JP2003206261A - Method for producing phenyl ester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a phenyl ester by performing the reaction of benzene with a carboxylic acid and molecular oxygen in the presence of a solid catalyst loaded with palladium, capable of maintaining the activity of the solid catalyst stably for a long period. <P>SOLUTION: This method for producing a phenyl ester by performing the reaction of benzene with the organic carboxylic acid and molecular oxygen in the presence of the solid catalyst loaded with palladium is provided by performing the reaction by dissolving a palladium compound in benzene and/or the organic carboxylic acid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the reaction of benzene, an organic carboxylic acid and molecular oxygen in the presence of a specific catalyst by dissolving a palladium compound in benzene and / or an organic carboxylic acid and reacting them. , A method for producing a phenyl ester stably in a high yield.
The product phenyl ester, for example phenylacetate, can be easily hydrolyzed to produce phenol.

[0002]

2. Description of the Related Art Various methods for producing phenyl esters by reacting benzene, an organic carboxylic acid and molecular oxygen in the presence of a specific catalyst in a gas phase or a liquid phase have been proposed. In this reaction, VII of the periodic table is used as a catalyst.
Noble metals of Group I, especially palladium, are used. For example, Japanese Examined Patent Publication No. 46-33024 discloses a method for producing a phenyl ester using palladium or platinum as a catalyst. In Japanese Examined Patent Publication No. 48-18219, in order to obtain a catalyst having a higher activity, the catalysts of the periodic table IV, V, V are used as an activity promoter of a palladium or platinum catalyst.
A method of reacting in the presence of an alkali metal acetate using a catalyst to which a Group I element, particularly bismuth and tellurium is added has also been proposed. However, in this method, the activity of the catalyst is low, and a large amount of alkali metal acetate is required,
Not necessarily industrially practical. Japanese Patent Sho 55-1
In the 5455 publication, cadmium, zinc, uranium, tin,
A method for producing phenylacetate by adding lead, antimony, bismuth, tellurium and thallium as a cocatalyst and mixing and coexisting a fatty acid salt of an alkali metal and nitric acid is disclosed, but it cannot be said that the activity of the catalyst is sufficient. Also, in addition to the need for a large amount of alkali metal acetate, the use of nitric acid causes problems such as corrosion of equipment, which is not practical from an industrial viewpoint.

Further, when the reaction is carried out in the gas phase as in the above example, there is a drawback that the activity of the catalyst is lowered in a short time.

On the other hand, in the case of the reaction in the liquid phase, antimony,
There is a drawback that a catalyst component such as bismuth, lead or palladium is eluted into the reaction solution, and the catalytic activity is lowered with time.

Japanese Patent Laid-Open No. 174950/1988 proposes a method in which bismuth or lead is allowed to exist in the reaction system as a method for suppressing the decrease in the catalytic activity over time. However, in this method, by supplying bismuth or lead, when the oxygen concentration is low, it is possible to improve the elution of palladium as a catalyst component, but when the oxygen concentration is increased to an industrially practical level, the elution of palladium occurs, Continuous operation for a long time is difficult.

As described above, the conventional method is not satisfactory in terms of industrial practicality.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for efficiently producing a phenyl ester by maintaining the activity and stability of the catalyst when producing the phenyl ester.

[0008]

The present inventors have made extensive studies in order to solve the above-mentioned problems of the prior art.
As a result, when benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of a solid catalyst supporting palladium, benzene and / or
Alternatively, they have found that a phenyl ester can be produced with high activity and stability by dissolving a specific compound in an organic carboxylic acid to carry out the reaction, and completed the present invention. That is, the present invention involves reacting benzene, an organic carboxylic acid and molecular oxygen in the presence of a solid catalyst on which palladium is carried out to produce a phenyl ester, and dissolving a palladium compound in benzene and / or an organic carboxylic acid. The present invention provides a method for producing a phenyl ester, which is characterized by carrying out the reaction.

That is, the present invention is characterized in that a palladium compound is dissolved in benzene and / or an organic carboxylic acid and the reaction is carried out to stably maintain the activity of the solid catalyst for a long period of time.

The palladium compound is not particularly limited as long as it is a substance soluble in benzene and / or an organic carboxylic acid. For example, palladium nitrate, palladium acetate, palladium chloride, palladium oxide, dinitrodiammine palladium, tetraammine palladium. And other palladium compounds can be used. Of these, palladium acetate is particularly preferable.

The amount of the palladium compound to be dissolved in benzene and / or the organic carboxylic acid is excellent in the effect of suppressing the deterioration of the solid catalyst performance and the economical efficiency.
Alternatively, it is preferably 0.001 to 10 ppm in terms of palladium with respect to the amount of the organic carboxylic acid supplied.

