JP2516815B2 - Method for producing lactones - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing lactones. More specifically, the present invention relates to an improvement in a method for producing a lactone by hydrogenating a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester in a liquid phase.

(Prior Art) A method for producing a lactone by hydrogenating a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester has been studied for a long time, and many proposals have been made so far. For example, as a catalyst, a nickel-based catalyst (Japanese Patent Publication No. 43-6947), a cobalt-based catalyst (JP-A-51-9505)
No. 7), a copper-chromium catalyst (Japanese Patent Publication No. 38-20119), a copper-zinc catalyst (Japanese Patent Publication No. 42-14463), etc. for hydrogenation in a fixed bed or suspension phase. Methods for carrying out the reaction are known.

On the other hand, a method of carrying out the above hydrogenation reaction using a homogeneous ruthenium-based catalyst is also known, for example, US Pat.
No. 7 describes a method for producing lactones by hydrogenating under pressure of 40 to 400 psi using a [RuXn (PR ₁ R ₂ R ₃ ) xLy] type ruthenium-based catalyst, and US Pat. No. 4,485,246. Describes that a similar catalytic hydrogenation reaction is carried out in the presence of an organic amine.

(Problems to be Solved by the Invention) However, in the conventional method using a solid catalyst such as the above nickel-based catalyst, cobalt-based catalyst, copper-chromium-based catalyst, copper-zinc-based catalyst, the reaction condition is several tens of atmospheres. However, there is a problem that it is inevitable to adopt the above severe conditions. On the other hand, the method of using the homogeneous ruthenium-based catalyst,
While the hydrogenation reaction proceeds under relatively mild conditions, the catalyst activity is rather low, the catalyst life is short, and the use of halogen causes corrosion of the reactor. There's a problem.

Therefore, the present applicant previously proposed a method of hydrogenating in a liquid phase using a ruthenium-based catalyst containing ruthenium, an organic phosphine, and a conjugate base of an acid having a pKa value of less than 2 as a catalyst (JP-A-1- 25771 publication). In this method, since a highly active ruthenium catalyst is used, the hydrogenation reaction can be satisfactorily carried out under mild conditions, but the hydrogenation reaction can be performed using dicarboxylic acid, dicarboxylic acid anhydride and / or dicarboxylic acid ester as a raw material. When the reaction is carried out, a high boiling point component is generated in the reaction zone due to decomposition or polycondensation,
There is a drawback that the yield of lactones decreases.

The present invention aims to solve the above-mentioned problems of the method using a ruthenium catalyst and to industrially advantageously produce a lactone from a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester. is there.

(Means for Solving the Problems) As a result of studies to achieve the above object, the present inventors have found that a ruthenium catalyst is used to hydrogenate a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester in a liquid phase. If the concentration of dicarboxylic acid anhydride in the hydrogenation reaction zone is maintained at a specific ratio or lower in the case of producing lactones by oxidization, not only the yield of lactones is improved but also the hydrogenation activity of the catalyst is improved. The inventors have found that it is also effective and have reached the present invention. That is, the gist of the present invention is
In the method for producing a lactone by hydrogenating a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester in a liquid phase in the presence of a ruthenium catalyst, the concentration of the dicarboxylic acid anhydride in the hydrogenation reaction zone is 3% by weight. It exists in the manufacturing method of the lactone characterized by holding below.

To explain the present invention in detail, examples of the raw material in the present invention include saturated or unsaturated dicarboxylic acids having 3 to 7 carbon atoms, anhydrides thereof, or esters of dicarboxylic acids thereof. Is preferably a lower alkyl ester. Specifically, for example, maleic acid, fumaric acid, succinic acid, maleic anhydride, succinic anhydride,
Dimethyl maleate, diethyl fumarate, succinic acid-
Di-n-butyl or the like is used.

The ruthenium catalyst used in the present invention is not particularly limited, but includes, for example, (a) ruthenium, (b) an organic phosphine, and (c) a ruthenium catalyst containing a conjugate base of an acid having a pKa of less than 2, or a ruthenium catalyst. A catalyst in which (d) a neutral ligand is further contained in the catalyst is preferably used.

