CN108218686A - A kind of method that Anderson heteropoly acid catalysis oxidation prepares Pyromellitic Acid - Google Patents

Abstract

The invention discloses a kind of methods that Anderson heteropoly acid catalysis oxidation prepares Pyromellitic Acid.It is as follows：1) after mixing durol, catalyst, additive and solvent, occur oxidation reaction under oxidant effect, oxidizing reaction temperature is 80 130 DEG C, and gauge pressure is 1.0 4.0MPa, the reaction time for 7 for 24 hours；2) after oxidation reaction, removing catalyst is refiltered, extraction agent and water are added in, through organic phase and water phase is obtained by extraction；Organic phase concentrates and purifies to obtain Pyromellitic Acid；The catalyst is in Anderson type heteropoly acids.Reaction condition of the present invention is mildly, using hydrogen peroxide, air or oxygen as oxidant, and environmental-friendly, product yield high, catalyst reaction activity is high, and specificity is good, recycles, easy to operate, suitable for industrialized production.

Description

A kind of method for preparing pyromellitic acid by catalytic oxidation of Anderson heteropoly acid

technical field

The invention belongs to the technical field of catalytic chemistry and relates to the catalysis of polyoxometalates, in particular to a method for preparing pyromellitic acid by catalytic oxidation of Anderson heteropolyacids.

Background technique

Catalysis is the most promising and practical research direction in the application of polyoxometalates (also known as polyacids or polyoxometalates, or POMs for short). Polyoxometallates combine the excellent properties of acid-base catalysts, redox catalysts, and metal oxide nanocatalysts, and are considered to be green multifunctional catalysts with wide applications. As early as the beginning of the 20th century, people began to study the catalytic performance of polyacids.

Pyromellitic acid (1,2,4,5-Benzenetetracarboxylic acid), white crystalline powder, molecular formula C ₁₀ H ₆ O ₈ , molecular weight 254.16, slightly soluble in water, easily soluble in ethanol, slightly soluble in ether, capable of sublimation . Density 1.79 (g/mL, 25/4°C), boiling point 397-400°C (dihydrate), used to prepare polyester, polyamide and polyimide, etc., dehydrated at high temperature to form acid anhydride, acid in air The medium can slowly absorb moisture, making it the main raw material for the production of matting curing agents.

The traditional production method of pyromellitic acid is to prepare pyromellitic acid by heating with potassium bisulfate and sulfuric acid. During the reaction process, high temperature and long-time heating are required, so the quality of the product is poor and the yield is not high. And there will be a variety of side reactions, which make separation difficult.

In addition, in the prior art, the synthesis of pyromellitic acid also includes the following methods;

(1) Prepared by heating benzene hexacarboxylic acid with potassium bisulfate and sulfuric acid (Olah G A, Kuhn S J.Ferricchloride and aluminumchloride catalyzed chlorin ateion of benzenealkylbenzenes and halobenzenes[J].Am.Chem.Soc.,1964, 86(6):1055～1060)

(2) Obtained by catalytic oxidation of naphthalene and its derivatives under the condition of ruthenium salt as a catalyst: Patil R D, Sasson Y. Naphthalenes Oxidation by Aqueous Sodium Hypochlorite Catalyzed by Ruthenium Salts Under Phase-Transfer Catalytic Conditions[J].CatalysisLetters, 2016,146(5):991-997.Patil R D,Sasson Y.Naphthalenes Oxidation by Aqueous Sodium Hypochlorite Catalyzed by Ruthenium Salts Under Phase-Transfer Catalytic Conditions[J].Catalysis Letters,2016,146(5):991-997.Patil R D,Sasson Y.Naphthalenes Oxidation by Aqueous Sodium Hypochlorite Catalyzed by Ruthenium Salts Under Phase-Transfer Catalytic Conditions[J].Catalysis Letters,2016,146(5):991-997.Patil R D,Sasson Y.Naphthalenes Oxidation by Aqueous Sodium Hypochlorite Catalyzed Ruthenium Salts Under Phase-Transfer Catalytic Conditions[J].Catalysis Letters,2016,146(5):991-997.

Obviously, when the above synthesis of 1,2,4,5-benzenetetracarboxylic acid is prepared with mellitic hexacarboxylic acid, potassium hydrogensulfate and sulfuric acid or with naphthalene and its derivatives of naphthalene as raw materials, the reaction process and post-treatment are all cumbersome , all need to produce a large amount of three wastes, which brings pressure to environmental protection and life. And need high temperature, heating for a long time, thereby the quality of product is poor, and productive rate is not high. And there will be a variety of side reactions, which make separation difficult.