The method of supplying the palladium compound to benzene and / or the organic carboxylic acid is not particularly limited, and examples thereof include a method of continuously or intermittently supplying. Further, it is also possible to supply while changing the palladium concentration as appropriate according to changes in the performance of the solid catalyst. The solid catalyst used in the present invention is a solid catalyst in which palladium is supported on a carrier, and in particular, a solid catalyst in which palladium and tellurium are supported on a carrier is preferable. However, the raw materials used for preparing an ordinary palladium catalyst can be used.

Examples of raw materials for palladium include palladium metal, ammonium hexachloropalladate, potassium hexachloropalladate, sodium hexachloropalladate, ammonium tetrachloropalladate, potassium tetrachloropalladate, sodium tetrachloropalladate, tetrabromopalladate. Potassium, palladium oxide, palladium chloride, palladium bromide, palladium iodide, palladium nitrate, palladium acetate, potassium dinitrosulfite palladium,
Chlorocarbonylpalladium, dinitrodiamminepalladium, tetraamminepalladium, dichlorodiaminepalladium, dichloro (ethylenediamine) palladium, potassium tetracyanopalladate, etc. can be used. Examples of the raw material of tellurium include metal tellurium, tellurium (II) chloride, tellurium (IV) chloride, and tellurium oxide (I).
V), tellurium oxide (VI), telluric acid (H ₆ TeO ₆ ),
Potassium tellurate, sodium tellurate and the like can be used.

Examples of the carrier for effectively operating the solid catalyst as a catalyst include silica, silica-alumina, alumina, zirconia, activated carbon, diatomaceous earth, zeolite and the like, among which silica and zirconia are preferable.

The amount of palladium supported on the carrier of the solid catalyst is preferably 0.01 to 10% by weight as palladium metal, based on the total weight of the solid catalyst including palladium and the carrier, and in some cases tellurium. , Especially 0.1-5
Weight percent is preferred.

In the case of a solid catalyst in which palladium and tellurium are supported on a carrier, a solid catalyst having a high catalytic activity is obtained, so the amount of tellurium is tellurium to palladium: tellurium / palladium = 0.01 / 1 to 10 /. 1 is preferred.

The method for preparing the solid catalyst is not particularly limited, and palladium can be used as a carrier by a generally used method.
Alternatively, palladium and tellurium can be supported.
For example, an impregnation method, a deposition method, an ion exchange method or the like is used.

When preparing a solid catalyst supporting palladium or palladium and tellurium by the impregnation method, the palladium raw material and the tellurium raw material may be impregnated and supported at the same time. The remaining raw materials may be impregnated and supported.

After the supporting, the solvent is removed by an operation such as decantation, filtration, heating or heating under reduced pressure according to a conventional method such as an impregnation method or an ion exchange method. For drying after removing the solvent, heat drying, reduced pressure drying, or the like can be used.

After the drying, the reduction may be carried out as it is, or the method may be such that the palladium compound or the palladium compound and the tellurium compound are decomposed by baking in air and then reduced.

The firing is preferably carried out at 100 to 1000 ° C. in an atmosphere of oxygen, oxygen diluted with an inert gas such as nitrogen, helium or argon, or air.

A known method is used for the reduction of the solid catalyst. For example, a method of reducing in a gas phase using hydrogen, carbon monoxide, ethylene, or methanol as a reducing agent,
Alternatively, a method of reducing in a liquid phase using hydrazine hydrate, formalin, formic acid or the like can be used. When reducing in the gas phase, the reduction temperature is preferably 100 to 1000 ° C, particularly preferably 200 to 800 ° C.

In the method of the present invention, benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of a palladium-supported solid catalyst in a state where a palladium compound is dissolved in benzene and / or an organic carboxylic acid to react with phenyl ester. To manufacture.

As the organic carboxylic acid used in this case, any organic carboxylic acid corresponding to the desired product phenyl ester can be used. For example, aliphatic carboxylic acids such as acetic acid, propionic acid and butyric acid, and aromatic carboxylic acids such as benzoic acid can be used. When hydrolyzing the obtained phenyl ester to produce phenol,
Acetic acid and propionic acid, which are inexpensive and available in large quantities, are preferable, and acetic acid is particularly preferable. The benzene is also not particularly limited. In addition, a solvent may be added as necessary during the reaction.

