Bipyridine coordinated catalyst, preparation method, composite catalyst and application

Abstract

The invention discloses a bipyridine coordinated catalyst, a preparation method, a composite catalyst and application. The general formula of the bipyridine coordinated catalyst is # imgabs0 # B, and the bipyridine coordinated catalyst is lithium ions, sodium ions, cesium ions, magnesium ions, strontium ions, ammonium ions, hexadecyl tetramethyl benzyl ammonium ions, octadecyl tetramethyl ammonium ions, octadecyl hexamethyl ammonium ions, dodecyl dibutyl phosphonium ions, tetradecyl propyl phosphonium ions, butyl phosphonium ions and tributyl ethyl phosphonium ions. The ionic liquid is a tetrabutyl phosphonium ion, a tributyl hexyl phosphonium ion, a trimethyl ammonium ion, a tetrapropyl ammonium ion, a tributyl ethyl ammonium ion, a benzyl dimethyl ammonium ion or a benzyl dimethyl phosphonium ion; m is Mn, Fe, Cu, Cd, Zr, Sn, Pb, Ni, Mo, V, Cr or Co; r is selected from C1-C14 alkyl groups; x is an integer between 1 and 18; and y is an integer between 1 and 36. The catalyst provided by the invention can improve the selectivity of nicotinic acid oxidation reaction and has strong reaction activity.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemistry, and in particular relates to a bipyridine coordinated catalyst, a preparation method, a composite catalyst and applications. Background Art

[0002] Nicotinic acid, also known as nicotinic acid, belongs to the vitamin B family and is the vitamin with the simplest structure and the most stable physical and chemical properties. Nicotinic acid is an important chemical raw material and is widely used in daily chemicals, video, medicine and other fields. In the field of medicine, niacin can be used as an intermediate to synthesize a variety of drugs. Nicotinic acid itself can also treat skin diseases and vitamin deficiency. In terms of food, niacin is an indispensable nutrient for animals and humans. It is one of the substances that make up enzymes and can also be used as a preservative for food. In addition, niacin can also be used as an electroplating additive, dye intermediate, etc.

[0003] The traditional synthesis method of nicotinic acid is mainly to directly oxidize 3-methylpyridine in the presence of potassium permanganate or nitric acid in the presence of a catalyst. Although this method has a high yield, it is highly restricted in large-scale industrial production due to its high cost and serious pollution. Nicotinic acid can also be obtained by electrolytic oxidation of nicotine with lead dioxide. This method has the advantages of mild conditions and low production cost, but due to the poor permselectivity of the isolation membrane used in the electrolytic cell, its electrolysis efficiency is limited, so it is difficult to be used as a mainstream industrial production method.

[0004] Therefore, in view of the above technical problems, it is necessary to provide a catalyst that can effectively promote the oxidation of 3-methylpyridine to prepare nicotinic acid.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a bipyridine coordinated catalyst, a preparation method, a composite catalyst and application, wherein the bipyridine coordinated catalyst is provided.

[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:

[0008] A bipyridine coordinated catalyst, the general formula of which is shown in formula (I):

[0009]

[0010] Wherein, B is a lithium ion, a sodium ion, a cesium ion, a magnesium ion, a strontium ion, an ammonium ion, a hexadecyltetramethylbenzylammonium ion, an octadecyltetramethylammonium ion, an octadecylhexamethylammonium ion, a dodecyldibutylphosphonium ion, a tetradecylpropylphosphonium ion, a butylphosphonium ion, a tributylethylphosphonium ion, a tetrabutylphosphonium ion, a tributylhexylphosphonium ion, a trimethylammonium ion, a tetrapropylammonium ion, a tributylethylammonium ion, a benzyldimethylammonium ion or a benzyldimethylphosphonium ion;

[0011] M is selected from Mn, Fe, Cu, Cd, Zr, Sn, Pb, Ni, Mo, V, Cr or Co;

[0012] R is selected from C1-C 14 alkyl;

[0013] x is selected from an integer between 1 and 18;

[0014] y is an integer selected from 1 to 36.

[0015] Another specific embodiment of the present invention provides a technical solution as follows:

[0016] A method for preparing a bipyridine coordinated catalyst comprises the following steps:

[0017] Add deionized water to the metal compound, adjust the pH of the solution to 1-4 after dissolution, and then add peroxide to obtain a metal peroxide solution;

[0018] Alkyl-substituted bipyridine and salt are added to the metal peroxide solution, stirred, centrifuged, filtered and dried to obtain a bipyridine-coordinated catalyst having the general formula shown in formula (I).

[0019] In one or more embodiments of the present invention, the metal compound is selected from sodium manganate, cobalt nitrate, manganese nitrate nonahydrate, copper nitrate, cobalt sulfate, nickel nitrate nonahydrate, chromium sulfate, chromium nitrate and sodium metachromate.

[0020] In one or more embodiments of the present invention, the alkyl-substituted bipyridine is selected from 3-ethyl-bipyridine, 3-propyl-bipyridine, 3-isopropyl-bipyridine, 3-n-butyl-bipyridine, 3-tert-butyl-bipyridine and 3-isobutyl-bipyridine.

