JP2785363B2 - Lactone purification method - Google Patents

Description

The present invention relates to a dicarboxylic acid, a dicarboxylic anhydride and / or
Alternatively, the present invention relates to a method for purifying a lactone obtained by hydrogenating a dicarboxylic acid ester.

[Conventional technology]

Methods for producing lactones by hydrogenating dicarboxylic acids, dicarboxylic anhydrides and / or dicarboxylic esters have been studied for a long time, and various catalysts have been proposed so far.

For example, nickel-based catalysts (for example, JP-B-43-6947), cobalt-based catalysts (for example, JP-A-51-95057), copper-chromium-based catalysts (for example, JP-B-38-20119), and copper-based catalysts Numerous proposals have been made on a method for producing lactones by a hydrogenation reaction system such as a fixed bed or a liquid suspension phase using a zinc-based catalyst (for example, Japanese Patent Publication No. 42-14463). On the other hand, a method for producing lactones in which the above-mentioned hydrogenation reaction is carried out using a homogeneous ruthenium catalyst is also known. For example, US Pat. No. 3,957,827 discloses [RuXn (PR ₁ R ₂ R ₃ ) xLy] -type catalysts at 40-400 psi, and U.S. Pat. No. 4,485,246 describes hydrogenation with similar catalysts. It is described that the conversion reaction is carried out in the presence of an organic amine.

However, in the conventional methods using a nickel-based catalyst, a cobalt-based catalyst, a copper-chromium-based catalyst, a copper-zinc-based catalyst, and the like, it is inevitable to employ harsh conditions of several tens atmospheres or more. There was a problem that there is no. On the other hand, the conventional method using a homogeneous ruthenium catalyst described above has a feature that the hydrogenation reaction proceeds under relatively mild conditions, but the catalyst activity is not only at a slightly lower level, but also the catalyst life Is extremely short, and the use of halogen has a fatal problem that corrosion of the reactor occurs.

Accordingly, the present applicant has previously described a method for producing lactones by hydrogenation reaction in a liquid phase using a ruthenium-based catalyst containing ruthenium, an organic phosphine and a conjugate base of an acid having a pKa smaller than 2 as disclosed in Japanese Patent Laid-Open No. No. 25771.

According to the method of the present applicant, lactones can be produced with extremely high yield.

[Problems to be solved by the invention]

However, even if the ruthenium catalyst was improved, there was a point that the quality of the produced lactones had to be further improved.

That is, even when the ethers and / or polyethers are used as the solvent in the ruthenium catalyst method, the solvent is decomposed, though very little, and the decomposition product is mixed in the lactone as a product in a small amount. is there.

Lactones are products that require high purity, and the presence of trace impurities is extremely disadvantageous industrially.

Therefore, development of a method for removing the trace impurities from lactones has been desired.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve such an object, and as a result, in the presence of a solvent of ethers and / or polyethers, a dicarboxylic acid, a dicarboxylic anhydride and / or a dicarboxylic acid ester was converted to hydrogen with a ruthenium catalyst. The inventors have found that impurities in lactone can be removed by treating lactones obtained by the treatment with silica gel or an ion exchange resin, and completed the present invention.

 Hereinafter, the present invention will be described in detail.

The dicarboxylic acid, dicarboxylic anhydride and dicarboxylic acid ester used as a raw material in the present invention are a saturated or unsaturated dicarboxylic acid derivative having 3 to 7 carbon atoms, and the ester is preferably an alkyl ester, particularly a carboxylic acid skeleton. Is preferably a derivative having 4 carbon atoms. Specific examples include fumaric acid, succinic acid, maleic anhydride, succinic anhydride, dimethyl maleate, diethyl fumarate, and di-n-butyl succinate.

The catalyst used in the method of the present invention is not particularly limited as long as it is a ruthenium-based catalyst. In particular, the ruthenium-based catalyst containing a conjugate base of an acid having a ruthenium organic phosphine pKa smaller than 2 is preferable, and the ruthenium-based catalyst is more preferably a neutral catalyst. Those containing a ligand are preferably used.

