JP5217167B2 - Method for producing carbonyl compound - Google Patents

Description

  The present invention relates to a method for producing a carbonyl compound by carrying out a hydrogen transfer reaction of a raw material compound in the presence of a ruthenium complex.

  Ruthenium complex catalysts are used for hydrogen transfer reactions such as hydrogenation reactions and dehydrogenation reactions. In particular, the reaction for producing a carbonyl compound by dehydrogenation of an alcohol in the presence of a ruthenium complex catalyst has attracted industrial attention, and several systems have already been proposed. For example, a reaction to obtain a lactone compound by dehydrogenating a ruthenium-tetrahydrido-tristriphenylphosphine complex as a catalyst, a dehydrogenation reaction of methanol using a ruthenium-chloro-tetraacetoxy-ethyldiphenylphosphine complex as a catalyst, acetic acid- Examples include a dehydrogenation reaction of methanol using a phosphine-ruthenium complex catalyst and an ester synthesis reaction by dehydrogenation of alcohols using a trifluoroacetic acid-triphenylphosphine-ruthenium complex as a catalyst.

However, none of these reactions have sufficient catalytic activity, and therefore, it is necessary to add an excess amount of a hydrogen acceptor such as acetone, which is not an industrially advantageous reaction.
As a method for solving this problem, production of a carbonyl compound by dehydrogenation of alcohols using a ruthenium complex containing a trialkylphosphine as a ligand has been proposed (Patent Document 1).

However, when decomposition of trialkylphosphine or disappearance due to reaction with other components occurs, the ligand becomes insufficient, and the ruthenium metal of the catalyst may be deposited. In order to avoid such catalyst deterioration, an excessive amount of catalyst ligand may be added (Patent Document 2), but the increase in cost associated with the addition of an excessive amount of trialkylphosphine becomes a problem.
As a method for reducing this catalyst deterioration, it is conceivable to use a bidentate ligand, for example, 1,4-using a ruthenium catalyst having a ligand in which two phosphorus atoms are bridged by two methylene chains. A synthesis reaction of gamma-butyrolactone by dehydrogenation of butanediol has been proposed (Non-patent Document 1). However, since this catalyst requires a very large amount of ligand for continuous long-term use, a hydrogen transfer reaction including a dehydrogenation reaction in the presence of a smaller amount of an organic phosphine ligand. There has been a demand for a catalyst capable of carrying out the above in a highly efficient manner.
JP 2001-240595 A JP 2003-171372 A Organometallics. 2005, 24, 2441-2446

  In view of the above problems, the present invention provides a carbonyl compound with a higher yield and a higher reaction rate in a low complex concentration in the presence of a small amount of an organic phosphine ligand when performing a hydrogen transfer reaction of a raw material compound using a ruthenium complex. An object of the present invention is to provide a method of producing

  As a result of intensive studies to solve the above problems, the present inventors have solved the above problems by using a ruthenium complex comprising a metal ruthenium or a ruthenium compound and an organic phosphorus ligand represented by the following general formula (a). As a result, the present invention has been completed.

(Ra to Rd each represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and R represents a hydrocarbon group having a main chain having 3 to 12 carbon atoms. )

  According to the present invention, in a hydrogen transfer reaction using a ruthenium complex, a carbonyl compound can be produced with high efficiency by using a smaller amount of an organic phosphorus ligand.

The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents. The details will be described below.
In the method for producing a carbonyl compound by hydrogen transfer reaction using a ruthenium complex, the present invention is characterized in that the ruthenium complex has an organic phosphorus ligand represented by the general formula (a). In order to obtain such a ruthenium complex, for example, a metal ruthenium or ruthenium compound and an organic phosphorus ligand represented by the general formula (a) may be used.

