JP2002205969A - Method for producing aromatic compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for oxidizing an aromatic compound having at least one alkyl substituent, comprising oxidizing the aromatic compound in the presence of a catalyst which does not use corrosive bromide ion, is stable without being decomposed even in an oxidizing atmosphere, and can be recycled as a catalyst. SOLUTION: This method for oxidizing an aromatic compound having at least one alkyl substituent comprises oxidizing the aromatic compound in the presence of a catalyst containing at least one element selected from the group consisting of the periods 4 to 6 elements of the groups IB, VA, VIIA, and VIII in the periodic table, and a heteropolyoxometalate anion which contains at least one element selected from the group consisting of phosphorus, silicon and germanium as the heteroatom, contains at least one element selected from the group consisting of molybdenum, tungsten, vanadium and niobium as the polyatom, and has two defective structure sites.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an aromatic compound by oxidizing the alkyl group of an aromatic compound having at least one alkyl substituent.

[0002]

2. Description of the Related Art Conventionally, for example, a method for producing an aromatic carboxylic acid by oxidizing an alkyl group of an aromatic compound having at least one alkyl substituent involves the presence of a bromine compound or a compound of a transition metal such as cobalt or manganese. It is carried out in a liquid phase using lower alkanoic acid such as acetic acid and water as a solvent below.

[0003] JP-A-2000-103758 discloses RC
A method for producing an aromatic ketone by subjecting an aromatic compound having an H ₂ — group to liquid phase oxidation is disclosed. The heteropolyacid used here is a heteropolyacid having no deficient structure site, and is intended for a method for producing an aromatic ketone. JP-A-8-53391, JP-A-9-1696
No. 94 and JP-A-9-286756 disclose a method for producing an aromatic carboxylic acid in an aqueous medium using a compound obtained by incorporating a transition metal into a heteropolyacid skeleton having a defective structure site as a catalyst. . JP-A-9-2867
No. 57 discloses a method for producing an aromatic carboxylic acid using a catalyst obtained by heat-treating a heteropolyacid ion having a defective structure site and a transition metal salt in an aqueous medium at 100 ° C. or higher. JP-A-11-1447 discloses a method for producing an aromatic carboxylic acid in an aqueous solution in the presence of a heteropolyacid or a salt thereof and a transition metal not incorporated in the heteropolyacid. However, there is no specific disclosure of a heteropolyacid catalyst having a two-defective structure in the heteropolyacid catalyst used for producing an aromatic carboxylic acid disclosed in these publications.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to the use of at least one alkyl-substituted catalyst which does not use corrosive bromide ions as a catalyst and does not decompose even in an oxidizing atmosphere and is stable and reusable. It is intended to provide a method for producing an aromatic compound containing oxygen by oxidizing an aromatic compound having a group.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for oxidizing an alkyl group of an aromatic compound having at least one alkyl substituent with a molecular oxygen-containing gas, wherein the heteroatom is converted from phosphorus, silicon, and germanium. A heteropolyoxometallate anion, which is at least one element selected and whose poly atom is at least one element selected from molybdenum, tungsten, vanadium, and niobium, and has a two-defective structure site, and a periodic table I
The present invention relates to a method of oxidizing using a catalyst containing at least one or more elements selected from the group consisting of elements of groups B, VA, VIIA, and VIII having 4 to 6 cycles.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the catalyst according to the present invention, the hetero atom is at least one element selected from phosphorus, silicon and germanium, and the poly atom is molybdenum, tungsten,
A heteropolyoxometalate anion having at least two elements selected from the group consisting of vanadium and niobium, and IB, VA, VII of the periodic table
A, and at least one element selected from the group consisting of elements of groups VIII having 4 to 6 cycles. 4-6 of groups IB, VA, VIIA, and VIII of the periodic table
Preferred elements among at least one or more elements selected from the group of periodic elements are V, Mn, Fe, Co, Ni,
Au and the like, particularly preferably V and Au. IB, VA, VIIA, and VI of the periodic table in the present invention
At least one element selected from the group of elements having 4 to 6 periods of Group II may be incorporated or at least partially incorporated into a heteropolyoxometallate anion skeleton having two defective sites in the catalyst. You do not have to.

