Catalyst for preparing benzophenone compound as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for preparing benzophenone compounds and a preparation method and application of the catalyst, the catalyst is alkaline manganese oxide and is expressed as aZOx.bMnO2, Z is any one of lithium, potassium, sodium, magnesium and calcium; x is the number of oxygen atoms required by the oxidation state of the metal element Z; a and b are respectively the atom number of Z and Mn in the catalyst, and the atom number ratio of Z to Mn in the catalyst is 0.2-10. According to the catalyst provided by the invention, the preparation method is simple, the benzophenone or halogenated benzophenone can be prepared by catalyzing efficient oxidation of diphenylmethane and halogenated diphenylmethane containing a passivation group, the catalyst activity is high, the product selectivity is high, the product is easy to separate, and the catalyst can be recycled.

Description

Technical Field

[0001] This invention belongs to the technical field of preparing benzophenone compounds, specifically relating to a catalyst for preparing benzophenone compounds, its preparation method, and its application. Background Technology

[0002] Polyetheretherketone (PEEK) is an important organic chemical material with excellent comprehensive properties such as high temperature resistance, self-lubrication, and corrosion resistance, and is widely used in aerospace, robotics, and medical fields. Benzophenone compounds, including halogenated benzophenones, are key monomers, and their synthesis technology has attracted widespread attention.

[0003] Patent CN113321574A discloses a technical route for synthesizing 4,4′-dichlorobenzophenone and 4,4′-difluorobenzophenone from chlorobenzene and 4-chlorobenzyl chloride. The catalyst is a homogeneous manganese salt catalyst. This method has mild reaction conditions and a simple synthetic route, but the homogeneous catalyst is difficult to recover and reuse, and the product separation and purification are also challenging. Patent CN113304759A discloses a method for catalytic oxidation of diphenylmethane to benzophenone using a heterogeneous catalyst supported on a γ-Al₂O₃ support, but the supported catalyst has a low content of active components, requires a large amount of heterogeneous catalyst, and has low efficiency.

[0004] Therefore, there is a need to develop a novel catalyst for the preparation of benzophenone compounds and a catalytic oxidation method that is mild and easy to operate. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a catalyst for preparing benzophenone compounds, its preparation method, and its application. The catalyst enables the preparation of benzophenone compounds from diphenylmethane compounds, exhibiting high catalytic activity, high product selectivity, and easy separation.

[0006] A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, denoted as aZO. x ·bMnO2, where Z is any one of lithium, potassium, sodium, magnesium, and calcium; x is the number of oxygen atoms required to satisfy the oxidation state of metal element Z; a and b are the number of Z and Mn atoms in the catalyst, respectively, and the ratio of Z to Mn atoms in the catalyst is 0.2-10.

[0007] The method for preparing the catalyst for preparing benzophenone compounds includes the following steps: (1) Potassium permanganate and ZnO x The precursor is dispersed in deionized water or ethanol, stirred evenly, transferred to a reaction vessel and stirred at 20-160℃ for 4-24 hours, filtered, and washed with deionized water or ethanol. (2) Drying, roasting in air atmosphere.

[0008] Preferably, the ZO x The precursor is at least one of KOH, K2CO3, KHCO3, NaOH, Na2CO3, NaHCO3, Mg(OH)2, MgCO3, Ca(OH)2, CaCO3, LiOH, and Li2CO3.

[0009] Preferably, the drying conditions are drying at 80-120℃ for 6-16 hours; the calcination conditions are calcination at 250-450℃ for 4-6 hours.

[0010] The method for using the catalyst to prepare benzophenone compounds involves mixing the catalyst with a diphenylmethane-based raw material, stirring the mixture at 90-200°C for 8-36 hours under an oxygen-containing gas atmosphere, adding a dissolving solvent to dissolve the reaction product, filtering, collecting the filtrate, and recrystallizing.

[0011] Preferably, the method further includes the addition of a reaction solvent.

[0012] Preferably, the reaction solvent is at least one selected from cyclohexane, dichloroethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and sulfolane; and the dissolving solvent is any one selected from dichloroethane, ethanol, acetonitrile, and ethyl acetate.