(Ra to Rd each represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and R represents a hydrocarbon group having a main chain having 3 to 12 carbon atoms. )

According to the production method of the present invention, in the method of producing a carbonyl compound by carrying out a hydrogen transfer reaction of a raw material compound using a ruthenium complex, the amount of the organic phosphorus ligand used can be reduced, and the reaction can be carried out efficiently. .
Although this reason is not necessarily clear, it is estimated as follows.
In general, in a ruthenium complex having an organophosphorus ligand, a complex using a monodentate ligand has a high catalytic activity, and a complex using a bidentate or higher ligand tends to have a low catalytic activity. According to the study by the present inventors, it is considered that this is related to the distance between phosphorus atoms in the complex. Therefore, by combining two phosphorus atoms in a bidentate ligand with a hydrocarbon group having a main chain having a specific carbon number, a complex is formed using an organic phosphorus ligand having a specific structure. The angle formed by the ruthenium metal center and the two phosphorus atoms (bit-angle) can be kept large to some extent, and a structure similar to a complex using a monodentate ligand with high catalytic activity can be formed. It is done.

On the other hand, monodentate organic ligands tend to dissociate from the ruthenium metal center and easily deteriorate as a catalyst, but the bidentate in which two phosphorus atoms in the ligand are connected by a hydrocarbon group. If it is a ligand, it can be presumed that a phosphorus atom can be prevented from dissociating from the ruthenium metal center and a complex that hardly deteriorates as a catalyst can be formed.
For this reason, the ruthenium complex according to the present invention is an excellent complex that can achieve both high catalytic activity and low catalyst deterioration, which has been difficult in the past, in a method for producing a carbonyl compound by performing a hydrogen transfer reaction of a raw material compound. It is believed that there is.

  The hydrogen transfer reaction in the present invention is a reaction in which hydrogen moves, such as a hydrogenation reaction and a dehydrogenation reaction. The hydrogenation reaction and the dehydrogenation reaction are in a forward / reverse reaction and are usually reversible reactions. This reversible reaction is selectively used according to the purpose. If it is desired to proceed with the hydrogenation reaction, the reaction may be carried out under hydrogen pressure, while if it is desired to proceed with the dehydrogenation reaction, the reaction may be carried out while releasing hydrogen gas out of the system. Good. In this hydrogenation reaction and dehydrogenation reaction, which are reversible reactions, the same complex is considered to be effective in reducing activation energy, which is a barrier for allowing the reaction to proceed at a high rate.

  That is, the present invention relates to a method for producing a carbonyl compound in the presence of a ruthenium complex, for example, by a hydrogenation reaction or a dehydrogenation reaction. For example, a method for producing a carbonyl compound by dehydrogenating the alcohol using a raw material compound, a method for producing a carbonyl compound by a hydrogenation reaction using carboxylic anhydrides, imides or the like as the raw material compound, etc. Is mentioned. Preferably, the present invention is applied to the production of a carbonyl compound by dehydrogenation of an alcohol or the production of a carbonyl compound by a hydrogenation reaction of carboxylic anhydrides, imides and the like. In particular, it is preferably applied to the production of a carbonyl compound by alcohol dehydrogenation.

  The alcohol used for producing the carbonyl compound by the dehydrogenation reaction of the alcohol is not particularly limited as long as it is a monovalent or polyhydric alcohol that can be converted into the carbonyl compound by the dehydrogenation reaction. Such alcohols include primary or secondary alcohols; linear (straight or branched) or cyclic alcohols; saturated or unsaturated aliphatic alcohols or aromatic alcohols, all of which can be used. . Of these, those having 1 to 50 carbon atoms are preferred, and those having 1 to 10 carbon atoms are particularly preferred. In addition, these alcohols may have a substituent containing a hetero element such as an amino group, a sulfide group, or an ether group.

  Examples of the monohydric alcohol include primary saturation such as methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol and 1-decanol. Alcohol: 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, 2-hexanol, 3-hexanol, 2-heptanol, 3-heptanol, 4-heptanol, 2-octanol, 3-octanol, 4- Secondary saturated alcohols such as octanol, 2-nonanol, 3-nonanol, 4-nonanol, 5-nonanol, 2-decanol, 3-decanol, 4-decanol, 5-decanol; cyclohexanol, cyclopentanol, cyclohepta Cyclic alcohols such as knolls; Primary unsaturated aliphatic alcohols such as alcohol, 1-butenol, 1-pentenol, 1-hexenol, 1-heptenol, 1-octenol, 1-nonenol, 1-decenol; 2-butenol, 2-pentenol, 2-hexenol, 3-hexenol, 2-heptenol, 3-heptenol, 2-octenol, 3-octenol, 4-octenol, 2-nonenol, 3-nonenol, 4-nonenol, 2-decenol, 3-decenol, 4- Examples include secondary unsaturated aliphatic alcohols such as decenol and 5-decenol; aromatic alcohols such as phenethyl alcohol and 2-phenylethyl alcohol; amino alcohols such as methanolamine and ethanolamine. In the case of an unsaturated aliphatic alcohol, the position of the unsaturated bond is arbitrary.

