JPS6114134B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing oxygen-containing compounds such as methanol, ethanol, and ethylene glycol from synthesis gas, that is, a mixed gas of carbon monoxide and hydrogen. According to the method of the present invention, oxygen-containing compounds can be efficiently produced under relatively mild conditions. Oxygen-containing compounds such as methanol, ethanol, and ethylene glycol are all a group of important basic chemicals with a wide range of applications, and there is always hope for inexpensive industrial production methods. Conventionally, many methods using rhodium-based catalysts have been proposed to directly produce oxygen-containing compounds such as methanol, ethanol, and ethylene glycol in one step using carbon monoxide and hydrogen as raw materials. However, these methods, such as those exemplified in Japanese Patent Publication No. 53-31122, use expensive rhodium and are accompanied by difficulties in practical application on an industrial scale, such as recovering and reusing the rhodium catalyst.
In addition, since the catalyst performance is not necessarily sufficient,
The reality is that the process of practical application has not yet been completed. On the other hand, as one way to avoid the drawbacks of these rhodium catalysts, several methods have been proposed that use ruthenium catalysts, which are cheaper than rhodium. For example, U.S. Pat.
No. 4170605 discloses a method for producing ethylene glycol using a catalyst consisting of ruthenium and pyridine ligands. In this case, the amount of pyridine ligand used is 10 moles or less per mole of ruthenium complex, and the reaction pressure is 10,000 psi (705.2 Kg/
cm ² ) to 50,000 psi (3526.1 Kg/cm ² ). More specifically, in the examples, 2-hydroxypyridine was replaced with ruthenium 1
Using 5.74 moles per g atom, 15000 psi (1057.8
Kg/cm ² ) is shown. In addition, other pyridine ligands include 2-aminopyridine,
An example of 2-(dimethylamino)pyridine is also described, but there is no example of it actually being used, and there is no description of what kind of effects can be obtained. Further, JP-A-55-115834 proposes a method in which a Lewis base is used as an unspecified promoter together with ruthenium. However, in this case, various amines, iminium salts, alkali metal halides, alkaline earth halides, etc. are specified as examples of Lewis bases. However, the Lewis bases described in the examples are iminium salts, alkali metal halides, and alkaline earth metal halides, and it is unclear specifically what kind of structure exhibits an excellent effect, especially for organic N bases. There are no examples. In addition, JP-A-56-100728 discloses a system in which a ruthenium compound is dispersed in a low-melting phosphonium salt, an ammonium base, or an ammonium salt, while JP-A-56-123925 discloses a system in which a ruthenium compound is dispersed in an acetic acid solvent system. A composite metal system of rhodium and rhodium has been proposed. The activity of the ruthenium catalysts shown in the above-mentioned prior art cannot be said to be at a high level in any case, and in many cases, there are many examples of reactions under high pressure of around 1000 atmospheres, making it difficult to efficiently produce oxygen-containing compounds. The standard has not been reached. The present inventors have arrived at the present invention as a result of extensive studies to increase the activity of ruthenium catalysts. That is, the present invention provides a method for producing an oxygen-containing compound by reacting carbon monoxide and hydrogen, which is characterized in that the reaction is carried out in the presence of (a) a ruthenium compound and (b) an imidazopyridine. The present invention provides a method for manufacturing. The ruthenium compounds used in the method of the invention include, for example, ruthenium halides, carboxylates, inorganic acid salts, oxides, various organic and/or
Alternatively, there are compounds with complex bonds with inorganic ligands, metal ruthenium, etc. Specifically, ruthenium chloride, ruthenium bromide,
Ruthenium iodide, Ruthenium _formate , Ruthenium acetate, Ruthenium nitrate, Ruthenium oxide (), Ruthenium oxide (), Ruthenium acetylacetonate (), ( _C5H5 )( _CH3 )Ru(CO) ₂ ,
( _C5H5 ) _{2Ru , Ru3} (CO) ₁₂ , _Ru6C (CO) ₁₇ , HRu
(CO) ₄ ^- , Ru ₆ (CO) ₁₈ ^2- , HRu ₄ (CO) ₁₃ ^- ,
_H2Ru4 (CO) _{13 , H6Ru4 (} CO) ₁₂ , _HRu3
(CO) ₁₁ ^- , Ru ₆ C (CO) ₁₆ ^2- , [Ru(CO) ₃ Cl ₂ ] ₂ , etc. can be exemplified. The amount of ruthenium to be used is 1×10 ^-6 to 100 gram atoms of ruthenium per reaction solution, preferably 1×
10 ^-5 to 10 gram atoms. The imidazopyridines used in the method of the present invention are imidazo[1,2-
a] It is a derivative of pyridine and imidazo[1,5-a]pyridine, and its general formula is as follows. In the above general formulas () and (), R ₁ , R ₂ ,
R ₃ , R ₄ , R ₅ and R ₆ represent hydrogen, an alkyl group, etc. which may be the same. C ₁ as an alkyl group
~ _C10 lower alkyl groups. Specific examples of such compounds include imidazo[1,2-a]pyridine, imidazo[1,5-a]pyridine, and imidazo[1,5-a]pyridine.
a] Pyridine, 3-methylimidazo[1,2-
a] Pyridine, 2-methylimidazo[1,2-
a] Pyridine, 1-methylimidazo[1,5-
a] Pyridine, 3-methylimidazo[1,5-
a] Pyridine, 5,6-dimethylimidazo[1.
2-a]pyridine, 5,6-dimethylimidazo[1,5-a]pyridine, and the like. The various imidazopyridines mentioned above can be used alone or in combination. The amount of imidazopyridines used is ruthenium 1
The number of moles of imidazopyridine per gram atom is 1 to 5,000, preferably 2 to 2,000.
However, this does not apply when imidazopyridines are used as a solvent. As the reaction solvent, those described below can be used. For example, ethers such as diethyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether,
Ketones such as acetone, diethyl ketone and acetophenone; alcohols such as methanol, ethanol, n-butanol and ethylene glycol; carboxylic acids such as formic acid, acetic acid and propionic acid; phenols such as phenol and methoxyphenol; methyl acetate and acetic acid Esters such as ethyl, ethylene glycol diacetate and γ-butyrolactone, sulfones such as sulfolane and dimethylsulfone, sulfoxides such as dimethylsulfoxide and diethylsulfoxide, N/N-dimethylformamide, N/N-dimethylacetamide, N-
Amides such as methylpyrrolidinone, N-isopropylpyrrolidinone, N-methyl-2-pyridone,
N・N・N′・N′-tetramethylurea, N・N′-
Substituted ureas such as dimethylimidazolidinone, phosphoric acid triamides such as hexamethyl phosphoric acid triamide and tripiperidinophosphine oxide, aromatic hydrocarbons such as benzene, toluene, xylene, and tetralin, n-hexane, n- Aliphatic or alicyclic hydrocarbons such as octane, cyclohexane and decalin, nitro compounds such as nitromethane and nitrobenzene, triethylamine, tri-n-butylamine, pyridine, N-methyl-piperidine, N-methylmorpholine, α-picoline, 2・
These include tertiary amines such as 6-lutidine and 1-methylimidazole, nitriles such as acetonitrile and benzonitrile, and carbonic acid esters such as dimethyl carbonate and ethylene carbonate. In the method of the present invention, the reaction is carried out under heated and pressurized conditions. The reaction pressure is usually 1 to 2000
Kg/ ^cm2G , preferably in the range of 30-1000Kg/ ^cm2G . At this time, the ratio of carbon monoxide and hydrogen supplied to the reaction system as raw material gas for ethylene glycol production is usually in the range of 0.05 to 20, preferably 0.1 to 10 as a molar ratio of carbon monoxide to hydrogen gas. be. Also, the reaction temperature is usually 50 to 350
℃, preferably in the range of 100 to 300℃. Furthermore, the reaction time is usually 0.1 to 20 hours, preferably 0.3 hours.
A range of ~10 hours is used. This method is batch type,
It can be carried out semi-continuously or continuously. The present invention will be explained in detail with reference to Examples below.
The present invention is not limited to the following examples. Example 1 Ruthenium dodecacarbonyl (21.3 mg, 0.1
gram atom), imidazo[1.2-a]pyridine (1.181 g, 10 mmol) and N.N'-dimethylimidazolidinone (7.5 ml). After installing this autoclave in a heating furnace, a mixed gas with a molar ratio of carbon monoxide to hydrogen of 1:1 was introduced and exhausted several times from the gas introduction pipe to replace the gas in the system, and the mixture was prepared at room temperature. A mixed gas was charged so that the pressure was 360Kg/cm ² G. Heat this autoclave, and from the time the temperature of the reaction system reaches 230℃,
A time reaction was performed. The reaction pressure during this period is up to 480
Kg/cm ² G was reached, and immediately before the reaction stopped, it decreased to 455 Kg/cm ² G. After the reaction was completed, the autoclave was cooled to room temperature, and the contents were analyzed by gas chromatography. The results are shown in Table-1. Example 2 The reaction was carried out in the same manner as in Example 1 except that imidazo[1.5-a]pyridine was used instead of imidazo[1.2-a]pyridine. The results are shown in Table-1. Example 3 The reaction was carried out in the same manner as in Example 1 except that tetraglyme solvent was used instead of N·N'-dimethylimidazolidinone. The results are shown in Table-1. Example 4 The reaction was carried out in the same manner as in Example 2, except that tetraglyme solvent was used instead of N·N'-dimethylimidazolidinone. The results are shown in Table-1. Example 5 The amount of imidazo[1,2-a]pyridine added
Example 1 except that the amount was changed to 2.362 g (20 mmol)
The reaction was carried out in the same manner. The results are shown in Table-1. Comparative Example 1 Triruthenium dodecacarbonyl (21.3 mg,
The reaction was carried out in the same manner as in Example 1, except that 7.5 ml of N·N'-dimethylimidazolidinone was used as the solvent. The results are shown in Table-1. Comparative Example 2 The reaction was carried out in the same manner as in Comparative Example 1, except that 7.5 ml of tetraglyme was used as the solvent. Display the results -
Shown in 1. Comparative Example 3 Imidazo[1,2-a] 2-instead of pyridine
The reaction was carried out in the same manner as in Example 1, except that hydroxypyridine (10 mmol) was used. Display the results -
Shown in 1.

【table】

[Table] From the above Examples and Comparative Examples, it is clear that according to the method of the present invention, oxygen-containing compounds can be efficiently produced under relatively mild conditions.

Claims (1)

[Claims] 1. A method for producing an oxygen-containing compound by reacting carbon monoxide and hydrogen, the method comprising reacting in the presence of (a) a ruthenium compound and (b) imidazopyridines.