JPS6033375B2 - Method for producing 1,4-diacyloxybutene-2 - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 1,4-diasiloxyptene-2.

Specifically, the present invention relates to a method for producing 1,4-disilotoxybutene-2 by oxidizing 1,3-butadiene with molecular oxygen in the presence of a carboxylic acid.

1,4-Diacyloxybutene-2 becomes 1,4-butanediol by hydrogenation and hydrolysis, and is an extremely important raw material industrially.

Various methods for producing 1,4-diacyloxybutene-2 by oxidative acyloxylation reaction of 1,3-ptadiene have been proposed. However, these known methods have the disadvantage that 3,4-diacyloxybutene-1, which is of little industrial value, is produced as a significant by-product, and it is difficult to say that it is an industrially advantageous production method.

For example, published patent publication 1973-? According to 2090 Example 1 and Published Patent Publication 1983-140406 Example 1,
The production ratio of 1,4-diacetoxybutene-2 and 3,4-diacetoxybutene-1 is 86:14 and 81:1, respectively.
It is 9.

Therefore, in order to increase the yield of 1,4-diacyloxybutene-2, it is necessary to
It is necessary to isomerize 1 to 1,4-diacyloxyptene-2, and in fact, this isomerization method has also been proposed (for example, Japanese Patent Application Publication No. 47-30610 and Japanese Patent Application Publication No. 126-12611).

However, performing isomerization increases the number of steps and is extremely disadvantageous from an industrial perspective.Moreover, 3,4-diacyloxybutene-1 is a type of pinyl compound, and side reactions such as polymerization reactions occur. is likely to occur, and the isomerization yield to 114-diacyloxybutene-2 is also unsatisfactory. The inventors of the present invention made extensive studies to overcome these drawbacks, and found that palladium metal and the general formula R, R2R4N1 (herein R
, R2, R3 and R4 each represent a hydrogen atom or a hydrocarbon group.

Note that R, R2 or R.R2R3 may be linked to each other to form a nitrogen-containing polycyclic ring). We have discovered a method for industrially advantageous production. That is, the present invention includes palladium metal and ammonium iodide salt, and the composition thereof is such that the ammonium iodide salt is 0.1 to 1.
The present invention provides a novel method for producing 1,4-diacyloxybutene-2 by reacting 1,3-butadiene with a carboxylic acid and molecular oxygen using 5 mol of a catalyst.

According to the method of the present invention, as explained in the examples,
The selectivity of 1,4-diacyloxybutene-2 in the produced diacyloxybutene is extremely high, and the amount of 3,4-diacyloxybutene-1 produced is extremely small, and is substantially 1.4-diacyloxybutene-2.
It is possible to produce only diacyloxybutene-2.

The first component of the catalyst used in the present invention is palladium metal, and the second component has the general formula R, R2R3R4N1 (where R
, , R2, R3, and R4 each represent a hydrocarbon group. Note that R, R2 or R. It is an ammonium iodide salt represented by R2R3 (sometimes R2R3 connects with each other to form a nitrogen-containing heterocycle). Examples of the ammonium iodide salt as the second component include ammonium iodide (NHI), tetraethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, trimethylbenzylammonium iodide, and trimethylamine hydrogen iodide. , triethylamine hydrogen iodide, tributylamine hydrogen iodide,
Examples include pyridine hydrogen iodide and piperazine hydrogen iodide.

Generally, in oxidation reactions using catalysts containing palladium as a main component, efforts are made to increase the catalytic activity by adding metal halides, carboxylates, etc. as promoters.

At this time, the metal C, which is a co-catalyst. It is generally considered advisable to use genides, carboxylates, etc. in excess of palladium in terms of molar ratio. However, the present inventors have developed a catalyst consisting of palladium metal as the first component and ammonium iodide salt as the second component. It has been found that the selectivity of 1,4-diacyloxybutene-2 is improved only within a very limited range of .5 mol, and the catalytic activity is also improved.

This fact is not observed when other ammonium halide salts other than ammonium iodide salts are used as the second component of the catalyst, and is a completely unexpected effect that only ammonium iodide salts exhibit. This is a phenomenon that cannot be imagined from common sense.

In addition, the fact that a good composition ratio of the catalyst components palladium metal and ammonium iodide salt is extremely limited is different from the conventional concept of main catalyst and co-catalyst, and the fact that each catalyst component can form a new compound such as a complex compound. It is assumed that this new compound exhibits remarkable catalytic activity.

The catalyst components used in the present invention, palladium metal and ammonium iodide salt, are desirably supported on an inert carrier commonly used in catalytic reactions, and activated carbon is particularly preferred as the carrier.

In addition, when preparing a supported catalyst, for example, it is convenient to prepare a desired content of supported palladium according to a conventional method, and then add this to a water or carboxylic acid solution of an ammonium iodide salt. It is.

At this time, it is also possible to substitute a commercially available palladium with a carrier.

Although the supported amount of each component of the catalyst can be arbitrarily selected, it is usually desirable that palladium metal be in a weight percent range of 0.05 to 2.

The carboxylic acid used in the present invention is not particularly limited, but a fatty acid carboxylic acid having 2 to 5 carbon atoms is preferred, and acetic acid is particularly preferred.

The purity of oxygen used in the present invention is not particularly limited, and air or pure oxygen is used, but it is also possible to use these diluted with nitrogen or carbon dioxide.

There is no particular restriction on the amount of oxygen used, as long as the composition of the mixed gas of 1,3-butadiene or carboxylic acid and oxygen is kept outside the explosive limit. In carrying out the present invention, either a gas phase reaction or a liquid phase reaction can be adopted as the reaction method.
A liquid phase reaction is preferred.

Further, the present invention can be carried out under normal pressure or increased pressure,
In the case of pressurization, it is desirable to carry out under 150k9' (gauge pressure).

Furthermore, when carrying out the present invention, the reaction temperature is between 50 and 25
0qC is preferable, and 60 to 130qo is particularly preferable.

When carrying out the present invention, the amount of catalyst can be selected arbitrarily;
In the case of a liquid phase reaction, the amount of palladium metal in the reaction solution 1 is preferably 0.5 to 100 hours, and in the case of a gas phase reaction, the space velocity is usually in the range of 100 to 50,000 hours. It is desirable that the amount of catalyst is as follows.

When carrying out the present invention in a liquid phase reaction, a solvent is not particularly required, but a solvent inert to the oxidation reaction may be used.

As a solvent inert to the oxidation reaction, the product 1.4
Examples include 1,4-diasiloxybutene-2 such as -diacetoxybutene-2, ethylene glycol esters such as ethylene glycol diacetate, and ethanol esters such as ethyl acetate.

The present invention will be explained in more detail below using Examples and Comparative Examples.

Example 1 20 equipped with a fly scaler, a thermometer, a gas blowing pipe, and a gas outlet part
100ml of acetic acid was added to 4ml of France, and then 2.5mmol of tetrabutylammonium iodide was added and dissolved.

To this solution, an amount equivalent to 2.5 milligram atoms of 5% palladium carbon manufactured by Nippon Engelhard Co., Ltd. as palladium metal was added while stirring, and the mixture was allowed to react for 2 hours. After that, 1
After raising the temperature to 00 qo, 1,3-butadiene and oxygen were flowed at a flow rate of 40 [/mjn].

After 1 hour of reaction, the catalyst was separated from the furnace and the furnace liquid was analyzed by gas chromatography. It was found that 1.01 ta of 1,4-diacetoxybutene-2 (abbreviated as 1,4-DAB) was produced, and 3
・4-Diacetoxybutene-1 (abbreviated as 3.4-DAB) and 3.4-hydroxyacetoxybutene-1 (3.
4-HAB) is extremely rare (3.4-DAB and 3.4-HAB).
The total amount of 4 HABs produced was less than 0.005 ta). This result shows that the total acetoxybutene produced (D
The selectivity of 1,4-DAB in (abbreviated as AB) is 99.5%.
That's all.

Example 2 The procedure is as in Example 1, except that tetrabutylammonium iodide is added at 0.75 mmol in Example 2, 1.25 mmol in Example 3, 1.25 mmol in Example 4, and 1.25 mmol in Example 5. 3 mmol was used.

The results of Examples 3 to 12 and Comparative Examples 1 to 5 are shown in Table 1. Examples 6 and 7 The same operation as in Example 1 was carried out, but the reaction temperature was 7500 in Example 6 and 11000 in Example 7.

Examples 8 to 10 The same operation as in Example 1 is carried out, but instead of 2.5 mmol of tetrabutylammonium iodide, 2.5 mmol of tetraethylammonium iodide is used in Example 8, and triethyl iodide is used in Example 9. Example 10
In this case, trimethylphenylammonium iodide was used.

Example 11 2.5 mmol of ammonium iodide was dissolved in 100M water, and to this aqueous solution was added 5% palladium carbon manufactured by Nippon Engelhard Co., Ltd. in an amount equivalent to 2.5 milligram atoms as palladium metal.

After leaving it for 2 hours, evaporate the water to dryness on a water bath and then add 120q.
Vacuum drying was performed at o for 3 hours.

The catalyst obtained in this way was mixed with 100% acetic acid,
200M4 equipped with thermometer, gas inlet pipe and gas outlet
After putting it in a Tulo flask and heating it to 100 qo, the same operation as in Example 1 was performed.

Example 12 The same operation as in Example 11 is carried out except that ammonium iodide 2.
2.5 mmol of triethylamine hydrogen iodide instead of 5 mmol
Millimoles were used.

Example 13 Palladium chloride in a solution of 0.5 parts of concentrated hydrochloric acid and 100 parts of water.

5 mmol was added and heated on a water bath to 40-60 mm to dissolve.

13. 30-50 mesh activated carbon from this solution.
After adding 0.0 mL of water and leaving it for 2 hours, the water was evaporated to dryness.

Activated carbon adsorbed with palladium chloride was packed in a glass reaction tube, and nitrogen gas was introduced at 200 min. at 150 min. After drying at a flow rate of 2 hours for 2 hours, the temperature was raised to 300 qo, and then hydrogen gas was added at a flow rate of 200 qo/min. It ran for 3 hours at a flow rate of .

Thereafter, it was thoroughly washed with water and vacuum dried at 120 qo. The same operation as in Example 1 was performed except that the 2% palladium carbon thus prepared was used instead of the 5% palladium carbon manufactured by Nippon Engelhard. Comparative example
1 The same procedure as in Example 1 is carried out, but using 5 mmol of tetrabutylammonium iodide.

Comparative Examples 2 and 3 The same operation as in Example 1 was carried out, but instead of 2.5 mmol of tetrabutyl ammonium iodide, 2.5 mmol of tetraethyl ammonium chloride was used in Comparative Example 2, and tetraethylammonium bromide was used in Comparative Example 3. there was.

Comparative Example 4 The same machine as in Example 11 was operated, but ammonium iodide 2
．． 2.5 mmol of ammonium chloride was used instead of 5 mmol.

Comparative Example 5 Into the same four-ring flask as used in Example 1, 2% palladium carbon manufactured by Nippon Engelhard Co., Ltd., equivalent to 2.5 milligram atoms of palladium metal, and 100 grams of acetic acid were added.

Thereafter, the same oxidation reaction as in Example 1 was performed. Table-1

Claims (1)

[Claims] 1. When producing 1,4'-diacyloxybutene-2 by reacting 1,3-butadiene with carboxylic acid and molecular oxygen, palladium metal and general formulas R_1, R_2, R
_3, R_4NI (here R_1, R_2, R_3, R
_4 each represents a hydrogen atom or a hydrocarbon group. Note that R_1, R_2, or R_1, R_2, and R_3 may be linked to each other to form a nitrogen-containing heterocycle), and the ammonium iodide salt contains 1 gram of palladium metal. 0.1 per atom
A method for producing 1,4-diacyloxybutene-2, characterized in that a catalyst having a composition of 1.5 mol is used. 2. The method for producing 1,4-diacyloxybutene-2 according to claim 1, wherein the catalyst composition is 0.3 to 1.25 moles of ammonium iodide salt per gram atom of palladium metal. 3. A method for producing 1,4-diacyloxybutene-2 as claimed in claim 1, in which the catalyst component is supported on activated carbon. 4. The method for producing 1,4-diacyloxybutene-2 according to claim 1, wherein acetic acid is used as the carboxylic acid. 5. The method for producing 1,4-diacyloxybutene-2 according to claim 1, wherein the reaction is carried out in a liquid phase. 6. The method for producing 1,4-diacyloxybutene-2 according to claim 1, wherein the reaction temperature is 60 to 130°C.