JPH10306051A - Production of ketones - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a ketone by condensing an aldehyde with a ketone under hydrogenation conditions, enabling to profitably obtain the ketone in a high yield and in a high selectlvity by carrying out the condensation reaction in the presence of a basic substance and a hydrogenation catalyst. SOLUTION: This method for producing a ketone comprises subjecting an aldehyde of the formula: R<1> CHO (R<1> is a 1-30C saturated or unsaturated aliphatic hydrocarbon, a 6-20C aromatic hydrocarbon) (e.g. acetaldehyde, butanal), a ketone of the formula: R<2> COCH2 R<3> (R<2> is a 1-6C alkyl; R<3> is H, a 1-6C alkyl) (preferably acetone) and hydrogen in the presence of a basic substance [preferably an alkali(ne earth) metal hydroxide] and a hydrogenation catalyst (preferably palladium carbon, palladium alumina) to obtain the objective compound of the formula: R<2> COCH(R<3> )CH2 R<4> (R<4> is the same as R<1> or the hydrogenation product of the unsaturated group of R<1> , when R<1> is the unsaturated hydrocarbon, or R<4> is the same as R<1> , when R<4> is the other).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing ketones. The ketones provided by the production method of the present invention are compounds useful not only as solvents or fragrances but also as synthetic intermediates for fragrances, medicines, agricultural chemicals and the like.

[0002]

BACKGROUND OF THE INVENTION For ketones or aldehydes,
It is known that when a dimerization reaction is carried out under hydrogenation conditions, saturated ketones or aldehydes having twice the number of carbon atoms are obtained. For example, as a method of synthesizing methyl isobutyl ketone by dimerizing acetone under hydrogenation conditions, i) a method of performing a reaction in the presence of an acidic ion exchange resin and palladium carbon (German Patent No. 1238)
No. 453), ii) a method in which a reaction is carried out using a catalyst in which palladium is supported on zirconium phosphate (Japanese Patent Publication No. 49-6994), and iii) a part or all of the substitutable groups of the synthetic zeolite are replaced. A method of carrying out a reaction using a catalyst in which palladium is supported on a substance substituted with hydrogen ions (H-type zeolite) (see Japanese Patent Publication No. 46-2643), iv) a carrier comprising alumina and an oxide of an alkaline earth metal For carrying out the reaction using a catalyst carrying palladium on the surface (see Japanese Patent Publication No. 6-2702), v) Method for carrying out the reaction using a catalyst comprising niobic acid and palladium
(See Japanese Patent Publication No. 3-5374), vi) A method in which a metal oxide or metal hydroxide treated with an organosilicon compound is reacted with palladium in the presence of palladium (JP-A-4-21793).
No. 8).

[0003] In contrast, although there are few reports on the method of condensing aldehydes and ketones with each other under hydrogenation conditions to obtain ketones in one step, the following methods A to E have been reported. ing. Method A: A method in which the reaction is carried out in the presence of an oil-soluble condensation catalyst containing a Group II metal, lead, manganese or cobalt and a hydrogenation catalyst (see US Pat. No. 3,316,303).

Method B: A method in which a reaction is carried out using a catalyst containing nickel and / or cobalt and zinc oxide (see JP-B-59-15021).

Method C: A method of carrying out a reaction using a catalyst containing a compound containing iron, antimony, tin or the like added to a catalyst containing zinc oxide and nickel or cobalt (Japanese Patent Publication No. 60-88)
No. 58).

Method D: Rare earth metal oxide or salt and
A method in which a reaction is carried out using a catalyst in which a Group VIII metal is supported on an inert carrier (see Japanese Patent Publication No. 41612/1986).

Method E: A method in which a reaction is carried out in the presence of a silicoaluminophosphate molecular sieve described in US Pat. No. 4,440,871 and a hydrogenation catalyst containing a transition metal such as nickel, cobalt, palladium or the like (Japanese Patent Application Laid-open No. 64-16733).

[0008]

However, the above-mentioned methods A to E have the following problems.

