JPH07138203A - Production of carboxylic acid vinyl ester - Google Patents

Abstract

PURPOSE:To obtain a carboxylic acid vinyl ester in a high yield by carrying out transesterification reaction between a carboxylic acid and vinyl acetate using a catalyst consisting of a Pd compound, a halide of an alkali metal and a Na salt or Li salt of a specific acid and, simultaneously, neutilize the catalyst. CONSTITUTION:An aromatic or aliphatic carboxylic acid and vinyl acetate are subjected to transesterification reaction to obtain the objective carboxylic acid vinyl ester. In this reaction, as a catalyst, a catalyst consisting essentially of a palladium compound (e.g. palladium chloride), a halide of an alkali metal and a sodium salt or lithium salt of an acid having >=1 acid dissociation exponent pKa is used. As the halide of the alkali metal, chloride, bromide or iodide of an alkali metal is preferably used. As the acid having >=1 acid dissociation exponent pKa, the aromatic or aliphatic carboxylic acid used in the reaction or a mixture of the acid with other acid is preferably used and as the Na salt or the Li salt, sodium or lithium di-or triphosphate or sodium or lithium carbonate is preferably used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a carboxylic acid vinyl ester, the object of which is to obtain a desired product in a high yield in a short reaction time, and to prevent deterioration of a conventional palladium compound and this compound. It is possible to proceed the reaction without using the copper compound, which was thought to be absolutely necessary for prevention, while maintaining the reactivity of the palladium compound used as a catalyst at a high level. After completion, the palladium compound used can be easily recovered in high yields without the need for complicated separation / recovery operations, and can be generally used as an industrial production method of vinyl carboxylate. It is to provide a method for producing a vinyl ester.

[0002]

2. Description of the Related Art As a method for producing a vinyl carboxylate ester by a transesterification reaction, a method of reacting with a mercury salt catalyst such as mercury acetate or mercury sulfate in the presence of a strong acid such as sulfuric acid or toluenesulfonic acid has long been known. Was known. However, after the toxicity of mercury salt was confirmed,
A method of using a safe palladium salt as a catalyst instead of a mercury salt was reported by J. Smidt et al. [J. Smidt
Et al., Angew. Chemie, 74 , 93-128 (1962), West German Patent No.
1,127,888, A. Salbe et al., Ber. 102 , 2939-2950 (1
969)]. However, in the method reported by J. Smidt et al., The amount of the palladium compound used as a catalyst is 0.05 to 10 mol% based on the starting carboxylic acid.
It is known that a large amount of metal palladium is deposited and the catalytic activity is lost by the reaction for a long time, so that a high yield cannot be obtained. Since palladium is an expensive precious metal, it is necessary to control the amount to the limit that is effective as a catalyst in order to industrially use it as a catalyst, and to prevent deterioration of the catalytic activity of palladium used and side reactions. Suppression of generation is required. In light of such a situation, a plurality of techniques as shown below have already been disclosed regarding the transesterification reaction using a palladium compound as a catalyst.

Japanese Patent Publication No. 61-816 discloses a technique in which a palladium carboxylate is used as a main catalyst, and an alkali metal carbonate, hydrogen carbonate or hydroxide is used as a promoter in the main catalyst. Was there. In addition,
Japanese Patent No. 26661 discloses a technique in which a main catalyst made of a palladium compound uses a cocatalyst made of a copper compound and an alkali metal compound, at least one of which is a halide. Furthermore, in Japanese Patent Publication No. 57-20290,
A technique has been disclosed in which a palladium compound is adsorbed and supported on a carrier surface such as activated carbon or alumina to form a solid catalyst, and a copper compound and an alkali metal compound, at least one of which is a halide, are used as a cocatalyst in the solid catalyst. .
On the other hand, in JP-A-63-39835, palladium salts and II
A technique in which a divalent copper salt, lithium halide, and an alkali di- or tri-phosphate are used as catalysts has been disclosed.

