JP2611831B2 - Method for producing 1,4-butanediol and / or tetrahydrofuran - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing 1,4-butanediol and / or tetrahydrofuran. More specifically, the present invention relates to an improvement in a method for producing 1,4-butanediol and / or tetrahydrofuran from succinic acid and / or succinic anhydride.

(Prior Art) Conventionally, succinic acid and / or succinic anhydride is hydrogenated.
Many proposals have been made for a method for producing 1,4-butanediol and / or tetrahydrofuran. For example, a palladium-rhenium catalyst (JP-A-43-218636), a ruthenium catalyst (JP-A-57-109736),
Cobalt catalyst (JP-B-47-42832), nickel-
There is known a method of performing a hydrogenation reaction using a fixed bed or a suspension phase using a solid catalyst such as a rhenium catalyst (Japanese Patent Publication No. 54-12430) and a copper-chromium catalyst (Japanese Patent Publication No. 62-54289). Have been.

(Problems to be Solved by the Invention) However, the conventional methods using the above-mentioned catalysts have severe reaction conditions and cannot be said to be at a level that is sufficiently satisfactory in terms of activity and selectivity. However, this is not necessarily an industrially advantageous method.

The present invention solves the above-mentioned problems of the conventional method, and hydrogenates succinic acid and / or succinic anhydride with an excellent selectivity under mild conditions to efficiently provide 1,4-butanediol and / or It is an object of the present invention to provide a method for producing tetrahydrofuran.

(Means for Solving the Problems) The present inventors have made intensive studies to achieve the above object, and as a result, hydrogenated succinic acid and / or succinic anhydride to obtain 1,4-butanediol and / or Or, when producing tetrahydrofuran, using a ruthenium-based catalyst consisting of a specific component, and when performing a hydrogenation reaction in a specific method, it is found that the target product can be obtained with good selectivity under mild conditions, The present invention has been completed. That is, the gist of the present invention is to provide a method for producing 1,4-butanediol and / or tetrahydrofuran by hydrogenating succinic acid and / or succinic anhydride in a liquid phase, comprising (a) ruthenium and (b) an organic phosphine. And (c) performing a hydrogenation reaction in the presence of a ruthenium-based catalyst comprising a hexafluorophosphate anion using a solvent having low compatibility with 1,4-butanediol produced by the reaction. 4-butanediol and / or tetrahydrofuran.

Hereinafter, the present invention will be described in detail. The raw material of the present invention is succinic acid and / or succinic anhydride or a mixture of both. These raw materials do not necessarily have to be pure, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid or maleic anhydride, which are raw materials for producing succinic acid and / or succinic anhydride, are used as impurities. It may be mixed.

In the present invention, the following catalyst components (a), (b) and (c) are used.

(A) Ruthenium: As the ruthenium constituting the ruthenium-based catalyst in the present invention, any of metal ruthenium and ruthenium compounds can be used. As the ruthenium compound, oxides, halides, hydroxides, inorganic acid salts, organic acid salts or complex compounds of ruthenium are used, and specifically, for example, ruthenium dioxide, ruthenium tetroxide, ruthenium dihydroxide, chloride Ruthenium, ruthenium bromide, ruthenium iodide, ruthenium nitrate, ruthenium acetate, ruthenium tris (acetylacetone), sodium hexachlororuthenate, dipotassium tetracarbonylruthenate, ruthenium pentacarbonyl, cyclopentadienyldicarbonylruthenium, dipromotricarbonylruthenium , Chlorotris (triphenylphosphine) hydryldolthenium, bis (tri-n-butylphosphine) tricarbonylruthenium, dodecacarbonyltriruthenium, tetrahydridodecacarboni Tetra ruthenium, octadecanol carbonyl hexa ruthenate Jiseshiumu, undecalactone carbonyl hydride tri ruthenate tetraphenylphosphonium the like. The amount of the metal ruthenium and ruthenium compound used is usually 0.000.00 as ruthenium in 1 liter of the reaction solution.
It is about 01 to 100 mmol, preferably 0.001 to 10 mmol.