Further, in the present invention, the I of the periodic table
When at least one element selected from the group consisting of elements of groups 4 to 6 of the groups B, VA, VIIA and VIII is incorporated into the skeleton of the heteropolyoxometallate anion having two defective structures, It is more preferable that two heteropolyoxometallate anions having the following formulas are incorporated, and more preferably two are incorporated so as to form a ridge-sharing with each other. IB, VA, VIIA, and VIII of the periodic table
It is preferred that at least one element selected from the group of elements having 4 to 6 periods of the group be present in an amount of 0.001 or more per molecule of the heteropolyoxometallate anion.

The skeleton of the heteropolyoxometalate anion having a two-defective structure site used herein has a Keggin-type heteropolyacid ion structure. The general formula for this structure is

[0009]

Embedded image

(Where Y represents at least one element selected from the group consisting of silicon, germanium and phosphorus, and M represents at least one element selected from the group consisting of molybdenum, tungsten, vanadium and niobium) And q represents a positive integer determined by the valence of the ions of the element Y and the element M.)

This structural formula is shown in FIG. 1 for easy understanding. For example, the preparation of a heteropolyoxometalate anion having a two-defective structure site used in the present invention is described in Mizuno et al. Am. Chem. Soc. 1998,12
0,9267. In general, the Keggin-type heteropolyoxometalate anion having a two-deficient structure site has isomers such as γ-type, δ-type, and ε-type, but in the present invention, it is preferably γ-type. As the counter cation of the heteropolyoxometallate anion having a two-defective structure site, for example, when the oxidation reaction is carried out in an aqueous medium, a water-soluble proton or an alkali metal ion such as Na, K, or Rb is preferably used. When the reaction is carried out in an organic solvent, a tetraalkylammonium ion, a pyridium ion substituted with an alkyl group, or the like is used. However, there is no restriction on the choice.

Further, the heteropolyoxometallate anion skeleton having a two-deficient structure site has a periodic table IB, V
In order to incorporate at least one element selected from the group consisting of groups A, VIIA, and VIII having 4 to 6 periods, a heteropolyoxometalate anion is dissolved in a solvent, and then the periodic table IB, VA, VIIA, or VIII is incorporated. It is also possible to add a compound of at least one element selected from the group of elements having 4 to 6 cycles to perform heat treatment. The amount of the catalyst used in the present invention is selected in the range of 1: 1 to 1: 1,000,000, preferably in the range of 1:10 to 1: 100,000, as represented by the molar ratio of the catalyst to the reaction substrate. Is selected.

The reaction substrate used in the present invention includes:
Aromatic compounds having at least one alkyl substituent are used. The alkyl group usually has 1 to 8 carbon atoms.
Although a certain amount is used, an alkyl group such as a methyl group, an ethyl group, an n-propyl group and an iso-propyl group is preferable. The aromatic ring also includes a polycyclic aromatic ring such as a naphthalene ring.

Further, the aromatic compound includes a hetero element-containing aromatic compound containing nitrogen and sulfur elements, such as a pyridine compound and a thiophene compound. The present invention also applies to aromatic compounds further substituted with a hydroxyl group, a carbonyl group, a carboxyl group or the like in addition to the alkyl group.

As these starting materials, those obtained by any method can be used. Specific examples of such a compound include toluene, ethylbenzene, ethyltoluene, diethylbenzene, isopropylethylbenzene, isopropylbenzene, n-propylbenzene,
4,4′-dimethylbiphenyl, cumene, butylbenzene, 4-t-butyl-1-methylbenzene, 3-ethyltoluene, 4-ethyltoluene, chloroethylbenzene, dichloroethylbenzene, nitroethylbenzene,
o-, m-, p-cresol, o-, m-, p-xylene, o-, m-, p-diisopropylbenzene, 1,
2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2,2
4,5-tetramethylbenzene, o-, m-, p-toluic acid, o-, m-, p-tolualdehyde, 2,4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, or a mixture thereof And the like.

The aromatic carbonyl compound which is a compound obtained according to the present invention is an aromatic compound having a carbonyl group directly on an aromatic ring, and specifically includes benzaldehyde, acetophenone, hydroxybenzaldehyde, carboxybenzaldehyde, acetoxybenzaldehyde, Can be mentioned. Further, the aromatic carboxylic acid which is a compound obtained according to the present invention is an aromatic compound having at least one carboxyl group directly on an aromatic ring, and specifically includes benzoic acid, terephthalic acid, hydroxybenzoic acid and the like. Can be mentioned.

In the present invention, it is presumed that the oxidation of the alkyl group attached to the aromatic ring to the carboxyl group proceeds via the corresponding carbonyl group. For example, in the case of toluene oxidation, it is considered that it is further oxidized via benzaldehyde and proceeds to benzoic acid.

The oxidation method of the present invention is carried out by contacting a reaction substrate with a molecular oxygen-containing gas in the presence of a catalyst. The reaction can be performed in a liquid phase homogeneous system by dissolving the catalyst and the reactant in a typical solvent. A typical solvent is water or an organic solvent which is generally inert to the reaction. Of course, it is also possible to carry out the reaction in a mixed system or a two-phase system of water and an organic solvent. For example, acetic acid, organic acids such as propionic acid, acetonitrile, propionitrile, nitriles such as benzonitrile, formamide, acetamido, amides such as dimethylformamide, benzene,
Aromatic hydrocarbons such as naphthalene; aliphatic hydrocarbons such as hexane and octane; halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane and chlorobenzene; nitro compounds such as nitrobenzene and nitromethane; esters such as ethyl acetate and butyl acetate; Ethers such as dimethyl ether, tetrahydrofuran, dimethyl sulfoxide, and mixtures thereof are used as solvents. The substrate can also be a solvent.
When a solvent other than the reaction substrate is used, the weight ratio between the solvent and the reaction substrate is selected in the range of 1:10 to 1000: 1,
Preferably it is selected from the range of 1: 1 to 100: 1. The catalyst can be suspended in a liquid phase without being dissolved in a solvent, and a so-called heterogeneous reaction system in which the catalyst is a solid phase and the reactant is a gas phase is also possible. For example, the catalyst can be supported on a carrier or used as a solid itself, to which the reaction substrate can be added. As the carrier for the catalyst, there can be used carriers generally used for heterogeneous contact reactions, such as various ion exchange resins, silica, alumina and other oxides.

The molecular oxygen-containing gas used in the present invention is not particularly limited. It may be pure oxygen or oxygen diluted with an inert gas such as nitrogen, helium, argon, carbon dioxide. Air is preferred in terms of safety, operability, and economy. The amount of the molecular oxygen-containing gas to be used can be selected according to the type of the reaction raw material substrate or the target product compound, and is 0.01 mol or more, preferably 0.1 to 100 mol, more preferably 0.1 mol or more per mol of the substrate. 1 to 50 mol.

The reaction temperature ranges from 50 to 350 ° C.
More preferably 100 to 250 ° C., still more preferably 1 to 250 ° C.
00-220 ° C.

The reaction pressure may be normal pressure or a pressurized state, but is usually normal pressure to 10 MPa, preferably normal pressure to 8 MPa
a.

The reaction time is selected depending on the reaction temperature, the reaction pressure, the type of the catalyst used, and the like.
Time, preferably in the range of 2 to 48 hours.

When considering the stability of the catalyst, the pH of the reaction solution is adjusted each time using a pH buffer or the like.

The oxygen-containing aromatic compound produced according to the present invention is separated and purified by a method such as filtration, centrifugation, or distillation. The solution containing the used catalyst after the intended oxygen-containing aromatic compound has been separated can be reused by adding a catalyst, if necessary.

[0025]

EXAMPLES The present invention will be described more specifically by showing examples, but the present invention is not limited to these examples.
The following examples illustrate embodiments of the present invention.

Preparation of potassium salt of 2-deficient structure type γ-silicotungstic acid (K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] .12H ₂ O) (1 defect structure type K ₈ [β ₂ -Si ₁ W _11] O ₃₉ ] ・ 14H ₂ O
Preparation) A beaker was charged with 182 g of sodium tungstate dihydrate and 300 ml of water. 165 ml of 4 mol / l hydrochloric acid was added to this solution over about 10 minutes while stirring. An aqueous solution of 14.2 g of sodium silicate nonahydrate dissolved in 100 ml of water was separately added to the reaction solution.
Further, stirring was continued at room temperature for 15 minutes while maintaining the pH at 5 to 6 with 4 mol / liter hydrochloric acid to complete the reaction. 90 g of potassium chloride was added thereto for salting out. The obtained white solid was collected by filtration, and the filtrate was collected at 2 mol / mol.
Purification was performed by washing with 100 ml of an aqueous liter-KCl solution. The recovered solid was dried by air drying for 12 hours to obtain potassium salt of 1-defective structure type γ-silicotungstic acid (K ₈ [β ₂ -Si ₁ W ₁₁ O ₃₉ ] .14H ₂ O).

(2 deficient K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] · 1
2H ₂ O 1 deficient K ₈ obtained on the preparation) of [β ₂ -Si ₁
30 g of [W ₁₁ O ₃₉ ] · 14H ₂ O were dissolved in 100 ml of water. Any insolubles were immediately removed by filtration. 2 mol / l-K ₂ CO ₃ is added to this solution,
The pH was quickly adjusted to 9.1. While maintaining this pH value, stirring was continued for 16 minutes. Subsequently, 80 g of potassium chloride was added for salting out. The solution was filtered, and the filtrate was further washed with 1 mol / liter-KCl (100 ml).
Air-dried for 2 hours to form 2 deficient K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] · 12
H ₂ O was obtained.

Catalyst A (disubstituted silicotungstate substituted by iron element: [(C ₄ H ₉ ) ₄ N] _3.5 H _2.5 [γ-
Preparation of Si ₁ W ₁₀ {Fe (OH ₂ )} ₂ O ₃₈ ] · H ₂ O] 2-deficient K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] · 12H ₂ O
0 g was dissolved in 30 ml of water and the pH was adjusted to 3.9 with concentrated nitric acid.
0.81g of ferric nitrate nonahydrate in 5ml of water
Was added, and the mixture was stirred for 5 minutes. Subsequently, 3.04 g of tetrabutylammonium nitrate was added,
Stir for 15 minutes. The resulting white-yellow solid was suction-filtered and dried. The recovered solid was dissolved in 15 ml of acetonitrile, 300 ml of water was slowly added, and the mixture was immersed in ice water with stirring to perform recrystallization. The resulting tan solid was collected by filtration, washed twice with 50 ml of water, and suction-dried. Further, this recrystallization operation was repeated once to obtain a catalyst A (hereinafter, the catalyst is referred to as Fe-POM).

Catalyst B (Preparation of γ-Keggin type 2-deficient heteropolyoxometalate compound substituted with Mn element) 2-deficient K ₈ [γ-SiW ₁₀ O ₃₆ ] .12H ₂ O 3.0
g in 30 ml of ion-exchanged water to make it acidic, then add 0.57 g of manganese (II) nitrate hexahydrate, and after stirring,
4.1 g of tetrabutylammonium nitrate was added to obtain a precipitate. The precipitate was filtered, dissolved in 15 ml of acetonitrile, and then re-precipitated by adding 300 ml of water twice to purify the product to obtain a catalyst B (hereinafter referred to as Mn-POM). Notation).

Catalyst C (Preparation of γ-Keggin type 2-deficient heteropolyoxometalate compound substituted with Co element) In the preparation of catalyst A, cobalt (II) nitrate hexahydrate was used instead of ferric nitrate nonahydrate. The catalyst was prepared in the same manner as the catalyst A except that 0.58 g of the product was used.
OM).

Catalyst D (Preparation of potassium salt compound of γ-Keggin type 2-deficient heteropolyoxometalate substituted by Co element) 2-deficient K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] · 12H ₂ O
0 g was dissolved in 30 ml of water and the pH was adjusted to 3.9 with concentrated nitric acid.
Then, an aqueous solution in which 0.58 g of cobalt (II) nitrate hexahydrate was dissolved in 5 ml of water was added, and the mixture was stirred for 5 minutes. Subsequently, 30 g of potassium chloride was added, and the mixture was stirred for 15 minutes. Then, it was concentrated under reduced pressure to dryness. After dissolving the obtained solid in 100 ml of water, ether was added, and the precipitate was filtered and the pressure was reduced to remove the ether in the solid, and the potassium salt of a γ-Keggin type 2-deficient heteropolyoxometalate substituted with Co element was removed. A compound was obtained (hereinafter, the catalyst was used as Co-POM-
K).

Catalyst E (Preparation of γ-Keggin Type 2-Deficient Heteropolyoxometalate Compound Substituted with Ni Element) Nickel (II) nitrate hexahydrate instead of ferric nitrate nonahydrate in the preparation of catalyst A The catalyst was prepared in the same manner as the catalyst A except that 0.58 g of the product was used.
OM).

2. Catalyst F (Preparation of γ-Keggin type 2-deficient heteropolyoxometalate compound substituted with V element) 2-deficient K ₈ [γ-Si ₁ W ₁₀ O ₃₆ ] · 12H ₂ O
0 g was dissolved in 1 mol / l-HCl 11 mol, and the pH was adjusted to 3.9 with concentrated nitric acid.
4.1 ml of a liter-NaVO ₃ solution was added, and the mixture was stirred for 5 minutes. After filtering the precipitate, 2.654 g of tetrabutylammonium bromide was added thereto, followed by stirring for 15 minutes.
The resulting white-yellow solid was suction-filtered and dried. The recovered solid was dissolved in 15 ml of acetonitrile, 300 ml of water was slowly added, and the mixture was immersed in ice water with stirring to perform recrystallization. The generated yellow-brown solid was collected by filtration, and 50 m of water was collected.
After washing twice with 1 l, suction drying was performed. Further, this recrystallization operation was repeated once to obtain a catalyst F (hereinafter, the catalyst is referred to as V-POM).

Catalyst G (Preparation of γ-Keggin type 2-deficient heteropolyoxometalate compound substituted with Au element) In the preparation of catalyst A, instead of ferric nitrate nonahydrate,
The catalyst was prepared in the same manner as Catalyst A, except that an aqueous solution in which 0.82 g of chloroauric acid tetrahydrate was dissolved in ml of water was used (hereinafter, the catalyst is referred to as Au-POM).

Catalyst H (monosubstituted silicate tungstate substituted with iron element: [(C ₄ H ₉ ) ₄ N] _4.25 H _0.75 [α
Preparation of —SiW ₁₁ ｛Fe (OH ₂ )｝ O ₃₉ ] 1-deficient K ₈ [β ₂ -SiW ₁₁ O ₃₉ ] -14H ₂ O 32 g
Was dissolved in 60 ml of water heated to 95 ° C., and 4.1 g of ferric nitrate nonahydrate was added to this solution. After 10 minutes, the solution was filtered, 100 ml of a methanol-ethanol mixed solution (1: 1) was added to the filtrate, and the resulting precipitate was collected by filtration and further purified with a water-methanol mixed solution to obtain K ₅ [ SiFe (OH ₂ ) W ₁₁ O ₃₉ ] · 14H ₂ O
I got A precipitate formed by adding 4.3 g of tetrabutylammonium bromide to an aqueous solution of 2.5 g of the potassium salt is purified by repeatedly performing an operation of dissolving in acetonitrile and precipitating with water to obtain an iron 1-substituted silicate tungstate [( C ₄ H ₉ ) ₄ N] _4.25 H _0.75 [α-SiW ₁₁ ｛F
e (OH ₂ )｝ O ₃₉ ] (hereinafter, the catalyst was converted to 1-PO
M-Fe).

Catalyst I (trisubstituted silicotungstate substituted by iron element: [(C ₄ H ₉ ) ₄ N] _3.25 H _3.75 [α
Preparation of —SiW ₉ ｛Fe (OH ₂ )｝ ₃ O ₃₇ ]） ₃ deficient structure type Na ₁₀ [α-SiW ₉ O ₃₄ ] · 18H ₂ O
Preparation of 182 g of sodium tungstate dihydrate and 11 g of sodium silicate nonahydrate in 200 m of hot water at 85 ° C
and stirred for 30 minutes, then 6 mol / l
130 ml of HCl were added dropwise. Then, after concentrating until the volume became about 300 ml, it filtered. An aqueous solution of 50 g of anhydrous sodium carbonate dissolved in 150 ml of water was slowly added to the filtrate, and stirring was continued for 3 hours. The generated white precipitate was filtered, and the filtrate was dispersed in 4 mol / l-NaCl (1000 ml), and further stirred for 1 hour. Then, the white precipitate was filtered and ethanol 10
After washing twice with 0 ml and further with 100 ml of ethyl ether, the 3-deficient structure type Na ₁₀ [α-SiW ₉ O ₃₄ ] · 18H ₂
O was obtained.

6.8 g CH_ThreeCOONa 3H_TwoO to 1
Dissolve in 00 ml of water, then dissolve in 50 ml of water
5.39 g of an aqueous solution of ferric nitrate nonahydrate was added. So
And heated to 70 ° C. to obtain the 3-defective structure type obtained by the above method.
Na_Ten[Α-SiW₉O₃₄] ・ 18H_TwoO 11.25g
Was added over 1 hour. Then, after stirring for 1 hour,
Cool. The solution thus obtained is Na⁺Mold cation
Pass through the exchange resin three times and pour the clear yellow-brown solution into 40 ml of water.
Dissolved tetrabutylammonium bromide 16.8
g of an aqueous solution was added, and the mixture was stirred at room temperature for 1 hour and filtered. yellowish-brown
Dissolve the recovered solid in 40 ml of acetonitrile and
500 ml of water was added thereto, and the mixture was stirred in an ice water bath for 1 hour and filtered.
Dry overnight at room temperature and iron 3-substituted silicate tungstate
[(C _FourH₉)_FourN]_3.25H_3.75[Α-SiW₉｛Fe (O
H_Two)_Three｝ O₃₇(Hereinafter referred to as 3-POM-F
e).

Example 1 An oxidation reaction of toluene was carried out. 5 ml of dimethyl sulfoxide and 1.5 ml of 1,2-dichloroethane as a solvent
Then, 1.5 μmol of catalyst A and 19 mmol of toluene were added to a reaction vessel containing 0.1 ml of acetonitrile, and the reaction vessel was cooled to 0 ° C., and then the gas phase was filled with pure oxygen. The reaction was carried out for 24 hours with vigorous stirring in an oil bath. Then, the reaction solution was cooled to room temperature, and the product was analyzed by liquid chromatography. As a result, the yield of benzaldehyde was 0.6 mol% and the yield of benzoic acid was 2.7 mol% based on the charged toluene. After completion of the reaction, the organic matter in the reaction solution was removed by drying under reduced pressure, and the residue was reused as catalyst A to obtain Example 2. Table 1 shows the results.

Example 2 The reaction solution of Example 1 was dried under reduced pressure to remove organic components, the residue was used in place of the catalyst A of Example 1, and the reaction was carried out according to Example 1 except that the solvent was changed to 15 ml of acetic acid. Done. Table 1 shows the results. Thus, it was found that the catalyst could be reused.

Example 3 A toluene oxidation reaction was carried out according to Example 1, except that catalyst D was used as a catalyst and 15 ml of water was used as a solvent. Table 1 shows the results.

Example 4 1.5 μmol of 2-deficient potassium salt K ₈ [γ-
SiW ₁₀ O ₃₈ ] 12H ₂ O and ferric nitrate nonahydrate 4 μm
ol, and the toluene oxidation reaction was carried out according to Example 1 except that only 15 ml of water was used as a solvent. Table 1 shows the results.

Example 5 The oxidation reaction of toluene was carried out according to Example 1 except that catalyst C was used as the catalyst. Table 1 shows the results.

Example 6 An oxidation reaction of toluene was carried out according to Example 1 except that catalyst E was used as a catalyst. Table 1 shows the results.

Comparative Example 1 The oxidation reaction of toluene was carried out according to Example 1 except that catalyst H was used instead of catalyst A as the catalyst. Table 1 shows the results.

Comparative Example 2 An oxidation reaction of toluene was carried out according to Example 1 except that catalyst I was used instead of catalyst A as the catalyst. Table 1 shows the results.

Example 7 An oxidation reaction of p-cresol was carried out according to Example 1, except that p-cresol was used in place of toluene as a reaction substrate and catalyst F was used as a catalyst. Table 1 shows the results.

Example 8 An ethylbenzene oxidation reaction was carried out according to Example 1 except that ethylbenzene was used instead of toluene as a reaction substrate, and catalyst F was used as a catalyst. Table 1 shows the results.

Example 9 Example 1 was repeated except that acetoxytoluene was used in place of toluene as a reaction substrate, and catalyst F was used as a catalyst.
, An acetoxytoluene oxidation reaction was performed.
Table 1 shows the results.

Example 10 The procedure of Example 1 was repeated, except that p-toluic acid was used in place of toluene as a reaction substrate, catalyst F was used as a catalyst, and water was used as a solvent. Was oxidized. Table 1 shows the results.

Example 11 p-xylene was oxidized according to Example 1 except that p-xylene was used in place of toluene as a reaction substrate and catalyst F was used as a catalyst. Table 1 shows the results.

Example 12 p-xylene was oxidized according to Example 11 except that catalyst B was used as the catalyst. The result is
It is shown in Table 1.

Example 13 The oxidation reaction of p-xylene was carried out according to Example 11 except that catalyst G was used as the catalyst. The result is
It is shown in Table 1.

[0053]

[Table 1]

[0054]

According to the present invention, a useful oxygen-containing aromatic carbonyl compound is obtained by oxidizing an aromatic compound having at least one alkyl group with a minimum amount of a catalyst without corroding the apparatus. And / or aromatic carboxylic acids can be produced.

[Brief description of the drawings]

FIG. 1 shows the molecular structure of polyoxometalate [γ-SiW ₁₀ {M} ₂ O ₃₈ ] ^q- substituted with two representative metal ions. M is shown as a shaded octahedron. W
O ₆ is shown as a white octahedron. SiO ₂ is shown as a black tetrahedron at the center. The numbers in the figure represent n of Wn, and Wn
Indicates the number based on IUPAC in WO ₆ in the Keggin structure.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 49/78 C07C 49/78 51/265 51/265 63/06 63/06 63/26 63/26 E F 65/03 65/03 A 65/30 65/30 67/29 67/29 69/157 69/157 211/63 211/63 // C07B 61/00 300 C07B 61/00 300 F term (reference) 4G069 AA06 AA08 BA21A BA21B BB07A BB07B BC03B BC23A BC30A BC33B BC53A BC54B BC55A BC59A BC60A BC60B BC61A BC62B BC65A BC66B BC67B BC68B BC69A BD05A BD05B BD07A BE17B CB07 DA02 FA30 BA30 BA30 BA14 BA30 BA14 BA30 BA44 BA30 CA62 CA65 CC30

Claims (3)

[Claims] 1. The method according to claim 1, wherein when oxidizing the alkyl group of the aromatic compound having at least one alkyl substituent with a gas containing molecular oxygen, the hetero atom is selected from the group consisting of phosphorus, silicon and germanium. A heteropolyoxometallate anion having at least one element selected from the group consisting of molybdenum, tungsten, vanadium, and niobium, wherein the polyatom is a single element, and has a two-defective structure; IB, VA, VIIA and VIII of 4-6
A method for producing an aromatic carbonyl compound and / or aromatic carboxylic acid, comprising using a catalyst containing at least one element selected from the group consisting of periodic elements. 2. A keggin having a two-defective structure site in which a skeleton of a heteropolyoxometallate anion having a two-defective structure site contains at least one of γ, δ, and ε isomers represented by the following general formula (1). The method according to claim 1, wherein the heteropolyacid ion is a type heteropolyacid ion. Embedded image (In the formula (1), Y represents at least one element selected from the group consisting of silicon, phosphorus, and germanium, and M represents at least one element selected from the group consisting of molybdenum, tungsten, vanadium, and niobium.) , Q represents a positive integer determined by the valence of the ions of the element Y and the element M.) 3. At least two of at least one element selected from the group consisting of elements of groups 4 to 6 of groups IB, VA, VIIA and VIII of the periodic table are shared by the skeleton of the heteropolyoxometallate anion. 3. The method according to claim 2, wherein the components are incorporated adjacently to form