That is, in the case of the method A, an aldehyde having two hydrogen atoms at the α-position of the carbonyl group preferentially undergoes a dimerization reaction between the aldehydes before reacting with the ketones, Condensates of ketones and ketones cannot be obtained selectively. Further, in the same method, even in the reaction of an aldehyde having one hydrogen atom at the α-position of the carbonyl group with a ketone, the desired ketone can be obtained only in an extremely low yield (about 25%).

In the case of methods B and C, relatively high temperatures (1
(80-200 ° C.) and high pressure (18-20 bar) to carry out the reaction, so that a special reactor is required, and carbonyl groups of aldehydes or ketones used as raw materials are hydrogenated. Many by-products such as alcohols are obtained, and the yield of desired ketones is low (60
%Less than).

In the case of the method D, similarly to the case of the method B or the method C, a high temperature (180 to 220 ° C.) and a high pressure (18 to 3)
(0 bar), the reaction is performed under special conditions, and a special reactor is required. In addition, the use of a catalyst in which an expensive rare earth metal oxide and a transition metal are combined increases the production cost.

In the case of method E, the reaction is carried out at a high temperature (175-22
5 [deg.] C.) and the conversion of the raw materials is low (10 to 20%), so that the productivity of the desired ketones is low.

[0013] As described above, several methods for producing ketones by condensing aldehydes and ketones with each other under hydrogenation conditions are known, but from the viewpoint of industrial implementation, desired methods are desired. There is a problem to be solved in terms of the yield, productivity, production facilities, etc. of the ketone.

The present invention has been made in view of the above circumstances, and provides a method for industrially advantageously producing ketones by condensing aldehydes and ketones with each other under hydrogenation conditions. That is the task.

[0015]

According to the present invention, the above object is achieved by the formula (I)

[0016]

Embedded image R ¹ CHO (I) (wherein, R ¹ has ¹ to 5 carbon atoms which may have a substituent.
A saturated or unsaturated aliphatic hydrocarbon group having 30 or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent; ) And an aldehyde represented by the formula (II)

[0017]

R ² COCH ₂ R ³ (II) (wherein R ² has 1 to 6 carbon atoms which may have a substituent)
R ³ represents a lower alkyl group having 1 to 6 carbon atoms which may have a substituent or a hydrogen atom. Wherein the ketone of the formula (III) is reacted with hydrogen in the presence of a basic substance and a hydrogenation catalyst.

[0018]

R ² COCH (R ³ ) CH ₂ R ⁴ (III) (wherein R ² and R ³ are the same as defined above, and R ⁴ is
If R ¹ is not an unsaturated aliphatic hydrocarbon group is the same as R ^1, when R ¹ is an unsaturated aliphatic hydrocarbon groups R ¹ and which is or R ¹ hydrogen can be added at the same Is a group corresponding to a group obtained by hydrogenating at least a part of an unsaturated bond. The present invention provides a method for producing a ketone represented by the formula (1).

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The method for producing a ketone of the present invention is characterized by reacting hydrogen with an aldehyde and a ketone in the presence of a basic substance and a hydrogenation catalyst. Here, the aldehydes are represented by the formula (I)

[0021]

Embedded image R ¹ CHO (I) (wherein, R ¹ has ¹ to 5 carbon atoms which may have a substituent.
A saturated or unsaturated aliphatic hydrocarbon group having 30 or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent; ) Is used. Where R
Examples of the saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms represented by ¹ include an alkyl group such as a methyl group, an ethyl group, a propyl group and an isobutyl group; an alkenyl group such as a vinyl group and a propenyl group; And cycloalkyl groups such as cyclooctyl group. Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ¹ include an aryl group such as a phenyl group, a tolyl group, and a naphthyl group; and an aralkyl group such as a benzyl group.

R ¹ may have a substituent, but it is necessary that R ¹ be a substituent which is inactive under basic conditions, since the reaction is carried out in the presence of a basic substance. Examples of such a substituent include an alkoxy group, a formyl group protected in an acetal type, and a hydroxyl group.