[0021] In one or more embodiments of the present invention, the salt is selected from tetradecyldimethylammonium chloride, tetradecyldimethylammonium bromide, cesium chloride, sodium chloride, aluminum chloride, magnesium chloride, calcium chloride, ammonium bromide, magnesium acetate, ammonium acetate, tetradecyldimethylbenzylammonium bromide, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, hexadecyldimethylammonium chloride, hexadecyldimethylbenzylammonium bromide, octyldibutylphosphonium bromide, hexabutylphosphonium bromide, amyldibutylphosphonium bromide, tributylmethylphosphonium bromide, tetrabutylphosphonium bromide, tributylpropylphosphonium bromide, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride and benzyltripropylammonium chloride.

[0022] Another specific embodiment of the present invention provides a technical solution as follows:

[0023] A composite catalyst comprises the above-mentioned bipyridine coordinated catalyst.

[0024] In one or more embodiments of the present invention, a cocatalyst is further included, and the weight ratio of the bipyridine-coordinated catalyst to the cocatalyst is 100:(1-500);

[0025] The auxiliary catalyst is selected from manganese nitrate, manganese acetate, zirconium acetate, ferric nitrate, copper sulfate, magnesium sulfate, magnesium acetate, manganese sulfate and sodium molybdate.

[0026] In one or more embodiments of the present invention, a regulator is further included, and the weight ratio of the bipyridine-coordinated catalyst to the regulator is 100:(1-500);

[0027] The regulator is selected from molybdic acid, phosphotungstic acid, tetrapropyl sodium bromide, boric acid, silicomolybdic acid, copper nitrate and phosphotungstic vanadic acid.

[0028] In one or more embodiments of the present invention, a protective agent is further included, and the weight ratio of the bipyridine-coordinated catalyst to the protective agent is 100:(1-500);

[0029] The protective agent is selected from potassium acetate, sodium bromide, ammonium bromide, tetradecyl dimethyl ammonium bromide, phenyl dimethyl sodium bromide, phenyl dimethyl ammonium bromide, potassium molybdate and N-hydroxyphthalimide.

[0030] In one or more embodiments of the present invention, a solvent is further included, and the weight ratio of the bipyridine-coordinated catalyst to the solvent is 100:(20-10000);

[0031] The solvent is selected from the group consisting of dichloroethane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, 1,4-dioxane and ethyl acetate.

[0032] Another specific embodiment of the present invention provides a technical solution as follows:

[0033] A method for preparing a composite catalyst comprises the following steps:

[0034] Prepare a bipyridine-coordinated catalyst, a cocatalyst, a regulator, a protective agent and a solvent represented by formula (I);

[0035] Add the protective agent to the solvent and mix well to obtain a solution;

[0036] Add the bipyridine coordinated catalyst represented by formula (I) to the solution, and stir at 20 to 120° C. for 10 to 40 minutes;

[0037] Then add the auxiliary catalyst and ultrasonicate at 20-120°C for 20-40 minutes;

[0038] Then add a regulator, stir at 20-120°C for 20-40 minutes to obtain a composite catalyst;

[0039] Wherein, the auxiliary catalyst is selected from manganese nitrate, manganese acetate, zirconium acetate, iron nitrate, copper sulfate, magnesium sulfate, magnesium acetate, manganese sulfate and sodium molybdate;

[0040] The regulator is selected from molybdic acid, phosphotungstic acid, tetrapropyl sodium bromide, boric acid, silicomolybdic acid, copper nitrate and phosphotungstic vanadic acid;

[0041] The protective agent is selected from potassium acetate, sodium bromide, ammonium bromide, tetradecyl dimethyl ammonium bromide, phenyl dimethyl sodium bromide, potassium molybdate and N-hydroxyphthalimide;

[0042] The solvent is selected from the group consisting of dichloroethane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, 1,4-dioxane and ethyl acetate.

[0043] Another specific embodiment of the present invention provides a technical solution as follows:

[0044] An application of the bipyridine coordinated catalyst or the composite catalyst in the reaction of oxidizing 3-methylpyridine to prepare nicotinic acid.

[0045] Compared with the prior art, the bipyridine coordinated catalyst of the present invention can make the selectivity of the nicotinic acid oxidation reaction very high, increase the reaction activity, and can be applied multiple times, with a high utilization rate. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] A specific embodiment of the present invention provides a bipyridine coordinated catalyst, the general formula of which is shown in formula (I):

[0048]

[0049] Wherein, B is lithium ion, sodium ion, cesium ion, magnesium ion, strontium ion, ammonium ion, hexadecyltetramethylbenzylammonium ion, octadecyltetramethylammonium ion, octadecylhexamethylammonium ion, dodecyldibutylphosphonium ion, tetradecylpropylphosphonium ion, butylphosphonium ion, tributylethylphosphonium ion, tetrabutylphosphonium ion, tributylhexylphosphonium ion, trimethylammonium ion, tetrapropylammonium ion, tributylethylammonium ion, benzyldimethylammonium ion or benzyldimethylphosphonium ion; M is selected from Mn, Fe, Cu, Cd, Zr, Sn, Pb, Ni, Mo, V, Cr or Co; R is selected from Cl-C 14 alkyl; x is selected from an integer between 1 and 18; y is selected from an integer between 1 and 36.

[0050] Specifically, bipyridine can be used as a catalyst for oxidation reactions. The present invention selects the above-mentioned types of M and B to form a bipyridine-coordinated metal peroxide catalyst, which can catalyze the oxidation of 3-methylpyridine to produce nicotinic acid with high selectivity and high reaction activity.

[0051] Preferably, B is selected from octadecyltetramethylammonium ion, octadecylhexamethylammonium ion, dodecyldibutylphosphonium ion, lithium ion, sodium ion, cesium ion; M is Fe, Cu, Cd, Zr, Sn, Pb or Co, R is selected from C1-C5 alkyl, x is selected from an integer between 1 and 5, and y is selected from an integer between 1 and 5.

[0052] Preferably, B is selected from ammonium ion, lithium ion, sodium ion, dodecyldibutylphosphonium ion, tetradecylpropylphosphonium ion, M is Fe, Cu, Cd, Zr, Sn, Pb or Co, R is selected from C1-C3 alkyl, x is 1, and y is 1 or 2.

[0053] Specifically, the bipyridine coordinated catalyst is:

[0054]

[0055] Another specific embodiment of the present invention provides a method for preparing a bipyridine coordinated catalyst, comprising steps 1-2.

[0056] Step 1, add deionized water to the metal compound, adjust the solution pH to 1-4 after dissolution, and then add peroxide to obtain a metal peroxide solution.

[0057] Specifically, in step 1, the solution temperature when the peroxide is added is 30°C, the reagent used to adjust the pH of the solution is hydrochloric acid or sulfuric acid, the concentration of dilute hydrochloric acid is 2 mol / L, and the concentration of dilute sulfuric acid is 2 mol / L. The metal compound is selected from sodium manganate, cobalt nitrate, manganese nitrate nonahydrate, copper nitrate, cobalt sulfate, nickel nitrate nonahydrate, chromium sulfate, chromium nitrate and sodium metachromate, and the peroxide is selected from hydrogen peroxide and urea peroxide, and the concentration of hydrogen peroxide is 30%.

[0058] Step 2, adding alkyl-substituted bipyridine and salt to the metal peroxide solution, filtering and drying, to obtain a bipyridine-coordinated catalyst having a general formula as shown in formula (I).

[0059] Specifically, in step 2, the alkyl-substituted bipyridine is selected from 3-ethyl-bipyridine, 3-propyl-bipyridine, 3-isopropyl-bipyridine, 3-n-butyl-bipyridine, 3-tert-butyl-bipyridine and 3-isobutyl-bipyridine. The salt is selected from the group consisting of tetradecyldimethylammonium chloride, tetradecyldimethylammonium bromide, cesium chloride, sodium chloride, aluminum chloride, magnesium chloride, calcium chloride, ammonium bromide, magnesium acetate, ammonium acetate, tetradecyldimethylbenzylammonium bromide, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, hexadecyldimethylammonium chloride, hexadecyldimethylbenzylammonium bromide, octyldibutylphosphonium bromide, hexabutylphosphonium bromide, amyldibutylphosphonium bromide, tributylmethylphosphonium bromide, tetrabutylphosphonium bromide, tributylpropylphosphonium bromide, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride and benzyltripropylammonium chloride.

[0060] Another specific embodiment of the present invention provides a composite catalyst, including a bipyridine-coordinated catalyst shown in formula (I).

[0061] Furthermore, the composite catalyst also includes a cocatalyst, a regulator, a protective agent and a solvent, and the weight ratio of the bipyridine-coordinated catalyst, the cocatalyst, the regulator, the protective agent and the solvent is 100: (1-500): (1-500): (1-500): (50-10000). By limiting the ratio of each raw material, the composite catalyst is conducive to better exerting the catalytic effect.

[0062] Specifically, the cocatalyst is selected from manganese nitrate, manganese acetate, zirconium acetate, ferric nitrate, copper sulfate, magnesium sulfate, magnesium acetate, manganese sulfate and sodium molybdate. The above cocatalysts are helpful to improve the selectivity, stability and activity of the bipyridine coordinated catalyst, and are helpful for the reaction.

[0063] The regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrapropylammonium bromide, boric acid, silicomolybdic acid, copper nitrate and phosphotungstic vanadic acid. The above regulators can promote the oxidation reaction, adjust the catalytic activity of the catalyst, and enhance the stability of the catalyst.

[0064] The protective agent is selected from potassium acetate, sodium bromide, ammonium bromide, tetradecyl dimethyl ammonium bromide, phenyl dimethyl sodium bromide, phenyl dimethyl ammonium bromide, sodium tungstate and N-hydroxyphthalimide. Selecting the above types of protective agents helps to stabilize the reaction environment and reduce the occurrence of excessive oxidation or other side reactions.

[0065] The solvent is selected from the group consisting of dichloroethane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, 1,4-dioxane and ethyl acetate.