Here, as the ruthenium, both metal ruthenium and ruthenium compounds can be used in the form of supply. As the ruthenium compound, an oxide, a hydroxide, an inorganic acid salt, an organic acid salt or a complex compound of ruthenium is used. Specifically, ruthenium dioxide,
Ruthenium tetroxide, ruthenium dihydroxide, ruthenium chloride, ruthenium bromide, ruthenium iodide, ruthenium nitrate, ruthenium acetate, tris (acetylacetone) ruthenium, sodium hexachlororuthenate, dipotassium tetracarbonylruthenate, ruthenium pentacarbonyl, cyclopentadiene Enyldicarbonylruthenium, dibromotricarbonylruthenium, chlorotris (triphenylphosphine) hydridoruthenium, bis (tri-n-butylphosphine) tricarbonylruthenium, dodecacarbonyltriruthenium, tetrahydridodecacarbonyltetraruthenium, octadecacarbonylhexaruthenate Cesium, undecacarbonyl hydride tetraphenyl phosphonium triruthenate and the like. .

The amount of the metal ruthenium and ruthenium compound used is such that the concentration in the reaction solution is 0.0001 to 100 mol, preferably 0.001 to 10 mol, as ruthenium per liter of the reaction solution.

It is considered that the use of the organic phosphine together with ruthenium contributes to controlling the electronic state of ruthenium and stabilizing the active state of ruthenium. Specific examples of such organic phosphines include trialkylphosphines such as tri-n-butylphosphine and dimethyl-n-octylphosphine; tricycloalkylphosphines such as tricyclohexylphosphine; triarylphosphines such as triphenylphosphine; Alkylarylphosphines such as dimethylphenylphosphine,
And polyfunctional phosphines such as 1,2-bis (diphenylphosphino) ethane.

The amount of the organic phosphine used is in the range of 0.1 to 1000 mol, preferably 1 to 100 mol, per 1 mol of ruthenium. In addition, these organic phosphines can be supplied to the reaction system alone or in the form of a complex with ruthenium.

Further, by using a conjugate base of an acid having a pKa of less than 2 as an additional promoter for ruthenium constituting the hydrogenation reaction main catalyst, the advantage of ruthenium as a main component can be taken advantage of under relatively mild conditions. In addition to allowing the hydrogenation reaction to proceed, it is possible in particular to improve the activity of the hydrogenation catalyst, the stability of the activity, and the selectivity of the target product.

The conjugate base of an acid having a pKa of less than 2 may be any as long as it produces such a conjugate base during the preparation of a catalyst or in a reaction system. And the like.

Specifically, inorganic acids such as nitric acid, perchloric acid, borofluoric acid, hexafluorophosphoric acid, and fluorosulfonic acid, trichloroacetic acid, dichloroacetic acid, trifluoroacetic acid, methanesulfonic acid, dodecylsulfonic acid, octadecylsulfonic acid, and trifluorofluoric acid Brönsted acids such as organic acids such as methanesulfonic acid, benzenesulfonic acid, paratoluenesulfonic acid, and sulfonated styrene-divinylbenzene copolymer, or alkali metal salts, alkaline earth metal salts, ammonium salts, and silver salts of these acids. And the like.

Also, the conjugate base of these acids may be added in the form of an acid derivative which is considered to be formed in the reaction system. For example, the same effect can be expected even if it is added to the reaction system in the form of an acid halide, acid anhydride, ester, acid amide or the like.

The use amount of these acids or salts thereof is 0.01 to 1000 mol, preferably 0.1 to 100 mol, based on ruthenium.

The ruthenium-based catalyst can further contain a neutral ligand.

Hydrogen as such a neutral ligand; olefins such as 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, benzyl stearate, valerolactone, and other oxygen-containing compounds; nitric oxide, acetonitrile, propionitrile, benzonitrile, Cyclohexylisonitrile, butylamine, aniline, toluidine, triethylamine, pyrrole, pyridine, N-methylformamide, acetamide, 1,1,3,3-tetra Methylurea, N- methylpyrrolidone, caprolactam, nitrogen-containing compounds such as nitromethane; carbon disulfide, n- butyl mercaptan, thiophenol, dimethyl sulfide, dimethyl disulfide,
Sulfur-containing compounds such as thiophene, dimethyl sulfoxide and diphenyl sulfoxide; tributyl phosphine oxide, ethyl diphenyl phosphine oxide, triphenyl phosphine oxide, diethyl phenyl phosphinate, diphenyl ethyl phosphinate, diphenyl methyl phosphonate, 0, 0-dimethyl Phosphorus-containing compounds other than organic phosphines, such as methylphosphonothiolate, triethyl phosphite, triphenyl phosphite, triethyl phosphate, triphenyl phosphate, and hexamethylphosphoric triamide.

Solvents used in the present invention include ethers such as diethyl ether, anisole, tetrahydrofuran, ethylene glycol dimethyl ether and dioxane, and polyglymers such as tetraglyme (tetraethylene glycol dimethyl ether), triglyme (triethylene glycol dimethyl ether) and 18-crown-6. Ethers.

