JPS5825654B2 - Production method of di(acyloxy)alkene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing unsaturated esters, more specifically, a method for producing unsaturated esters.
This invention relates to a method for producing (acyloxy) alkenes.

According to the invention, a substantially gas phase mixture consisting of a conjugated diene, a carboxylic acid, a corresponding carboxylic acid anhydride and oxygen, palladium and antimony in their metallic state or their salts of said carboxylic acid Provided is a method for producing di(acyloxy)alkenes, which comprises contacting the di(acyloxy)alkenes with a solid catalyst supported on a solid support in the form of:

This method is applicable to di(
It is particularly useful in the production of acyloxy)butenes.

The carboxylic acids and carboxylic acid anhydrides used in the present invention are preferably lower aliphatic carboxylic acids (especially those having 2 to 4 carbon atoms) and their anhydrides, more particularly acetic acid, propionic acid and lactic acid, and their anhydrides. It is an anhydride of.

The acyl group of the produced di(acyloxy)alkene is the acyl group of the raw material carboxylic acid used.

The process of the present invention is extremely useful for the production of diacetoxybutene using butadiene, acetic acid and acetic anhydride in the raw reaction mixture.

It has already been proposed to produce diacetoxybutenes by reacting a gas phase mixture containing butadiene, acetic acid and oxygen in the presence of a catalyst consisting of palladium and a promoter element from groups 5 or 6 of the periodic table. ing.

As used herein, the periodic table refers to the 23rd and 24th periodic tables in "Advanced Inorganic Chemistry, 2nd Edition" by F. A. Cotton and G. Wilkinson (Interscience Publishing, New York, 1966). Refers to the periodic table of long periods of membranes written on the page and displayed on its back cover.

Promoter elements selected from Groups 5 and 6 that have been published so far are phosphorus, arsenic, antimony, bismuth, selenium and tellurium (% 48-4416 and Belgian Patent No. 827837, Same No. 8285
(See No. 88).

Other promoter elements that have previously been suggested as advantageous to include in the catalyst are alkali metals or alkaline earth metals.

The inventor has discovered, however, that for such conventional methods, although the initial diester production rate is good, the production rate drops rapidly.

However, according to the present invention, for example, the presence of a certain proportion of acetic anhydride together with acetic acid maintains a good product production rate for a long time.

In processes for reacting conjugated dienes, carboxylic acids and oxygen in the liquid phase in the presence of palladium catalysts, it has been proposed to add acid anhydrides to reduce the proportion of reaction product water in the liquid reaction medium. (British Patent No. 11)
No. 70222), the addition of an acid anhydride in a gas phase reaction method has not been previously reported.

However, the present inventor has found that a good production rate can be further prolonged by not only blending a carboxylic anhydride corresponding to the raw material carboxylic acid in the reactant raw material mixture, but also adding antimony in a certain proportion in the form of a salt of the raw material carboxylic acid. We have discovered that it can be maintained over time, and not only can it be maintained, but it can also be increased.

This is a preferred embodiment of the invention.

Furthermore, it can be used to contact a gas phase mixture containing a conjugated diene (e.g., butadiene), a carboxylic acid (e.g., acetic acid), and oxygen (but no acid anhydride or antimony carboxylate salt is present in this mixture). It has also been found that the presence of carboxylic anhydride and antimony carboxylate in the reaction mixture of the palladium-antimony solid catalyst &ζ, which lost its activity during the reaction, restored its activity.

When antimony is present in the form of a carboxylic acid salt in the reaction mixture, a compound of antimony (e.g. antimony trioxide) can be added to the carboxylic acid anhydride before evaporation, or in a mixture of carboxylic acid and carboxylic acid anhydride before evaporation. Advantageously, the antimony carboxylate is formed by dissolving the antimony carboxylate.

The catalyst used in the present invention is a solid catalyst containing palladium and antimony supported on a solid carrier in the form of a metal or a salt of a starting carboxylic acid.

Suitable catalyst supports can be used, such as silica, alumina, silica/alumina mixtures, agnesia, diatomaceous earth, pumice and carbon.

Particular preference is given to silica. The proportion of palladium relative to the total catalyst and support can vary within a wide range, but is preferably 0.
It is 1 to 20 wt%.

The proportion of antimony suitably ranges from 0.1 to 20 gram atoms per gram atom of palladium, preferably from 1 to 20 gram atoms per gram atom of palladium.
In the 10 gram atom range.

The catalyst may also contain an alkali metal or alkaline earth metal carboxylate.

This is because diacetoxybutene selectivity is thereby improved to some extent.

In particular, salts of lower aliphatic carboxylic acids (especially acetic acid) can be used.

The proportion of the alkali metal or alkaline earth metal carboxylate salt can vary within a wide range, but is suitably from 0.1 to 20 gram atoms, preferably from 0.9 to 10 gram atoms per gram atom of palladium.

Suitable alkali metals and alkaline earth metals are lithium, sodium, potassium, rubidium, cesium, calcium, barium, strontium and magnesium.

Cesium is the preferred alkali metal.

Instead of alkali metal or alkaline earth metal carboxylates, quaternary ammonium carboxylates, especially tetraalkylammonium carboxylates (more particularly those in which the alkyl group is a lower alkyl group of 1 to 4 carbon atoms) It may be advantageous to use

Preferably, such a carboxylate is a lower aliphatic carboxylate, especially an acetate.

Quaternary ammonium carboxylates are used in similar proportions as alkali metal or alkaline earth metal carboxylates.

Tetramethylammonium acetate is a particularly suitable example.

Solid catalysts containing metallic palladium and antimony can be prepared by a suitable method, for example by impregnating a support with a solution of a palladium salt (e.g. palladium chloride) and a solution of a compound of a cocatalyst element (e.g. antimony trichloride), using a suitable solvent. (e.g. water), then dried and the catalyst reduced before use, for example by heating in a stream of hydrogen or by treatment with a reducing agent such as hydrazine or formalin.

If the catalyst is to contain a carboxylate of an alkali metal, alkaline earth metal or quaternary ammonium, it can be impregnated with a solution of the carboxylic acid, for example after reduction of the palladium compound.

However, when solid catalysts are made by impregnating a support with carboxylates of palladium and carboxylates of antimony (when impregnating with carboxylates corresponding to the carboxylic acids used in the process, e.g. acetate), generally It is not necessary to pre-reduce the catalyst.

Although catalyst life is greatly increased by the method of the present invention, the catalyst eventually deteriorates.

Spent catalyst can be regenerated by treatment with dilute ammonia.

The process of the invention is carried out by passing a vapor mixture of carboxylic acid and carboxylic anhydride together with a conjugated diene (eg, butadiene) and an oxygen-containing gas over a solid catalyst at a selected temperature.

When a carboxylate of antimony is present in the reaction raw material mixture, it is preferable to dissolve the antimony compound (eg, antimony oxide) in the carboxylic acid and/or carboxylic acid anhydride before evaporation.

The reaction is preferably carried out at a temperature within the range of 120-200<0>C.

The preferred temperature is 130 to 160°C, more preferably 1
The temperature is 40-150°C.

Although the pressure is not critical, it is preferred to carry out the reaction at atmospheric pressure or at slightly higher pressure, for example from 1 to 20 bar (absolute), although pressures outside this range are not excluded.

Although pure oxygen may be used, it is preferred to use air.

However, in addition to this, there are other gases that are inert in reaction with oxygen (
for example nitrogen or argon) may be used.

When the antimony carboxylate is present in the reaction mixture, it is preferably fed continuously, but it may be fed intermittently.

Generally, when considered over an operating time of at least several hours, the rate is such that there is a substantial equilibrium between the amount of antimony carboxylate salt fed into the feed mixture and the amount removed into the reaction product. Preferably, the antimony carboxylate is supplied at

The antimony carboxylic acid salt has an amount of 0.01 to 0.01 to the total of the acid and acid anhydride in the reaction raw materials, calculated as antimony.
Preferably, it is provided at a level within the range of 5 wt%.

For this purpose, antimony trioxide dissolved in acetic anhydride is preferably used.

The total amount of conjugated diene, carboxylic acid and carboxylic acid anhydride and the relative proportions between oxygen can vary within a wide range depending on the selection.

In practice, the conversion per pass can be limited;
Unreacted raw materials are collected and recycled.

The product di(acyloxy)alkene can be recovered from the effluent reaction vapors by condensation.

Condensation usually provides a solution of the product diester in excess carboxylic acid and carboxylic acid anhydride, which acid and anhydride can be removed from the product diester by distillation.

Antimony salts entrained in the product can be removed by conventional methods, such as treating the product containing the antimony salt with water to convert the salt into an insoluble oxide and separate the oxide. can be removed from the product by

When the method of the present invention is used in the production of diacetoxybutenes in a preferred embodiment in which antimony carboxylate is present in the raw material mixture, a high production rate (for example, 1001 or more/kg of catalyst/hour) can be achieved. , such production rates are maintained for extended periods of time (eg, at least 100 hours).

As used herein, "diacetoxybutene(s)" means a combination of cis-type and trans-type 1,4-diacetoxybutene and 3,4-diacetoxybutene, and 3,4-diacetoxybutene Butene is about 10w of total
t%.

Diacetoxybutene is a useful intermediate for conversion to butane by hydrolysis and hydrogenation.

Butanediol is a useful intermediate for the production of polyesters and for the production of tetrahydrofuran.

The invention is illustrated by the following examples.

Comparative Example A solution of 0.165P palladium chloride and 0.752P antimony chloride in a 10% aqueous hydrochloric acid solution was mixed with 102 silica.

(The silica was 8-16 mesh).

The mixture was evaporated to dryness.

The catalyst was reduced with alkaline hydrazine, washed with water until neutral, and then dried under reduced pressure.

0.72 in water for this dry catalyst? A solution of cesium acetate was added thereto, and the mixture was evaporated to dryness.

20ml of the above catalyst was loaded into the reactor.

