at least one member selected from the group consisting of
n represents the number of 1-40. X can be single or several different
May be. Among them, compounds in which X is an oxygen atom are preferred.
Often used. Specifically, rhenium heptaoxide, trioxide
An example is rhenium oxide such as rhodium. Also, the general formula
In (II), Y is ReO_Three-Groups and substituents
Has an alkyl group, an aryl group,
Alkylcarbonyl group, arylcarbo
A nyl group or Z_Three-Si- group (Z has a substituent and
An alkyl group or an aryl group)._Three−
O-CH_Three, ReO_Three-O-CO-CH_Three, ReO_Three-O-
SiPh_Three(Where Ph represents a phenyl group), ReO_Three
-O-Si (CH_Three)_ThreeAnd the like. In the present invention, a catalyst
The rhenium compound used for this purpose is
Um is preferred. The amount of these rhenium compounds used is
0.0001 times to 10 times the molar ratio of the shim compound.
Times, preferably 0.001 to 2 times, and the solvent
The amount in the range is from 10 ppm by weight to 50% by weight.
Preferably from 100 ppm by weight to 40% by weight,
Preferably it is 0.1 to 40% by weight.

In the present invention, a ligand compound capable of forming a complex with a rhenium compound can coexist in the reaction system. Examples of the ligand compound include nitrogen-containing heterocyclic compounds having a skeleton such as a pyridine ring, a pyrrole ring, an imidazole ring, an indole ring, a triazole ring, a quinoline ring, a bipyridyl ring, and a phenanthroline ring, and derivatives thereof, and amines such as EDTA. Various ligands such as a system ligand and an acetylacetone oxygen-containing ligand can be used.

The oxime compound in the present invention is not particularly limited, and examples thereof include cyclohexanone oxime, cyclopentanone oxime, cyclododecanone oxime, acetone oxime, 2-butanone oxime, acetophenone oxime and benzophenone oxime. Among them, cyclohexanone oxime is preferably used in the present invention.

Examples of the solvent used in the present invention include ethers such as tetrahydrofuran, dioxane, anisole and diphenyl ether; glymes such as diethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether; esters such as dibutyl phthalate and gamma butyrolactone; propylene carbonate; Relatively large solvents such as carbonates, nitriles such as adiponitrile and acetonitrile, nitro compounds such as nitrobenzene, S-containing solvents such as sulfolane, and amides such as N, N 'dimethylformamide are preferably used. . Further, a mixed solvent of these solvents may be used. on the other hand,
Aromatic hydrocarbons such as benzene and toluene, aliphatic hydrocarbons such as dodecane, and halogenated hydrocarbons such as chlorobenzene can also be used, but the solubility of catalysts and oximes in solvents having low polarity is insufficient. In some cases,
It can also be used in the form of a mixed solvent with the polar solvent.

In the second invention of the present invention, it is necessary to dry the oxime compound and the solvent used in the reaction. Further, in the first invention of the present invention, as a specific method for reducing the water content in a solution in which the oxime compound is dissolved in a solvent to 100 ppm or less, it is also possible to use the oxime compound and the solvent after drying. The drying of the oxime compound and the solvent is preferably performed in the following steps, respectively. A common industrial process for producing oximes involves reacting ketones with hydroxylamine sulfate and ammonia. The oxime compound obtained through such a production method generally contains about 5 to 10% of water. This is used in combination with a dried solvent to be described below to reduce the water content as described above to an extent that satisfies the above. Specific methods include general distillation, distillation using a thin film evaporator, crystallization, drying of solid oxime under reduced pressure, and the like, and these may be combined. The amount of the oxime compound to be used is generally 0.1 to 50% by weight, preferably 0.5 to 30% by weight in a solvent. Further, in the present invention, it is necessary to dry the solvent. Specific examples include general distillation, distillation using a thin film evaporator, drying using molecular sieves, a method using metal sodium, etc., and drying using salts such as sodium sulfate and magnesium sulfate. Techniques can be used. These can also be combined. When a solvent in which the solvent is sufficiently dried can be obtained, this step is not necessarily required.

In the present invention, a rearrangement reaction is carried out using the oxime compound obtained through the drying step and a solvent.
It is preferable to control the degree of drying to the following state. That is, in the present invention, in a state where the oxime compound is dissolved in a solvent, the water content in a solution containing no catalyst is 100 pp.
m, and the reaction is carried out by adding a catalyst thereto. Preferably 50pmm or less, more preferably 2
It is preferably at most 5 ppm. The measurement of the water content may be performed by a known method, and the Karl Fischer method is exemplified. In the present invention, by reducing the water content as described above, the selectivity of the amide compound is remarkably improved, and the reaction rate is also improved. The improvement in selectivity is particularly useful from an industrial viewpoint. It is presumed that the reason why the selectivity was improved by controlling the water concentration was because the side reaction of generating ketones in the presence of the oxime compound, water and the catalyst was suppressed.

The rearrangement reaction is usually carried out by dissolving the oxime compound and the rhenium compound represented by the formula (I) or (II) in a solvent and heating. Reaction temperature is 0
C. to 300.degree. C., preferably room temperature to 250.degree. C., more preferably 40.degree. In addition, the reaction is preferably performed in an atmosphere of a dry gas, and it is preferable to avoid mixing with air containing moisture. Usually nitrogen,
This is performed in an inert gas atmosphere such as argon and helium. Dry air can also be used. The pressure conditions are not particularly limited. However, depending on the reaction temperature, it is necessary to prevent evaporation and sublimation of the solvent and oximes, so that the operation can be performed under the pressurized condition using the gas. In the present invention, the target amide compound can be obtained from the obtained reaction solution by performing a separation operation by a known method such as distillation, crystallization, or extraction without performing the neutralization treatment. .

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A molten cyclohexanone oxime obtained by reacting hydroxylamine sulfate, ammonia and cyclohexanone and containing about 3.5% by weight of water was crystallized at room temperature. The obtained crystals were finely crushed, and then dried at 50 ° C. and 0.5 torr for 8 hours.
It dried under reduced pressure for hours. The solid content of the dried cyclohexanone oxime thus obtained was measured by the Karl Fischer method to find that the water content was 35 ppm. Under nitrogen circulation 3
100 g of molecular sieve baked at 00 ° C for 3 hours
Was added to 500 g of commercially available polyethylene glycol (250) dimethyl ether (average degree of polymerization = 4.6) and kept in a nitrogen atmosphere. The water concentration after the treatment was measured by the Karl Fischer method and found to be 28 ppm.
Under a nitrogen atmosphere, 25.75 g of polyethylene glycol dimethyl ether subjected to drying treatment and 0.2829 g of cyclohexanone oxime subjected to drying treatment were dissolved. The water concentration of this solution measured by the Karl Fischer method was 29 ppm. Rhenium heptoxide (Re ₂ O ₇ ) was added to a glass round bottom flask in an amount of 0.0242 g with respect to 26.11 g of the solution and dissolved in a nitrogen atmosphere. The flask was placed in an oil bath heated to 140 ° C., the inside of the reactor was stirred, and a Beckmann rearrangement reaction was performed. When the reaction solution after 7 minutes from the start of heating was analyzed by liquid chromatography, the conversion of cyclohexanone oxime was 100% and the selectivity for ε-caprolactam was 90.4%. Comparative Example 1 A solution of 0.2829 g of cyclohexanone oxime subjected to the same drying treatment as in Example 1 was dissolved in 25.75 g of polyethylene glycol dimethyl ether that was not subjected to a drying operation under a nitrogen atmosphere. The water concentration of this solution measured by the Karl Fischer method was 500 ppm. Rhenium heptoxide (Re ₂ O ₇ ) was added in an amount of 0.0242 g to 26.11 g of the solution applied to the reactor, and dissolved in a nitrogen atmosphere. The flask was placed in an oil bath heated to 140 ° C., the inside of the reactor was stirred, and a Beckmann rearrangement reaction was performed. When the reaction solution 6 minutes after the start of heating was analyzed by liquid chromatography, the conversion of cyclohexanone oxime was 43% and the selectivity for ε-caprolactam was 85.7%. 30 minutes after the start of heating, the conversion of cyclohexanone oxime was 69.5.
%, Selectivity for ε-caprolactam was 74.1%.

Example 2 Molecular sieve 1 fired at 300 ° C. under nitrogen flow
00 g of commercially available N, N'-dimethylformamide 50
In addition to 0 g, it was kept in a nitrogen atmosphere. When the water concentration in the solvent was measured by the Karl Fischer method, the water concentration was 3 ppm. In a nitrogen atmosphere, 0.57 g of the cyclohexanone oxime subjected to the drying treatment described in Example 1 was dissolved in 25 g of the dried N, N-dimethylformamide. The water concentration of this solution measured by the Karl Fischer method was 4 ppm. To a glass round-bottom flask, rhenium heptoxide (Re ₂ O ₇ ) was added in an amount of 0.0242 g to 25.57 g of the solution, and dissolved in a nitrogen atmosphere. The flask was placed in an oil bath heated to 100 ° C., and the inside of the reactor was stirred to perform a Beckmann rearrangement reaction. When the reaction solution 10 minutes after the start of heating was analyzed by liquid chromatography, the conversion of cyclohexanone oxime was 69.8% and the selectivity for ε-caprolactam was 99.8%. Comparative Example 2 25 g of N, N'-dimethylformamide, which was not subjected to a drying operation, and 0.57 g of cyclohexanone oxime subjected to the drying treatment described in Example 1 were dissolved in a nitrogen atmosphere. When the water concentration of this solution was measured,
pm. To a glass round-bottom flask, rhenium heptoxide (Re ₂ O ₇ ) was added in an amount of 0.0242 g to 25.57 g of the solution, and dissolved in a nitrogen atmosphere. The flask was placed in an oil bath heated to 100 ° C., and the inside of the reactor was stirred to perform a Beckmann rearrangement reaction.
When the reaction solution 10 minutes after the start of heating was analyzed by liquid chromatography, almost no ε-caprolactam was produced.