However, the technique disclosed in Japanese Patent Publication No. 61-816 discloses that the carboxylate of a palladium compound used as a catalyst can be almost completely recovered as reduced palladium, but the objective vinyl ester. The reaction rate was less than 50%, and there was a problem that the reaction efficiency was very poor. Further, the technology disclosed in JP-B-57-26661 is a technology in which reduction or deactivation of the palladium compound does not occur during the reaction step, and the palladium compound can be reused in a state having catalytic activity, A complicated operation is required to separate and recover the palladium dissolved in the reaction solution from the reaction solution and reuse it, and the loss of the palladium compound occurs during this operation. There was the problem that a very long reaction time was required to obtain the vinyl ester product. Further, the technology disclosed in JP-B-57-20290 is a reusable manufacturing method in which the palladium catalyst can be easily separated and recovered, but the palladium catalyst eluted from the carrier surface into the reaction solution is recovered. However, there is a problem that, as the solid catalyst is reused, an effective amount of the palladium compound must be replenished depending on the number of times of reuse. In addition, the Japanese Patent Publication No.
In the technology disclosed in JP-B No. 57-20290 and JP-B No. 57-20290, the reaction conversion rate from the raw material carboxylic acid to the target vinyl ester is about 50%, and there is a problem that the reaction conversion efficiency is not sufficient. . On the other hand, Japanese Patent Laid-Open No. 63-39835 discloses an excellent technique capable of maintaining the catalytic activity of the palladium compound used and obtaining a high conversion rate. When using sodium or lithium salt as the, there is a problem that it is difficult to dissolve in the reaction solution, and in the case of a lithium salt, the reaction solution, due to poor solubility in the reaction solution,
There was also a problem that the reaction conversion rate becomes low.

Therefore, in a transesterification reaction using a palladium compound as a catalyst, it is possible to obtain a desired vinyl ester in a high yield, and as a technique capable of suitably maintaining the catalytic activity of the palladium compound as a catalyst. There is a technique disclosed in Japanese Patent Laid-Open No. 2-172946. The disclosed technique includes a main catalyst composed of palladium metal and / or a palladium compound, a redox agent selected from copper and bromine compounds, at least one of which is bromide, lithium carboxylate, lithium carbonate, lithium hydrogen carbonate and lithium hydroxide. It was a technique of performing a transesterification reaction in the presence of at least one lithium compound selected from

[0006]

However, the technique disclosed in Japanese Patent Application Laid-Open No. 2-172946 is not suitable for recovering and reusing the palladium metal and / or the palladium compound used as the catalyst after the reaction. Since the copper salt used as a redox agent is mixed, a separation operation of palladium and copper must be performed, a loss of palladium occurs due to this separation operation, and a separation and recovery operation becomes complicated. There were challenges. Further, in the disclosed technique, when a copper salt as a redox agent and lithium bromide as a cocatalyst are used for the main catalyst composed of palladium metal and / or palladium compound, a specific sodium salt or lithium salt as an alkali metal compound is used. There is a disclosure that the reaction conversion rate is lowered by using.

In view of the above situation, the present inventors have found that when producing a carboxylic acid vinyl ester by a transesterification reaction using palladium as a catalyst, a desired reaction product is extremely reacted in a short time. It can be obtained in a high yield, the reaction efficiency is extremely excellent, the palladium compound used as a catalyst can be repeatedly used as a catalyst without being reduced or deactivated during the reaction step, and the reaction is completed. After that, the carboxylic acid can be easily recovered without requiring a complicated operation, and further, when a specific sodium salt or lithium salt is used as a catalyst, the reaction conversion rate can be maintained high, etc. We have created an excellent production technology that can be widely used as an industrial production method for vinyl esters.

[0008]

According to the present invention, an aromatic or aliphatic carboxylic acid and vinyl acetate are mixed with a palladium compound, an alkali metal halide and a sodium salt of an acid having an acid dissociation index pKa value of more than 1. By transesterifying a lithium salt with a catalyst as an essential component in the presence of a catalyst to produce a vinyl carboxylate, a method for producing a vinyl carboxylate is provided, which solves the above-mentioned conventional problems. Resolve.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The structure of the method for producing a carboxylic acid vinyl ester according to the present invention will be described in detail below. In this invention, an aromatic or aliphatic carboxylic acid and vinyl acetate are used as starting materials. Examples of the aromatic carboxylic acid include benzoic acid, alkylbenzoic acid, oxybenzoic acid, chlorobenzoic acid, and the like, but are not particularly limited. As the aliphatic carboxylic acid, for example, propionic acid, butyric acid, valeric acid, caproic acid, lauric acid, saturated carboxylic acid such as palmitic acid, acrylic acid, methacrylic acid, crotonic acid, unsaturated carboxylic acid such as sorbic acid, Saturated or unsaturated monobasic or polybasic carboxylic acids such as adipic acid, malic acid, or acylsingoic acid are exemplified as suitable examples, but not limited thereto. Further, these aromatic or aliphatic carboxylic acids may have a substituent unless the object of the present invention is impaired, and a specific example thereof is chloropropionic acid.

In the present invention, the above-mentioned aromatic or aliphatic carboxylic acid and vinyl acetate are used as starting materials, and the starting materials are subjected to a transesterification reaction in the presence of a catalyst to give vinyl carboxylates. To manufacture. As the catalyst used here, a catalyst containing a palladium compound, a halide of an alkali metal, and a sodium salt or lithium salt of an acid having an acid dissociation index pKa value of 1 or more as essential components is used.

Palladium compounds are preferably exemplified by palladium salts such as palladium chloride, palladium bromide and palladium acetate, but are not particularly limited. It is desirable that the amount of such a palladium compound used is limited to an extreme amount, that is, 0.005 to 0.1 mol%, more preferably 0.01 to 0.05 mol%, relative to the raw material carboxylic acid. The reason for this is that when the amount of the palladium compound used is less than 0.005 mol% with respect to the raw material carboxylic acid, the catalytic action of the palladium compound is not sufficiently exhibited, while on the other hand, when it is used in excess of 0.1 mol% However, since a product proportional to the amount used is not obtained, either case is not preferable. That is, by using the palladium compound in the range of 0.005 to 0.1 mol% with respect to the raw material carboxylic acid, the expensive palladium compound as an industrial raw material can be effectively used in the necessary minimum amount. , Based on experimental knowledge of the inventors.

Examples of alkali metal halides include alkali metal chlorides, bromides and iodides. Specific examples thereof include lithium bromide, sodium bromide, potassium bromide, lithium chloride and sodium chloride. Potassium chloride, lithium iodide, sodium iodide, potassium iodide, etc. are illustrated as suitable examples, but not limited thereto. The amount of such an alkali metal halide used is preferably 0.01 to 0.3 mol%, more preferably 0.1 to 0.2 mol% with respect to the raw material carboxylic acid. The reason is that the amount of the alkali metal halide used is 0.01 mol% with respect to the raw material carboxylic acid.
If it is less than, a sufficient reaction rate of the conversion reaction cannot be obtained,
On the other hand, even if the alkali metal halide is used in an amount of more than 0.3 mol% with respect to the raw material carboxylic acid, the same effect can be obtained, which is not preferable in any case.

As the sodium salt or lithium salt of an acid having an acid dissociation index pKa value of more than 1, the sodium salt or lithium salt of the raw material acid (aromatic or aliphatic carboxylic acid) to be subjected to the reaction, or the above raw material acid and other The sodium salt or lithium salt of an acid consisting of a mixture with the above acid can be preferably used. As specific examples thereof, second or third sodium phosphate or second or third lithium phosphate, sodium carbonate or lithium carbonate, sodium hydrogen carbonate or lithium hydrogen carbonate, sodium acetate or lithium acetate, etc. are preferably exemplified. However, it is not particularly limited. Thus, the use of an acid having an acid dissociation index pKa value of more than 1, for example, a sodium salt or a lithium salt of a raw material acid as one of the essential components of the catalyst is a sodium salt of an acid having an acid dissociation index pKa value of less than 1. Even if a lithium salt such as sodium bromide or sodium chloride is used, the transesterification reaction aimed at by the present invention hardly occurs, and even if the acid has an acid dissociation index pKa value of more than 1, the sodium salt or the lithium salt is used. The use of an alkali salt other than the salt, such as potassium acetate, causes the catalyst to be deactivated and the reaction for obtaining the target product becomes very slow, which is not preferable in any case, and the acid dissociation index pKa value of an acid larger than 1 is not preferable. By using sodium salt or lithium salt as one of the essential components together with the above-mentioned alkali metal halide The desired product in a short time of reaction, because it is possible to obtain a very high yield, yet the enhanced reactivity of the palladium compound, based on the experimental Chitoku according to the inventors conducted intensive studies.

The amount of such an acid having an acid dissociation index pKa value larger than 1, for example, sodium salt or lithium salt of the raw material acid is 0.2 to 10 mol% with respect to the raw material carboxylic acid, and more preferably 1 to It is preferably 3 mol%. The reason for this is that when the amount used is less than 0.2% with respect to the raw material carboxylic acid, the reaction rate becomes slow and the desired vinyl ester cannot be obtained in a high yield. If used, the deactivation of the catalyst is accelerated, and as a result, the vinyl ester cannot be obtained in a high yield, which is not preferable in any case.

In the present invention, the palladium compound, the alkali metal halide and the acid dissociation index pKa as described above are used.
The intended purpose is achieved by carrying out the transesterification reaction in the presence of a catalyst containing an acid having a value of more than 1 as an essential component, for example, a sodium salt or a lithium salt of a raw material acid. Further, in the present invention, the use ratio of the raw material carboxylic acid and vinyl acetate is 1 mol of the raw material carboxylic acid,
Vinyl acetate is about 0.1 to 10 times, more preferably 0.
It is desirable to use about 5 to 6 times. The reason is that the amount of vinyl acetate used is
If it is less than 0.1 times, the reaction rate will be high, but the yield of the desired product will be low, which is not preferable.
If used in excess of 0 times, the yield of vinyl ester is improved, but it takes a long time to reach it and it is not economical because it is necessary to recover a large amount of unreacted vinyl acetate. Because there is no.

In the present invention, the reaction temperature for transesterification is not particularly limited as long as it proceeds from 60 ° C. to the reflux temperature of the reaction mixture. By advancing the reaction in such a temperature range, the reaction can be terminated with almost no precipitation of palladium due to the reduction of the palladium compound, and the raw material carboxylic acid can be produced at an extremely high production rate of 75 to 90% or more. It is possible to convert the desired acid to a vinyl ester. The method for producing a carboxylic acid vinyl ester of the present invention is as described above, and thus, in the presence of a specific catalyst,
By transesterification, the desired vinyl ester can be produced and recovered in a short time at an extremely high conversion rate, and the palladium compound used as a catalyst can be theoretically used without any loss of palladium. The reaction can be terminated, and the palladium compound can be recovered very easily after the reaction.

That is, in the present invention, after completion of the reaction, the reaction mixture is distilled as it is, and unreacted vinyl acetate, acetic acid and vinyl carboxylic acid ester are successively recovered, and the palladium compound remains as a residue settling on the bottom of the vessel. . Specifically, it varies depending on the distillation temperature or time, but is 1/3 to 2 / of the added palladium compound.
It has been experimentally confirmed that 3 remains without being decomposed. Therefore, the transesterification reaction as described above can be repeated by adding a palladium compound in an amount corresponding to the decomposed palladium content to the distillation residue and allowing the raw material carboxylic acid and vinyl acetate to react again. In this way, the transesterification reaction is repeated at least 10 times, and in some cases 30 to 50 times, and then the palladium compound decomposed and deposited from the reaction solution can be separated by filtration to regenerate the palladium compound by a conventional method. In the present invention, since the palladium compound is not taken out of the reaction system, the loss of palladium is very small, and since it does not contain other metal such as copper salt, the palladium compound after use can be easily regenerated. You can

[0018]

EXAMPLES The method for producing a carboxylic acid vinyl ester according to the present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples.

(Example 1) A four-necked flask having a capacity of 300 ml equipped with a stirring and reflux cooling device and a thermometer was charged with p.
-Tert-butylbenzoic acid 53.5 g (0.3 mol),
Vinyl acetate 155 g (1.8 mol), palladium chloride (PdCl ₂ ) 20.3 mg, lithium bromide 52.1 m
g and 0.738 g of sodium acetate were charged, and the mixture was stirred and
The reaction was carried out at 0 ° C for 12 hours. The reaction solution was a transparent light amber color, and the reaction rate was 78.9 mol% as a result of measurement by gas chromatography. A distillation apparatus was attached to the four-necked flask that had undergone the above reaction, and excess vinyl acetate and the acetic acid produced were recovered from the reaction solution containing the catalyst by atmospheric pressure or reduced pressure distillation, and further 2-4 mmHg.
Was distilled under reduced pressure to obtain 38.1 g of p-tert-butylbenzoic acid vinyl ester (yield of 62.3% based on the raw material p-tert-butylbenzoic acid). Into a four-necked flask containing the residue obtained by distillation under reduced pressure, p-tert-butylbenzoic acid 3
3.3 g, vinyl acetate 155 g and PdCl ₂ 9 mg
(9 mg of PdCl _{2 in the} residue had been decomposed) was added, and the mixture was reacted again at 70 ° C. for 11 hours. The reaction rate by gas chromatography was 78.5%, the reaction solution was a transparent, light amber color, and a trace amount of black powder had settled at the bottom of the reactor. Distillation in the same manner as above, p-te
37.8 g of rt-butyl benzoic acid vinyl ester (raw material p
The yield was 99.0% based on -tert-butylbenzoic acid. In this way, the reaction was repeated 14 times without discharging the palladium catalyst out of the reaction system. As a result, the reaction time for each time was 8 to 14 hours, and the reaction rate by gas chromatography was 75 to 80%. Generate p-tert
-The average yield of butyl benzoic acid vinyl ester is 37.
With 5 g, the average yield based on the charged p-tert-butylbenzoic acid was 99.2%. The black powder that precipitated from the 14th reaction solution was separated by filtration and dried to recover 89 mg of palladium. The recovery rate was 98%.

(Example 2) The same reaction as in Example 1 was carried out for 12 hours except that 1.48 g of sodium triphosphate was used instead of sodium acetate in Example 1, and the reaction rate was 80.5%. Was obtained and recovered in the same manner as in Example 1 above to give p-tert-butylbenzoic acid vinyl ester 38.
9 g (yield 63.5%) was obtained. (Example 3) Using 61.8 mg of sodium bromide instead of lithium bromide in Example 1, the reaction was carried out in the same manner as in Example 1 above, and a reaction solution having a reaction rate of 79.3% was obtained in 12 hours. It was Example 4 Using 71.4 mg of potassium bromide instead of lithium bromide of Example 1, the reaction was carried out in the same manner as in the same example, and a reaction solution having a reaction rate of 75.0% was obtained in 13 hours. (Example 5) Palladium bromide of Example 1 was replaced with 30.3 mg of palladium bromide and lithium bromide was replaced with lithium chloride, the reaction was carried out in the same manner as in Example 1, and the reaction rate was 75 in 13 hours. A 0.2% reaction solution was obtained. (Example 6) Instead of p-tert-butylbenzoic acid of Example 1, 36.6 g of benzoic acid was used, and the reaction and recovery were carried out in the same manner as in Example 1, and the reaction was carried out for 4 hours to 24.4 g.
g (yield 55.0%) of vinyl benzoate was obtained.

Example 7 122.5 g (0.6 mo) of o-acetylmalic acid α-monoethyl ester was placed in a four-necked flask equipped with a stirring and reflux cooling device and a thermometer.
1), vinyl acetate 206.7 g (2.4 mol), palladium chloride (PdCl ₂ ) 44.13 mg, lithium bromide 104.2 mg, sodium triphosphate 983.7 m.
was charged, and the reaction was carried out at 70 ° C. for 40 hours with stirring. As a result, α-ethylmaleate α-ethyl-β was obtained by vacuum distillation.
83.8 g (yield 60.7%) of vinyl ester were obtained. (Example 8) Instead of the o-acetylmalic acid α-monoethyl ester of Example 7, 170.4 g of stearic acid was used.
Was reacted in the same manner as in Example 7 for 12 hours.
1.2 g (yield 70.5%) was obtained.

Example 9 A device similar to that of Example 1 was charged with 61.2 g of pivalic acid, 309.6 g of vinyl acetate, 43 mg of palladium chloride, 100 mg of lithium bromide, and 980 mg of sodium acetate, and the mixture was stirred at 70 ° C. for 18 hours. After reacting for a time and analyzed by gas chromatography,
83.7% of pivalic acid vinyl ester was formed. (Example 10) 616 g of butyric acid was added to the same apparatus as in Example 1,
When 3010 g of vinyl acetate, 990 mg of palladium chloride, 2.44 g of lithium bromide and 8.61 g of sodium acetate were charged, the reaction was carried out for 8 hours in the same manner as in the above-mentioned Example, and it was analyzed by gas chromatography to find that vinyl butyrate was 88.
2% was produced. (Example 11) Caproic acid 19 was added to the same apparatus as in Example 1.
8 g, vinyl acetate 266 g, palladium chloride 120 m
g, lithium bromide 300 mg, sodium acetate 2.1 g
Was charged, reacted for 19 hours in the same manner as in the above-mentioned Example, and analyzed by gas chromatography to find that 64.4% of vinyl caproate was produced. (Example 12) The same apparatus as in Example 1 was charged with 1000 g of cyclohexanecarboxylic acid, 4026 g of vinyl acetate, 552 mg of palladium chloride, 1.357 g of lithium bromide, and 19.2 g of sodium acetate.
After reacting for 0 hour and analyzed by gas chromatography, vinyl cyclohexanecarboxylate contained 74.3%.
Was being generated. (Example 13) The reaction was performed in the same manner as in the above-mentioned example except that 0.594 g of lithium acetate was used in place of the sodium acetate of Example 5, and p-tert-butylbenzoic acid vinyl ester was converted to 81.5% in 12 hours. % Was generated. (Example 14) The reaction was performed in the same manner as in the above-mentioned example except that sodium chloride was used instead of lithium chloride in Example 13, and the p-tert-butyl vinyl benzoate was converted to 8% in 19 hours.
0.3% was produced.