The reactor consisted of a 22 mm diameter glass tube in which a central hot wall with an internal diameter of 7 mm was placed.

The reactor was heated to 145°C and then the butadiene, acetic acid,
Mixture of oxygen and nitrogen (molar ratio 25:50:5:20
) was fed at a space velocity of 500/h.

The production rate of diacetoxybutene after 3 hours was 65 g/kg of catalyst/hour, and after 6 hours this was 45'? /kg of catalyst/hour, then after 13 hours 221/kg of catalyst
It gradually descended until g1 o'clock.

Example 1 A catalyst (20 Ttl) prepared as in the comparative example above was loaded into a comparative reactor.

The reactor was heated to 145°C and then butadiene, acetic anhydride, acetic acid, oxygen and nitrogen (molar ratio 24:3:48:5
:20) was fed at a space velocity of 500/h.

The production rate of diacetoxybutene after 3 hours was 65 z/kg catalyst/hour, which was maintained for 6 hours, but gradually decreased to 35 v/kg catalyst/hour after 13 hours.

Example 2 (Regeneration) The catalyst used in the comparative example was mixed with butadiene, acetic acid, acetic anhydride, oxygen and nitrogen (molar ratio 24:48) at 145°C.
:3:5:20) at a space velocity of 500/hour.

In addition, for the total of the above acetic acid and acetic anhydride, 2.
It contained 5 wt% antimony oxide.

After 7 hours of operation, the production rate of diacetoxybutene was 52
．． 5? /kg of catalyst/hour.

When the content of antimony oxide in the acetic acid and acetic anhydride feedstock was changed to 0.5 wt% to balance the antimony content in the effluent, the production rate increased to 112P/kg catalyst/hour, which resulted in loss of activity. It was maintained for 40 hours without any change.

Changing the feedstock to acetic acid (without acetic anhydride) while maintaining the same antimony, butadiene, oxygen, and nitrogen levels resulted in a rapid decrease in activity and a decrease in the rate of diacetoxybutene formation to 101 within 5 hours. It decreased to 1 hour/kg of catalyst.

Example 3 In a solution of palladium acetate, antimony oxide and cesium acetate in acetic acid and acetic anhydride, 10
? of silica support (8 to 16 meshes) was immersed.

This mixture was evaporated to dryness to give 1% Pd, 4% Sd, 5%
A solid catalyst containing % Cs was obtained.

The reactor of Comparative Example 1 was loaded with the solid catalyst (20 groups),
Butadiene, acetic acid, acetic anhydride, oxygen, nitrogen (molar ratio 24
:48:3:5220) at a space velocity of 500/h.

In addition, 0.5% of the total of this acetic acid and acetic anhydride
of antimony oxide.

Catalyst temperature was maintained at 145°C.

The production rate of diacetoxybutene is 120 P/kg of catalyst.
/h, which was maintained for 100 hours without loss of activity.

Example 4 The procedure of Example 3 was repeated, but this time using tetramethylammonium acetate instead of cesium acetate in the preparation of the catalyst, 0.1% Pd, 14% sb and 5
A catalyst containing % (CH3)4N10 was prepared.

Under the reaction conditions of Example 3, the maximum production rate of diacetoxybutene was IIFI/ky/hour of catalyst, which corresponded to 91% of the total acetoxylated products.

Example 5 Example 3 was repeated, but this time a catalyst containing 0.1% Pd and 4% sb was made without using cesium acetate during catalyst preparation.

Under the reaction conditions of Example 3, the maximum production rate of diacetoxybutene was 871/kg catalyst/hour, which corresponded to 83% of the total acetoxylated products.

Example 6 Repeat the procedure of Example 3 and add 0.1% Pd.

A catalyst containing 4% sb and 5% Cs was obtained.

Under the reaction conditions of Example 3, the maximum production rate of diacetoxybutene was 120 P/kg catalyst/hour, which corresponded to 94% of the total acetoxylation products.

Claims (1)

[Scope of Claims] 1. A substantially gas phase mixture consisting of a conjugated diene, a carboxylic acid and oxygen supported on a solid support with palladium and antimony in their metallic state or in the form of their salts of the above-mentioned carboxylic acids. When producing a di(acyloxy)alkene by contacting it with a solid catalyst containing
A method for producing a di(acyloxy)alkene, which comprises blending a carboxylic anhydride corresponding to the above-mentioned carboxylic acid into a reactant raw material mixture. 2. The method according to claim 1, characterized in that an antimony salt of a raw material carboxylic acid is present in the reactant raw material mixture. 3. Contacting a substantially gas phase mixture of a conjugated diene, a carboxylic acid and oxygen with a solid catalyst comprising palladium and antimony in their metallic state or in the form of their salts of the above-mentioned carboxylic acids supported on a solid support. When producing di(acyloxy)alkenes by
Blending a carboxylic anhydride corresponding to the carboxylic acid into the reactant raw material mixture, making an antimony salt of the carboxylic acid exist in the reactant raw material mixture, and adding a quaternary ammonium carboxylate to the catalyst. A method for producing di(acyloxy)alkenes characterized by containing also.