(B) Organic phosphine: In the present invention, it is necessary to use an organic phosphine as a catalyst component. The organic phosphine controls the electronic state of ruthenium as a main catalyst or stabilizes the active state of ruthenium. It is thought to contribute to Specific examples of the organic phosphine include trialkylphosphines such as tri-n-butylphosphine and dimethyl-n-octylphosphine; tricycloalkylphosphines such as tricyclohexylphosphine; and triarylphosphines such as triphenylphosphine. ,
Examples include alkylaryl phosphines such as dimethylphenyl phosphine, and polyfunctional phosphines such as 1,2-bis (diphenylphosphino) ethane. The amount of the organic phosphine used is usually based on 1 mole of ruthenium.
It is 0.1 to 1000 mol, preferably 1 to 100 mol. The organic phosphine can be supplied to the reaction system by itself or in the form of a complex with a ruthenium catalyst.

(C) Hexafluorophosphate anion: As the catalyst component of the present invention, it is necessary to further use a hexafluorophosphate anion (PF ₆ ⁻ ), which is used as an additional promoter for ruthenium as a main catalyst. However, it is considered that the hydrogenation reaction proceeds under relatively mild conditions by utilizing the advantages of ruthenium, and also contributes to the improvement of the catalytic activity, the stability of the catalytic activity, and the selectivity of the target product.

The supply form of the hexafluorophosphate anion may be any as long as it produces a conjugate base during the preparation of the catalyst or during the hydrogenation reaction.For example, Bronsted acid or an alkali metal salt thereof, an alkaline earth metal salt, an ammonium salt, Salt forms such as a silver salt may be mentioned. The amount of such an acid or a salt thereof is 0.01 to 1 mol of ruthenium.
It is in the range of 10001000 mol, preferably 0.1-100 mol.

The ruthenium-based catalyst of the present invention may optionally contain a neutral ligand in addition to the above components (a), (b) and (c). As the neutral ligand, ethylene, propylene, butene, cyclopentene, cyclohexene, butadiene, cyclopentadiene, cyclooctadiene,
Olefins such as 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,
Oxygenated 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-
Butyl mercaptan, thiophenol, dimethyl sulfide, dimethyl disulfide, thiophene, dimethyl sulfoxide, sulfur-containing compounds such as diphenyl sulfoxide, tributyl phosphine oxide, ethyl diphenyl phosphine oxide, triphenyl phosphine oxide, diethyl phenyl phosphinate, diphenyl methyl phosphinate, Phosphorus-containing compounds other than organic phosphines, such as o, o-dimethylmethylphosphonothiolate, triethyl phosphite, triphenyl phosphite, triethyl phosphate, triphenyl phosphate, and hexamethylphosphoric triamide.

The hydrogenation reaction of the present invention is carried out in a liquid phase, and it is characterized in that the reaction is carried out using a solvent having low compatibility with 1,4-butanediol, which is a reaction product, while performing phase separation. Examples of the solvent having low compatibility with 1,4-butanediol include aromatic hydrocarbons or aliphatic hydrocarbons having about 5 to 30 carbon atoms.Specifically, for example, benzene, toluene, xylene, ethylbenzene, naphthalene, Biphenyl, hexane, octane, pentadecane, squalane, tetralin, cyclohexane, decalin and the like are used. The amount of the solvent used is preferably about 30% by weight to about 95% by weight of the solvent based on the total amount of the reaction solution.

In order to carry out the hydrogenation reaction of succinic acid and / or succinic anhydride according to the method of the present invention, a raw material, the above-mentioned catalyst component and a solvent are charged into a reaction vessel, and hydrogen is introduced therein. Hydrogen may be diluted with an inert gas such as nitrogen or carbon dioxide. The reaction temperature is usually 50-250 ° C, preferably 100-200 ° C. The preferred hydrogen partial pressure in the reaction system for industrial implementation is usually 0.1 to 200 kg / cm ² , particularly 1 to 150 kg / cm ² . The reaction can be carried out in either a batch mode or a continuous mode,
The required reaction time in the case of a batch system is usually 1 to 20 hours.

After completion of the reaction, the target substance, 1,4-butanediol and / or tetrahydrofuran, can be recovered from the reaction product liquid by ordinary separation means such as distillation and extraction. The distillation residue is circulated to the reaction system as a catalyst component.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples unless it exceeds the gist.

