JPH08231466A - Production of xylylene diacetate - Google Patents

Abstract

PURPOSE: To obtain the subject compound useful as a perfume, a solvent and an intermediate for industrial chemicals in high yield industrially and advantageously by reacting xylene with acetic acid and molecular oxygen using a specific catalyst. CONSTITUTION: (B) Xylene is reacted with (C) acetic acid and (D) molecular oxygen in the presence of (A) a catalyst prepared by supporting palladium and gold on a carrier such as active carbon or silica, for example, in a liquid phase, to give the objective compound. The reaction is carried out by keeping the component D or a mixed gas of the component D with an inert gas under atmospheric pressure to 100kg/cm<2> G, especially atmospheric pressure to 50kg/cm<2> G at 80 to 230 deg.C, especially 120-200 deg.C. The component A, for example, is obtained by supporting each metal raw material salt on a carrier and heat-treating the salt in the presence of an inert gas at >=200 deg.C.

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 xylylene diacetate in which the side chain of xylene is esterified with acetic acid and molecular oxygen. The compound obtained by esterifying the side chain of these xylenes with acetic acid has uses such as a fragrance and a solvent, and is industrially useful as an intermediate for industrial chemicals.

[0002]

2. Description of the Related Art Conventionally, it has been known that palladium is useful as a catalyst for esterifying a side chain of xylene with acetic acid and molecular oxygen.

For example, "The Journal of Organic Chemistry" (J. Org. Chem), (3
4) 4,1106-1108 (1969), a method of synthesizing xylylene diacetate by using palladium acetate as a catalyst and aeroxidizing xylene in acetic acid is reported. However, this method is slow in the production rate of xylylene diacetate, and cannot be said to be an industrial method.

Other than this, methods using various supported catalysts have also been reported.

For example, Japanese Examined Patent Publication (Kokoku) No. 50-28945 discloses a method of using palladium supported on activated carbon, and Japanese Unexamined Patent Publication (Kokai) No. 50-108232 discloses that the main components are palladium and antimony, and further alkali metals and alkaline earth metals are used. Method using a catalyst supporting a carboxylate of a metal selected from metals, zinc, cadmium and lead, JP-A-53-
Japanese Patent No. 147039 uses a catalyst composed of a combination of palladium and arsenic with an alkali metal or alkaline earth metal, and Japanese Patent Laid-Open No. 53-79832 discloses a combination of palladium and bismuth with manganese or A catalyst in which chromium is further combined and supported on silica, in JP-A-57-102840, two or more compounds selected from cobalt, nickel or tin compounds are supported on activated carbon in addition to palladium and an alkali metal compound. The above-mentioned catalysts and the like are disclosed, and the catalytic activity and life of each are improved.

[0006]

However, from the industrial viewpoint, the above-mentioned known technique does not have a sufficient reaction rate for the side-chain acetoxylation of xylene, and the production of monoacetate is prioritized, which is not always satisfactory. No results were obtained.

The present invention has been made in view of the above problems, and an object thereof is to provide an industrially useful method for producing xylylene diacetate.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that xylene, acetic acid, and molecular oxygen are reacted with each other to produce xylylene diacetate. The inventors have found that the amount of xylylene diacetate produced is significantly improved when a catalyst in which gold is supported on a carrier is used, and the present invention has been completed.

That is, the present invention relates to a method for producing xylylene diacetate by reacting xylene, acetic acid and molecular oxygen, wherein a catalyst in which palladium and gold are supported on a carrier is used. is there.

Hereinafter, the present invention will be described in detail.

In the present invention, in a method for producing xylylene diacetate by reacting xylene, acetic acid and molecular oxygen, a catalyst having palladium and gold supported on a carrier is used. The carrier used for the catalyst of the present invention is not particularly limited as long as it is a porous substance. For example, silica,
Alumina, magnesia, titania, silica-alumina, zeolite, diatomaceous earth, silica magnesia or other crystalline or non-crystalline metal oxide, or composite oxide, teniolite,
Examples thereof include layered clay compounds such as hectorite, activated carbon and the like, and among these, silica and activated carbon are particularly preferable.

The shape of the catalyst is not particularly limited, and it can be used in the form of powder as it is or after being molded depending on the reaction mode. In the suspension bed, powder or granules are preferably used in order to improve contact between the catalyst and xylene, acetic acid, or oxygen.
In the fixed bed, in order to reduce the pressure loss of the reactor, tablet compression molded products, spherical or rod-shaped extrusion molded products and the like are preferably used.

There are no particular restrictions on the palladium and gold compounds that can be used in preparing the catalyst of palladium and gold supported on the carrier used in the present invention. More specifically, examples of the palladium raw material include palladium metal, ammonium hexachloropalladate, ammonium tetrachloropalladate, dinitrodiamine palladium, palladium bromide, chlorocarbonyl palladium, palladium chloride, palladium iodide, palladium nitrate and palladium oxide. , Palladium sulfate, palladium acetate, potassium dinitrosulfite palladium, potassium hexachloropalladate, potassium tetrabromopalladate, potassium tetrachloropalladate, sodium hexachloropalladate, sodium tetrachloropalladate, tetraamminepalladium chloride, tetraamminepalladium nitrate , Cis-dichlorodiamine palladium, trans-dichlorodiamine palladium, di Lolo (ethylenediamine) palladium, can be exemplified potassium tetracyanoethylene palladium acid,
As a raw material of gold, gold, gold cyanide, potassium dicyanoaurate, tetrachloroauric acid, potassium tetracyanoaurate,
Examples include sodium gold sulfite and chloroauric acid.

The amount of palladium supported on the catalyst used is usually 0.1 to 10% by weight, preferably 0.5 to 5% by weight, as the metal of palladium, based on the total weight of the catalyst including the carrier. The supported amount is usually 0.1 to 20, preferably 0.5 to 15, in atomic ratio (Au / Pd) with respect to palladium.

The method of supporting the metal and / or salt of palladium and gold on the carrier is not particularly limited, and can be supported by a known method. Specifically, it can be prepared by, for example, a precipitation method, an ion exchange method, an impregnation method, a deposition method or the like.

In the case of preparation by the impregnation method, for example, a palladium compound and / or a gold compound is dissolved in a suitable solvent, this is mixed with a carrier, and if necessary, allowed to stand for a predetermined time and then dried. It can be prepared. After drying, the catalyst used in the present invention can be obtained by heat treatment in an inert gas, and in some cases, reduction and / or calcination treatment may be performed after the heat treatment. Either of the metal and / or the compound of palladium and gold may be supported first or simultaneously.

In the method of the present invention, it is preferable to use the catalyst as a catalyst after heat treatment in an inert gas atmosphere at the stage when the salts of palladium and gold are loaded on the carrier.

Further, it can be used as a catalyst after heat treatment followed by reduction or after calcination.

The heat treatment temperature is usually 200 ° C. to 700 ° C.
In order to shorten the reaction time, suppress reaction time, and suppress side reactions, the temperature is preferably in the range of 300 ° C to 600 ° C. Specifically, the atmosphere of this heat treatment is performed under an atmosphere of at least one gas selected from the group consisting of nitrogen, helium, argon and carbon dioxide.

As the reducing agent for the reduction after the heat treatment, hydrogen, carbon monoxide, gases such as ethylene, alcohol, hydrazine hydrate and the like can be used. Alternatively, heat treatment may be performed in an atmosphere of an oxidizing gas such as dinitrogen oxide.

The raw materials xylene and acetic acid used in the present invention may be produced by any method. That is, xylene, those separated from petroleum fractions, those separated from cracked oil obtained by decomposing petroleum fractions, those produced by a disproportionation reaction can be used, acetic acid, Any of those produced by the oxidation of acetaldehyde, those produced by the oxidation of hydrocarbons, those produced as a byproduct during the production of peracetic acid, and those synthesized from methanol and carbon monoxide can be used.

The mixing ratio of these xylene and acetic acid is usually
The reaction can be carried out at an arbitrary mixing ratio in the range of 0.1 to 10 (molar ratio) of acetic acid based on xylene.

In the present invention, the reaction method can be carried out by a batch method using a suspension bed, a semi-batch method, a continuous method, or a fixed bed flow method.

The amount of catalyst used cannot be uniformly defined because it depends on the reaction method. For example, in the case of a fixed bed, the unit catalyst volume and the total supply amount of xylene and acetic acid per unit time are 0.1. 10 to 10 h ^-1 is preferable, and in the case of a suspension bed, the concentration of the catalyst is preferably 0.1 to 30% by weight, more preferably 0.5 to 1% by weight of the raw material.
5% by weight is good.

The reaction according to the method of the present invention is carried out under heating, under pressure of oxygen or a mixed gas of oxygen and an inert gas.
The reaction temperature is usually 80 to 230 ° C., preferably 120 to 230 ° C.
200 ° C is chosen. If it is higher than this, the progress of side reactions only increases, and if it is lower than the above range, it may be disadvantageous in terms of reaction rate.

The pressure of oxygen or a mixed gas of oxygen and an inert gas is selected from atmospheric pressure to 100 kg / cm ² G, preferably atmospheric pressure to 50 kg / cm ² G. In the method of the present invention, the desired reaction proceeds sufficiently within this range,
High pressures above this are unnecessary.

The reaction time varies depending on the setting method of temperature, pressure, amount of catalyst and the like or the reaction method, so it is difficult to determine the range unconditionally, but the batch type in the suspension bed,
In the semi-batch method, it is usually 0.5 hours or more, preferably 1 to 20 hours.

In the continuous reaction using a suspension bed or the fixed bed flow reaction, the residence time is usually 0.1 to 1
0 hours is enough.

[0029]

EXAMPLES Hereinafter, this reaction will be described in more detail with reference to Examples, but it goes without saying that this reaction is not limited to these Examples.

Example 1 Palladium chloride was weighed so that palladium was 1% by weight as a metal with respect to 10 g of activated carbon and suspended in 100 ml of ion-exchanged water. 2 ml of a 1N aqueous hydrochloric acid solution was added dropwise to this solution, and while heating, palladium chloride was completely dissolved.

20 ml of ion-exchanged water was added to 10 g of activated carbon to make a slurry, and an aqueous solution of palladium chloride was added dropwise while stirring.

After filtering off the solid, it is dried in air at 90 ° C. overnight.

20 ml of ion-exchanged water was added to the dried solid to form a slurry, and an aqueous solution prepared by dissolving tetrahydrate of chloroauric acid in 40 ml of ion-exchanged water, which was weighed so that gold was 3% by weight, was prepared. Added with stirring.

The solid was filtered off again and dried in air at 90 ° C. overnight.

The catalyst precursor thus obtained was heat-treated at 400 ° C. for 2 hours in a nitrogen stream to obtain a catalyst.

In a 500 cc stainless steel autoclave, p-xylene 42.5 g (0.4 mol) and acetic acid 196 were added.
g (3.3 mol) and 2 g of the above-mentioned catalyst were put therein, and after filling with oxygen at 4 kg / cm ² G (5 atm) at room temperature, 150
The temperature was raised to ° C and the reaction was carried out for 8 hours.

After the catalyst was filtered off from the resulting reaction mixture, n-octane was added to the filtrate as an internal standard substance and analyzed by gas chromatography. The results are shown in Table 1.

[0038]

[Table 1]

At this time, the amount of palladium dissolved in the reaction solution was 0.29% by weight of the palladium present in the catalyst.

Example 2 A catalyst was prepared and reacted in the same manner as in Example 1 except that the amount of gold supported was 1% by weight. The results are also shown in Table 1.

Comparative Example 1 A catalyst was prepared and reacted in the same manner as in Example 1 except that gold was not supported. The results are also shown in Table 1.

At this time, the amount of palladium dissolved in the reaction solution was 4.58% by weight of the palladium present in the catalyst.

Comparative Example 2 A catalyst was prepared and reacted in the same manner as in Example 1 except that palladium was not supported. The results are also shown in Table 1.

At this time, xylylene diacetate was not produced.

Example 3 Palladium chloride was weighed so that palladium was 1% by weight as a metal with respect to 10 g of silica, and suspended in 100 ml of ion-exchanged water. 2 ml of a 1N aqueous hydrochloric acid solution was added dropwise to this solution, and while heating, palladium chloride was completely dissolved.

20 ml of ion-exchanged water was added to 10 g of silica to make a slurry, and an aqueous solution of palladium chloride was added dropwise with stirring.

The solid was filtered off and dried in air at 90 ° C. overnight. 20 ml of ion-exchanged water was added to the dried solid to make a slurry, and an aqueous solution prepared by dissolving chloroauric acid tetrahydrate in 40 ml of ion-exchanged water was weighed so that the amount of gold was 1% by weight while stirring. added.

The solid was filtered off again and dried in air at 90 ° C. overnight.

The catalyst precursor thus obtained was heat-treated at 400 ° C. for 2 hours in a nitrogen stream to obtain a catalyst.

In a 500 cc stainless autoclave, p-xylene 42.5 g (0.4 mol) and acetic acid 196 were added.
g (3.3 mol) and 2 g of the above-mentioned catalyst were put therein, and after filling with oxygen at 4 kg / cm ² G (5 atm) at room temperature, 150
The temperature was raised to ° C and the reaction was carried out for 8 hours.

After the catalyst was filtered off from the resulting reaction mixture, n-octane was added to the filtrate as an internal standard substance and analyzed by gas chromatography. The results are also shown in Table 1.

Comparative Example 3 A catalyst was prepared and reacted in the same manner as in Example 7 except that gold was not supported. The results are also shown in Table 1.

Example 4 A catalyst was prepared and reacted in the same manner as in Example 1 except that the amount of gold supported was 0.5% by weight. The results are also shown in Table 1.

At this time, the amount of palladium dissolved in the reaction solution was 0.48 of the palladium present in the catalyst.
% By weight.

Example 5 A catalyst was prepared and reacted in the same manner as in Example 1 except that the amount of gold supported was 5% by weight. The results are also shown in Table 1.

At this time, the amount of palladium dissolved in the reaction solution was 0.19 of the palladium present in the catalyst.
% By weight.

Example 6 A catalyst was prepared and reacted in the same manner as in Example 2 except that the heat treatment temperature of the catalyst precursor was changed to 300 ° C. The results are also shown in Table 1.

Example 7 A catalyst was prepared and reacted in the same manner as in Example 2 except that the heat treatment temperature of the catalyst precursor was changed to 500 ° C. The results are also shown in Table 1.

Example 8 Palladium chloride and chloroauric acid tetrahydrate were weighed so that palladium was 1% by weight as a metal and gold was 1% by weight as a metal with respect to 10 g of activated carbon, and dissolved in 100 ml of ion-exchanged water. Let

20 ml of ion-exchanged water was added to 10 g of activated carbon to make a slurry, and an aqueous solution containing palladium chloride and chloroauric acid was added dropwise with stirring.

After filtering off the solid, it was dried in air at 90 ° C. overnight.

The catalyst precursor thus obtained was heat-treated at 400 ° C. for 2 hours in a nitrogen stream to obtain a catalyst.

In a 500 cc stainless steel autoclave, p-xylene 42.5 g (0.4 mol) and acetic acid 196 were added.
g (3.3 mol) and 2 g of the above-mentioned catalyst were put therein, and oxygen was charged at 4 kg / cm ² G (5 arm) at room temperature, and then 150
The temperature was raised to ° C and the reaction was carried out for 8 hours.

After the catalyst was filtered off from the resulting reaction mixture, n-octane was added to the filtrate as an internal standard substance and the mixture was analyzed by gas chromatography. The results are also shown in Table 1.

[0065]

EFFECTS OF THE INVENTION According to the present invention, in the method for producing xylylene diacetate by reacting xylene with acetic acid and molecular oxygen, palladium and gold supported on a carrier are used as a catalyst to give a high yield of xylylene. It is industrially very useful because it can produce range acetate.

Claims (4)

[Claims] 1. A method for producing xylylene diacetate by reacting xylene with acetic acid and molecular oxygen,
A method for producing xylylene diacetate, which comprises using a catalyst in which palladium and gold are supported on a carrier. 2. A catalyst in which palladium and gold are carried on a carrier is a catalyst which is prepared by carrying respective metal raw material salts on a carrier and then heat-treating at 200 ° C. or higher in the presence of an inert gas. The manufacturing method according to claim 1. 3. The production method according to claim 1, wherein xylene, acetic acid and molecular oxygen are reacted in a liquid phase in the presence of a catalyst in which palladium and gold are supported on a carrier. . 4. The manufacturing method according to claim 1, wherein the carrier is activated carbon or silica.