In order to carry out the hydrogenation reaction according to the method of the present invention, the reaction raw materials, catalyst components and, if desired, a solvent are charged into a reaction vessel, and hydrogen is introduced into the reaction vessel. Hydrogen may be diluted with a gas inert to a reaction such as nitrogen or carbon dioxide.

The reaction temperature is usually 50 to 250 ° C, preferably 100 to 200 ° C.
It is. The hydrogen partial pressure in the reaction system is usually 0.1 to 100 kg / cm ² ,
Preferably it is 1 to 10 kg / cm ² . Of course, it is not impossible to operate at a lower or higher pressure, but this is not industrially advantageous.

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.

From the reaction product solution, the target lactones can be obtained by ordinary separation and purification means such as distillation and extraction. Although the solvent is very small, it is hydrolyzed under hydrogenation reaction conditions to produce a decomposed product, and a part or all of this is mixed into the lactone as an impurity. The present invention is characterized in that the impurities are treated with silica gel or an ion exchange resin.

The treatment with silica gel or an ion exchange resin can be performed on the reaction product solution, but usually, after a catalyst + solvent solution (hereinafter referred to as a catalyst solution) and a lactone + product water are separated by a known method such as distillation. Advantageously, it is carried out on the lactone + produced water, and most particularly on the lactone after separation of the lactone and water.

The treatment can be performed in either a batch system or a continuous flow system. Processing conditions are usually -60 ° C for silica gel.
Temperature of ~ 200 ° C, treatment time is several minutes to tens of hours, and the amount of silica gel is silica gel / lactone =
The pressure is preferably from normal pressure to several + kg / cm ² G, but it is not particularly critical and can be used under reduced pressure. The silica gel may be a commercially available one, but a silica gel having a specific surface area (m ² / g) of 400 or more, preferably 500 or more has a large effect.

Prior to use, the silica gel may be subjected to a known pretreatment such as degassing at high temperature and / or vacuum, and pickling with an aqueous nitric acid solution or an aqueous hydrochloric acid solution.

The processing conditions in the case of the ion exchange resin are usually a temperature of 0 ° C. to 200 ° C., a processing time of several minutes to several tens of hours, and an amount of the ion exchange resin in terms of a weight ratio to the lactone. 0.0005 or more, preferably 0.0005 to 10, and the pressure is preferably normal pressure to several + kg / cm ² G, but it is not particularly critical and can be used under reduced pressure.

The ion exchange resin may be a cation exchange resin or an anion exchange resin regardless of the type and ionic form, but is preferably an acidic cation exchange resin, more preferably a strongly acidic cation exchange resin, Preferably H
Strongly acidic cation exchange resin is effective.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Comparative Example-1 1.99 g (Ru; 5 mmol) of ruthenium acetylacetonate, 18.5 g (50 mmol) of trioctylphosphine, 8.4 para-toluenesulfonic acid in a 10SUS autoclave
g (44 mmol) and 3.2 kg of triglyme were charged and heat-treated at 200 ° C. for 2 hours in an argon atmosphere. 400 g (4 mol) of succinic anhydride was charged as a reaction raw material into this catalyst solution, and hydrogen was injected at 40 atm at room temperature and heated to 205 ° C.
Allowed to react for hours.

After a predetermined reaction time, the autoclave was opened, and the reaction product was quantified by gas chromatography. As a result, the conversion of succinic anhydride was 91.4%, and γ-butyrolactone (hereinafter GB)
The L selectivity was 90.2% and the yield was 82.4%.

When the reaction product was analyzed by capillary gas chromatography, 61.4 ppm of diethylene glycol monomethyl ether, which was a hydrolyzate of triglyme, and 11.1 ppm of ethylene glycol monomethyl ether were detected in the reaction product. Methanol was not detected.

Next, 1.5 kg of the reaction product liquid was subjected to batch distillation in a 30-stage distillation column. The degree of vacuum at the top of the column was 30 ^mm to 10 ^{mm of} mercury, the kettle temperature was 130 to 150 ° C, and the reflux ratio was 10.

An initial fraction (main component was water) and a γ-butyrolactone fraction were distilled off by batch distillation, and the bottom was a solvent + catalyst liquid + unreacted raw material. As a result of analysis by gas chromatography, the yield of the γ-butyrolactone fraction was 98.2%, which was 0.7% during the initial distillation and 1.1% in the bottom, respectively.

As a result of analysis by capillary gas chromatography, diethylene glycol monomethyl ether (hereinafter referred to as DGME) in the distillate in γ-butyrolactone was 574.8 ppm, and ethylene glycol monomethyl ether (hereinafter referred to as MGME) was 10.2 ppm.
Met.

Example 1 A γ-butyrolactone fraction obtained in Comparative Example 1 was treated using a commercially available (manufactured by Toyoda Kako Co., Ltd.) silica gel 50-100 mesh product having a specific surface area of 700 m ² / g. Silica gel and γ-butyrolactone fraction are charged into a 0.2 glass flask in a silica gel / γ-butyrolactone fraction at a weight ratio of 0.1, and the mixture is stirred at a temperature of 20 ° C. pressure: normal pressure (under N ₂ ) time of 1.0 hr. After treatment with, silica gel was passed.

DGME in γ-butyrolactone is 114 ppm, MGME is 1.1 ppm
Decreased to.

Example 2 The experiment was performed in exactly the same manner as in Example 1 except that a commercially available (manufactured by Toyoda Chemical Co., Ltd.) silica gel 50-100 mesh product having a specific surface area of 450 m ² / g was used. As a result, DGME was 271.5 ppm, MGME was 2.7 ppm
Decreased to.

Example-3 Commercial product having a specific surface area of 700 m ² / g (Fuji Devison) 1
The experiment was carried out in exactly the same manner as in Example 1 except that a 100-200 mesh product was pickled and washed with 1N hydrochloric acid and then dried. As a result, DGME was reduced to 102 ppm and MGME was reduced to 1.0 ppm or less.

Example 4 The experiment was performed in exactly the same manner as in Example 3 except that the treatment temperature was -5 ° C and the silica gel / γ-butyrolatone ratio was 0.01. As a result, DGME was reduced to 120.6 ppm and MGME was reduced to 1.3 ppm.

Example-5 The γ-butyrolactone fraction obtained in Comparative Example-1 was treated using H-type strongly acidic cation exchange resin RCP-170H (manufactured by Mitsubishi Kasei Co., Ltd.).

A resin and a γ-butyrolactone fraction were charged into a 0.2-ml glass flask at a resin / γ-butyrolactone fraction = 0.03 weight ratio, and agitated at a temperature of 120 ° C. under pressure: normal pressure (under N ₂ ) for 1.0 hour. After the treatment, the ion exchange resin was passed. DGME in γ-butyrolactone was reduced to 50 ppm and MGME to 1.0 ppm.

Example-6 The experiment was performed exactly as in Example-5 except that the treatment temperature was 60 ° C and the reaction time was 2.0 hours. As a result, DGME is 280pp
m, MGME decreased to 4.0ppm.

Example -7 An experiment was carried out in exactly the same manner as in Example -5 except that H-type strongly acidic cation exchange resin RCP-160H (manufactured by Mitsubishi Kasei) was used. As a result, DGME was reduced to 55 ppm and MGME was reduced to 1.2 ppm.

Example-8 The experiment was performed exactly as in Example-5, except that the resin / γ-butyrolactone = 0.1 weight ratio. As a result, DGME is 10pp
m, MGME decreased to less than 1.0ppm.

Comparative Example-2 The γ-butyrolactone fraction obtained in Comparative Example-1 was tested under the same conditions as in Example-1 using the following adsorbents.
DGME and MGME were not absorbed and removed at all. Activated carbon, γ-alumina, molecular sieve 3A, 4A, 5
A, 13X, activated clay, and silica alumina were used.

〔The invention's effect〕

As described above, according to the present invention, a decomposition product of ethers or polyethers used as a solvent is removed, and lactones with high purity can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinji Isotani 3-10, Utsudori, Kurashiki-shi, Okayama Prefecture Mizushima Plant, Mitsubishi Kasei Co., Ltd. (56) References JP-A-1-25771 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) C07D 307/32

Claims (2)

(57) [Claims] A lactone obtained by hydrogenating a dicarboxylic acid, a dicarboxylic anhydride and / or a dicarboxylic ester with a ruthenium catalyst in the presence of an ether or a polyether as a solvent is treated with silica gel. A method for purifying lactones. 2. A method for treating a lactone obtained by hydrogenating a dicarboxylic acid, a dicarboxylic anhydride and / or a dicarboxylic ester with a ruthenium catalyst in the presence of an ether or a polyether as a solvent, using an ion exchange resin. A method for purifying lactones, characterized in that: