JPS645585B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic ketones.
Specifically, the present invention provides a method for producing aromatic ketones by catalytic gas phase oxidation of diphenylmethane derivatives, and more specifically, the present invention provides a method for producing aromatic ketones by catalytic gas phase oxidation of diphenylmethane derivatives.

【formula】

[Formula] (In the formula, R represents any substituent of an alkyl group having 1 to 3 carbon atoms, m ₁ and n ₁ are each 0 to 5, and m ₂ and n ₂ are each 0 to 5.
Represents four identical or different substituents. ) is catalytically gas phase oxidized with molecular oxygen to produce the corresponding aromatic ketones, consisting of lead oxide as component A and titanium oxide, zirconium oxide, tin oxide and cerium oxide as component B The present invention provides a method for producing aromatic ketones, characterized by using a catalyst containing at least one selected from the group as a catalytically active substance. The present inventors previously disclosed in Japanese Patent Application No. 57-227457 that aromatic ketones are characterized in that a catalyst containing a lead compound is used as a catalytically active substance when producing the aromatic ketones from the raw materials. Disclosed is a manufacturing method. However, the above-mentioned catalysts still have the disadvantage of low activity and yield, and as a result of further intensive studies, the present inventors have found that the production method disclosed in the present invention has significantly improved activity and yield. The information shall be disclosed to the public. Aromatic ketones, such as benzophenone, which are the object of the present invention, have conventionally been obtained by the reaction of benzoyl chloride and benzene or benzene and phosgene. However, the former method consumes more than an equimolar amount of anhydrous aluminum chloride, and the latter method uses phosgene, which is problematic in handling. Furthermore, anthraquinone is obtained by catalytic gas phase oxidation of anthracene using a vanadium catalyst, but recently it has become difficult to obtain the raw material anthracene. Also, fluorenone is obtained from fluorene, and 2-methylbenzophenone is obtained from 2-methyldiphenylmethane by catalytic gas phase oxidation using a vanadium catalyst, but they have the disadvantage of producing many by-products such as benzoic acid and maleic acid. be. Each of the aromatic ketones disclosed in the present invention is industrially useful. For example, benzophenone is used as a polymerization inhibitor, flavor fixative, etc., and anthraquinone is used as a synthetic intermediate for dyes, as a bulb cooking aid, etc.
Fluorenone is used as an insecticide, and 2-methylbenzophenone is used as a raw material for anthraquinone. The raw material diphenylmethane derivative used in the present invention is represented by the above general formula () or (), and when it has a substituted alkyl group (R), examples of R include a methyl group, an ethyl group, and a propyl group, particularly methyl Groups are preferred. That is, R
When is a methyl group, specific examples include the following compounds. In the above general formula (), diphenylmethane derivatives in which a methyl group is not present at the ortho position include diphenylmethane, 3-methyl or 4-methyldiphenylmethane, or 4,4'-dimethyl or 3,4'-dimethyldiphenyl. dimethyl-substituted diphenylmethane, such as methane, or 3,4,5
- trimethyl-substituted diphenylmethane, such as trimethyl or 3,4,3'-trimethyldiphenylmethane, or 3,4,5,3'-tetramethyl or 3,5,3',5'-tetramethyldiphenylmethane. Tetramethyl-substituted diphenylmethane, or pentamethyl-substituted diphenylmethane, such as 3,4,5,3',5'-pentamethyldiphenylmethane, or 3,4,5,3',4',5'-hexamethyldiphenylmethane etc. are listed. In addition, diphenylmethane derivatives having at least one methyl group at the ortho position in the general formula () include:
2-methyldiphenylmethane, or 2,4-dimethyl, 2,3-dimethyl, 2,5-dimethyl,
2,2'-dimethyl, 2,3'-dimethyl or 2,
Dimethyl-substituted diphenylmethane, such as 4'-dimethyldiphenylmethane, or 2,3,2'-trimethyl, 2,4,2'-trimethyl, 2,5,2'-trimethyl, 2,6,2'-trimethyl, 2,5,
4'-trimethyl, 2,6,4'-trimethyl, 2,
3,4'-trimethyl, 2,3',4'-trimethyl,
Trimethyl-substituted diphenylmethane, such as 2,3',5'-trimethyl or 2,4,6-trimethyldiphenylmethane, or 2,3,2',3'-tetramethyl, 2,3,3',4'- Tetramethyl, 2,
4,2',4'-tetramethyl, 2,4,2',6'-tetramethyl, 2,5,2',5'-tetramethyl,
2,6,2',4'-tetramethyl or 2,6,2',
tetramethyl-substituted diphenylmethane such as 6′-tetramethyldiphenylmethane or 2,4,6,
pentamethyl-substituted diphenylmethane, such as 2',6'-pentamethyldiphenylmethane, or 2,
hexamethyl-substituted diphenylmethane, such as 4,6,2',4',6'-hexamethyldiphenylmethane;
Or heptamethyl-substituted diphenylmethane such as 2,3,5,6,3',4',6'-heptamethyldiphenylmethane, or diphenylmethane substituted with 8 to 10 methyls. Similarly, compounds in which R is a plurality of different types of ethyl, propyl, methyl, ethyl, and propyl groups may also be targeted. Compounds included in the above general formula () include fluorene, or when R is a methyl group, monomethyl-substituted fluorene such as 1-methyl or 2-methylfluorene, or fluorene substituted with 2 to 8 methyl groups, etc. It is raised. In this case as well, compounds in which R is a plurality of different types of ethyl, propyl, methyl, ethyl, and propyl groups may also be targeted. The above-mentioned raw material diphenylmethane derivatives are supplied into the catalyst as a single compound or as a mixture of two or more. Aromatic ketones, which are oxidation products, can be obtained as a single compound or a mixture, and if desired, they can be obtained as a single compound by known methods such as distillation and extraction. The action of the catalyst disclosed in the present invention in producing the corresponding aromatic ketones by catalytic gas phase oxidation of the diphenylmethane derivative disclosed in the present invention with molecular oxygen is surprising. For example, when producing benzophenone from the diphenylmethane derivative shown in the above general formula (), if the raw material diphenylmethane derivative does not have a substituted alkyl group at the ortho position of the benzene nucleus, it does not matter whether there are substituted alkyl groups at other positions. A benzophenone without any substituted alkyl group is obtained. In addition, when anthraquinone is produced from the diphenylmethane derivative shown in the above general formula (), as long as there is at least one substituted alkyl group, especially a methyl group, at the ortho position of the benzene nucleus in the diphenylmethane derivative as the raw material, it can be substituted at any other position. Even if a conceivable number of substituted alkyl groups are present, anthraquinones without substituted alkyl groups are obtained. 2-
The same applies to methylbenzophenone and fluorenone. In addition, another specific catalytic action of the catalyst disclosed in the present invention is that phthalic acid,
Oxidation by-products such as maleic acid and benzoic acid are either completely absent or extremely low. These newly discovered catalytic actions make it possible to produce the aromatic ketones disclosed in the present invention by an industrially advantageous production method in terms of inexpensive acquisition of raw materials and/or product purification. It is something that connects. Up until now, the use of lead oxide as a catalyst in a method for producing aromatic ketones by catalytic gas phase oxidation of diphenylmethane derivatives with molecular oxygen was not known until disclosed in the above-mentioned Japanese Patent Application No. 57-227457. Not yet. Moreover, the catalyst disclosed in the present invention which is an improvement on the above-mentioned prior