  Examples of the polyhydric alcohol include chain aliphatic alcohols such as 1,3-propanediol, 1,4-butanediol, 1,5-hexanediol, 1,6-hexanediol, and 2,4-pentanediol; 1,2-cyclohexyldimethylol, 1,3-cyclohexyldimethylol, 1-hydroxymethyl-2- (2-hydroxyethyl) cyclohexane, 1-hydroxy-2- (3-hydroxypropyl) cyclohexane, 1-hydroxy-2 Cyclic aliphatic alcohols such as-(2-hydroxyethyl) cyclohexane; 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1-hydroxymethyl-2- (2-hydroxyethyl) benzene, 1-hydroxy- 2- (3-hydroxypropyl) benzene, 1-hydroxy-2- ( - and aromatic alcohols such as hydroxyethyl) benzene.

  Among the above alcohols, the use of a dihydric alcohol is preferred, a divalent chain aliphatic alcohol is more preferred, a divalent chain saturated alcohol is more preferred, and 1,4-butanediol is particularly preferred. In the case of a dihydric alcohol, there is an advantage that an intramolecular cyclization reaction proceeds and lactones useful as a carbonyl compound can be produced by the production method of the present invention. Of these, divalent chain aliphatic alcohols are preferred because they are easy to react. In particular, by using 1,4-butanediol as a raw material compound, γ-butyrolactone having a wide range of uses as a lactone can be obtained.

  Although it does not specifically limit as a raw material compound used when manufacturing a carbonyl compound by hydrogenation reaction, Preferably carboxylic anhydrides and imides are mentioned. Examples of carboxylic anhydrides include maleic anhydride, succinic anhydride, citraconic anhydride, itaconic anhydride, glutaric anhydride, phthalic anhydride, and the like. Examples of the imides include maleimide, succinimide, citraconic imide, itaconic imide, glutarimide, and phthalimide. Of these, carboxylic anhydrides are preferable, and maleic anhydride and succinic anhydride are more preferable.

  One feature of the present invention is that an organophosphorus ligand represented by the general formula (a) is used as the ligand of the ruthenium complex.

(Ra to Rd each represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and R represents a hydrocarbon group having a main chain having 3 to 12 carbon atoms. )

  In formula (a), R is a divalent hydrocarbon group connecting two phosphorus atoms, and has a main chain having 3 to 12 carbon atoms. When the number of carbon atoms is 2 or less, the main chain is too short, and the catalytic activity of the ruthenium complex becomes low. On the other hand, when the number of carbon atoms is too large, the main chain becomes too long, and the possibility that two phosphorus atoms coordinate to different ruthenium atoms increases. Therefore, it is difficult to obtain the complex having the specific structure, and the catalytic activity of the ruthenium complex is lowered. The main chain preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, still more preferably 3 to 6 carbon atoms, and most preferably 3 or 5 carbon atoms. The main chain may be either an aliphatic hydrocarbon or an aromatic hydrocarbon, but is preferably composed of a chain aliphatic hydrocarbon. An alkylene group is particularly preferable. Specifically, propylene group, butylene group, pentylene group, hexylene group, heptylene group and octylene group are preferable, propylene group, butylene group, pentylene group and hexylene group are more preferable, and propylene group or pentylene group is most preferable. .

The main chain may have a substituent such as an alkyl group, a cycloalkyl group, or an aryl group on an arbitrary carbon atom as long as the effects of the present invention are not significantly impaired. However, the substituent preferably does not contain a hetero group. Most preferably, the main chain has no substituent.
In formula (a), Ra to Rd are each independently a chain or cyclic aliphatic hydrocarbon group having 1 to 20 carbon atoms, and these aliphatic hydrocarbon groups further have a substituent. It may be.

