JPH10298138A - Production of unsaturated glycol diester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce an unsaturated glycol diester by reaction of a conjugated diene, a carboxylic acid and oxygen in the presence of a rhodium catalyst. SOLUTION: A rhodium compound and tellurium compound are dissolved in an organic solvent containing <50 wt.% water and the resultant solution is supported on an inorganic porous carrier, then baked when necessary and reduced. The resultant catalyst is used to carry out the above-stated ester- formation reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an unsaturated glycol diester. More specifically, the present invention relates to a method for producing an unsaturated glycol diester using a rhodium-tellurium-based catalyst prepared by a specific method.
Unsaturated glycol diesters such as butenediol diester are important intermediate compounds for producing 1,4-butanediol, which is a raw material for engineering plastics, elastomers, elastic fibers, synthetic leather, and the like. In addition, butenediol diester is an important intermediate for producing tetrahydrofuran, which is a raw material for high-performance solvents and elastic fibers, and also a solvent having a low boiling point and excellent solubility.

[0002]

2. Description of the Related Art Conventionally, many methods have been proposed for producing this butenediol diester. In particular, palladium as a main component and a second component selected from tellurium, selenium, antimony and the like coexist. A method for producing butenediol diacetate by reacting butadiene with acetic acid and molecular oxygen using a solid catalyst thus obtained is well known. While this is a great method,
It is desired to further increase the activity of the catalyst and the selectivity of 1,4-diacetoxy-2-butene.

[0003] Further, a catalyst system containing rhodium as a main component has also been proposed and is known. For example, JP-A-52-13
Japanese Patent Application Laid-open No. 9004 discloses that rhodium, tellurium and / or selenium are used as active ingredients.
No. 09 discloses the use of rhodium or rhodium and tellurium and / or selenium as active ingredients, and JP-A-53-44502 discloses that a catalyst obtained by further adding molybdenum thereto is used. It has been disclosed. JP-A-53-2414 discloses that at least one metal selected from rhodium, palladium and platinum is used in combination with sulfur.
In Japanese Patent Application Laid-Open No. 52-91817, Japanese Patent Application Laid-Open No. 52-91817 discloses that at least one metal selected from palladium, rhodium and platinum is used in combination with tellurium and / or sulfur. The use of rhodium, platinum, palladium and tellurium as active ingredients is disclosed respectively.

[0004]

However, the reaction results of these rhodium-based catalysts are not yet satisfactory. Since rhodium is a particularly expensive metal, it is required that the reaction result be excellent. The present invention addresses this need.

[0005]

According to the present invention, a conjugated diene is reacted with a carboxylic acid and molecular oxygen in the presence of a solid catalyst containing rhodium and tellurium as active components to form a carboxylic acid of the corresponding unsaturated glycol. In the method for producing an acid diester, a catalyst obtained by reducing a rhodium compound and a tellurium compound supported on an inorganic porous material as a solution of an organic solvent having a water content of less than 50% by weight as a solid catalyst is used. By using the compound, excellent reaction results can be achieved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a catalyst prepared by reducing a rhodium compound and a tellurium compound supported on an inorganic porous material as a solution of an organic solvent having a water content of less than 50% by weight is prepared. A supported catalyst is used. As the inorganic porous material, those which do not substantially change under the esterification reaction conditions are used. For example, a carbonaceous carrier such as activated carbon or graphite, or an oxide carrier composed of an oxide such as silica, alumina, titania, zirconia, or a mixed oxide thereof is used. In particular, silica is preferably used because it has excellent activity and selectivity and gives a catalyst excellent in strength.

The rhodium and tellurium compounds used in the preparation of the catalyst must be soluble in organic solvents having a water content of less than 50% by weight, preferably less than 10% by weight. Rhodium compounds satisfying these conditions include inorganic salts, organic acid salts such as acetic acid, organic complex salts, carbonyl complexes, and acetylacetonate salts, depending on the type of organic solvent. Some examples are rhodium chloride, rhodium nitrate, rhodium sulfate, rhodium acetate, hexachlororhodium sodium, hexachlororhodium ammonium, chloropentaamminerhodium, chlorohexamminerhodium, hexacyanorhodium potassium, trichlorotripyridinerhodium, chlorocyclooctadidium. Enyl rhodium, tetrarhodium dodecacarbonyl, dicarbonylacetylacetonatotrodium and the like. As the tellurium compound, tellurium chloride (I
I), (IV), sodium hydrogen telluride (N
aHTe), diphenyl ditelluride (PhTe) _{2 and the} like, and among them, a compound having at least one Te-aromatic bond, particularly a Te-phenyl group bond is preferably used. Further, a compound containing both rhodium and tellurium represented by trisdiphenyltellurium rhodium trichloride (RhCl ₃ (TePh ₂ ) ₃ ) also has a water content of 50%.
Those that are soluble in less than the weight% of the organic solvent can be used.
At least one of the rhodium compound and the tellurium compound is
Organic compounds such as organic acid salts and those containing carbon monoxide as a ligand are preferred.

[0008] The solvent used in the preparation of the catalyst must be an organic solvent having a water content of less than 50% by weight. If the other solvent is used, the effect of the present invention is not exhibited. Although the reason is unknown, water in the solvent affects the dispersion state of rhodium and tellurium on the carrier, and by using an organic solvent having a low water content, alloying of rhodium and tellurium is promoted. It is presumed that both are supported on the inorganic porous material so that they can be easily carried out.

The solvent used in the present invention may be any organic solvent having a water content of less than 50% by weight, preferably less than 10% by weight. Several tens or less of organic compounds are used. Some preferred examples thereof include hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, and toluene, carbonyl compounds such as acetone, methyl butyl ketone, and methyl ethyl ketone, dioxane, tetrahydrofuran, dihydropyran, ethers such as furan, and acetic acid. Ester such as ethyl, ethyl formate, methyl benzoate, acetic acid,
Examples include carboxylic acids such as propionic acid, and alcohols such as ethanol, methanol, isopropanol, and phenol. If desired, two or more organic solvents may be used in combination.

In preparing the catalyst, a solution in which the rhodium compound and the tellurium compound are dissolved in the above-mentioned organic solvent is brought into contact with the inorganic porous material to support the rhodium compound and the tellurium compound on the inorganic porous material. The loading is also performed simultaneously using an organic solvent solution in which both the rhodium compound and the tellurium compound are dissolved, a solution in which the rhodium compound is dissolved and a solution in which the tellurium compound is dissolved are prepared, and both are sequentially loaded. Any of the supporting methods can be used. For example, it can be supported by a method in which an organic solvent solution of a rhodium compound is brought into contact with an inorganic porous material, then dried once, and then contacted with a solution of a tellurium compound in an organic solvent, or vice versa. Loading can be carried out by any conventional method such as an impregnation method, a dipping method, a precipitation method, and a pore filling method.

In addition, the support may be carried in a necessary amount at once, or may be carried in several times. However, in the case of loading a plurality of times, it is preferable to carry out drying or reduction for each loading. The higher the supported amount of rhodium, the higher the reaction activity per unit weight of the catalyst. However, too much rhodium is not economical. Therefore, usually, the supported amount of rhodium is 0.01 to 20% by weight as rhodium metal based on the total amount of the catalyst.
And more preferably 0.1 to 10% by weight. On the other hand, if the supported amount of tellurium is too large, it is not preferable because the reaction is inhibited and the selectivity is lowered. On the other hand, if the amount is too small, there is a problem that rhodium is eluted out of the catalyst system during the reaction in addition to the fact that the reaction activity is low. The amount of tellurium supported is usually selected from the range of 0.01 to 2.0 in atomic ratio with respect to rhodium, but is preferably selected from the range of 0.05 to 1.0.

When a solution of a rhodium compound and a tellurium compound is brought into contact with an inorganic porous material to support them, it is preferable to dry the solution in order to remove the solvent from the inorganic porous material before reduction. Drying may be performed by a conventional method such as a method in which a heated drying gas is passed, a method in which the drying is performed under reduced pressure, and a method in which steam heated to 100 ° C. or more is passed. When a dry gas is allowed to flow, nitrogen, oxygen, argon, hydrogen, or a mixed gas of these gases may be used. In the case of a mixed gas, the composition ratio is arbitrary as long as it is industrially safe. Gas flow rate, the normal inorganic porous material is chosen with 20 hr ^-1 or more ranges at a space velocity (SV), 1000~8000hr ^-1 are preferred. If the SV value is too low, the drying time becomes longer, and
If it is too high, the amount of gas used increases, which is uneconomical. The drying temperature is usually selected in the range of 40 to 150 ° C, but is preferably selected in the range of 60 to 120 ° C.

The degree of reduced pressure in the case of drying under reduced pressure may be basically not more than normal pressure, but in order to obtain a practical drying speed, it is not more than 100 torr, especially 50 torr.
rr or less is preferable. Although the drying temperature is sufficient even at room temperature, it may be heated to increase the drying speed. In the case of heating, the temperature may be 50 to 300 ° C.

The inorganic porous body carrying rhodium and tellurium is reduced after drying to form a catalyst, but may be calcined before that. For calcination, either a method of heating under a flow of a dry gas or a method of heating without a flow of a gas can be adopted. When flowing a gas, nitrogen, oxygen, argon, or a mixed gas of these gases is used. In the case of a mixed gas, the composition ratio is arbitrary. The gas flow rate is usually selected in the range of 20 hr ^-1 or more in space velocity (SV) with respect to the inorganic porous material. Firing is 200 ~ 8
The heat treatment may be performed at 00 ° C., preferably 300 to 600 ° C., for 1 to 20 hours, preferably 1 to 5 hours.

The reduction of rhodium and tellurium carried on the inorganic porous material can be performed by either gas phase reduction or liquid phase reduction. The liquid phase reduction can be carried out according to a conventional method using a commonly used reducing agent such as hydrazine, sodium boron hydride (NaBH ₄ ), formic acid, and formalin. The gas phase reduction can also be carried out according to a conventional method using common hydrogen, methanol, or a mixed gas obtained by diluting these reducing gases with an inert gas. The reduction temperature is 100-600 ° C, preferably 150-500.
It is selected from the range of ° C. It is considered that rhodium and tellurium are reduced to metal by this reduction treatment, and that both form an alloy.

In the present invention, an unsaturated glycol diester can be produced by reacting a conjugated diene, a carboxylic acid and molecular oxygen according to a conventional method except that the catalyst prepared as described above is used. The conjugated diene of the reaction material is usually butadiene, but this need not necessarily be pure, but may be an inert gas such as nitrogen gas, a saturated hydrocarbon such as methane, ethane, or butane, or butene. And unsaturated hydrocarbons such as As conjugated dienes, besides butadiene, isoprene,
Alkyl-substituted butadienes such as 2,3-dimethylbutadiene and piperylene, and cyclic dienes such as cyclopentadiene can also be used. These conjugated dienes need not necessarily be pure.

As the carboxylic acid which is another reaction raw material, lower aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid and butyric acid are usually used, and acetic acid is particularly preferred in terms of reactivity and cost. . The amount of the carboxylic acid used is preferably in the range of 1 to 60 mol per 1 mol of the conjugated diene. Usually, it is preferable to use a large amount of the carboxylic acid also as a solvent. If desired, other organic solvents such as saturated hydrocarbons and esters can be used, but even in this case, it is preferable that 50% by weight or more of the reaction medium is a carboxylic acid as a raw material.

As the molecular oxygen, one diluted with an inert gas such as nitrogen, for example, air is usually used. Pure oxygen is not preferred for safety reasons. The amount of oxygen used is not particularly limited as long as it is equal to or more than the reaction equivalent. The reaction can be performed in either a batch system or a continuous system. Further, as the state of accommodating the catalyst in the reactor, any system such as a fixed bed system, a fluidized bed system, and a suspension tank system can be adopted.

The reaction is usually carried out at a temperature of 20 ° C. or higher, but a preferable reaction temperature is 50 to 120 ° C. in consideration of the reaction rate and by-product formation. The reaction pressure can be normal pressure or pressurization, but pressurization is more preferable to increase the reaction rate. Preferably, it is selected from the range of 1 to 100 atmospheres. After completion of the reaction, the desired product, unsaturated glycol diester, is separated from the reaction mixture by ordinary means such as distillation, and the unreacted conjugated diene and carboxylic acid are recovered, circulated and reused in the reaction system.

[0020]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition,
In the following, “%” indicates “% by weight”.

Example 1 <Preparation of catalyst> In a 50 mL volumetric flask, dicarbonylacetylacetonatotrodium (I) (Rh (acac) (CO) ₂ ) was placed.
1.35 g and about 15 mL of toluene were added and dissolved while heating on a hot water bath. Diphenyl ditelluride
0.32 g of ((TePh) ₂ ) was added, and the total amount was made up to 50 mL by further adding toluene. The weight of the solution is 4
The weight was 3.80 g. Silica (Q-15, particle size 6-10 mesh, average pore diameter 14.0 nm, pore volume 0.99 ml / g) manufactured by Fuji Silysia Chemical Ltd.
49 g was added and stirred for about 1 hour. After visually confirming that the solution had penetrated into the silica interior, centrifugal drainage was performed. The weight of the obtained wet silica was 60.64 g. The supported amount of rhodium calculated from this was 1.1% by weight, and the Te / Rh atomic ratio was 0.3. The wet silica was dried at 80 ° C. under reduced pressure for 3 hours. Furthermore, SV = 10
The temperature was raised to 200 ° C. in 30 minutes under a stream of hydrogen of 00 hr ⁻¹ and reduced at this temperature for 2 hours to obtain a catalyst.

<Diacetoxylation reaction of butadiene> 6.02 g of this catalyst was filled in a glass tube having an inner diameter of 12 mm.
Acetic acid (12 mL / hour), butadiene (6.4 g / hour), and oxygen-nitrogen mixed gas (1800 mL / hour) containing 9% by volume of oxygen were supplied, and the mixture was reacted at a reaction temperature of 80 ° C. for 8 hours. During this time, sampling was performed twice, one hour for 5 to 6 hours and one hour for 6 to 7 hours from the start of the reaction, and the product was quantified by gas chromatography. Table 1 shows the average values of the activity and the selectivity calculated from the two analysis values.

Example 2 Silica subjected to centrifugal dewatering and drying was subjected to SV = 1000 hr ^-1.
The catalyst was prepared and the butadiene diacetoxylation reaction was carried out in the same manner as in Example 1 except that the temperature was raised to 400 ° C. in 1 hour under a hydrogen stream of, and reduced at this temperature for 2 hours. Table 1 shows the results.

The air stream of Example 3 dried SV = 2000 hr ^-1, performed for 3 hours at 0.99 ° C., then a stream of hydrogen of SV = 1000 hr ^-1, the temperature was raised to 400 ° C. in 1 hour, 2 at this temperature Preparation of a catalyst and diacetoxylation reaction of butadiene were carried out in the same manner as in Example 1 except that the reduction was carried out for an hour. Table 1 shows the results.

The nitrogen stream in Example 4 Dry the SV = 2000 hr ^-1, performed for 3 hours at 0.99 ° C., then a stream of hydrogen of SV = 1000 hr ^-1, the temperature was raised to 400 ° C. in 1 hour, 2 at this temperature Preparation of a catalyst and diacetoxylation reaction of butadiene were carried out in the same manner as in Example 1 except that the reduction was carried out for an hour. Table 1 shows the results.

Comparative Example 1 0.10 g of tellurium metal was placed in a 25-mL volumetric flask, and dissolved by adding 10 mL of 35% aqueous nitric acid. To this, 5.39 g of a 5.00% rhodium nitrate solution (manufactured by NE Chemcat) was added, and a 35% nitric acid aqueous solution was further added to make a total volume of 25 mL. The weight of this solution is 30.6
6 g. To this solution was added silica (Q-15, manufactured by Fuji Silysia Chemical Ltd., particle size 6-10 mesh, average pore diameter 1).
4.0 nm, pore volume 0.99 ml / g) 14.55 g
Was added and stirred for about 1 hour. After visually confirming that the solution had penetrated into the silica interior, centrifugal drainage was performed. The weight of the obtained wet silica was 31.99 g. The supported amount of rhodium calculated from this is 1.1% by weight, Te /
The Rh atomic ratio was 0.3. This wet silica is SV =
It was dried at 150 ° C. for 3 hours under a nitrogen stream of 2000 hr ⁻¹ . Further, under a hydrogen stream of SV = 500 hr ^-1 ,
The temperature was raised to 00 ° C. and reduced at this temperature for 2 hours to prepare a catalyst. The diacetoxylation reaction of butadiene was carried out in the same manner as in Example 1. Table 1 shows the results.

Example 5 0.98 g of tetrarhodium dodecacarbonyl (Rh ₄ (CO) ₁₂ ) was placed in a 50-mL volumetric flask, and about 15 mL of acetone was added thereto and dissolved. To this, 0.32 g of diphenyl ditelluride ((TePh) ₂ ) was added, and acetone was further added to adjust the total amount to 50 mL. The weight of the solution is
39.87 g. Silica (Q-15, particle size: 6-10 mesh, average pore diameter: 14.0 nm, pore volume: 0.99 ml / g) manufactured by Fuji Silysia Chemical Ltd. 3
2.76 g was added and stirred for about 1 hour. After visually confirming that the solution had penetrated into the silica interior, centrifugal drainage was performed. The weight of the obtained wet silica was 58.35 g. The supported amount of rhodium calculated from this was 1.1% by weight, and the Te / Rh atomic ratio was 0.3. The wet silica was dried at 50 ° C. under reduced pressure for 3 hours. Further, SV = 100
The temperature was raised to 400 ° C. in 1 hour under a hydrogen stream of ⁰ hr ⁻¹ ,
The catalyst was reduced at this temperature for 2 hours. The diacetoxylation reaction of butadiene was carried out in the same manner as in Example 1. Table 1 shows the results.

Example 6 A catalyst was prepared and a butadiene diacetoxylation reaction was carried out in the same manner as in Example 5, except that drying was carried out at 150 ° C. for 3 hours in an air stream of SV = 2000 hr ⁻¹ . Table 1 shows the results.

Example 7 A 50 mL volumetric flask was charged with 0.552 g of trisdiphenyltellurium rhodium trichloride (RhCl ₃ (TePh ₂ ) ₃ ), and dissolved by adding about 15 mL of acetone. To this was added 1.105 g of rhodium chloride (rhodium metal content 39% by weight, manufactured by NE Chemcat), and acetone was further added to adjust the total volume to 50 mL. The weight of the solution is
40.83 g. Silica (Q-15, particle size 6-10 mesh, average pore diameter 14.0 nm, pore volume 0.99 ml / g) manufactured by Fuji Silysia Chemical Ltd. 3
2.11 g was added and stirred for about 1 hour. After visually confirming that the solution had penetrated into the silica interior, centrifugal drainage was performed. The weight of the obtained wet silica was 57.53 g. The supported amount of rhodium calculated from this is 0.93
% By weight, and the atomic ratio of Te / Rh was 0.33. The wet silica was dried at 50 ° C. under reduced pressure for 3 hours. Furthermore, SV =
The temperature was raised to 400 ° C. in 1 hour under a hydrogen stream of 1000 hr ⁻¹ and reduced at this temperature for 2 hours to obtain a catalyst. The diacetoxylation reaction of butadiene was carried out in the same manner as in Example 1. Table 1 shows the results.

Example 8 A catalyst was prepared and a diacetoxylation reaction of butadiene was carried out in the same manner as in Example 7 except that drying was carried out at 150 ° C. for 3 hours in an air stream of SV = 2000 hr ⁻¹ . Table 1 shows the results.

COMPARATIVE EXAMPLE 2 0.49 g of tetrarhodium dodecacarbonyl (Rh ₄ (CO) ₁₂ ) was placed in a 50-mL volumetric flask, and 25 mL of aqueous acetone (water content 60%) was added thereto to dissolve. The tetrarhodium dodecacarbonyl hardly dissolved, and catalyst preparation was impossible.

[0032]

[Table 1]

* 1: Activity evaluation: Among the reaction products, 3,4-diacetoxybutene 3-hydroxy-4-acetoxybutene 1-acetoxycyclotonaldehyde 1,4-diacetoxybutene which is a medium boiling point product ( 1,4-DABE) 1-hydroxy-4-acetoxybutene and 1,4-dihydroxybutene-2, a high boiling point product, diacetoxyoctatriene 1,1,4-triacetoxybutene-2 The number of mmol per hour per gram atom of rhodium was expressed (mmol product /
g · atm-Rh / hr).

* 2: 1,4-DABE selectivity Of the total product amount obtained by adding the following low-boiling product production amount to the total of the above-mentioned high and medium-boiling product production amounts, 1,
The ratio of the number of mmols occupied by 4-diacetoxybutene is m
ol%. Low boiling products furan acrolein monoacetoxybutene butanol monoacetoxy-1,3-butadiene

[0035]

According to the present invention, there is provided a method for producing a carboxylic acid diester of an unsaturated glycol by reacting a conjugated diene with a carboxylic acid and molecular oxygen in the presence of a solid catalyst. And a method in which a tellurium compound is supported on an inorganic porous material as a solution of an organic solvent having a water content of less than 50% by weight and then reduced to thereby use a catalyst obtained by reducing the unsaturated glycol diester with high activity and high selectivity. Therefore, its industrial utility value is extremely large.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07C 67/055 C07C 67/055 // C07B 61/00 300 C07B 61/00 300

Claims (11)

[Claims] 1. A method for producing a corresponding carboxylic acid diester of unsaturated glycol by reacting a conjugated diene with a carboxylic acid and molecular oxygen in the presence of a solid catalyst containing rhodium and tellurium as active components. And a rhodium compound and a tellurium compound having a water content of 5
A process for producing an unsaturated glycol diester, comprising using a catalyst obtained by reducing a solution supported on an inorganic porous material as a solution of an organic solvent of less than 0% by weight. 2. The method according to claim 1, wherein at least one of the rhodium compound and the tellurium compound is an organometallic compound. 3. The method according to claim 1, wherein the rhodium compound and the tellurium compound are supported on the inorganic porous material as a solution of an organic solvent having a water content of less than 10% by weight. 4. The method according to claim 1, wherein the organic solvent is an organic compound having 10 or less carbon atoms. 5. The method according to claim 4, wherein the organic solvent is at least one selected from hydrocarbons, carbonyl compounds, ethers, esters, carboxylic acids and alcohols. 6. The method according to claim 1, wherein the rhodium compound has at least one carbon monoxide as a ligand. 7. The method according to claim 6, wherein the rhodium compound is selected from the group consisting of rhodium dicarbonyl acetylacetonate, hexarhodium hexadecacarbonyl and tetrarhodium dodecacarbonyl. 8. The tellurium compound, wherein at least one Te compound is used.
The method according to any one of claims 1 to 7, wherein the compound is a compound having an interaromatic bond. 9. The tellurium compound comprising at least one Te
The method according to any one of claims 1 to 7, which is a compound having a phenyl group bond. 10. The method according to claim 1, wherein the tellurium compound is diphenyl ditelluride or trisdiphenyl tellurium rhodium trichloride. 11. The method according to claim 1, wherein the rhodium compound and the tellurium compound supported on the inorganic porous material are dried and then reduced.