Specific examples of the aldehyde of the formula (I) include acetaldehyde, propanal, butanal,
-Methylpropanal, pentanal, 3-methylbutanal (isovaleraldehyde), 2,2-dimethylpropanal, hexanal, 4-methylpentanal,
3,3-dimethylbutanal, cyclohexanecarbaldehyde, heptanal, octanal, 3-phenylpropanal, 3- (4-methylphenyl) propanal, 3-methyl-2-butenal (senecioaldehyde), 3,7-dimethyl Octanal (tetrahydrocitral), 3,7-dimethyl-6-octenal (citronellal), 3,7-dimethyl-2,6-octadienal (citral), 3,7,11-trimethyldodecanal (hexahydrofaral) Nessar), 3,7,
11-trimethyl-2,6,10-dodecatrienal (farnesal), 3- (5-methyl-1,3-dioxa-2-cyclohexyl) butanal, 4- (4-methyl-2-tetrahydrofuranyloxy)- Examples thereof include 3-methylbutanal, besizaldehyde, P-methylbenzaldehyde, P-anisaldehyde, and naphthylaldehyde.

The ketones selectively condensed with the aldehydes of the formula (I) include those of the formula (II)

[0025]

R ² COCH ₂ R ³ (II) (wherein R ² has 1 to 6 carbon atoms which may have a substituent)
R ³ represents a lower alkyl group having 1 to 6 carbon atoms which may have a substituent or a hydrogen atom. ) Is used. Here, examples of the lower alkyl group having 1 to 6 carbon atoms which may have a substituent of R ² or R ³ include a methyl group, an ethyl group, and an isopropyl group. Those having a number of 1 to 4 are preferred. R ² and / or R ³ may have a substituent, but it is necessary that the substituent be inactive under basic conditions because the reaction is performed in the presence of a basic substance. . Examples of such a substituent include an alkoxy group, a formyl group protected in an acetal type, and a hydroxyl group.

Specific examples of the ketones represented by the formula (II) include acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone and the like.

Among these, in carrying out the production method of the present invention, it is preferable to use ketones of the formula (II) wherein R ² is a methyl group or R ³ is a hydrogen atom, More preferably, acetone is used.

The target compound of the present invention obtained from the aldehydes of the formula (I) and the ketones of the formula (II) is represented by the formula (II)
I)

[0029]

Embedded image R ² COCH (R ³ ) CH ₂ R ⁴ (III) (wherein R ² and R ³ are the same as defined above, and R ⁴ is
If R ¹ is not an unsaturated aliphatic hydrocarbon group is the same as R ^1, when R ¹ is an unsaturated aliphatic hydrocarbon groups R ¹ and which is or R ¹ hydrogen can be added at the same Is a group corresponding to a group obtained by hydrogenating at least a part of an unsaturated bond. ). Here, R ^{1 of} R ⁴
Specific examples of "a group corresponding to a group obtained by hydrogenating at least a part of a hydrogenatable unsaturated bond" include, for example,
When citronellal is used as the compound of the formula (I),
Since R ¹ is a 2,6-dimethyl-5-heptenyl group which is a kind of unsaturated aliphatic hydrocarbon group, R ⁴ is
The carbon-carbon double bond at the 5-position of the 6-dimethyl-5-heptenyl group becomes a hydrogenated 2,6-dimethylheptyl group.

The starting materials and target compounds of the production method of the present invention have been described above. Next, the reaction conditions and reaction operation of the production method of the present invention will be described.

Although the ratio of the aldehyde of the formula (I) to the ketone of the formula (II) used in the present invention is not particularly limited, the aldehyde of the formula (I) is generally more expensive than the ketones and has a higher self-condensing property. Increasing the selectivity of the target ketone on a standard basis is advantageous for industrial implementation.
Accordingly, the ketone of the formula (II) is usually used in an amount of 0.9 to 10 mol, preferably 1 to 10 mol, per mol of the aldehyde of the formula (I).
It is used in a range of 5 mol, more preferably 1.1 to 3 mol.

Examples of the basic substance used in the present invention include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; hydroxides of alkaline earth metals such as barium hydroxide and calcium hydroxide. Carbonates of alkali metals such as potassium carbonate; and amines such as 1,5-diazabicyclo [5.4.0] undecene-5 (DBU) and piperidine. These can be used alone or in combination of two or more.

Although the basic substance can be used as it is, it can also be used as an aqueous solution. In the present invention, among the above basic substances, it is preferable to use an alkali metal hydroxide or an alkaline earth metal hydroxide, and the form of use is usually a 0.5 to 50% by weight aqueous solution, Preferably, it is an aqueous solution of 1 to 30% by weight.

The amount of the basic substance to be used is generally 0.001 to 0.3 mol per 1 mol of the aldehyde of the formula (I), but preferably 0.01 to 0.3 mol in view of the reaction rate and the production cost. ~ 0.3 mol, more preferably 0.02 ~ 0.
It is 2 mol, particularly preferably 0.01 to 0.1 mol.

The hydrogenation catalyst used in the present invention is generally a catalyst used in a catalytic hydrogenation reaction.
A catalyst used for selectively hydrogenating a carbon-carbon double bond of an α, β-unsaturated carbonyl compound can be used. For example, a catalyst containing palladium, rhodium, nickel, or platinum as an active component can be used. Can be mentioned.

The form of these hydrogenation catalysts may be any of metals themselves; metal oxides or alloys with other metals; and those supported on a carrier such as activated carbon, alumina, silica gel, or diatomaceous earth. Among these, palladium carbon, palladium alumina, Raney nickel and platinum carbon are preferred, and palladium carbon and palladium alumina are more preferred.

The amount of the hydrogenation catalyst to be used is usually 0.0005 to 0.1 part by weight per 1 part by weight of the aldehyde of the formula (I). Therefore, it is preferably 0.001 to 0.03 parts by weight based on 1 part by weight of the aldehyde of the formula (I).

In the present invention, the use of a solvent is not always necessary, but a solvent may be used as long as it does not adversely affect the reaction. Examples of usable solvents include aliphatic alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol and t-butanol; tetrahydrofuran,
Ethers such as 1,4-dioxane, diethyl ether, diisopropyl ether and dibutyl ether; and hydrocarbons such as hexane, heptane, octane, benzene, toluene and xylene.

As a specific reaction operation of the production method of the present invention, an aldehyde of the formula (I), a ketone of the formula (II), a basic substance and hydrogen in a predetermined reaction temperature range and a hydrogen atmosphere. An operation of mixing the added catalyst without using a special device (for example, a high-temperature and high-pressure kettle) and using a general-purpose device in a normal operation method can be exemplified. In this case, there is no particular limitation on the mixing order and mixing speed of each component to be subjected to the reaction, and all components to be subjected to the reaction, namely, aldehydes of the formula (I), ketones of the formula (II), basic substances and The hydrogenation catalyst may be mixed at once, or one or two of the aldehydes of the formula (I), the ketones of the formula (II) and the basic substance may be charged into the reaction vessel together with the hydrogenation catalyst, and the remaining May be continuously added into the reaction vessel. Here, "continuous addition"
"Includes adding the component to be added in multiple portions. In particular, as a method of mixing the components, a hydrogenation catalyst is suspended in the ketone of the formula (II) in order to suppress runaway of the reaction and to obtain the ketone of the formula (III) with high yield and high selectivity. It is preferred that the basic substance and the aldehyde of the formula (I) are each added continuously to the suspension. By mixing the components in this manner, a large excess of the ketone of the formula (II) with respect to the aldehyde of the formula (I) in the reaction system during most of the period from the start to the end of the reaction. As a result, side reactions such as condensation of the aldehydes of the formula (I) can be suppressed, and the desired ketones of the formula (III) can be obtained with high yield and high selectivity.

The reaction temperature is usually in the range of 20 to 180 ° C., but in order to make the reaction rate practical, and to increase the selectivity to the desired ketone of the formula (III), the reaction temperature is 40 to 180 ° C.
Preferably it is in the range of 140 ° C.

The time required for the reaction depends on the type, concentration, reaction temperature and the like of the basic substance used, but as described above, the hydrogenation catalyst is suspended in the ketone of the formula (II). When the basic substance and the aldehyde of the formula (I) are continuously added to the mixture, the time required for adding the basic substance and the aldehyde of the formula (I) is usually 0.5
10 to 10 hours, and 0 to 20 hours as an additional time after completion of the addition.

During the addition of the basic substance and the aldehyde of the formula (I) and during the driving of the reaction, it is desirable to sufficiently stir the reaction mixture.

In the present invention, the hydrogen may be brought into contact with the surface of a mixture of the aldehyde of the formula (I), the ketone of the formula (II), the basic substance and the hydrogenation catalyst, and the hydrogen is introduced into the mixture. (Bubbling).

The pressure of hydrogen in the reaction system is usually from 1 to 100.
The pressure is in the range of 1 to 10 atm.

After completion of the reaction, the desired ketone of the formula (III) is separated from the reaction mixture after removing the hydrogenation catalyst from the reaction mixture by filtration or centrifugation, and the aqueous layer is separated and removed. The method of distilling the layer, the hydrogenation catalyst is filtered from the reaction mixture, the desired ketones are extracted from the filtrate with an organic solvent, and the organic solvent is distilled off from the obtained organic layer under normal pressure or reduced pressure. It can be isolated by a general method such as a method. In addition, as the organic solvent used for the above extraction, for example, a hydrocarbon solvent such as toluene, benzene, hexane, and cyclohexane; a halogenated hydrocarbon solvent such as methylene chloride, chloroform, carbon tetrachloride, and dichloroethane can be used.

As described above, according to the production method of the present invention, an aldehyde of the formula (I), a ketone of the formula (II) and hydrogen are reacted in the presence of a basic substance and a hydrogenation catalyst. By doing so, the ketones of the formula (III) can be produced in one step with high yield and high selectivity based on the aldehydes of the formula (I).

Particularly, a raw material for producing isophytol, which is an intermediate for producing vitamin E (Journal of the Society of Synthetic Organic Chemistry, No. 20)
Vol. 824-836 (1962)).
Alternatively, a raw material for synthesizing a fragrance such as tetrahydrolinalool, dihydrogeraniol (for example, Bull. Soc.
Chim. Fr. , 1586 (1955)), 6-methyl-2-heptanone, one of the saturated ketones of the formula (III), is industrially produced according to the production method of the present invention. Inexpensive raw materials (isovaleraldehyde as an aldehyde of formula (I) and acetone as a ketone of formula (II)) are used, and they are converted to hydrogen in the presence of a basic substance and a hydrogenation catalyst. By contacting with, it can be produced in one step with high yield and high selectivity based on isovaleraldehyde.

[0048]

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

Example 1 732.1 g (12.6 mol) of acetone was charged into a 5-liter stainless steel autoclave equipped with a stirrer, and 3.1 g of 10% palladium carbon (hydrogenation catalyst) was added under a nitrogen atmosphere. Was. Set the internal temperature of the autoclave to 1
When the temperature was raised to 15 ° C., the pressure in the autoclave became about 4 kg / cm ² (gauge pressure).

[0050] Thereafter, hydrogen was introduced into the autoclave and the autoclave with 7 Kg / cm ² (gauge pressure) [hydrogen pressure: 3 Kg / cm ^2], then 2%
360.0 g (0.18 mol) of aqueous sodium hydroxide solution
And 1033.2 g of isovaleraldehyde (12.0
Mol) were continuously added to the mixture obtained above using a feed pump over 3 hours. During the addition, while keeping the liquid temperature of the reaction mixture at 110 to 120 ° C., the amount of hydrogen consumed in the reaction was supplied to the autoclave, and the pressure in the autoclave was increased to 7 kg / cm ^2.
(Gauge pressure). After the addition of the aqueous sodium hydroxide solution and isovaleraldehyde was completed, stirring was continued for 1.5 hours while keeping the temperature of the reaction mixture in the above range to drive the reaction, and then the mixture was cooled to room temperature.

After removing palladium carbon from the reaction mixture by filtration, the organic layer was separated from the filtrate separated into two layers, and subjected to gas chromatography (column: silicon DC).
QF1 (Gascro Industry Co., Ltd.), column temperature 60 ° C
Analysis at 200 ° C. (heating rate: 5 ° C./min) revealed that 1339.6 g of 6-methyl-2-heptanone was contained in 1517.3 g of the organic layer (yield based on isovaleraldehyde: 87.1). %) Was found to be included. In addition,
The conversion of isovaleraldehyde is 97.9%, and the selectivity from isovaleraldehyde to the target compound is 89.
It was 0%.

By distilling 1517.3 g of the organic layer obtained above under reduced pressure, 60.5-methyl-2-heptanone (boiling point = 103 ° C./100 mmHg) was converted to 1260.5 g.
g was obtained.

Example 2 122.0 g (2.1 mol) of acetone was charged into a 1-liter glass autoclave equipped with a stirrer.
0.50 g of 10% palladium carbon (hydrogenation catalyst)
Was added. Then, the atmosphere of the reaction system (the atmosphere in the autoclave) was replaced with 5 kg / cm ² (gauge pressure) of hydrogen, and the resulting mixture was heated to 65 ° C.

Thereafter, a 2% aqueous sodium hydroxide solution 14
3.0 g (71.5 mmol) and 172.2 g (2.0 mol) of isovaleraldehyde were each continuously added to the mixture obtained above using a feed pump over 3 hours. During the addition, the temperature of the reaction mixture was raised to 6
While maintaining the temperature at 5 to 66 ° C., hydrogen consumed in the reaction was supplied to the autoclave so that the pressure in the autoclave was maintained at 5 kg / cm ² (gauge pressure).
After the addition of the aqueous sodium hydroxide solution and isovaleraldehyde was completed, stirring was continued for 1.5 hours while maintaining the temperature of the reaction mixture within the above range to drive the reaction, and then the mixture was cooled to room temperature.

After removing palladium carbon from the reaction mixture by filtration, the organic layer was separated from the filtrate separated into two layers and analyzed by gas chromatography in the same manner as in Example 1. As a result, it was found that 238.7 g of the organic layer was contained. 6-methyl-
It was found that 180.4 g of 2-heptanone was contained (yield based on isovaleraldehyde: 70.4%). The conversion of isovaleraldehyde was 97.1%.
And the selectivity for the target compound from isovaleraldehyde was 72.5%.

By distilling 238.68 g of the organic layer obtained above under reduced pressure, 171.3 g of 6-methyl-2-heptanone (boiling point = 103 ° C./100 mmHg) was obtained.
Obtained.

Example 3 95.9 g (1.65 mol) of acetone was charged into a 1-liter glass autoclave equipped with a stirrer.
0.38 g of Raney nickel (hydrogenation catalyst) was added.
Then, the atmosphere of the reaction system (the atmosphere in the autoclave) was replaced with hydrogen of 5 kg / cm ² (gauge pressure), and the resulting mixture was heated to 55 ° C.

Thereafter, a 2% aqueous sodium hydroxide solution 15
1.8 g (75.8 mmol) and 129.1 g (1.5 mol) of isovaleraldehyde were each added continuously over 3 hours to the mixture obtained above using a feed pump. During the addition, the temperature of the reaction mixture was adjusted to 5
While maintaining the temperature at 9 to 61 ° C., hydrogen consumed in the reaction was supplied to the autoclave so that the pressure in the autoclave was maintained at 5 kg / cm ² (gauge pressure).
After the addition of the aqueous sodium hydroxide solution and isovaleraldehyde was completed, stirring was continued for 6 hours while keeping the temperature of the reaction mixture within the above range to drive the reaction, followed by cooling to room temperature.

After removing Raney nickel from the reaction mixture by filtration, the organic layer was separated from the filtrate separated into two layers.
Analysis by gas chromatography in the same manner as in Example 1 revealed that 166.6 g of the organic layer contained 113.8 g of 6-methyl-2-heptanone (yield based on isovaleraldehyde: 59.2%). It turned out that. The conversion of isovaleraldehyde was 96.9%, and the selectivity from isovaleraldehyde to the target compound was 61.1%.

Example 4 In a stainless steel autoclave having an internal volume of 300 ml and equipped with a stirrer, 43.6 g (0.75 mol) of acetone, 43.1 g (0.5 mol) of isovaleraldehyde and 50% of a 2% aqueous sodium hydroxide solution were added. In a nitrogen atmosphere, 0.126 g of 10% palladium carbon (hydrogenation catalyst) was added. Then, the atmosphere of the reaction system (atmosphere in the autoclave) was replaced with hydrogen of 6 kg / cm ² (gauge pressure), and the temperature of the reaction mixture was reduced to 60 ° C.
And the pressure inside the autoclave is 6 kg
The reaction was carried out while supplying the amount of hydrogen consumed in the reaction to the autoclave so as to be maintained at / cm ² (gauge pressure). After continuing the reaction at the same temperature for 4 hours, it was cooled to room temperature.

The palladium carbon was removed from the reaction mixture by filtration, and the organic layer was separated from the filtrate separated into two layers.
When analyzed by gas chromatography in the same manner as in Example 1, 62.1 g of organic layer contained 42.1 g of 6-methyl-2-heptanone (yield based on isovalaldehyde:
65.8%). The conversion of isovaleraldehyde was 99.7%, and the selectivity from isovaleraldehyde to the target compound was 66.0%.
Met.

Examples 5 to 18 The aldehyde compounds shown in Table 1 were used in place of isovalealdehyde, and the aldehyde compounds, acetone, 2% aqueous sodium hydroxide solution and palladium carbon were used in the amounts shown in Table 1. Further, the reaction was carried out at the reaction temperature and the hydrogen pressure shown in Table 1 according to the procedure of Example 1, except that the reaction time was set to the time (feed time, addition time) shown in Table 1.

As a result, ketones were obtained in the yields shown in Table 2.

[0064]

[Table 1]

[0065]

[Table 2] Example Product (saturated ketones) Yield (%) 5 2-hexanone 57.6 6 5-methyl-2-hexanone 82.1 7 5,5-dimethyl-2-hexanone 58.4 8 2-undecanone 68 0.096- (4-methylphenyl) -2-hexanone 68.4 106-methyl-2-heptanone 68.5 11 6,10-dimethyl-2-undecanone 76.9 12 6,10-dimethyl-2 -Undecanone 76.4 13 6,10-Dimethyl-2-undecanone 71.5 14 6,10,14-Trimethyl-2-pentadecanone 60.9 15 6,10,14 Trimethyl-2-pentadecanone 67.4 16 6- (5-Methyl-1,3-dioxa-2-cyclohexyl) 2-heptanone 79.8 17 7- (4-Methyl-2-tetrahydrodiperanyloxy) -6-methyl-2-heptanone 66.4 18 4- Phenyl-2-butanone 66.8

[0066]

According to the production method of the present invention, specific aldehydes, ketones, and hydrogen are reacted in the presence of a basic substance and a hydrogenation catalyst to form the corresponding ketones in one step. It can be produced with high yield and high selectivity (based on aldehydes). Therefore, the production method of the present invention is an industrially advantageous method for producing ketones.

Claims (4)

[Claims] 1. A compound represented by the formula (I): R ¹ CHO (I) (wherein R ¹ has ¹ to 5 carbon atoms which may have a substituent)
A saturated or unsaturated aliphatic hydrocarbon group having 30 or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent; And an aldehyde represented by the formula (II): R ² COCH ₂ R ³ (II) (wherein R ² has 1 to 6 carbon atoms which may have a substituent)
R ³ represents a lower alkyl group having 1 to 6 carbon atoms which may have a substituent or a hydrogen atom. )) And hydrogen in the presence of a basic substance and a hydrogenation catalyst, wherein R ² COCH (R ³ ) CH ₂ R ⁴ ( III) wherein R ² and R ³ are the same as defined above, and R ⁴ is
If R ¹ is not an unsaturated aliphatic hydrocarbon group is the same as R ^1, when R ¹ is an unsaturated aliphatic hydrocarbon groups R ¹ and which is or R ¹ hydrogen can be added at the same Is a group corresponding to a group obtained by hydrogenating at least a part of an unsaturated bond. )). 2. The method for producing ketones according to claim 1, wherein the basic substance is at least one selected from the group consisting of an alkali metal hydroxide and an alkaline earth metal hydroxide. 3. The method of claim 1, wherein the hydrogenation catalyst is reacted with a compound of formula (I) in the presence of hydrogen.
The ketones according to claim 1 or 2, wherein the reaction is carried out while continuously adding the aldehydes of the formula (I) and the basic substance to a suspension obtained by suspending the ketones of the formula (I). Production method. 4. The process for producing a ketone according to claim 1, wherein the ketone of the formula (II) is acetone (R ² is a methyl group and R ³ is a hydrogen atom). .