  The aliphatic hydrocarbon group is preferably an alkyl group or a cycloalkyl group. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n- Pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, Examples include a cyclononyl group, a cyclodecyl group, a cycloundecyl group, and a cyclododecyl group.

Although carbon number of an aliphatic hydrocarbon group is 1-20, Preferably it is 1-12, More preferably, it is 1-8, More preferably, it is 1-6.
As the substituent that the aliphatic hydrocarbon group may have, any substituent that does not significantly impair the effects of the present invention can be used. For example, an aryl group, an alkoxy group, an aryloxy group, an alkylaryloxy group, an amino group, an alkyl group An amino group, a sulfide group, etc. are mentioned. However, it is most preferable not to have a substituent.

Ra to Rd may be the same or different.
The organic phosphorus ligand in the present invention is not particularly limited as long as it satisfies the formula (a). For example, 1,3-bis (diethylphosphino) propane, 1,3-bis (dimethylphosphino) propane, 1,3-bis (dipropylphosphino) propane, 1,3-bis (dibutylphosphino) propane 1,4-bis (diethylphosphino) butane, 1,5-bis (diethylphosphino) pentane, 1,6-bis (diethylphosphino) hexane, 1,4-bis (dimethylphosphino) butane, , 5-bis (dimethylphosphino) pentane, 1,6-bis (dimethylphosphino) hexane, 1,4-bis (dipropylphosphino) butane, 1,5-bis (dipropylphosphino) pentane, , 6-Bis (dipropylphosphino) hexane, 1,4-bis (dibutylphosphino) butane, 1,5-bis (dibutylphosphino) pentane 1,6-bis (dibutylphosphino) hexane, 1,4-bis (dihexylphosphino) butane, 1,5-bis (dihexylphosphino) pentane, 1,6-bis (dihexylphosphino) hexane, 1, Compounds such as 3-bis (dioctylphosphino) propane, 1,4-bis (dioctylphosphino) butane, 1,5-bis (dioctylphosphino) pentane, 1,6-bis (dioctylphosphino) hexane, Used. Of these, 1,3-bis (diethylphosphino) propane and 1,5-bis (diethylphosphino) pentane are particularly preferable.

In the present invention, one type of organic phosphorus ligand is usually used, but two or more types of organic phosphorus ligands can be used in combination. If necessary, other ligands may be used in combination as long as the effects of the present invention are not significantly impaired.
The method for preparing the ruthenium complex in the present invention is not particularly limited. In the preparation, both metal ruthenium and ruthenium compounds can be used.

  Examples of ruthenium compounds include oxides such as ruthenium dioxide and ruthenium tetroxide; inorganic salts such as ruthenium hydroxide and ruthenium nitrate; tris (acetylacetonato) ruthenium, tris (hexafluoroacetylacetonato) ruthenium and dimethylbutadieneacetyl. Acetonatorthenium, bis (2-methylallyl) (1,5-cyclooctadiene) ruthenium, tris (2,2,6,6-tetramethyl-3,5-heptanedionato) ruthenium, dipotassium tetracarbonylruthenate, pentacarbonyl Ruthenium, cyclopentadienyldicarbonylruthenium, dibromotricarbonylruthenium, bis (tri-n-butylphosphine) tricarbonylruthenium, dichloro (tetrakisdimethylsulfoxide) rutenium , Tetra hydrido dodecacarbonyltriruthenium tetra ruthenium, dodecacarbonyl tri ruthenium, octadecanol carbonyl hexa ruthenate Jiseshiumu, undecalactone carbonyl hydride tri ruthenate tetraphenyl phosphonium complex compounds such as iodonium, and the like.

Of these, complex compounds are preferable, and tris (acetylacetonato) ruthenium, tris (hexafluoroacetylacetonato) ruthenium, dimethylbutadieneacetylacetonatruthenium, bis (2-methylallyl) (1,5-cyclooctadiene) are particularly preferable. Ruthenium is particularly preferred.
In the method for producing a carbonyl compound of the present invention, the concentration of the ruthenium complex in the reaction solution is preferably 10 ppm by weight or more as the ruthenium metal equivalent concentration. The reaction rate of the hydrogenation reaction can be further increased, and the reactor size can be reduced. More preferably, it is 30 weight ppm or more, More preferably, it is 100 weight ppm or more. However, the ruthenium metal equivalent concentration is preferably 100,000 ppm by weight or less. This is because if the concentration is too high, the reaction rate is not affected and the cost increases. More preferably, it is 10,000 weight ppm or less, More preferably, it is 3,000 weight ppm or less. Note that when a ruthenium complex is prepared in a reaction vessel immediately before the hydrogen transfer reaction, the ruthenium metal equivalent concentration can also be calculated from the amount of metal ruthenium or ruthenium compound used as a ruthenium source.

  The amount of the organophosphorus ligand relative to ruthenium is such that the organophosphorus ligand is usually at least 1 molar equivalent per mole of ruthenium atom. As the amount of the organophosphorus ligand is larger than this, the catalytic activity of the complex tends to increase. Preferably it is 2 molar equivalents or more. Moreover, it is made to become below normally 10 molar equivalent. This is because even if the amount is too large, the catalytic activity does not increase any more and costs increase. Preferably it is 8 molar equivalents or less, More preferably, it is 6 molar equivalents or less.

The method for preparing the ruthenium complex is not particularly limited. For example, it may be prepared in a reaction vessel immediately before the hydrogen transfer reaction, and the hydrogen transfer reaction may be carried out as it is, or one prepared in advance in a separate vessel may be added to the reaction vessel for the hydrogen transfer reaction and used. .
As a method of preparing in advance, for example, a method in which a ruthenium compound and an organic phosphorus ligand are heated and stirred in a solvent or in the absence of a solvent in a hydrogen atmosphere or an inert gas atmosphere such as nitrogen or argon. is there. The pressure in this case may be normal pressure or pressurized. Usually, it is 0.1 MPa or more and 10 MPa or less, preferably 1 MPa or less. The temperature at which heating and stirring is performed is usually 30 ° C. or higher. This is to accelerate the preparation of the complex. Preferably it is 100 degreeC or more, More preferably, it is 150 degreeC or more. Moreover, it is 250 degrees C or less normally. This is to suppress the progress of thermal decomposition of the complex. Preferably it is 230 degrees C or less, More preferably, it is 210 degrees C or less. By adding the complex or complex solution thus prepared to the reaction vessel containing the reaction raw material compound, the target hydrogen transfer reaction can proceed.

Even when the complex is prepared in the reaction vessel immediately before the hydrogen transfer reaction, the complex may be prepared under the conditions as described above, and the target hydrogen transfer reaction can be advanced by adding the raw material compound of the reaction after the preparation. Can do.
Next, the manufacturing method of the carbonyl compound of this invention is demonstrated.
The temperature at which the carbonyl compound is produced by the hydrogen transfer reaction is usually 50 ° C. or higher. This is to increase the reaction rate and increase productivity. Preferably it is 100 degreeC or more, More preferably, it is 130 degreeC or more. Moreover, it is 300 degrees C or less normally. This is to suppress degradation of the complex. Preferably it is 250 degrees C or less, More preferably, it is 210 degrees C or less.

When the raw material compound and the carbonyl compound to be produced are liquid, a solvent is not particularly required, but a solvent may be used depending on the purpose. Moreover, when the raw material compound and the carbonyl compound to be produced are solid, it is preferable to use a solvent. Maleic anhydride, succinic anhydride and the like are usually solid.
The solvent to be used is not particularly limited as long as it can dissolve the raw material compound and the generated carbonyl compound and does not adversely influence the reaction. For example, ethers such as diethyl ether, anisole, tetrahydrofuran, ethylene glycol dimethyl ether and dioxane; esters such as methyl acetate, butyl acetate and benzyl benzoate; aromatic hydrocarbons such as benzene, toluene, ethylbenzene and tetralin; n- Aliphatic hydrocarbons such as hexane, n-octane and cyclohexane; Nitro compounds such as nitromethane and nitrobenzene; Carboxylic acid amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; Hexamethylphosphorus Other amides such as acid triamide; ureas such as N, N′-dimethylimidazolidinone, sulfones such as dimethylsulfolane; sulfoxides such as dimethyl sulfoxide; γ-butyrolactone, caprolactone, etc. Lactone compounds; tetraglyme, polyethers such as triglyme; dimethyl carbonate, carbonates such as ethylene carbonate. Of these, ethers and polyethers are preferred.

As for the atmosphere and pressure, there are preferable conditions for each of the hydrogenation reaction and the dehydrogenation reaction.
When the hydrogenation reaction is performed, for example, the reaction can be performed in the presence of air, hydrogen gas, carbon dioxide gas; hydrocarbon gas such as methane, ethane, or butane; inert gas such as nitrogen, argon, or helium. Among these, in order to promote the hydrogenation reaction, it is preferable to carry out the reaction in a hydrogen atmosphere.

  The reaction can be carried out under normal pressure, reduced pressure, or increased pressure. However, under reduced pressure, the dehydrogenation reaction, which is a reverse reaction, is suppressed and the reaction proceeds more rapidly. For this reason, the pressure is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and particularly preferably 1.0 MPa or more. Further, since the high pressure resistant reactor is expensive, the pressure is preferably 100 MPa or less, more preferably 10 MPa or less, and particularly preferably 5 MPa or less, in order to perform the process at a low cost.

  On the other hand, the dehydrogenation reaction can be performed, for example, in the presence of air, hydrogen gas; carbon dioxide gas; hydrocarbon gas such as methane, ethane, or butane; inert gas such as nitrogen, argon, or helium. . In order to promote the dehydrogenation reaction, it is preferable to carry out the reaction while releasing generated hydrogen. For example, the system is opened and the reaction is carried out while extracting the produced hydrogen.

  The reaction can be carried out under normal pressure, reduced pressure, or increased pressure, but a lower pressure is preferred in order to suppress the reverse hydrogenation reaction and allow the reaction to proceed more rapidly. For this reason, the pressure is preferably 1 MPa or less, more preferably 0.5 MPa or less, and particularly preferably 0.3 MPa or less. In order to keep the reaction components in a liquid and facilitate the reaction, the pressure is preferably 0.01 MPa or more, more preferably 0.03 MPa or more, and particularly preferably 0.08 MPa or more.

Note that both the dehydrogenation reaction and the hydrogenation reaction can be carried out by either a batch system or a continuous system.
By the above method, a carbonyl compound can be obtained in a high yield while keeping the amount of the organic phosphorus ligand used low. For example, aldehydes such as formaldehyde, ethanal, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, decanal; ketones such as 2-propanone, 2-butanone, 2-pentanone, 3-pentanone; acetylacetone, etc. Diketones: Carbonyl compounds such as lactones such as γ-butyrolactone can be produced, and among them, they are suitable for producing γ-butyrolactone. In particular, according to the present invention, γ-butyrolactone can be efficiently produced at a high yield by dehydrogenation of 1,4-butanediol, and a yield of 90% or more can also be mentioned.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.

Example 1
In a 30 mL glass flask, add 2.5 g of 1,4-butanediol, 2.5 g of triglyme, 11 mg of tris (acetylacetonato) ruthenium, and 27 mg of 1,5-bis (diethylphosphino) pentane. The temperature was raised and dissolved. At this time, the metal equivalent concentration of ruthenium (Ru) in the solution was 560 ppm by weight, and the ratio of the organophosphorus ligand to the ruthenium metal atom was 4.4 molar equivalents. And the said solution was heated and stirred at 200 degreeC for 10 hours, and the dehydrogenation reaction was performed. As a result of analyzing the obtained reaction liquid by gas chromatography, the conversion of 1,4-butanediol was 100 mol%, and the yield of γ-butyrolactone was 99 mol%. The results are shown in Table 1.

Example 2
In a 30 mL glass flask, 2.5 g of 1,4-butanediol, 2.5 g of triglyme, 8.9 mg of bis (2-methylallyl) cyclooctadiene ruthenium, and 21 mg of 1,5-bis (diethylphosphino) pentane were added. In addition, the temperature was raised to 200 ° C. and dissolved. At this time, the metal equivalent concentration of ruthenium in the solution was 560 ppm by weight, and the ratio of the organophosphorus ligand to the ruthenium metal atom was 2.8 molar equivalents. And the said solution was heated and stirred at 200 degreeC for 13 hours, and the dehydrogenation reaction was performed. The change in the yield of γ-butyrolactone (GBL) over the course of the reaction time (h: time) is shown in FIG. As a result, no deterioration of the complex was observed, and after 13 hours, the conversion of 1,4-butanediol was 99 mol% and the yield of γ-butyrolactone reached 97 mol%. The results are shown in Table 1.

Comparative Example 3
In a 30 mL glass flask, 2.5 g of 1,4-butanediol and 2.5 g of triglyme, 8.9 mg of bis (2-methylallyl) cyclooctadiene ruthenium, 1,3-bis (diethylphosphino) propane 13. 4 mg was added, and it heated up to 200 degreeC and made it melt | dissolve. At this time, the metal equivalent concentration of ruthenium in the solution was 560 ppm by weight, and the ratio of the organophosphorus ligand to the ruthenium metal atom was 4.4 molar equivalents. And the said solution was heated and stirred at 200 degreeC for 10 hours, and the dehydrogenation reaction was performed. As a result, the 1,4-butanediol conversion rate reached 100 mol%, and the γ-butyrolactone yield reached 94 mol%. The results are shown in Table 1.

Comparative Example 1
In a 30 mL glass flask, add 2.5 g of 1,4-butanediol, 2.5 g of triglyme, 8.9 mg of bis (2-methylallyl) cyclooctadiene ruthenium, and 14 mg of tributylphosphine. I let you. At this time, the metal equivalent concentration of ruthenium in the solution was 560 ppm by weight, and the ratio of the organophosphorus ligand to the ruthenium metal atom was 2.5 molar equivalents. And the said solution was heated and stirred at 200 degreeC for 13 hours, and the dehydrogenation reaction was performed. The change in the yield of γ-butyrolactone with the reaction time is shown in FIG.
As a result, the complex deteriorated in about 3 hours, and even after 13 hours, the 1,4-butanediol conversion was 56 mol% and the γ-butyrolactone yield was 21 mol%. The results are shown in Table 1.

Comparative Example 2
In a 30 mL glass flask, add 2.5 g of 1,4-butanediol, 2.5 g of triglyme, 11 mg of tris (acetylacetonato) ruthenium, 10 mg of 1,2-bis (dimethylphosphino) ethane and add up to 200 ° C. The temperature was raised and dissolved. At this time, the metal equivalent concentration of ruthenium in the solution was 560 ppm by weight, and the ratio of the organophosphorus ligand to the ruthenium metal atom was 3.8 molar equivalents. And the said solution was heated and stirred at 200 degreeC for 13 hours, and the dehydrogenation reaction was performed. As a result, the 1,4-butanediol conversion rate was 94 mol%, and the γ-butyrolactone yield was 87 mol%. The results are shown in Table 1.

From the above, it can be seen that Examples 1 and 2 have high reaction results, while Comparative Example 2 has poor reaction results. Further, FIG. 1 shows that although Comparative Example 1 has a high initial reaction result, the deterioration of the complex rapidly progressed and the reaction did not proceed after 3 hours. In other words, according to the method for producing a carbonyl compound using the specific ruthenium complex of the present invention, high reaction results can be obtained efficiently while keeping the amount of the organic phosphorus ligand used low.

6 is a graph showing changes with time in the yield of γ-butyrolactone in Example 2 and Comparative Example 1.

Claims (6)

In the method for producing a carbonyl compound by hydrogen transfer reaction of a raw material compound in the presence of a ruthenium complex, the ruthenium complex has an organophosphorus ligand represented by the following general formula (a). Manufacturing method.

(Ra to Rd each represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and R represents a hydrocarbon group having a main chain having 5 carbon atoms.) The said ruthenium complex has 1-10 molar equivalent of an organophosphorus ligand with respect to 1 mol of ruthenium atoms, The manufacturing method of Claim 1 characterized by the above-mentioned. The production method according to claim 1 or 2, wherein the ruthenium complex has a ruthenium metal equivalent concentration of 10 to 100,000 ppm by weight. The production method according to any one of claims 1 to 3, wherein the raw material compound is an alcohol, and the hydrogen transfer reaction is a dehydrogenation reaction. The production method according to claim 4, wherein the alcohol is a polyhydric alcohol. 6. The production method according to claim 5, wherein the polyhydric alcohol is 1,4-butanediol and the carbonyl compound is γ-butyrolactone.

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