[0013] Preferably, the mass of the catalyst is 1-25% of the mass of the diphenylmethane compound.

[0014] Preferably, the diphenylmethane compound is diphenylmethane or a halodiphenylmethane; the halodiphenylmethane is any one of 2-chlorodiphenylmethane, 4-chlorodiphenylmethane, 4,4'-dichlorodiphenylmethane, 2,4'-dichlorodiphenylmethane, 2-fluorodiphenylmethane, 4-fluorodiphenylmethane, 4,4'-difluorodiphenylmethane, and 2,4'-difluorodiphenylmethane.

[0015] Preferably, the oxygen-containing gas is oxygen or air, and the partial pressure of oxygen in the oxygen-containing gas is 0.1-3.0 MPa.

[0016] Advantages of this invention: The catalyst provided by this invention has a simple preparation method and can achieve efficient oxidation of diphenylmethane and halodiphenylmethane containing passivating groups (halogen substituents, which are inert groups) to prepare benzophenone or halodiphenylmethane. The catalyst has high activity, high product selectivity, and the products are easy to separate. The catalyst can be recycled. Detailed Implementation

[0017] Example 1 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, represented as 1K2O·10MnO2, and the atomic ratio of K to Mn in the catalyst is 0.2; The method for preparing the catalyst includes the following steps: (1) Disperse 15.79g of potassium permanganate and 1.12g of potassium hydroxide in 45mL of deionized water, stir evenly, transfer to a reaction vessel, stir and react at 80℃ for 18h, filter the precipitate and wash with deionized water; (2) Dry at 80°C for 12 hours, and calcine at 370°C for 4 hours in air atmosphere to obtain the catalyst.

[0018] Example 2 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, represented as 2K₂O·10MnO₂, and the atomic ratio of K to Mn in the catalyst is 0.4; The method for preparing the catalyst includes the following steps: (1) Disperse 15.79g of potassium permanganate and 5.52g of potassium carbonate in 60mL of deionized water, stir evenly, transfer to a reaction vessel, stir and react at 100℃ for 14h, filter the precipitate and wash with deionized water. (2) Dry at 100°C for 9 hours, and calcine at 450°C for 5 hours in air atmosphere to obtain the catalyst.

[0019] Example 3 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, represented as 6Na2O·10MnO2, and the atomic ratio of Na to Mn in the catalyst is 1.2; The method for preparing the catalyst includes the following steps: (1) Disperse 15.79g of potassium permanganate and 4.82g of sodium hydroxide in 50mL of deionized water, stir evenly, transfer to a reaction vessel, stir and react at 60℃ for 24h, filter the precipitate and wash with deionized water; (2) Dry at 120°C for 6 hours, and calcine at 320°C for 6 hours in air atmosphere to obtain the catalyst.

[0020] Example 4 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, denoted as 4MgO·1MnO2, and the atomic ratio of Mg to Mn in the catalyst is 4; The method for preparing the catalyst includes the following steps: (1) Disperse 1.61g potassium permanganate and 2.31g magnesium hydroxide in 20mL deionized water, stir evenly, transfer to a reaction vessel, stir and react at 20℃ for 24h, filter the precipitate and wash with deionized water; (2) Dry at 90°C for 9 hours, and calcine at 250°C for 6 hours in air atmosphere to obtain the catalyst.

[0021] Example 5 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, denoted as 8CaO·1MnO2, and the atomic ratio of Ca to Mn in the catalyst is 8; The method for preparing the catalyst includes the following steps: (1) Disperse 1.57g of potassium permanganate and 8.01g of calcium carbonate in 30mL of deionized water, stir evenly, transfer to a reaction vessel, stir and react at 160℃ for 4h, filter the precipitate and wash with deionized water. (2) Dry at 80°C for 9 hours, and calcine at 350°C for 4 hours in air atmosphere to obtain the catalyst.