Example 3 Molecular sieve 1 fired at 300 ° C. under nitrogen flow
00 g was added to 500 g of commercially available diethylene glycol dimethyl ether and kept in a nitrogen atmosphere. When the water concentration in the solvent was measured by the Karl Fischer method, the water concentration was 9 ppm. 28 g of dried diethylene glycol dimethyl ether, 0.68 g of cyclohexanone oxime obtained by subjecting to the drying treatment described in Example 1
In a nitrogen atmosphere. When the water concentration of this solution was measured by the Karl Fischer method, it was 11 pp.
m. In a glass round bottom flask, add the solution 2
Rhenium heptoxide (Re ₂ O ₇ ) was added in an amount of 0.0291 g to 8.68 g and dissolved in a nitrogen atmosphere. The flask was placed in an oil bath heated to 140 ° C., and the inside of the reactor was stirred to perform a Beckmann rearrangement reaction.
When the reaction solution 10 minutes after the start of heating was analyzed by liquid chromatography, the conversion of cyclohexanone oxime was 51.0%, and the selectivity for ε-caprolactam was 97.6.
%Met. On the other hand, when the reaction solution was analyzed by gas chromatography, the selectivity for cyclohexanone was 0.5%.
Met.

Example 4 Diethylene glycol dimethyl ether 28 of Example 3
g of the cyclohexanone oxime subjected to the drying treatment described in Example 1 in a proportion of 0.68 g under a nitrogen atmosphere. The water concentration of this solution was measured by the Karl Fischer method and found to be 11 ppm. To a glass round bottom flask, 0.0291 g of rhenium heptoxide (Re ₂ O ₇ ) and 0.0167 g of 2.6-dimethoxypyridine were added to 24.2 g of the solution, and dissolved in a nitrogen atmosphere. I let it. The flask was placed in an oil bath heated to 140 ° C., and the inside of the reactor was stirred to perform a Beckmann rearrangement reaction. When the reaction solution 10 minutes after the start of heating was analyzed by liquid chromatography, the conversion of cyclohexanone oxime was 52.2% and the selectivity of ε-caprolactam was 9
It was 9.5%.

Example 5 Instead of di-rhenium heptaoxide (Re ₂ O ₇ ) of Example 1,
Triphenylsiloxytrioxorhenium (Ph ₃ Si
Example 1 except that 0.0509 g of O-ReO ₃ ) was used.
The same was done. The conversion of cyclohexanone oxime was 100%, and the selectivity for ε-caprolactam was 90.1%.

[0018]

According to the present invention, amides can be industrially advantageously produced.

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Claims (9)

[Claims] 1. A method for obtaining an amide compound by rearranging an oxime compound in a liquid phase in the presence of a rhenium compound and a solvent, wherein the water content of the solution in which the oxime compound is dissolved in the solvent is 100 ppm or less. A method for producing a characteristic amide. 2. The method for producing amides according to claim 1, wherein the amount of water in the solution in which the oxime compound is dissolved in the solvent is 50 ppm or less. 3. The method for producing an amide according to claim 1, wherein the amount of water in the solution in which the oxime compound is dissolved in the solvent is 25 ppm or less. 4. A method for obtaining an amide compound by rearranging an oxime compound in a liquid phase in the presence of a rhenium compound and a solvent, wherein the oxime compound and the solvent used in the reaction are dried and used. Manufacturing method. 5. The method for producing amides according to claim 4, wherein the amount of water in the solution in which the oxime compound is dissolved in the solvent is 100 ppm or less. 6. The rhenium compound represented by the following general formula (I)
And / or (II)
The production of the amide according to any one of claims 1 to 5
Construction method. ## STR1 ## Re_mX_n ... (I) (wherein X is an oxygen atom, a halogen atom, a hydrogen atom, substitution
Alkyl group, aryl group, alkenyl which may have a group
Group, carbonyl group, phosphine ligand and nitrogen-containing coordination
Represents at least one member selected from the group consisting of children;
1 to 5 and n represent the number of 1 to 40. 2) ReO_Three-OY (II) (where Y is ReO_Three-May have a group or a substituent
An alkyl group, an aryl group, an optionally substituted
Alkylcarbonyl group, arylcarbonyl group, Z _Three-S
i-group (Z is an alkyl group which may have a substituent or
Aryl group). ) 7. The method for producing an amide according to claim 1, wherein the rhenium compound is dirhenium heptaoxide. 8. The method for producing an amide according to claim 1, wherein the oxime compound is cyclohexanone oxime. 9. The method for producing an amide according to claim 1, wherein the reaction is carried out in the presence of a ligand compound.