[0066] Preferably, in the composite catalyst, the bipyridine-coordinated catalyst shown in formula (I), the cocatalyst, the regulator, the protective agent and the solvent are coordinated in a weight ratio of 100: (1-40): (20-100): (20-40): (200-1000), the bipyridine-coordinated catalyst shown in formula (I) is selected from a catalyst centered on Cr, Mo, V, Co or Zr, the cocatalyst is selected from manganese acetate, zirconium acetate, copper acetate and iron acetate, the regulator is selected from phosphomolybdic acid and silicomolybdic acid, the protective agent is selected from potassium bromide, tetradecyldimethylammonium bromide, phenyldimethyl sodium bromide and N-hydroxyphthalimide, and the solvent is selected from methanol, ethanol and acetonitrile.

[0067] Another specific embodiment of the present invention provides a method for preparing a composite catalyst, which specifically includes steps 1-5.

[0068] Step 1, preparing a bipyridine-coordinated catalyst, a co-catalyst, a regulator, a protective agent and a solvent as shown in formula (I).

[0069] Step 2, adding the protective agent into the solvent, mixing well, and obtaining a solution.

[0070] Step 3, adding a bipyridine-coordinated catalyst represented by formula (I) to the solution, and stirring at 20 to 120° C. for 10 to 40 minutes;

[0071] Step 4, adding a co-catalyst and ultrasonicating at 20-120° C. for 20-40 min;

[0072] Step 5, adding a regulator, stirring at 20-120° C. for 20-40 minutes to obtain a composite catalyst.

[0073] Specifically, by limiting the temperature and time, a composite catalyst with stable performance can be obtained.

[0074] Another specific embodiment of the present invention provides the use of a bipyridine-coordinated catalyst or the above-mentioned composite catalyst in the reaction of oxidizing 3-methylpyridine to prepare nicotinic acid.

[0075] Specifically, the specific application method is: dissolve 3-methylpyridine in 10 times the solvent, add 0.01% to 2% of the weight of the composite catalyst to it, pass air at a speed of 1 to 10 mL / s, and stir the reaction at 30 to 150° C. for 1 to 8 hours.

[0076] Preferably, the reaction temperature is 100-180° C., the reaction time is 4-8 h, the air introduction rate is 1-5 mL / s, and the amount of the composite catalyst is 0.5%-1% of the weight of 3-methylpyridine.

[0077] The present invention is further described in detail below in conjunction with specific embodiments.

[0078] Bipyridine-coordinated catalyst examples

[0079] Example 1

[0080] Add 500 mL of deionized water to solid chromium nitrate (17.70 g, 0.1 mol) at room temperature. After the solid is completely dissolved, solution a is obtained. Dilute sulfuric acid is added dropwise to solution a until the pH of the solution is 2 to obtain solution b. After stirring for about 120 min, 100 mL of 30% hydrogen peroxide solution is slowly added to solution b to obtain solution c. Deionized water is added to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0081] Heat solution d to 25°C, add 3-isopropyl bipyridyl (20.10 g, 0.1 mol) and hexadecyl dimethyl ammonium chloride (71.17 g, 0.22 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 30 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 61.23 g of solid, which is the bipyridyl-coordinated catalyst YG-31-1-001, and the catalyst yield reaches 87.31%. The NMR characterization data are as follows:

[0082] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0083] Example 2

[0084] Add 500 mL of deionized water to solid chromium nitrate (17.70 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 120 min, then slowly add 100 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0085] Heat solution d to 25°C, add 3-isopropyl bipyridyl (20.10 g, 0.1 mol) and sodium chloride (12.86 g, 0.22 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 10 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 23.69 g of yellow solid, which is the bipyridyl-coordinated catalyst YG-31-1-002, and the catalyst yield reaches 85.48%. NMR characterization data are as follows:

[0086] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0087] Example 3

[0088] Add 1000 mL of deionized water to solid chromium nitrate (17.70 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute hydrochloric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 100 min, then slowly add 100 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0089] Heat solution d to 50°C, add 3-isopropyl bipyridyl (20.10 g, 0.1 mol) and magnesium acetate (14.24 g, 0.1 mol) to solution d, stir while heating for about 1 hour, and centrifuge for 30 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 70.31 g of solid. The yellow solid is the bipyridyl-coordinated catalyst YG-31-1-003, and the catalyst yield reaches 90.14%. The NMR characterization data are as follows:

[0090] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0091] Example 4

[0092] Add 1000 mL of deionized water to solid chromium nitrate (17.70 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute hydrochloric acid dropwise to solution a until the pH of the solution is 3 to obtain solution b. Continue stirring for about 5 minutes, then slowly add 100 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0093] Heat solution d to 120°C, add 3-isopropyl bipyridyl (20.10 g, 0.1 mol) and ammonium acetate (9.25 g, 0.12 mol) to solution d, stir while heating for about 2 hours, and centrifuge for 5 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 36.89 g of solid, which is the bipyridyl-coordinated catalyst YG-31-1-004, and the catalyst yield reaches 93.15%. The NMR characterization data are as follows:

[0094] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0095] Example 5

[0096] Add 1000 mL of deionized water to solid manganese nitrate (17.89 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute nitric acid dropwise to solution a until the pH of the solution is 3 to obtain solution b. Continue stirring for about 30 minutes, then slowly add 100 mL of 30% hydrogen peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0097] Heat solution d to 80°C, add 3-ethylbipyridyl (19.95g, 0.1mol) and hexadecyldimethylammonium chloride (39.06g, 0.22mol) to solution d, stir while heating for about 1h, and centrifuge for 30min. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 56.93g of solid, which is the bipyridyl-coordinated catalyst YG-31-1-005, and the catalyst yield reaches 86.28%. NMR characterization data are as follows:

[0098] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0099] Example 6

[0100] Add 1000 mL of deionized water to solid manganese nitrate (17.89 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 20 minutes, then slowly add 100 mL of 30% m-chloroperbenzoic acid solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0101] Heat solution d to 100°C, add 3-ethylbipyridyl (19.95 g, 0.1 mol) and sodium chloride (7.01 g, 0.12 mol) to solution d, stir while heating for about 5 hours, and centrifuge for 20 minutes. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 32.69 g of solid, which is the bipyridyl-coordinated catalyst YG-31-1-006, and the catalyst yield reaches 91.48%. NMR characterization data are as follows:

[0102] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0103] Example 7

[0104] Add 1000 mL of deionized water to solid manganese nitrate (17.89 g, 0.1 mol) at room temperature, and after the solid is completely dissolved, obtain solution a. Add dilute sulfuric acid dropwise to solution a until the pH of the solution is 2 to obtain solution b. Continue stirring for about 20 minutes, then slowly add 100 mL of 30% urea peroxide solution to solution b to obtain solution c. Add deionized water to solution c until the total liquid volume is 3000 mL to obtain solution d.

[0105] Heat solution d to 50°C, add 3-ethylbipyridyl (19.95g, 0.1mol) and magnesium acetate (8.54g, 0.06mol) to solution d, stir while heating for about 2h, and centrifuge for 20min. Filter, and place the solid obtained after filtration in a vacuum drying oven to dry to obtain 59.71g of solid, which is the bipyridyl-coordinated catalyst YG-31-1-007, and the catalyst yield reaches 86.15%. NMR characterization data are as follows:

[0106] 1H NMRδ: 9.05 (s, 1H), 8.83 (d, J=8.0Hz, 1H), 8.76 (d, J=5.6Hz, 1H), 8.01 (m, 1H); IRν: 3437, 1710, 1595, 1417, 748cm-1.

[0107] Composite catalyst embodiment

[0108] Example 8

[0109] The preparation method of the composite catalyst is as follows:

[0110] Step (1): adding 20.0 g of ethanol to 10.0 g of N-hydroxyphthalimide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0111] Step (2): add 1.0 g of bipyridine-coordinated catalyst YG-31-1-001 to the mixed solution of step (1), and heat at 100° C. with stirring for 40 min to obtain a mixture B;

[0112] Step (3): adding 0.1 g of manganese acetate to the mixture B formed in step (2) to obtain a mixture C;

[0113] Step (4): Add 0.1 g of copper nitrate to the mixture C formed in step (3), and stir at 120° C. for 100 minutes to obtain a total of 31.2 g of composite catalyst 1.

[0114] Example 9

[0115] The preparation method of the composite catalyst is as follows:

[0116] Step (1): add 20.0 g of ethanol to 10.0 g of sodium bromide, and stir at room temperature until the solid is completely dissolved to obtain a mixture A;

[0117] Step (2): add 1.0 g of bipyridine-coordinated catalyst YG-31-1-002 to the mixed solution of step (1), and heat at 80° C. with stirring for 30 min to obtain a mixture B;

[0118] Step (3): adding 0.1 g of manganese acetate to the mixture B formed in step (2) to obtain a mixture C;

[0119] Step (4): Add 0.1 g of copper nitrate to the mixture C formed in step (3), stir at 120° C. for 60 minutes, and obtain a total of 31.2 g of composite catalyst 2.

[0120] Example 10

[0121] The preparation method of the composite catalyst is as follows:

[0122] Step (1): add 20.0 g of methanol to 10.0 g of tetradecyl dimethyl ammonium bromide, and stir at room temperature until the solid is completely dissolved to obtain a mixture A;

[0123] Step (2): Add 1.0 g of bipyridine-coordinated catalyst YG-31-1-003 to the mixed solution of step (1), and heat at 100° C. with stirring for 80 min to obtain a mixture B;

[0124] Step (3): adding 0.1 g of manganese acetate to the mixture B formed in step (2) to obtain a mixture C;

[0125] Step (4): Add 0.1 g of copper nitrate to the mixture C formed in step (3), stir at 120° C. for 60 minutes, and obtain a total of 31.2 g of composite catalyst 3.

[0126] Embodiment 11

[0127] The preparation method of the composite catalyst is as follows:

[0128] Step (1): add 20.0 g of ethanol to 10.0 g of phenyldimethyl sodium bromide, and stir at room temperature until the solid is completely dissolved to obtain a mixture A;

[0129] Step (2): add 1.0 g of bipyridine-coordinated catalyst YG-31-1-004 to the mixed solution of step (1), and heat at 60° C. with stirring for 100 min to obtain a mixture B;

[0130] Step (3): adding 0.1 g of manganese acetate to the mixture B formed in step (2) to obtain a mixture C;

[0131] Step (4): Add 0.1 g of copper nitrate to the mixture C formed in step (3), and stir at 100° C. for 60 minutes to obtain a total of 31.2 g of composite catalyst 4.

[0132] Example 12

[0133] The preparation method of the composite catalyst is as follows:

[0134] Step (1): adding 30.0 g of methanol to a solid mixture of 5.0 g of sodium bromide and 5.0 g of tetradecyl dimethyl ammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0135] Step (2): add 1.0 g of bipyridine-coordinated catalyst YG-31-1-005 to the mixed solution of step (1), and heat at 120° C. with stirring for 80 min to obtain a mixture B;

[0136] Step (3): adding 0.1 g of zirconium acetate to the mixture B formed in step (2) to obtain a mixture C;

[0137] Step (4): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (3), and stir at 120° C. for 100 minutes to obtain a total of 41.2 g of composite catalyst 5.

[0138] Embodiment 13

[0139] The preparation method of the composite catalyst is as follows:

[0140] Step (1): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of tetradecyldimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0141] Step (2): Add 1.0 g of bipyridine-coordinated catalyst YG-31-1-006 to the mixed solution of step (1), and heat with stirring at 70° C. for 200 min to obtain a mixture B;

[0142] Step (3): adding 0.1 g of zirconium acetate to the mixture B formed in step (2) to obtain a mixture C;

[0143] Step (4): Add 0.1 g of phosphotungstic acid to the mixture C formed in step (3), and stir at 110° C. for 50 minutes to obtain a total of 41.2 g of composite catalyst 6.

[0144] Embodiment 14

[0145] The preparation method of the composite catalyst is as follows:

[0146] Step (1): adding 30.0 g of methanol to a solid mixture of 5.0 g of N-hydroxyphthalimide and 5.0 g of tetradecyldimethylammonium bromide, and stirring at room temperature until the solid is completely dissolved to obtain a mixture A;

[0147] Step (2): add 1.0 g of bipyridine-coordinated catalyst YG-31-1-007 to the mixed solution of step (1), and heat at 100° C. with stirring for 90 min to obtain a mixture B;

[0148] Step (3): adding 0.1 g of zirconium acetate to the mixture B formed in step (2) to obtain a mixture C;

[0149] Step (4): Add 0.1 g of phosphomolybdic acid to the mixture C formed in step (3), and stir at 120° C. for 60 minutes to obtain a total of 41.2 g of composite catalyst 7.

[0150] Application Examples

[0151] Embodiment 15

[0152] N-hydroxyphthalimide (0.05g), bipyridine-coordinated catalyst YG-31-1-001 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (100g), and 3-methylpyridine (10g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure inside the autoclave was 1.0MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 160°C, and air was passed through until the pressure inside the autoclave was 3.0MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after four hours. The reaction solution was pink, and the total weight of the reaction solution was weighed to be 116.90g.

[0153] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 50g of acetic acid to dilute, and then inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.676g and nicotinic acid is 8.799g. The calculated conversion rate of 3-methylpyridine is 73.24%, and the selectivity of nicotinic acid is 91.26%.

[0154] Example 16

[0155] Sodium bromide (0.05g), bipyridine-coordinated catalyst YG-31-1-002 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (30g), and 3-methylpyridine (100g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure inside the autoclave was 1.0MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 160°C, and air was passed through until the pressure inside the autoclave was 3.0MPa. The air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after four hours. The reaction solution was pink, and the total weight of the reaction solution was weighed to be 133.29g.

[0156] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and then inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 24.16g and nicotinic acid is 94.65g. The calculated conversion rate of 3-methylpyridine is 75.84%, and the selectivity of nicotinic acid is 94.55%.

[0157] Embodiment 17

[0158] Add ammonium bromide (0.05g), bipyridine-coordinated catalyst YG-31-1-003 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (100g), and 3-methylpyridine (10g) to a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure inside the autoclave is 1.0MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, the air tightness of the autoclave is considered good. After the nitrogen is discharged, heat it to 160°C, ventilate it with air until the pressure inside the autoclave is 3.0MPa, vent it continuously, control the flow rate to 400-500mL / min, and end the reaction after four hours. The reaction solution is pink, and the total weight of the reaction solution is 116.31g.

[0159] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.354g and nicotinic acid is 9.720g. The calculated conversion rate of 3-methylpyridine is 76.46%, and the selectivity of nicotinic acid is 96.32%.

[0160] Embodiment 18

[0161] Tetradecyl dimethyl ammonium bromide (0.1 g) (0.05 g), bipyridine-coordinated catalyst YG-31-1-004 (0.1 g), copper acetate (0.01 g), phosphomolybdic acid (0.01 g), ethanol (1.0 g), acetic acid (100 g), and 3-methylpyridine (10 g) were added to a 250 mL titanium autoclave. After the autoclave was installed, nitrogen was filled in until the pressure inside the autoclave was 1.0 MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 160°C, and air was passed through until the pressure inside the autoclave was 3.0 MPa. The air was passed through continuously, and the flow rate was controlled to be 400-500 mL / min. The reaction was terminated after four hours. The reaction solution was pink, and the total weight of the reaction solution was weighed to be 115.65 g.

[0162] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and then inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.388g and nicotinic acid is 9.259g. The calculated conversion rate of 3-methylpyridine is 76.12%, and the selectivity of nicotinic acid is 92.15%.

[0163] Embodiment 19

[0164] Add phenyldimethylammonium bromide (0.1g), bipyridine-coordinated catalyst YG-31-1-005 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (100g), and 3-methylpyridine (10g) into a 250mL titanium autoclave. After the autoclave is installed, fill it with nitrogen until the pressure inside the autoclave is 1.0MPa and keep it for 15 minutes. If the pressure drop does not exceed 5%, it is considered that the airtightness of the autoclave is good. After the nitrogen is discharged, heat it to 160°C, ventilate it with air until the pressure inside the autoclave is 3.0MPa, vent it continuously, control the flow rate to 400-500mL / min, and end the reaction after four hours. The reaction solution is pink, and the total weight of the reaction solution is 117.23g.

[0165] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.213g and nicotinic acid is 9.206g. The conversion rate of 3-methylpyridine is calculated to be 77.87%, and the selectivity of nicotinic acid is 89.56%.

[0166] Embodiment 20

[0167] Ammonium bromide (0.05g), sodium bromide (0.05g), bipyridine-coordinated catalyst YG-31-1-006 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (100g), and 3-methylpyridine (10g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure inside the autoclave was 1.0MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 160°C, and air was passed through until the pressure inside the autoclave was 3.0MPa. The air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after four hours. The reaction solution was pink, and the total weight of the reaction solution was weighed to be 116.45g.

[0168] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and then inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.443g and nicotinic acid is 9.110g. The calculated conversion rate of 3-methylpyridine is 75.57%, and the selectivity of nicotinic acid is 91.33%.

[0169] Embodiment 21

[0170] Tetradecyl dimethyl ammonium bromide (0.05g), sodium bromide (0.05g), bipyridine-coordinated catalyst YG-31-1-007 (0.1g), copper acetate (0.01g), phosphomolybdic acid (0.01g), ethanol (1.0g), acetic acid (100g), and 3-methylpyridine (10g) were added to a 250mL titanium autoclave in sequence. After the autoclave was installed, nitrogen was filled in until the pressure inside the autoclave was 1.0MPa and maintained for 15 minutes. If the pressure drop did not exceed 5%, the air tightness of the autoclave was considered good. After the nitrogen was discharged, the temperature was raised to 160°C, and air was passed through until the pressure inside the autoclave was 3.0MPa. Air was passed through continuously, and the flow rate was controlled to be 400-500mL / min. The reaction was terminated after four hours. The reaction solution was pink, and the total weight of the reaction solution was weighed to be 118.24g.

[0171] Take 0.1g of the reaction solution, 2-nitrobenzoic acid as the internal standard, take 0.1g of toluene, add 30g of acetic acid to dilute, and then inject the sample for testing. Substitute the test data into the internal standard curve to calculate that the remaining 3-methylpyridine is 2.48g and nicotinic acid is 9.02g. The calculated conversion rate of 3-methylpyridine is 75.2%, and the selectivity of nicotinic acid is 90.83%.

[0172] Comparative Example

[0173] The specific operation of the comparative example is consistent with that of Example 15, and the amount of material added and the experimental results are shown in Table 1:

[0174] Table 1 Material addition amount and experimental results in comparative examples

[0175]

[0176] As can be seen from Table 1, the bipyridine-coordinated catalyst disclosed in the present invention can effectively catalyze the oxidation of 3-methylpyridine with high selectivity and high 3-methylpyridine conversion rate. At the same time, combined with the comparative example, it can be seen that the use of the bipyridine-coordinated catalyst in combination with a cocatalyst, a protective agent, a regulator and a solvent can better promote the oxidation of 3-methylpyridine to produce nicotinic acid.

[0177] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0178] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A bipyridine coordinated catalyst, characterized in that: Its general formula is shown in formula (I): Wherein, B is a lithium ion, a sodium ion, a cesium ion, a magnesium ion, a strontium ion, an ammonium ion, a hexadecyltetramethylbenzylammonium ion, an octadecyltetramethylammonium ion, an octadecylhexamethylammonium ion, a dodecyldibutylphosphonium ion, a tetradecylpropylphosphonium ion, a butylphosphonium ion, a tributylethylphosphonium ion, a tetrabutylphosphonium ion, a tributylhexylphosphonium ion, a trimethylammonium ion, a tetrapropylammonium ion, a tributylethylammonium ion, a benzyldimethylammonium ion or a benzyldimethylphosphonium ion; M is selected from Mn, Fe, Cu, Cd, Zr, Sn, Pb, Ni, Mo, V, Cr or Co; R is selected from C1-C 14 alkyl; x is selected from an integer between 1 and 18; y is an integer selected from 1 to 36.

2. A method for preparing a bipyridine-coordinated catalyst, characterized in that: The steps include: Add deionized water to the metal compound, adjust the pH of the solution to 1-4 after dissolution, and then add peroxide to obtain a metal peroxide solution; Alkyl-substituted bipyridine and salt are added to the metal peroxide solution, filtered and dried to obtain a bipyridine-coordinated catalyst having the general formula shown in formula (I).

3. The method for preparing a bipyridine-coordinated catalyst according to claim 2, characterized in that: The metal compound is selected from the group consisting of sodium manganate, cobalt nitrate, manganese nitrate nonahydrate, copper nitrate, cobalt sulfate, nickel nitrate nonahydrate, chromium sulfate, chromium nitrate and sodium metachromate.

4. The method for preparing a bipyridine-coordinated catalyst according to claim 2, characterized in that: The alkyl-substituted bipyridine is selected from 3-ethyl-bipyridine, 3-propyl-bipyridine, 3-isopropyl-bipyridine, 3-n-butyl-bipyridine, 3-tert-butyl-bipyridine and 3-isobutyl-bipyridine.

5. The method for preparing a bipyridine-coordinated catalyst according to claim 2, characterized in that: The salt is selected from the group consisting of tetradecyldimethylammonium chloride, tetradecyldimethylammonium bromide, cesium chloride, sodium chloride, aluminum chloride, magnesium chloride, calcium chloride, ammonium bromide, magnesium acetate, ammonium acetate, tetradecyldimethylbenzylammonium bromide, tetradecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, hexadecyldimethylammonium chloride, hexadecyldimethylbenzylammonium bromide, octyldibutylphosphonium bromide, hexabutylphosphonium bromide, amyldibutylphosphonium bromide, tributylmethylphosphonium bromide, tetrabutylphosphonium bromide, tributylpropylphosphonium bromide, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride and benzyltripropylammonium chloride.

6. A composite catalyst, characterized in that: The invention comprises the bipyridine coordinated catalyst as claimed in claim 1.

7. The composite catalyst according to claim 6, characterized in that It also includes a co-catalyst, wherein the weight ratio of the bipyridine coordinated catalyst to the co-catalyst is 100:(1-500); The auxiliary catalyst is selected from manganese nitrate, manganese acetate, zirconium acetate, ferric nitrate, copper sulfate, magnesium sulfate, magnesium acetate, manganese sulfate and sodium molybdate.

8. The composite catalyst according to claim 6, characterized in that: It also includes a regulator, and the weight ratio of the bipyridine coordinated catalyst to the regulator is 100: (1-500); The regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrapropyl sodium bromide, boric acid, silicomolybdic acid, copper nitrate and phosphotungstic vanadic acid.

9. The composite catalyst according to claim 6, characterized in that: It also includes a protective agent, wherein the weight ratio of the bipyridine coordinated catalyst to the protective agent is 100:(1-500); The protective agent is selected from potassium acetate, sodium bromide, ammonium bromide, tetradecyl dimethyl ammonium bromide, phenyl dimethyl sodium bromide, phenyl dimethyl ammonium bromide, potassium molybdate and N-hydroxyphthalimide.

10. The composite catalyst according to claim 6, characterized in that: It also includes a solvent, wherein the weight ratio of the bipyridine coordinated catalyst to the solvent is 100:(20-10000); The solvent is selected from the group consisting of dichloroethane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, 1,4-dioxane and ethyl acetate.

11. A method for preparing a composite catalyst, characterized in that: The steps include: Prepare a bipyridine-coordinated catalyst, a cocatalyst, a regulator, a protective agent and a solvent represented by formula (I); Add the protective agent to the solvent and mix well to obtain a solution; Add the bipyridine coordinated catalyst represented by formula (I) to the solution, and stir at 20 to 120° C. for 10 to 40 minutes; Then add the auxiliary catalyst and ultrasonicate at 20-120°C for 20-40 minutes; Then add a regulator, stir at 20-120°C for 20-40 minutes to obtain a composite catalyst; Wherein, the cocatalyst is selected from manganese nitrate, manganese acetate, zirconium acetate, ferric nitrate, copper sulfate, magnesium sulfate, magnesium acetate, manganese sulfate and sodium molybdate; The regulator is selected from phosphomolybdic acid, phosphotungstic acid, tetrapropyl sodium bromide, boric acid, silicomolybdic acid, copper nitrate and phosphotungstic vanadic acid; The protective agent is selected from potassium acetate, sodium bromide, ammonium bromide, tetradecyl dimethyl ammonium bromide, phenyl dimethyl sodium bromide, phenyl dimethyl ammonium bromide, potassium molybdate and N-hydroxyphthalimide; The solvent is selected from the group consisting of dichloroethane, acetonitrile, methanol, ethanol, formic acid, acetic acid, propionic acid, 1,4-dioxane and ethyl acetate.

12. Use of the bipyridine-coordinated catalyst according to claim 1 or the composite catalyst according to any one of claims 6 to 10 in the reaction of oxidizing 3-methylpyridine to prepare nicotinic acid.

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