The ratio of benzene and the organic carboxylic acid can be appropriately selected. Among them, since the production efficiency is excellent, the molar ratio of benzene / organic carboxylic acid is 1 /
0.1 to 1/100 is preferable. In the method of the present invention, molecular oxygen is used with benzene and an organic carboxylic acid. Although molecular oxygen may be used as it is, oxygen diluted with an inert gas such as nitrogen, helium, or carbon dioxide, or air is used as a molecular oxygen source in order to keep the gas composition below the explosion range. be able to. The supply amount of molecular oxygen is appropriately set depending on the reaction type and the amount of solid catalyst. Among them, the molecular oxygen partial pressure in the solid catalyst layer is 0.00
1 to 100 kg / cm ² , especially 0.01 to 50 kg /
cm ² is preferred.

The reactor is not particularly limited, and a conventionally known reactor such as a fixed bed flow reactor, a multitubular reactor, a batch reactor, a suspension bed reactor and the like can be used.

The relationship between the supply amount of benzene and the organic carboxylic acid and the solid catalyst amount may be appropriately selected depending on the reaction method. For example, in the case of a fixed bed, the unit solid catalyst volume, the benzene and the organic carboxylic acid per unit time are fixed. The total supply amount (hereinafter referred to as LHSV) of 0.1 to 50 h ⁻¹ is preferable, and 0.1 to 30 h ⁻¹ is particularly preferable. Also, in the case of a suspension bed, the solid catalyst concentration is 0.05 to
30% by weight is preferred.

The reaction temperature is preferably 100 to 300 ° C., particularly 100 to 250 in order to allow the reaction to proceed efficiently.
C is preferred.

The reaction pressure may be a pressure equal to or higher than normal pressure, but it is necessary that a part of benzene and the organic carboxylic acid be in a liquid phase, preferably 1 to 200 kg / cm ² .

[0030]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Telluric acid (0.291 g) was dissolved in 8.3% by weight of dinitrodiammine palladium nitric acid aqueous solution (10.83 g).
After impregnating 30 g of zirconia (manufactured by Norton) with this aqueous solution, it was dried under reduced pressure at 50 ° C. and 0.02 kg / cm ² . After drying, the solid catalyst was reduced at 600 ° C. in a hydrogen stream.

10 ml of this solid catalyst was filled in a stainless steel reaction tube having an inner diameter of 13 mm, and a reaction temperature of 190 ° C. and a reaction pressure of 40 kg / cm ² were mixed with equimolar amounts of benzene and acetic acid containing 0.5 ppm of palladium acetate in terms of palladium. 2.2 g / min of raw material, 37 ml / min of molecular oxygen (0 ° C.,
Nitrogen was supplied at 173 ml / min (0 ° C., 1 atm conversion) and reacted.

23 hours and 118 hours after the start of the reaction, the reaction products were collected and analyzed by gas chromatography. The space-time yield of the produced phenylacetate (1 l of solid catalyst, phenyl converted per hour) The weight (g) of acetate: hereinafter referred to as STY) is
317 g / l-solid catalyst / hour and 279 g / l-solid catalyst / hour, and S converted per hour at that time
The amount of decrease in TY (hereinafter referred to as ΔSTY) is 0.40 g.
/ L-solid catalyst / hour.

Comparative Example 1 The reaction was carried out under the same solid catalyst preparation and reaction conditions as in Example 1, except that the mixed raw material of benzene and acetic acid did not contain a palladium acetate compound. 23 hours after the start of the reaction and 1
The STY of phenylacetate after 19 hours was 320 g / l-solid catalyst / hour and 274 g / l-, respectively.
Solid catalyst / hour, ΔSTY at that time is 0.48 g / l
-Solid catalyst / hour, the decrease in activity of the solid catalyst was significant.

Example 2 After Example 1, the reaction was continued. 3 after starting the reaction
From 11 hours to 647 hours, 2.2 g / min of a mixed raw material containing 1 ppm of palladium acetate in terms of palladium and having an equimolar ratio of benzene and acetic acid, and molecular oxygen of 37 ml / min (0
C. and 1 atm) and 173 ml / min of nitrogen (0.degree. C. and 1 atm) were supplied and reacted. The STYs after 311 hours and 647 hours were 236 g / l-solid catalyst / hour and 234 g / l-solid catalyst / hour, respectively, and the ΔS at that time.
TY was 0.006 g / l-solid catalyst / hour.

Comparative Example 2 The same reaction as in Example 2 was continuously carried out after Comparative Example 1 except that the mixed raw material of benzene and acetic acid did not contain a palladium compound. The STY of phenylacetate after 311 hours and 647 hours after the start of the reaction was 237 g / l-solid catalyst / hour and 191 g / hour, respectively.
1-solid catalyst / hour, ΔSTY at that time is 0.14 g
/ L-solid catalyst / hour, and the decrease in the activity of the solid catalyst was remarkable.

Comparative Example 3 After Example 2, the same reaction as in Example 2 was continued except that the mixed raw material of benzene and acetic acid did not contain a palladium acetate compound. 671 hours after the start of the reaction and 7
The STY of phenylacetate after 91 hours was 233 g / l-solid catalyst / hour and 214 g / l-, respectively.
Solid catalyst / hour, ΔSTY at that time is 0.16 g /
It was 1-solid catalyst / hour, and the decrease in the activity of the solid catalyst was remarkable.

Example 3 The same reaction as in Example 2 was continued except that after Comparative Example 3, a mixed solution containing 0.1 ppm of palladium acetate in terms of palladium and having an equimolar ratio of benzene and acetic acid was supplied. It was The STYs of phenylacetate at 1177 hours and 1487 hours after the start of the reaction were 191 and 187, respectively.
g / l-solid catalyst / hour and 168 g / l-solid catalyst /
The hourly ΔSTY was 0.07 g / l-solid catalyst / hour.

Example 4 0.13 g of telluric acid was dissolved in 7.25 g of a 8.3 wt% dinitrodiammine palladium nitric acid aqueous solution. This solution was impregnated with 20 g of silica beads (trade name Carract Q-30, manufactured by Fuji Silysia Chemical Ltd.), and then 50 ° C., 20
It was dried under reduced pressure at kg / cm ² . Next, it was calcined in air at 500 ° C. for 5 hours and then reduced in a hydrogen atmosphere at 400 ° C. for 5 hours to obtain a solid catalyst.

Reaction was carried out under the same conditions as in Example 1 except that 10 ml of this solid catalyst was filled in a stainless steel reaction tube having an inner diameter of 13 mm, and a mixed raw material containing 1 ppm of palladium acetate in terms of palladium and having an equimolar ratio of benzene and acetic acid was supplied. I went.

The STY of phenylacetate 22 hours and 166 hours after the start of the reaction was 116 / l, respectively.
Solid catalyst / hour and 106 / l-solid catalyst / hour,
At that time, ΔSTY was 0.07 g / l-solid catalyst / hour.

Comparative Example 4 The reaction was carried out under the same conditions as in Example 4 except that a mixed raw material of benzene and acetic acid containing no palladium acetate compound was supplied. The STY of phenylacetate 22 hours and 168 hours after the reaction was 101 g / l-solid catalyst / hour and 63 g / l-solid catalyst / hour, respectively, and ΔSTY at that time was 0.26 g / l-solid. The catalyst / hour was used, and the decrease in the activity of the solid catalyst was remarkable.

Comparative Example 5 After the reaction of Example 4, the reaction was performed under the same conditions as in Example 4 except that a mixed raw material of benzene and acetic acid containing no palladium acetate compound was fed after 337 hours from the start of the reaction. . The STY of phenylacetate 343 hours and 405 hours after the start of the reaction was 111 g / l-, respectively.
Solid catalyst / hour and 95 g / l-solid catalyst / hour, ΔSTY at that time was 0.26 g / l-solid catalyst / hour, and the feed material was switched to a mixed raw material of benzene and acetic acid containing no palladium acetate compound. The resulting decrease in the activity of the solid catalyst was remarkable. It was.

[0044]

INDUSTRIAL APPLICABILITY According to the present invention, when benzene, an organic carboxylic acid and molecular oxygen are reacted in the presence of a palladium-supported solid catalyst to produce a phenyl ester, benzene and / or an organic carboxylic acid are added. By dissolving the palladium compound and conducting the reaction, the activity of the solid catalyst can be stably maintained for a long period of time, and the phenyl ester can be efficiently produced.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4H006 AA02 AC48 BA15 BA25 BA30                       BA32 BA34 BA55 BA82 BC34                       BE30 BJ50 KA13                 4H039 CA66 CD10 CD30

Claims (3)

[Claims] 1. When producing a phenyl ester by reacting benzene, an organic carboxylic acid and molecular oxygen in the presence of a palladium-supported solid catalyst, a reaction is carried out by dissolving a palladium compound in benzene and / or an organic carboxylic acid. A method for producing a phenyl ester, which comprises: 2. A palladium compound is added to benzene and / or an organic carboxylic acid in an amount of 0.001 to 10 in terms of palladium.
2. The reaction is carried out by dissolving in ppm.
The method for producing a phenyl ester according to 1. 3. The method for producing a phenyl ester according to claim 1, wherein the solid catalyst is a solid catalyst in which palladium and tellurium are supported on a carrier.