Contents of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a catalytic oxidation method for preparing high-quality pyromellitic acid using durene as a raw material and Anderson heteropolyacid as a catalyst. The catalyst used in the invention has high catalytic activity, strong specificity, and can be recycled; the invention adopts a one-pot method, which is easy to operate, environmentally friendly, mild in reaction conditions, low in cost, and high in product yield, and is suitable for industrial production; The obtained product does not contain initiators, especially halogen initiators, and can be used in fields such as medicine and materials.

The inventors have found through research that using durene as a raw material, in the presence of a halogen-free catalyst Anderson type heteropolyacid, high-quality pyromellitic acid can be generated through oxidant oxidation, and the reaction chemical formula is as follows:

The technical solution of the present invention is specifically introduced as follows.

A kind of method for preparing pyromellitic acid by catalytic oxidation of Anderson type heteropolyacid, concrete steps are as follows:

1) After mixing durene, catalyst, additive and solvent, an oxidation reaction occurs under the action of an oxidizing agent. The oxidation reaction temperature is 80-130°C, the gauge pressure is 1.0-4.0MPa, and the reaction time is 7-24h;

2) After the oxidation reaction is finished, remove the catalyst by filtration, add an extraction reagent and water, and obtain an organic phase and an aqueous phase through extraction; the organic phase is concentrated and purified to obtain pyromellitic acid; wherein: the catalyst is selected from the Anderson type represented by the following molecular formula Any of heteropoly acids: (NH ₄ ) ⁿ⁺ [M(OH) ₆ Mo ₆ O ₁₈ ] ^n- , Na ⁿ⁺ [M(OH) ₆ Mo ₆ O ₁₈ ] ^n- , (NH ₄ ) ⁿ⁺ [ MMo ₆ O ₂₄ ] ^n- or Na ⁿ⁺ [MMo ₆ O ₂₄ ] ^n- ; wherein M=V, Cr, Mn, Fe, Co, Ni, Cu, Al, Zn or I; the oxidizing agent is selected from air, oxygen or any of hydrogen peroxide.

In the above step 1), the molar ratio of catalyst to durene is 1:1000˜1:100.

In the above step 1), the molar ratio of catalyst to durene is 1:200-1:100.

In the above step 1), the additive is sodium acetate, sodium formate, sodium carbonate or sodium chloride, and the molar ratio of the additive to durene is 1:100˜1:10.

Above-mentioned step 1) in, solvent is selected from one or more in acetic acid, acetonitrile, dimethyl succinate, diethyl succinate or diethyl malonate; The volume mass ratio of solvent and durene 1:1～40:1mL/g.

In the above step 1), when the oxidizing agent is hydrogen peroxide, a 30wt% hydrogen peroxide solution is used; the molar ratio of hydrogen peroxide to durene is 4:1˜8:1.

In the above step 1), the oxidation reaction temperature is 90-120° C., the gauge pressure is 1.0-3.0 MPa, and the reaction time is 8-15 hours. When the gauge pressure is 0, it is normal pressure.

In the above step 1), the oxidation reaction temperature is 100-110° C., the gauge pressure is 1.0-2.0 MPa, and the reaction time is 8-12 hours.

In the above step 2), the extraction reagent is selected from any one of ether, ethyl acetate or dichloromethane.

In the above step 2), column chromatography is used for purification.

Compared with the prior art, the beneficial effects of the present invention are:

1. In the oxidation reaction stage, the Anderson type heteropolyacid catalyst is selected to avoid the use of initiators, especially the use of halogen initiators, so that the final pyromellitic acid product does not contain peroxide and has high quality. Can be used in materials and other fields;

2. When the oxidation reaction uses hydrogen peroxide as the oxidant, the product is only water and no other pollutants, which is economical, environmentally friendly, green and efficient; the oxidant uses clean energy such as air and oxygen, which is green and environmentally friendly. low cost.

3. The catalyst is convenient to recycle, and after the reclaimed catalyst once, the yield of pyromellitic acid generated by catalysis is 91% (as in Example 5);

4. The present invention has mild reaction conditions, high product yield, easy operation and is suitable for industrial production.

Description of drawings

Figure 1 shows [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O, [NH ₄ ] 4 [CuMo ₆ O ₁₈ (OH) ₆ ] in Examples 1, 2, 3, ₄ , and 5 5H ₂ O, [NH ₄ ] ₃ [MnMo ₆ O ₁₈ (OH) ₆ ] 7H ₂ O and [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ] 7H ₂ O polyoxometalates Structure diagram.

Fig. 2 is the infrared spectrum of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Examples 1 and 2.

Fig. 3 is the infrared spectrum of [NH ₄ ] ₄ [CuMo ₆ O ₁₈ (OH) ₆ ]·5H ₂ O polyoxometalates in Example 3.

Fig. 4 is the infrared spectrum of [NH ₄ ] ₃ [MnMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate in Example 4.

Fig. 5 is the infrared spectrum of [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate in Example 5.

Fig. 6 is an infrared spectrum of [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate recovered once in Example 5.

Detailed ways

The content of the present invention is further explained or illustrated through specific embodiments below, but the embodiments should not be construed as limiting the protection scope of the present invention.

Example 1

1.3422g (0.01mol) of durene, 0.1201g (0.0001mol) of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates, 0.0106g (0.0001mol) of Sodium carbonate and 6 mL of solvent acetic acid were put into a dry reaction test tube. After the temperature was raised to 100° C., the reaction was carried out in the air. After the reaction was kept at a pressure (gauge pressure) of 1.0 MPa for 12 hours, the reaction was stopped. The reaction system was extracted 3 times with ethyl acetate, the solvent was removed from the obtained product under reduced pressure, and pyromellitic acid was obtained by column chromatography. The obtained product was subjected to LC-MS to obtain 2.3635 g of the product, with a yield of 93%. FIG. 1 is a diagram showing the structure of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Example 1. Fig. 2 is the infrared spectrum of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Example 1.

Example 2

1.3422g (0.01mol) of durene, 0.1201g (0.0001mol) of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates, 0.0106g (0.0001mol) of Put sodium carbonate and 10mL of solvent dimethyl succinate into a polytetrafluoroethylene-lined hydrothermal reaction kettle, pay attention, check whether the equipment is damaged before use, and add solvent and raw materials to the hydrothermal reaction kettle container , after stirring and dissolving, blow nitrogen into the container for a period of time to make the system in an inert atmosphere. Tighten the lid of the hydrothermal reaction kettle in use, then add the catalyst and place it in the oven. After the temperature rises to 100°C, connect the oxygen tank to make The pressure (gauge pressure) is about 1.0 MPa, and after 12 hours of heat preservation reaction, stop the reaction. After the kettle body is naturally cooled to room temperature, the lid of the kettle is opened, and the reaction system is extracted 3 times with ethyl acetate. The obtained product is decompressed to remove the solvent, separated by column chromatography to obtain pyromellitic acid, and the obtained product is subjected to LC-MS to obtain the product 2.3127g, the yield is 91%. FIG. 1 is a diagram showing the structure of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Example 1. Fig. 2 is the infrared spectrum of [NH ₄ ] ₃ [FeMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate in Example 2.

Example 3

1.3422g (0.01mol) of durene, 0.1191g (0.0001mol) of [NH ₄ ] ₄ [CuMo ₆ O ₁₈ (OH) ₆ ]·5H ₂ O polyoxometalate catalyst, 0.0136g (0.0001mol) sodium acetate, 0.05mol of 30wt% hydrogen peroxide and 6ml of solvent acetic acid were put into a dry and clean pressure-resistant tube, and after the temperature was raised to 100°C, the pressure (gauge pressure) was 1.0MPa and the reaction was incubated for 12 hours. The reaction was stopped, and the reaction system was extracted 3 times with ethyl acetate. The obtained product was decompressed to remove the solvent, separated by column chromatography to obtain pyromellitic acid, and the obtained product was subjected to LC-MS to obtain 2.2112 g of the product, with a yield of 87%. . FIG. 1 is a diagram showing the structure of [NH ₄ ] ₄ [CuMo ₆ O ₁₈ (OH) ₆ ]·5H ₂ O polyoxometalates in Example 3. Fig. 3 is the infrared spectrum of [NH ₄ ] ₄ [CuMo ₆ O ₁₈ (OH) ₆ ]·5H ₂ O polyoxometalates in Example 3.

Example 4

1.3422g (0.01mol) of durene, 0.1200g (0.0001mol) of [NH ₄ ] ₃ [MnMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate catalyst, 0.0136g (0.0001mol) ) sodium acetate additive, and 8mL of solvent acetonitrile were put into a dry reaction test tube. After the temperature was raised to 100°C, they were reacted in the air. Esters were extracted from the reaction system for 3 times, the solvent was removed from the obtained product under reduced pressure, and pyromellitic acid was separated by column chromatography to obtain 2.4652 g of the product with a yield of 97%. FIG. 1 is a diagram showing the structure of [NH ₄ ] ₃ [MnMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Example 4. Fig. 4 is the infrared spectrum of [NH ₄ ] ₃ [MnMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates in Example 4.

Example 5

1.3422g (0.01mol) of durene, 0.1197g (0.0001mol) of Anderson polyoxometalate [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O, 0.0106g (0.0001 mol) of sodium carbonate additive, and solvent acetonitrile of 3mL are put into the hydrothermal reaction kettle lined with polytetrafluoroethylene, note, before use, check whether the equipment is damaged, add solvent and raw materials in the hydrothermal reaction kettle container, After stirring and dissolving, blow nitrogen into the container for a period of time to make the system in an inert atmosphere. Tighten the lid of the hydrothermal reaction kettle in use, then add the catalyst and place it in the oven. After the temperature rises to 100°C, connect the oxygen tank to make the pressure (gauge pressure) is about 1.0MPa, after 12 hours of heat preservation reaction, stop the reaction. After the still body was naturally cooled to room temperature and the lid was opened, the reaction system was extracted 3 times with ethyl acetate, and the obtained product was decompressed to remove the solvent, separated by column chromatography to obtain trimellitic acid, and 2.3890 g of the product was obtained, with a yield of 94 %. The reaction system was extracted with ethyl acetate and deionized water, extracted 3 times to take the water phase, heated the water phase at 80°C for a period of time, filtered while it was hot, cooled to crystallize, dried, put into the above reaction, and the obtained pyromellitic acid was 2.3127g. The rate is 91%. Fig. 1 is a structural diagram of the [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate catalyst in Example 5. Fig. 5 is the infrared spectrum of [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalate in Example 5. Fig. 6 is the infrared spectrogram of [NH ₄ ] ₃ [CrMo ₆ O ₁₈ (OH) ₆ ]·7H ₂ O polyoxometalates recovered once in Example 5

Similar embodiments also have the following, which are simply presented in Table 1 here:

Table 1

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or modify the equivalent of equivalent changes. Example. But all without departing from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention, and each reference used in this application, It is hereby incorporated by reference in its entirety.

Claims (10)

1. a kind of Anderson heteropolyacid catalytic oxidation prepares the method for pyromellitic acid, it is characterized in that, concrete steps are as follows: 1) After mixing durene, catalyst, additive and solvent, an oxidation reaction occurs under the action of an oxidizing agent. The oxidation reaction temperature is 80-130°C, the gauge pressure is 1.0-4.0MPa, and the reaction time is 7-24h; 2) After the oxidation reaction is finished, remove the catalyst by filtration, add an extraction reagent and water, and obtain an organic phase and an aqueous phase through extraction; the organic phase is concentrated and purified to obtain pyromellitic acid; wherein: the catalyst is selected from the Anderson type represented by the following molecular formula Any of heteropoly acids: (NH ₄ ) ⁿ⁺ [M(OH) ₆ Mo ₆ O ₁₈ ] ^n- , Na ⁿ⁺ [M(OH) ₆ Mo ₆ O ₁₈ ] ^n- , (NH ₄ ) ⁿ⁺ [ MMo ₆ O ₂₄ ] ^n- or Na ⁿ⁺ [MMo ₆ O ₂₄ ] ^n- ; wherein M=V, Cr, Mn, Fe, Co, Ni, Cu, Al, Zn or I; the oxidizing agent is selected from air, oxygen or any of hydrogen peroxide. 2. The method according to claim 1, characterized in that, in step 1), the molar ratio of catalyst to durene is 1:1000˜1:100. 3. The method according to claim 1 or 2, characterized in that, in step 1), the molar ratio of catalyst to durene is 1:200˜1:100. 4. The method according to claim 1, characterized in that, in step 1), the additive is sodium acetate, sodium formate, sodium carbonate or sodium chloride, and the mol ratio of the additive to durene is 1:100～1:10 . 5. The method according to claim 1, characterized in that, in step 1), the solvent is selected from one of acetonitrile, acetic acid, dimethyl succinate, diethyl succinate or diethyl malonate One or several kinds; the volume-mass ratio of solvent and durene is 1:1-40:1mL/g. 6. method according to claim 1, it is characterized in that, in step 1), when oxygenant is hydrogen peroxide, adopt 30wt% hydrogen peroxide solution; The mol ratio of hydrogen peroxide and durene is 4:1～8: 1. 7. The method according to claim 1, characterized in that, in step 1), the oxidation reaction temperature is 90-120°C, the gauge pressure is 1.0-3.0MPa, and the reaction time is 8-15h. 8. The method according to claim 1 or 7, characterized in that, in step 1), the oxidation reaction temperature is 100-110° C., the gauge pressure is 1.0-2.0 MPa, and the reaction time is 8-12 hours. 9. The method according to claim 1, characterized in that, in step 2), the extraction reagent is selected from any one in ether, ethyl acetate or dichloromethane. 10. The method according to claim 1, characterized in that, in step 2), column chromatography is used for purification.