invention, that is, a catalyst containing lead oxide as the A component and at least one selected from the group consisting of titanium oxide, zirconium oxide, tin oxide and cerium oxide as the B component. The use of catalysts containing catalysts as active substances is not known at all. The present inventors conducted intensive studies on methods for producing aromatic ketones by catalytic gas phase oxidation using various diphenylmethane derivatives as starting materials. As a result, when using an oxidation catalyst containing each element as described above, The present inventors have newly discovered that the yield and activity are dramatically improved compared to the method disclosed in the prior invention, and that it is possible to produce industrially advantageous aromatic ketones, leading to the present invention. That is, the present invention is specified as follows. (1) Diphenylmethane derivatives represented by the following general formula () or ()

【formula】

[Formula] (In the formula, R represents any substituent of an alkyl group having 1 to 3 carbon atoms, m ₁ and n ₁ are each 0 to 5, and m ₂ and n ₂ are each 0 to 5. (representing four identical or different substituents) with molecular oxygen in a catalytic gas phase to produce the corresponding aromatic ketones, lead oxide as component A and oxidation as component B. A method for producing aromatic ketones, which comprises using a catalyst containing at least one selected from the group consisting of titanium, zirconium oxide, tin oxide, and cerium oxide as a catalytically active substance. (2) Component A is 1 to 90% by weight as PbO, component B is
_TiO2 and/or _ZrO2 and/or _SnO2
and/or the method according to (1) above, wherein the amount is 10 to 99% by weight as _CeO2 . The present invention will be explained in more detail below. All of the raw material diphenylmethane derivatives used in the present invention can be obtained by known methods. In particular, the aromatic ketones produced from the raw material diphenylmethane disclosed in the present invention include benzophenone when the alkyl group in the general formula () does not exist at the ortho position, and When one alkyl group, especially a methyl group, is present, examples include 2-methylbenzophenone or anthraquinone, and when the general formula () is present, examples include fluorenone. The catalyst used in the present invention is specified as an oxide catalyst containing each element as described above, and is not particularly limited in the type of catalyst raw material, the shape of the catalyst, the presence or absence of a promoter, the presence or absence of a support, and the manufacturing method. In other words, the lead compounds that serve as component A in the catalytic active components are not limited to oxides such as lead monoxide, dilead trioxide, trilead tetroxide, or lead trioxide, but also lead metals, sulfides, inorganic salt compounds, and organic Substances that change into oxides by heating or other treatments, such as salt compounds, organic compounds, or complex compounds, can be used. Examples of the above-mentioned inorganic salt compounds include lead fluoride, lead chloride, lead bromide, lead iodide, lead carbonate, lead sulfate, lead hydroxide, and lead hydroxy carbonate. Examples of organic salt compounds include lead acetate, lead propionate, lead oxalate, lead citrate, lead stearate, and lead benzoate. Examples of organic compounds include tetramethyl lead, tetraethyl lead, tetrapropyl lead, tetraphenyl lead, and tetraxyl lead. Examples of the complex compound include ammonium hexachloropate and the like. On the other hand, the metal compounds that serve as component B are as follows:
Titanium oxide represented by TiO ₂ , zirconium oxide represented by ZrO ₂ , tin oxide represented by SnO ₂ ,
Cerium oxide represented by CeO ₂ is not limited to oxides, but also ammonium salts, sulfates, and
Nitrates, halides, organic acid salts, hydroxides, etc.
It can be appropriately selected from the substances that change into oxides as mentioned above by heating. These may be used alone or as a mixture in any proportion. When used as a mixture, titanium,
It may be a composite oxide of each element of zirconium, tin, and cerium. At least a part of the above catalytically active substance is a composite oxide, such as lead titanate (PbTiO ₃ , PbTi ₃ O _7, etc.), lead zirconate (PbZrO _3, etc.), lead stannate (PbSnO ₃ , Pb ₂ SnO ₄ , etc.) , or titanium-lead zirconate (PbTi _x Zr _1-x O ₃ , 0<x<1, etc.), favorable results can also be obtained. In the catalyst of the present invention, the above catalyst active composition further includes alkali metals such as lithium, sodium, potassium, rubidium, and cesium, alkaline earth metals such as magnesium, calcium, strontium, and barium, boric acid, aluminum, and gallium. , indium, thallium,
Silicon, germanium, phosphorus, arsenic, antimony, bismuth, selenium, tellurium, copper, silver, gold, zinc, cadmium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, ruthenium, rhodium, One or more rare earth elements (excluding cerium) such as palladium, uranium, lanthanum, and samarium may be contained as a promoter component. The above-mentioned additional elements can be, for example, their respective oxides, salts or composite oxides with lead and/or titanium, zirconium, tin, cerium, etc. in the final catalyst. The composition ratio of each component of the catalytically active material is not particularly limited, but as a preferred composition ratio, lead as component A is 0.5 to 95% by weight calculated as lead monoxide (PbO) with respect to the total amount of the catalytically active material. , preferably in an amount of 1 to 90% by weight, and at least one selected from the group consisting of titanium oxide, zirconium oxide, tin oxide, and cerium oxide as component B,
Each oxide (TiO ₂ , ZrO ₂ , SnO ₂ , and
Amounts of from 5 to 99.5% by weight, preferably from 10 to 99% by weight, calculated as _CeO2 ) are used. When adding component C, at least one compound selected from the group consisting of the above elements is calculated as its highest valence oxide, and the amount is calculated based on the sum of components A and B.
Amounts of up to 30% by weight are used. Examples of methods for producing a catalyst using the above-mentioned catalyst raw materials include suspending powder of component B such as titanium oxide or zirconium oxide in an aqueous lead compound solution, concentrating the slurry, and then molding it; A catalyst is produced by spraying onto a heated carrier and then calcining at high temperature (400 to 800°C) in the presence of molecular oxygen. Alternatively, after mixing the above-mentioned lead compound and the above-mentioned B component compound such as titanium or zirconium, the mixture is fired at a high temperature (400 to 1300°C) in the presence of molecular oxygen, and then pulverized into an appropriate size and molded. Alternatively, it can be used as a catalyst by being supported on a carrier.
Alternatively, a coprecipitate is obtained by a known method from a homogeneous aqueous solution of the above-mentioned A and B components, filtered, dried and then molded, or supported on a carrier and heated to a high temperature (400 to 800°C).
It is made into a catalyst by calcining it. All suitable catalysts can be produced by the methods exemplified above, but are not limited thereto. In addition, the above-mentioned catalytically active substance may be used as a powdered or shaped catalyst by itself or together with a powder such as silicon carbide, alumina, iron oxide, silica or silicates such as magnesium or barium, or in some cases, the above-mentioned inert It is used by supporting it on a carrier made of a substance. The reaction conditions for catalytic gas phase oxidation of the diphenylmethane derivatives described above using the catalysts described above are set as follows. That is, the reaction temperature is 250-600℃, preferably
280~550℃, space velocity 100~10000Hr ^-1 (ST
P.), preferably 200 to 6000 Hr ^-1 (STP), the gas concentration in the conduction gas of the diphenylmethane derivative as the raw material is 0.04 to 2% by volume, preferably 0.08 to 1.0% by volume, and the conduction gas is air or molecular Although an oxygen-containing gas is used, it is preferable that the oxygen gas concentration in the conduction gas is 5 to 40% by volume. Furthermore, 0 to 20% by volume of water vapor may be added to the conduction gas. Further, the reaction pressure can be normal pressure or increased pressure up to 10 kg/cm ² G. Next, the present invention will be explained in more detail with reference to Examples. In the examples, selectivity refers to molar selectivity with respect to reacted raw materials. Example 1 (a) Catalyst Production Titanium oxide powder (anatase type, specific surface area 18.5 m ² /g) was added and suspended in water in which lead nitrate had been dissolved. This suspension was sprayed onto a spherical silicon carbide carrier having an average diameter of 3 mm and then calcined at 520°C to produce a catalyst. The catalyst composition at this time is
PbO:TiO ₂ =50:50 (weight ratio). (b) Oxidation reaction 90 parts by weight of the catalyst obtained in (a) of Example 1 was mixed with an inner diameter of 21 mm.
The mixture was filled into a tubular reaction tube, and the tube wall temperature was set at 455°C.
Next, a mixture of 4 parts by weight of 2-methylphenylmethane and 120,000 parts by volume of air is added per hour to SV=
It was introduced into the reaction tube at 1500 hr ^-1 . The raw material gas concentration at this time is 0.4% by volume. All unreacted raw materials and condensable products in the gas discharged from the reaction tube were collected by cooling and dissolved in a solvent, and each component was analyzed by gas chromatography, and the following results were obtained. Conversion rate 95.1% Selectivity anthraquinone 59.5% 2-methylbenzophenone 10.6% Non-condensable lower oxides (mainly CO, CO ₂ )
14.0% Although benzophenone, anthracene, and fluorenone were observed as other by-products, phthalic acid and maleic acid were not produced at all. Examples 2 to 4 The same procedure as in Example 1 was carried out except that the ratio of PbO and TiO ₂ in Example 1(a) was changed as shown in Table 1 below, and the results shown in Table 1 below were obtained.

[Table] Example 5 The procedure of Example 1 was repeated except that rutile TiO ₂ (specific surface area: 6.9 m ² /g) was used instead of anatase TiO ₂ in Example 1(a), and the following table - The results shown in 2 were obtained. Examples 6 to 8 In Example 1(a), instead of TiO ₂ powder, ZrO ₂ (specific surface area 22.8 m ² /g; Example 6) SnO ₂ (specific surface area
20.7m ² /g; Example 7) or CeO ₂ (specific surface area
18.4 m ² /g; Example 8) The procedure of Example 1 was repeated except that powder was used, and the results shown in Table 2 below were obtained. Example 9 (a) Production of catalyst Equimolar amounts of lead monoxide powder and titanium oxide powder were sufficiently mixed, and the powder mixture was heated in air at 500°C.
Baked for 12 hours. According to X-ray diffraction analysis of the heat-treated powder, the PbO and TiO ₂ patterns disappeared and lead titanate (PbTiO ₃ ) was newly formed. The above lead titanate powder (specific surface area 6.3m ² /g)
50 parts by weight and 50 parts by weight of silicon carbide powder were suspended in water, the suspension was sprayed onto a spherical silicon carbide carrier with an average diameter of 2 mm, and then heated at 400°C.
A lead titanate catalyst was produced by calcination. At this time, the catalyst composition is expressed as PbO and TiO ₂ and is PbO:
TiO ₂ =73.6:26.4 (weight ratio). (b) Oxidation reaction It was carried out in the same manner as in Example 1(b). The results are shown in Table 2 below. Example 10 (a) Production of catalyst A homogeneous aqueous solution containing 10 moles of lead nitrate and 10 moles of titanyl nitrate was added under stirring to an aqueous solution containing 22 moles of oxalic acid kept at 80°C to form a suspension of lead titanyl oxalate. I got the liquid. After removing water from this suspension by filtration and drying, it was molded under pressure. The mixture was then calcined at 530° C. for 6 hours and then pulverized to obtain a granular molded catalyst having a size of 5 to 10 meshes. According to X-ray diffraction, this was lead titanate. (b) Oxidation reaction It was carried out in the same manner as in Example 1(b). The results are shown in Table 2 below.

【table】

[Table] Examples 11 to 17 In Example 1(a), in addition to PbO:TiO ₂ =50:50 (weight ratio), the elements shown in Table 3 below were added as oxides shown in Table 3 below. The process was carried out in the same manner as in Example 1, except that the catalyst was manufactured by adding the parts by weight shown in Table 3 below to 100 parts by weight of the total amount of lead oxide and titanium oxide, and the results shown in Table 3 below were obtained. I got it. For chromium, ammonium dichromate was selected, and for the remaining metals, nitrates were used as catalyst raw materials.

[Table] Example 18 The same procedure as in Example 1 was carried out except that diphenylmethane was used as the raw material in Example 1(b), and the following results were obtained. The raw material gas concentration at this time is 0.2% by volume,
The tube wall temperature was set at 460°C. Conversion rate: 99.2% Benzophenone selectivity: 87.6% Most of the by-products are fluorenone and carbon dioxide gas, and benzoic acid and maleic acid are not observed. Example 19 The same procedure as in Example 1 was carried out except that fluorene was used as the raw material in Example 1(b), and the following results were obtained.
The raw material gas concentration at this time was 0.2% by volume, and the tube wall temperature was 430°C. Conversion rate: 97.5% Fluorenone selectivity: 73.6% Most of the by-products are carbon dioxide gas, and no benzoic acid or maleic acid is observed. Example 20 A catalyst was produced in the same manner as in Example 1(a) except that lead acetate was used instead of lead nitrate in Example 1(a), and in Example 1(b), 2,5,2 ′,5′-Tetramethyldiphenylmethane was used to control the tube wall temperature.
The procedure was carried out in the same manner as in Example 1(b) except that the temperature was 440°C, and the following results were obtained. Conversion rate: 89.9% Anthraquinone selectivity: 43.5% Other by-products were mostly carbon dioxide gas and no phthalic acid, maleic acid, etc. Example 21 2,2'-dimethyldiphenylmethane, 2,4', obtained by reaction of toluene and paraformaldehyde as raw materials in Example 1(b) using the catalyst of Example 9(a). -Using a mixture of dimethyldiphenylmethane and 4,4'-dimethyldiphenylmethane, the tube wall temperature was 430℃, and the raw material gas concentration was
The same procedure as in Example 1(b) was carried out except that the amount was changed to 0.3% by volume. As a result, the conversion rate of the mixed raw material was 98.2%, and the condensable reaction products were anthraquinone, 2-methylbenzophenone, and benzophenone, and their composition ratios were 55.5%, 10.0%, and 10.0%, respectively.
34.5% (by weight), and the selectivity to aromatic ketones was 73.6%. The other by-products were mostly carbon dioxide gas, with no phthalic acid, maleic acid, etc. Although this reaction was continued for 500 hours, a conversion rate of 98.0% and a selectivity of 73.8% were maintained. Example 22 In Example 1(b), the raw material was changed to 4-methyldiphenylmethane, the raw material gas concentration was set to 0.2% by volume,
The same procedure as in Example 1 was carried out except that the tube wall temperature was 440°C, and the results shown below were obtained. Conversion rate: 95.4% Benzophenone selectivity: 60.2% 4-methylbenzophenone, fluorenone, and carbon dioxide gas were mostly by-products.

Claims (1)

[Claims] 1 Diphenylmethane derivative represented by the following general formula () or () [Formula] [Formula] (wherein R represents any substituent of an alkyl group having 1 to 3 carbon atoms, m ₁ and n ₁ are each 0 to 5, and m ₂ and n ₂ are each 0 to 5.
Represents the number of 4 identical or different substituents. ) is catalytically gas phase oxidized with molecular oxygen to produce the corresponding aromatic ketones, consisting of lead oxide as component A and titanium oxide, zirconium oxide, tin oxide and cerium oxide as component B A method for producing aromatic ketones, characterized by using a catalyst containing at least one selected from the group as a catalytically active substance. 2 Component A is 1 to 90% by weight as PbO, component B is
2. The method according to claim 1, wherein the amount is 10 to 99% by weight as _TiO2 and/or _ZrO2 and/or _SnO2 and/or _CeO2 .