The present invention provides a dicarboxylic acid anhydride in a hydrogenation reaction zone when producing a lactone by hydrogenating the above-mentioned dicarboxylic acid, dicarboxylic acid anhydride and / or dicarboxylic acid ester in a liquid phase in the presence of the ruthenium catalyst. The main idea is to keep the concentration of 3% by weight or less, preferably 2% by weight or less. For this purpose, for example, a method of diluting with a solvent or increasing the catalyst concentration so that the concentration of the dicarboxylic acid anhydride in the hydrogenation reaction zone is 3% by weight or less is adopted. By such a method, the production of high-boiling substances due to the decomposition or polycondensation of the raw materials is suppressed, and not only the yield of lactones is improved but also the hydrogenation activity of the catalyst is improved.

 The present invention will be described in more detail below.

In the present invention, a ruthenium catalyst containing (a) ruthenium, (b) an organic phosphine, and (c) a conjugate base of an acid having a pKa value of less than 2 and optionally a neutral ligand is shown. Details are as follows.

(A) Ruthenium: As ruthenium, both metal ruthenium and ruthenium compounds can be used. As the ruthenium compound, ruthenium oxide, halide, hydroxide, inorganic acid salt, organic acid salt or complex compound is used, and specifically, for example, ruthenium dioxide, ruthenium tetroxide, ruthenium dihydroxide, chloride. Ruthenium, ruthenium bromide, ruthenium iodide, ruthenium nitrate, ruthenium acetate, tris (acetylacetone) ruthenium, sodium hexachlororuthenate, dipotassium tetracarbonyl ruthenate, pentacarbonyl ruthenium, cyclopentadienyl dicavonyl ruthenium, dibromotricarbonyl ruthenium , Chlorotris (triphenylphosphine) hydrido ruthenium, bis (tri-n-
Butylphosphine) tricarbonylruthenium, dodecacarbonyltriruthenium, tetrahydridodecacarbonyltetraruthenium, octadecacarbonylhexaruthenate dicesium, undecacarbonylhydridotriruthenate tetraphenylphosphonium and the like. The amount of these metal ruthenium and ruthenium compounds used was 0.
It is 0001 to 100 mmol, preferably 0.001 to 10 mmol.

(B) Organic phosphine: It is considered that the organic phosphine contributes to controlling the electronic state of ruthenium of (a) which is the main catalyst and stabilizing the active state of ruthenium. Specific examples of the organic phosphine include trialkylphosphines such as tri-n-octylphosphine, tri-n-butylphosphine and dimethyl-n-octylphosphine, tricycloalkylphosphines such as tricyclohexylphosphine, triphenylphosphine. Such as triarylphosphines, alkylarylphosphines such as dimethylphenylphosphine, and polyfunctional phosphines such as 1,2-bis (diphenylphosphino) ethane. The amount of organic phosphine used is usually 1
With respect to mol, about 0.1 to 1000 mol, preferably 1 to 100
Is a mole. Further, the organic phosphine can be supplied to the reaction system by itself or in the form of a complex with a ruthenium catalyst.

(C) Conjugate base of acid with pKa value less than 2: The conjugate base of acid with pKa value less than 2 acts as an additional promoter of ruthenium catalyst and has pKa value of 2 or less during catalyst preparation or reaction system. Any acid capable of producing a conjugate base of a smaller acid may be used, and as a supply form thereof, a Bronsted acid having a pKa value of less than 2 or various salts thereof is used. Specifically, for example, sulfuric acid, sulfurous acid, nitric acid,
Inorganic acids such as nitrous acid, perchloric acid, phosphoric acid, borofluoric acid, hexafluorophosphoric acid, tungstic acid, phosphomolybdic acid, phosphotungstic acid, silicon tungstic acid, polysilicic acid, fluorosulfonic acid, trichloroacetic acid, dichloroacetic acid, Organic acids such as trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, laurylsulfonic acid, benzenesulfonic acid and p-trienesulfonic acid,
Alternatively, ammonium salts and phosphonium salts of these acids can be mentioned. Further, the same effect can be obtained even if the conjugate base of these acids is added in the form of an acid derivative, such as an acid halide, an acid anhydride, an ester or an acid amide, which is considered to be produced in the reaction system. The amount of these acids or salts thereof used is in the range of 0.01 to 1000 mol, preferably 0.1 to 100 mol, and more preferably 0.5 to 20 mol, relative to 1 mol of ruthenium.