Example 1 In a 200 ml autoclave equipped with an induction stirrer, 0.20 g (0.5 mmol) of ruthenium acetylacetonate, 1.7 g (5.0 mmol) of trioctylphosphine, 0.41 g (2.5 mmol) of ammonium hexafluorophosphate, and 20 g (200 mmol) of succinic anhydride were added. Mmol) and 80 ml of m-xylene, and the inside of the autoclave was purged with nitrogen gas.
Heated to ° C. At this point, hydrogen is injected and the hydrogen pressure is 50 kg / cm ²
At 200 ° C. for 6 hours to carry out a hydrogenation reaction.
When the autoclave was opened after completion of the reaction, the autoclave was separated into two layers. The upper layer was mainly composed of m-xylene, and the lower layer was mainly composed of 1,4-butanediol as a product.

When the reaction product was analyzed, the conversion of succinic anhydride was 95.4% and the selectivity of 1,4-butanediol was 46.5.
% And the selectivity for tetrahydrofuran was 5.3%. The selectivity for the intermediate product γ-butyrolactone was 38.9%.

Example 2 In a 200 ml autoclave equipped with an induction stirrer, 0.20 g (0.5 mmol) of ruthenium acetylacetonate, 1.7 g (5.0 mmol) of trioctylphosphine, 0.41 g (2.5 mmol) of ammonium hexafluorophosphate, and 10 g (100 mmol) of succinic anhydride were added. Mmol) and 90 ml of n-heptane, and a hydrogenation reaction was carried out in the same manner as in Example 1. Analysis of the resulting reaction product showed that the conversion of succinic anhydride was 92.7% and the selectivity of 1,4-butanediol was
8.0% and the selectivity for tetrahydrofuran was 79.6%. The selectivity for γ-butyrolactone was 10.5%.

Example 3 In a 200 ml autoclave equipped with an induction stirrer, 0.10 g (0.25 mmol) of ruthenium acetylacetonate, 0.85 g (2.5 mmol) of trioctylphosphine, 0.205 g (1.25 mmol) of ammonium hexafluorophosphate,
10 g (100 mmol) of succinic anhydride and 90 ml of trimethylbenzene were charged and a hydrogenation reaction was carried out in the same manner as in Example 1. When the obtained reaction product was analyzed, the conversion of succinic anhydride was 96.7%, the selectivity of 1,4-butanediol was 46.0%, and the selectivity of tetrahydrofuran was 7.7%. The selectivity of γ-butyrolactone is 3
It was 1.2%.

Example 4 A hydrogenation reaction was carried out in the same manner as in Example 3 except that 90 ml of squalane was used instead of trimethylbenzene used in Example 3. When the obtained reaction product was analyzed, the conversion of succinic anhydride was 93.9%, the selectivity of 1,4-butanediol was 14.4%, and the selectivity of tetrahydrofuran was 20.7%. The selectivity for γ-butyrolactone was 34.9%.

Comparative Example 1 In a 200 ml autoclave with an induction stirrer, 0.20 g (0.5 mmol) of ruthenium acetylacetonate, 1.7 g (5.0 mmol) of trioctylphosphine, and 10 g of succinic anhydride
(100 mmol) and 90 ml of m-xylene, and a hydrogenation reaction was carried out in the same manner as in Example 1. Analysis of the resulting reaction product, the conversion of succinic anhydride was 97.7
%, The selectivity for 1,4-butanediol was 3.9%, and the selectivity for tetrahydrofuran was 0.6%. The selectivity for γ-butyrolactone was 84.5%.

(Effects of the Invention) According to the method of the present invention, in producing 1,4-butanediol and / or tetrahydrofuran by hydrogenating succinic acid and / or succinic anhydride in a liquid phase, the above (a), (b) By using a ruthenium-based catalyst consisting of (b) and (c) and using a solvent which is incompatible with 1,4-butanediol, the target compound can be obtained with excellent selectivity under relatively mild conditions. It can be manufactured, and its practical value is great.

Claims (1)

(57) [Claims] (1) A method for producing 1,4-butanediol and / or tetrahydrofuran by hydrogenating succinic acid and / or succinic anhydride in a liquid phase, comprising the steps of (a) ruthenium, (b) organic phosphine and (b) C) The hydrogenation reaction is carried out in the presence of a ruthenium-based catalyst comprising a hexafluorophosphate anion using a solvent having low compatibility with 1,4-butanediol produced by the reaction. -A process for producing butanediol and / or tetrahydrofuran.