[0022] Example 6 A catalyst for preparing benzophenone compounds, wherein the catalyst is a basic manganese oxide, denoted as 5Li₂O·1MnO₂, and the atomic ratio of Li to Mn in the catalyst is 10; The method for preparing the catalyst includes the following steps: (1) Disperse 1.58g of potassium permanganate and 2.4g of lithium hydroxide in 35mL of deionized water, stir evenly, transfer to a reaction vessel, stir and react at 120℃ for 12h, filter the precipitate and wash with deionized water; (2) Dry at 110°C for 7 hours, and calcine at 450°C for 6 hours in air atmosphere to obtain the catalyst.

[0023] Catalytic performance testing The method for using the catalyst to prepare benzophenone compounds involves mixing the catalyst with a diphenylmethane-based raw material, stirring the mixture at 90-200°C for 8-36 hours under an oxygen-containing gas atmosphere, with or without adding a reaction solvent during the reaction. After the reaction is complete, dichloroethane is added to dissolve the product, the catalyst is recovered by filtration, the filtrate is collected, and the reaction results are analyzed by gas chromatography. The reaction conditions and results are shown in Table 1. Table 1 Reaction conditions and results .

Claims

1. A catalyst for preparing benzophenone compounds, characterized in that: The catalyst is a basic manganese oxide, denoted as aZO. x ·bMnO2, where Z is any one of lithium, potassium, sodium, magnesium, and calcium; x is the number of oxygen atoms required to satisfy the oxidation state of metal element Z; a and b are the number of Z and Mn atoms in the catalyst, respectively, and the ratio of Z to Mn atoms in the catalyst is 0.2-10.

2. The method for preparing the catalyst for preparing benzophenone compounds according to claim 1, characterized in that: Includes the following steps: (1) Potassium permanganate and ZnO x The precursor is dispersed in deionized water or ethanol, stirred evenly, transferred to a reaction vessel and stirred at 20-160℃ for 4-24 hours, filtered, and washed with deionized water or ethanol. (2) Drying, roasting in air atmosphere.

3. The method for preparing the catalyst for preparing benzophenone compounds according to claim 2, characterized in that: The ZO x The precursor is at least one of KOH, K2CO3, KHCO3, NaOH, Na2CO3, NaHCO3, Mg(OH)2, MgCO3, Ca(OH)2, CaCO3, LiOH, and Li2CO3.

4. The method for preparing the catalyst for preparing benzophenone compounds according to claim 2, characterized in that: The drying conditions are 80-120℃ for 6-16 hours; the calcination conditions are calcination at 250-450℃ for 4-6 hours.

5. The method for preparing benzophenone compounds using the catalyst of claim 1, characterized in that: The catalyst is mixed with the raw material diphenylmethane compound and stirred at 90-200°C for 8-36 hours under an oxygen-containing gas atmosphere. After the reaction is completed, a dissolving solvent is added to dissolve the reaction product, the mixture is filtered, the filtrate is collected, and the product is recrystallized.

6. The method for preparing benzophenone compounds according to claim 5, characterized in that: The method also requires the addition of a reaction solvent.

7. The method for preparing benzophenone compounds according to claim 6, characterized in that: The reaction solvent is at least one of cyclohexane, dichloroethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, and sulfolane; the dissolving solvent is any one of dichloroethane, ethanol, acetonitrile, and ethyl acetate.

8. The method for preparing benzophenone compounds according to claim 5 or 6, characterized in that: The mass of the catalyst is 1-25% of the mass of the diphenylmethane compound.

9. The method for preparing benzophenone compounds according to claim 5, characterized in that: The diphenylmethane compound is diphenylmethane or halodiphenylmethane; the halodiphenylmethane is any one of 2-chlorodiphenylmethane, 4-chlorodiphenylmethane, 4,4'-dichlorodiphenylmethane, 2,4'-dichlorodiphenylmethane, 2-fluorodiphenylmethane, 4-fluorodiphenylmethane, 4,4'-difluorodiphenylmethane, and 2,4'-difluorodiphenylmethane.

10. The method for preparing benzophenone compounds according to claim 5, characterized in that: The oxygen-containing gas is oxygen or air, and the partial pressure of oxygen in the oxygen-containing gas is 0.1-3.0 MPa.