In addition to the components (a), (b) and (c) above, (d) a neutral ligand which may be optionally contained,
Olefins such as hydrogen, ethylene, propylene, butene, cyclopentene, cyclohexene, butadiene, cyclopentadiene, cyclooctadiene, norbonadiene, carbon monoxide, diethyl ether, anisole, dioxane, tetrahydrofuran, acetone, acetophenone, benzophenone, cyclohexanone, propionic acid , Caproic acid, butyric acid, benzoic acid, ethyl acetate, allyl acetate, benzyl benzoate, oxygen-containing compounds such as benzyl stearate, nitric oxide, acetonitrile, propionitrile, benzonitrile, cyclohexylisonitrile,
Butylamine, aniline, toluidine, triethylamine, pyrrole, pyridine, N-methylformamide, acetamide, 1,1,3,3-tetramethylurea, N-methylpyrrolidone, caprolactam, nitrogen-containing compounds such as nitromethane, carbon disulfide, n -Sulfur-containing compounds such as butyl mercaptan, thiophenol, dimethyl sulfide, dimethyl disulfide, thiophene, dimethyl sulfoxide, diphenyl sulfoxide, tributylphosphine oxide, ethyldiphenylphosphine oxide, triphenylphosphine oxide, diethylphenylphosphinate, diphenylmethylphosphinate, Diphenylethylphosphinate, o, o-dimethylmethylphosphonothiolate, triethylphosphite, triphenylphosphite, triethylphosphite Neighboring compounds other than organic phosphines such as sulfate, triphenyl phosphate, and hexamethylphosphoric triamide can be mentioned.

The method of the present invention can be carried out by using the raw material itself as a solvent without using a solvent, but it is also possible to use another solvent other than the raw material.

Examples of such a solvent include diethyl ether,
Ethers such as anisole, tetrahydrofuran, ethylene glycol diethyl ether, triethylene glycol dimethyl ether and dioxane; ketones such as acetone, methyl ethyl ketone and acetophenone; alcohols such as methanol, ethanol, n-butanol, benzine alcohol, ethylene glycol and diethylene glycol; Phenols; carboxylic acids such as formic acid, acetic acid, propionic acid, toluic acid; methyl acetate, acetic acid n
-Esters such as butyl and benzyl benzoate; aromatic hydrocarbons such as benzene, toluene, ethylbenzene and tetralin; aliphatic hydrocarbons such as n-hexane, n-octane and cyclohexane; halogenation of dichloromethane, trichloroethane, chlorobenzene and the like Hydrocarbons; Nitrated hydrocarbons such as nitromethane and nitrobenzene; N, N-dimethylformamide, N, N-dimethylacetamide, N-
Carboxylic acid amides such as methylpyrrolidone; Other amides such as hexamethylphosphoric triamide, N, N, N ', N'-tetraethylsulfamide; N, N'-dimethylimidozolidone, N, N, N , N-tetramethylurea and other ureas; dimethyl sulfone, tetramethylene sulfone and other sulfones;
Sulfoxides such as dimethyl sulfoxide and diphenyl sulfoxide; Lactones such as γ-butyrolactone and ε-caprolactone; triglyme (triethylene glycol dimethyl ether), tetraglyme (tetraethylene glycol dimethyl ether), 18-crown-6
And the like, nitriles such as acetonitrile and benzonitrile, and carbonic acid esters such as dimethyl carbonate and ethylene carbonate.

In order to carry out the hydrogenation reaction by the method of the present invention, the raw material, the above-mentioned catalyst component and optionally a solvent are introduced into a reaction vessel, and hydrogen is introduced therein. Hydrogen may be diluted with a reaction-inert gas such as nitrogen or carbon dioxide. The reaction temperature is usually 50 to 250 ° C, preferably 1
It is from 00 to 200 ° C. The hydrogen partial pressure in the reaction system is not particularly limited, but in industrial practice, it is usually 0.1 to 100 kg / cm ² ,
It is preferably 1 to 50 kg / cm ² . The reaction can be carried out in either a batch system or a continuous system. In the case of the batch system, the required reaction time is usually 1 to 20 hours. The desired lactone can be collected from the reaction product solution by a usual separation and purification means such as distillation and extraction. The distillation residue is circulated in the reaction system as a catalyst component.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples unless the gist thereof is exceeded.

Example 1 Preparation of catalyst liquid: 0.039% by weight of ruthenium acetylacetonate, 0.3
7% by weight trioctylphosphine and 0.16% by weight p
-Toluenesulfonic acid was dissolved in triethylene glycol dimethyl ether and heat-treated at 200 ° C for 2 hours to prepare a catalyst solution.

Hydrogenation reaction: The hydrogenation reaction was carried out using the flow-type reaction equipment shown in FIG. In FIG. 1, 1 is a reactor, 2 is a catalyst container, 3 is a compressor, 4 is a raw material container, 5 is a gas-liquid separator, and 6 is a distillation column.

The catalyst liquid is supplied from the catalyst container 2 to the reactor 1 at a flow rate of 2500 g / hr, the hydrogen gas is supplied from the compressor 3 to the reactor 1 at a flow rate of 8 Nm ³ / hr, and the pressure of the reactor 1 is 40 kg / cm. ² G, temperature 205
Heated and maintained at ° C. On the other hand, 80% by weight of succinic anhydride and γ
A raw material liquid containing 20% by weight of butyrolactone was continuously supplied from the raw material container 4 to the reactor 1 at a flow rate of 200 g / hr to carry out the hydrogenation reaction.

The reaction mixture was introduced into the gas-liquid separator 5 for gas-liquid separation, and the gas was circulated through the compressor 3 to partially purge it. The reaction product liquid after gas separation was sent to the distillation column 6 to separate the produced γ-butyrolactone and water from the column top by distillation, and the catalyst liquid was extracted from the column bottom and circulated in the catalyst container 2.

When the reaction was continued for 15 days by such a method and the product was analyzed by gas chromatography, the yield of γ-butyrolactone in the latter half (10 to 15 days after the start of the reaction) was 98.8%. The succinic anhydride concentration in the reactor 1 during the reaction period was 1.1% by weight. Furthermore, the reaction rate constant of succinic anhydride was 1.9 hr ^-1 .

Examples 2-3 and Comparative Examples 1-2 Feed amount of raw material liquid used in Example 1 (200 g / h
Example 1 except that r) was changed to various amounts shown in Table 1.
The reaction was carried out in exactly the same manner as. Table 1 shows the results.

Example 4 Instead of the catalyst liquid used in Example 1, 0.12% by weight of ruthenium acetylacetonate, 1.11
Wt% trioctylphosphine and 0.49 wt% p-
Toluene sulfonic acid was dissolved in triethylene recall dimethyl ether, a catalyst solution prepared by heating at 200 ° C. for 2 hours was used, and the feed rate of the raw material solution used in Example 1 was 400 g / hr. The reaction was carried out exactly as in Example 1. As a result, the yield of γ-butyrolactone was
98%, and the succinic anhydride concentration in the reactor 1 during the reaction period was 1.1% by weight. The reaction rate constant of succinic anhydride was 5.2 hr ^-1 .

Comparative Example 3 Instead of the catalyst liquid used in Example 1, 0.019% by weight of ruthenium acetylacetonate, 0.1
9% by weight trioctylphosphine and 0.08% by weight p
-Toluenesulfonic acid was dissolved in triethylene glycol dimethyl ether, a catalyst solution prepared by heat treatment at 200 ° C for 2 hours was used, and the feed rate of the raw material solution used in Example 1 was 210 g / hr. The reaction was carried out exactly as in Example 1. As a result, the yield of γ-butyrolactone was 95.0%, and the succinic anhydride concentration in the reactor 1 during the reaction period was 4.3% by weight. The reaction rate constant of succinic anhydride was 0.7 hr ^-1 .

(Effect of the Invention) According to the method of the present invention, when a lactone is produced by hydrogenating a dicarboxylic acid, a dicarboxylic acid anhydride and / or a dicarboxylic acid ester in a liquid phase using a ruthenium catalyst, hydrogenation is performed. By keeping the concentration of the dicarboxylic acid anhydride in the reaction zone at 3% by weight or less, not only the yield of lactones is improved, but also the hydrogenation activity of the catalyst is improved, which is of great value when industrially carried out. large.

[Brief description of drawings]

FIG. 1 is a process diagram of a flow-type reaction facility used for carrying out the present invention, in which 1 is a reactor, 2 is a catalyst container, 3 is a compressor,
4 is a raw material container, 5 is a gas-liquid separator, and 6 is a distillation column.

Continued Front Page (72) Inventor Shinji Isoya 3-10 Shiodori, Kurashiki City, Okayama Prefecture, Mizushima Plant, Mitsubishi Kasei Co., Ltd. (56) Reference JP-A-1-25771 (JP, A)

Claims (1)

(57) [Claims] 1. A dicarboxylic acid, a dicarboxylic acid anhydride and / or
Alternatively, in the method for producing a lactone by hydrogenating a dicarboxylic acid ester in a liquid phase in the presence of a ruthenium catalyst, the concentration of the dicarboxylic acid anhydride in the hydrogenation reaction zone is maintained at 3% by weight or less. Method for producing lactones.