(Comparative Example 1) 0.882 g of potassium acetate was used in place of the sodium acetate of Example 1, and the reaction was carried out in the same manner as in the above Example. The reaction rate was 5 in 12 hours.
Only 3.0 mol% of reaction liquid was obtained. (Comparative Example 2) When 0.926 g of sodium bromide was used in place of sodium acetate of Example 1, the reaction was carried out in the same manner as in the above-mentioned Example, but almost no reaction occurred. (Comparative Example 3) The same reactor as in Example 1 was used and p-te
rt-butylbenzoic acid 53.5 g, vinyl acetate 155 g,
Rapadium acetate 25.6 mg, potassium bromide 71.4 m
g, potassium acetate 0.832 g, and copper bromide 67 mg were charged, and the reaction was carried out in the same manner as in the above Example.
Only a reaction solution having a reaction rate of 50% was obtained in time.

(Comparative Example 4) In the reaction of Example 1, the reaction was carried out for 12 hours in the same manner as in the above Example except that sodium acetate was not added, and the amount was determined by gas chromatography to be p-tert-butyl. Only 5.3 mol% of vinyl benzoate was produced. (Comparative Example 5) In the reaction of Example 1, except that lithium bromide was not added, the reaction was carried out for 12 hours in the same manner as in the above Example, and quantified by gas chromatography.
Only 42.5 mol% of p-tert-butylbenzoic acid vinyl ester was produced. (Comparative Example 6) The reaction raw material of Example 1 was mixed with cupric bromide 67.
When the reaction was carried out in the same manner as in the above-mentioned example except that 0 mg was added, only 79% of p-tert-butylbenzoic acid vinyl ester was produced in 12 hours. This is almost the same production rate as in Example 1, and it can be seen that the added cupric bromide did not contribute to the reaction. Further, when recovering palladium from the remaining residue obtained by recovering the product from this reaction solution, it was difficult to recover palladium because a large amount of copper was mixed in the residue.

[0025]

As described in detail above, the present invention comprises an aromatic or aliphatic carboxylic acid and vinyl acetate, a palladium compound, an alkali metal halide, and a sodium salt of an acid having an acid dissociation index pKa of more than 1. Alternatively, since it is a method for producing a carboxylic acid vinyl ester, which comprises transesterifying a lithium salt with a catalyst as an essential component in the presence of a catalyst to produce a carboxylic acid vinyl ester, the results of the above examples are also obtained. As is apparent, the desired reaction product can be produced at an extremely high addition rate and can be recovered in a high yield, and the reaction efficiency is extremely excellent, and the reactivity of the palladium compound used as a catalyst is high. The reaction is allowed to proceed in a maintained state, and the palladium compound can be repeatedly used as a catalyst,
After completion of the reaction, the palladium compound can be efficiently and easily recovered in a very high yield without requiring a complicated separation / recovery operation, and can be widely used as an industrial production method of vinyl carboxylate. It has an excellent effect that it can be done.

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Claims (4)

[Claims] 1. An aromatic or aliphatic carboxylic acid and vinyl acetate as essential components, a palladium compound, an alkali metal halide, and a sodium salt or lithium salt of an acid having an acid dissociation index pKa value of more than 1. A process for producing a carboxylic acid vinyl ester, which comprises producing a carboxylic acid vinyl ester by transesterification in the presence of a catalyst. 2. The method for producing a carboxylic acid vinyl ester according to claim 1, wherein the alkali metal halide is an alkali metal chloride, bromide or iodide. 3. The sodium salt or lithium salt of an acid having an acid dissociation index pKa value of more than 1 is the sodium salt or lithium salt of an aromatic or aliphatic carboxylic acid used, or the aromatic or aliphatic carboxylic acid. The method for producing a carboxylic acid vinyl ester according to claim 1 or 2, which is a sodium salt or a lithium salt of an acid consisting of a mixture of an acid and another acid. 4. The sodium salt or lithium salt of an acid having an acid dissociation index pKa value greater than 1 is dibasic or tribasic sodium phosphate or lithium, sodium carbonate or lithium, sodium hydrogen carbonate or lithium, sodium acetate or lithium. 4. The method for producing a carboxylic acid vinyl ester according to claim 1, which is at least one sodium salt or lithium salt selected from the group consisting of: