Preparation method of porphyrin compound

Abstract

The invention provides a porphyrin compound preparation method, which comprises: (1) in the presence of a catalyst, carrying out a reaction on a benzaldehyde derivative and a sulfonation reagent to obtain sulfated benzaldehyde; (2) in the presence of an acid catalyst, reacting the sulfated benzaldehyde obtained in the step (1) with pyrrole to obtain a porphyrin compound; the benzaldehyde derivative in the step (1) has a structure as shown in a formula I; the catalyst in the step (1) comprises supported magnesium oxide and a nonionic surfactant; the molecular structure of the porphyrin compound contains sulfonic acid groups. According to the preparation method, the reaction condition is mild, the selectivity is high, the side reaction occurrence probability is greatly reduced, the obtained porphyrin compound is high in yield and purity, equipment cannot be corroded, the cost is reduced, aftertreatment is simple, and the method is safer and more environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing a porphyrin compound. Background Art

[0002] Porphyrin compounds are a class of macromolecular heterocyclic compounds formed by the interconnection of α-carbon atoms of four pyrrole subunits through methyl bridges. They have a unique 18π conjugated macrocyclic electronic structure, which gives porphyrin compounds unique physical and chemical properties or other functional properties. For example, porphyrin compounds have strong coordination ability and excellent photoelectric properties, and can be used to construct functional porous organic polymers. Secondly, porphyrin compounds can form ordered nanostructures through controllable self-assembly under the action of non-covalent bonds, and effectively regulate photoelectric properties through intermolecular synergy. Porphyrins have good photostability and thermal stability and are widely used in biology, medicine, materials science, molecular recognition, photochemistry, analytical chemistry and electrochemistry. In addition, porphyrin compounds can also obtain a variety of isoporphyrins by changing their macrocyclic parent design, and obtain porphyrin compounds with more unique structures and outstanding performance, which can further expand their scope of application.

[0003] Currently, the preparation methods of porphyrin compounds include gas phase oxidation, low temperature liquid phase oxidation, hydrogenation reduction, intermediate sulfonation, etc.

[0004] Among them, the gas phase oxidation method uses p-toluenesulfonic acid as the raw material, and prepares p-carbonylbenzenesulfonic acid through an oxidation reaction. Then, p-carbonylbenzenesulfonic acid is used as an intermediate raw material to further prepare porphyrin compounds. The methods for synthesizing aromatic aldehydes reported in the literature mainly include chemical oxidation method, electrochemical oxidation method, chlorination hydrolysis method and MnO2 method. The chemical oxidation method is to use a strong oxidant such as KMnO4 to oxidize toluene derivatives into benzoic acid derivatives under the combined action of air, and then react with thionyl chloride to form benzoyl chloride derivatives, which are hydrolyzed to obtain aromatic aldehydes; however, peroxides may be produced in this process, posing a safety hazard. The electrochemical oxidation method is to use an electrochemical method to convert Mn 2+ Oxidation to Mn 3+ , and then use Mn 3+ Oxidation of toluene derivatives produces benzaldehyde derivatives, but the electrochemical oxidation method requires complex equipment and high power consumption. The chlorination hydrolysis method is more cost-effective than the oxidation hydrolysis method, but there are more side reactions and the product quality cannot be guaranteed. The MnO2 method has a simple process, but it has high requirements for the activity of MnO2, the utilization rate is very low, and the industrial practical value is not great.

[0005] Low temperature liquid phase oxidation method, such as the prior art discloses that p-tert-butyltoluene is selectively oxidized to obtain p-tert-butylbenzaldehyde in an acidic solution under low temperature liquid phase conditions using manganese trioxide as a catalyst; then p-tert-butylbenzaldehyde is used as a raw material to prepare porphyrin compounds; manganese trioxide is soluble in sulfuric acid, and is stable in sulfuric acid of medium concentration, and will not be disproportionated into divalent manganese or manganese dioxide, and has similar oxidizing properties to trivalent ion salts in acidic solutions. During the reaction, manganese trioxide and sulfuric acid form a suspension, and after adding p-tert-butyltoluene, an oil, water, and solid three-phase reaction system is formed. The reaction end point is when the purple color of the aqueous phase fades away, and the reaction product is dissolved in the oil phase, and the product is obtained by distillation; however, the method uses liquid strong acid, which is easy to corrode the equipment, and there are also great difficulties in recovery and separation.

[0006] The hydrogenation reduction method uses benzoic acid or methyl benzoate as raw materials and supported manganese dioxide (γ-Al2O3 as catalyst carrier) as catalyst to prepare benzaldehyde through hydrogenation reaction, which can prepare highly selective benzaldehyde derivatives. However, it is difficult to directly obtain sodium p-sulfonate benzaldehyde through hydrogenation reaction because salt substances are difficult to vaporize.

[0007] The intermediate sulfonation method uses benzaldehyde and pyrrole as raw materials to prepare tetraphenylporphyrin; then the tetraphenylporphyrin is sulfonated to obtain a porphyrin compound containing a sulfonic acid group; when the method uses strong acid homogeneous catalysis, although the yield can be improved to a certain extent, the selectivity of the sulfonation reaction is not high, the liquid strong acid is easy to corrode the equipment, and there are also great difficulties in recovery and separation. When anhydrous aluminum chloride is used as a catalyst and chlorosulfonic acid is used as a sulfonation reagent; although anhydrous aluminum chloride improves the yield and the product does not contain by-products, anhydrous aluminum chloride is easy to react with water, which makes it difficult to separate the product; chlorosulfonic acid is used as a sulfonation agent, which has a significantly higher yield than sulfonation preparation in a concentrated sulfuric acid environment, and the operating conditions are relatively simple and the time is short, but chlorosulfonic acid is more corrosive. It is not conducive to production.

[0008] Therefore, developing a method for preparing porphyrin compounds with high yield, high purity, simple post-treatment, low cost, no equipment corrosion, and environmental protection is an urgent problem to be solved in the art. Summary of the invention

[0009] In view of the shortcomings of the prior art, the present invention aims to provide a method for preparing a porphyrin compound. The method has mild reaction conditions, high selectivity, greatly reduces the probability of side reactions, obtains a high yield and purity of porphyrin, does not corrode equipment, reduces costs, is simple to post-process, and is safer and more environmentally friendly.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a method for preparing a porphyrin compound, the method comprising the following steps: (1) reacting a benzaldehyde derivative with a sulfonating agent in the presence of a catalyst to obtain a sulfonated benzaldehyde; (2) reacting the sulfonated benzaldehyde obtained in step (1) with pyrrole in the presence of an acid catalyst to obtain a porphyrin compound; the benzaldehyde derivative in step (1) has a structure shown in formula I: In formula I, X is selected from halogen; the catalyst in step (1) comprises supported magnesium oxide and a nonionic surfactant; and the molecular structure of the porphyrin compound contains a sulfonic acid group.

[0012] In the present invention, the supported magnesium oxide is an activated catalyst, Mg 2+ The invention discloses a Lewis acidic site, which is a stable adsorption site of an aldehyde group. The magnesium in magnesium oxide combines with the aldehyde group in a benzaldehyde derivative to activate the halogen on the benzene ring, and then obtains sulfonated benzaldehyde through a substitution reaction. The supported magnesium oxide is adopted to improve the catalyst utilization rate and catalytic efficiency. The nonionic surfactant is a phase transfer catalyst. The nonionic surfactant and the supported magnesium oxide cooperate with each other to perform a two-phase catalytic sulfonation reaction, thereby improving the selectivity of the sulfonation reaction, reducing the probability of side reactions, and being beneficial to improving the yield and purity of the product. The magnesium oxide is a lipophilic catalyst, and the product is easy to separate. Meanwhile, the preparation method adopts the steps of sulfonation first and then addition, thereby further improving the selectivity of the sulfonation reaction, and improving the yield and purity of the product. The corrosion of the equipment by the strong acidic substance is avoided, the reaction conditions are mild, the production safety is improved, and the requirements of green chemistry are met.

[0013] In the present invention, the halogen includes F, Cl, Br, I; the benzaldehyde derivatives include p-chlorobenzaldehyde, p-bromobenzaldehyde and the like.

[0014] Preferably, the mass of the catalyst in step (1) is 5-15% of the mass of the benzaldehyde derivative, for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, etc.

[0015] Preferably, the mass ratio of the supported magnesium oxide to the nonionic surfactant is 1:(0.5-3), wherein the specific value in (0.5-3) can be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1. , 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, etc.; more preferably, it is 1:(1-2).

[0016] In the present invention, the mass ratio of the supported magnesium oxide to the nonionic surfactant is not within the above range, and the yield of the obtained porphyrin compound is low.

[0017] Preferably, the supported magnesium oxide comprises supported nano magnesium oxide.

[0018] Preferably, the carrier of the supported magnesium oxide comprises activated carbon fiber, that is, magnesium oxide (nano magnesium oxide) is supported on activated carbon fiber.

[0019] Preferably, the mass ratio of the activated carbon fiber to magnesium oxide is 1:(0.05-0.4), wherein the specific value in (0.05-0.4) can be, for example, 0.05, 0.06, 0.08, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, etc.; further preferably, it is 1:(0.1-0.2).

[0020] In the present invention, nano magnesium oxide is used and loaded on activated carbon fibers, which can avoid magnesium oxide aggregation, increase the contact area between the catalyst and the reactant, realize nano catalysis, and improve catalytic efficiency; and loading nano magnesium oxide on activated carbon fibers can improve the dispersibility and stability of magnesium oxide in the organic phase, reduce the loss of nano magnesium oxide, and improve the utilization rate of magnesium oxide.

[0021] In the present invention, the activated carbon fiber-supported magnesium oxide can be purchased directly from the market, or prepared by conventional methods; illustratively, the method includes: mixing and dispersing commercially available activated carbon fiber, commercially available nano magnesium oxide (average particle size of 1 to 100 nm), a dispersant and a solvent at room temperature and under stirring conditions for 0.5 to 2 hours to obtain a dispersion; then filtering the dispersion, and calcining the obtained solid at 400 to 800° C. in the presence of a protective atmosphere (such as nitrogen) for 1 to 5 hours to obtain the activated carbon fiber-supported nano magnesium oxide; wherein the dispersant includes but is not limited to PEG200, and its mass is 1 to 8% of the total mass of the activated carbon fiber and the nano magnesium oxide; the solvent includes water, and its mass is such that the solid content of the dispersion is 20 to 50%.

[0022] Preferably, the nonionic surfactant comprises polyethylene glycol and / or polyethylene glycol.

[0023] Preferably, the number average molecular weight of the polyethylene glycol is 200-20000, for example, it can be 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1200, 1500, 1800, 2000, 4000, 6000, 8000, 10000, 12000, 15000, 18000, 20000, etc.; more preferably, the number average molecular weight is 200-1000.

[0024] Preferably, the molar ratio of the benzaldehyde derivative to the sulfonating reagent in step (1) is 1:(1-2), wherein the specific values ​​in (1-2) can be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc.

[0025] Preferably, the sulfonating agent in step (1) comprises at least one of concentrated sulfuric acid, oleum, chlorosulfonic acid, sulfur trioxide, aminosulfonic acid, sulfite or bisulfite, and more preferably sulfite.

[0026] Preferably, the sulfite comprises sodium sulfite.

[0027] Preferably, the reaction in step (1) is carried out in a solvent.

[0028] Preferably, the solvent comprises a mixed solvent of an alcohol compound and water.

[0029] Preferably, the mass ratio of the alcohol compound to water is 1:(0.1-0.5), wherein the specific value in (0.1-0.5) can be, for example, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, etc.; more preferably, it is 1:(0.1-0.2).

[0030] Preferably, the number of carbon atoms in the alcohol compound is ≥4, for example, ≥4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 40, 60, 80, 100, etc.

[0031] Preferably, the alcohol compound includes at least one of n-butanol, n-pentanol, n-hexanol or polyethylene glycol.

[0032] In the present invention, step (1) uses a mixed solvent of an alcohol compound and water to form a reaction system with a certain solution interface, wherein the alcohol compound can effectively disperse the catalyst and the reactant, and the water is used to dissolve the sulfonation reagent. The alcohol compound and the water form a mutually soluble state, providing a transfer channel for the reactant and the catalyst, which is beneficial for the sulfonation reagent to enter the organic phase from the aqueous phase, thereby improving the sulfonation efficiency and the catalytic efficiency, and further helping to improve the product yield.

[0033] Preferably, the reaction temperature in step (1) is 70-90°C, for example, 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, etc.

[0034] In the present invention, when the reaction temperature is within the above range, the obtained porphyrin compound has high purity and yield; when the temperature is lower, the yield of the porphyrin compound is low; when the temperature is higher, the purity of the porphyrin compound is low.

[0035] Preferably, the reaction time of step (1) is 8 to 24 hours, for example, it can be 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, etc.

[0036] In the present invention, the reaction in step (1) can be carried out in a reactor, and the reaction raw materials can be pumped from the high-level tank into the reactor by a metering pump, and the dropping speed of the reaction raw materials is controlled. After the dropping is completed, a sulfonation reaction is carried out under normal pressure and 70-90° C. in a mixed solvent of a biphasic catalyst, an alcohol compound and water to obtain sulfonated benzaldehyde.

[0037] Preferably, the acid catalyst in step (2) comprises at least one of acetic acid, propionic acid, m-nitrobenzoic acid, o-nitrobenzoic acid or p-nitrobenzoic acid, preferably o-nitrobenzoic acid.

[0038] In the present invention, the acid catalyst in step (2) is a weak acid catalyst, which can provide a weak acid environment and improve the solubility of pyrrole in the reaction system on the one hand; on the other hand, it can catalyze the addition reaction and improve the product yield.

[0039] Preferably, the mass ratio of the acid catalyst to the sulfonated benzaldehyde in step (2) is (0.4-2):1, wherein the specific value in (0.4-2) can be, for example, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc.

[0040] Preferably, the molar ratio of the sulfonated benzaldehyde to pyrrole in step (2) is 1:(1-2), wherein the specific values ​​in (1-2) can be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc.

[0041] Preferably, the reaction in step (2) is carried out in an organic solvent.

[0042] Preferably, the organic solvent comprises xylene.

[0043] Preferably, the reaction in step (2) comprises a heating reflux reaction.

[0044] Preferably, the heating reflux time is ≥ 2 h, for example, it can be 2 h, 4 h, 6 h, 8 h, 10 h, etc.

[0045] Preferably, the reaction in step (2) further includes a post-treatment step.

[0046] Preferably, the post-treatment comprises cooling crystallization, washing and a first recrystallization performed sequentially.

[0047] In the present invention, the post-treatment comprises: after the reaction in step (2) is completed, cooling the reaction solution to room temperature, adding an alcohol solvent thereto, cooling with ice water and standing for at least 10 hours, filtering with suction, washing the obtained solid product with anhydrous ethanol until the filtrate is colorless, then washing with hot water, and drying; and recrystallizing the dried solid product in a mixed solvent of water and ethanol to obtain purple crystals.

[0048] In the present invention, the reaction in step (2) comprises: mixing sulfonated benzaldehyde with an acid catalyst and an organic solvent, heating and refluxing for 5 to 20 minutes, and then dripping a pyrrole solution therein for 20 to 40 minutes. After the dripping is completed, heating and refluxing for 2 hours or more, stopping the reaction, and performing post-treatment to obtain a product; the pyrrole solution is obtained by dissolving pyrrole in an organic solvent.

[0049] Preferably, the post-treatment further includes a desalination step.

[0050] In the present invention, when the sulfonating agent is selected from sulfite, bisulfite, etc., step (2) reacts to obtain a porphyrin salt compound; the porphyrin salt compound is subjected to a desalting treatment to obtain a porphyrin compound.

[0051] Preferably, the desalting treatment comprises acidification and a second recrystallization performed sequentially.

[0052] Preferably, the acidification comprises mixing the product obtained by post-treatment with an acidic liquid and a solvent for acidification.

[0053] Preferably, the solid-liquid mass ratio of the product obtained by the post-treatment to the acidic liquid is 1:(4-6), wherein the specific value in (4-6) can be, for example, 4, 4.5, 5, 5.5, 6, etc.

[0054] Preferably, the acidic liquid comprises dilute sulfuric acid.

[0055] Preferably, the solvent in the acidification comprises a mixed solvent of alcohol and water; the alcohol comprises at least one of methanol, ethanol, isopropanol, n-butanol, n-pentanol, n-hexanol or polyethylene glycol.

[0056] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0057] (1) in the presence of supported magnesium oxide and a nonionic surfactant, a benzaldehyde derivative is mixed with a sulfonating agent, a mixed solvent of an alcohol compound and water, and the mixture is reacted at 70 to 90° C. for 8 to 24 hours to obtain a sulfonated benzaldehyde;

[0058] (2) in the presence of an acid catalyst, mixing the sulfonated benzaldehyde obtained in step (1) with pyrrole and an organic solvent, heating and refluxing for 2 hours or more, cooling and crystallizing, washing, and performing a first recrystallization to obtain a porphyrin salt compound;

[0059] (3) The porphyrin salt compound obtained in step (2) is mixed with an acidic liquid, a mixed solvent of alcohol and water for acidification, and then subjected to a second recrystallization to obtain the porphyrin compound.

[0060] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] The preparation method provided by the present invention adopts a nonionic surfactant and a supported magnesium oxide dual-phase catalysis; at the same time, a synthetic route of first sulfonation and then addition is adopted, thereby improving the selectivity and catalytic efficiency of the sulfonation reaction, thereby improving the yield and purity of the product; avoiding the corrosion of equipment by strongly acidic substances, and having mild reaction conditions, thereby improving production safety and facilitating the large-scale production of porphyrin compounds. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0064] The materials used in the present invention can be purchased from the market or prepared by conventional methods. Unless otherwise specified, the raw materials used in the present invention are as follows:

[0065] Activated carbon fiber-supported nano-magnesium oxide: The mass ratio of activated carbon fiber to nano-magnesium oxide (average particle size of 50 nm) is 1:1.5; purchased from Jiangsu Quanhu Activated Carbon Co., Ltd. and Wuxi Zemei New Material Technology Co., Ltd., respectively. The specific preparation method includes: mixing and dispersing activated carbon fiber, nano-magnesium oxide, dispersant and solvent at room temperature and stirring conditions for 1 hour to obtain a dispersion; then filtering the dispersion, and calcining the obtained solid at 600°C in a nitrogen atmosphere for 2 hours to obtain the activated carbon fiber-supported nano-magnesium oxide; wherein the dispersant is PEG200, the mass of which is 4% of the total mass of activated carbon fiber and nano-magnesium oxide; the solvent is water, the content of which is such that the solid content of the dispersion is 30%.

[0066] Polyethylene glycol (PEG) with different number average molecular weights was purchased from Xingtai Xinlanxing Technology Co., Ltd.

[0067] Example 1

[0068] This embodiment provides a method for preparing a porphyrin compound, the preparation method comprising the following steps:

[0069] (1) 0.1 mol of p-chlorobenzaldehyde, 0.13 mol of sodium sulfite, a catalyst and a solvent are mixed and reacted at normal pressure and a temperature of 70° C. for 12 hours to obtain white crystals of sodium p-sulfonate benzaldehyde (with a yield of 92%); the molar ratio of p-chlorobenzaldehyde to sodium sulfite is 1:1.3; the mass of the catalyst is 8% of the mass of p-chlorobenzaldehyde; the catalyst comprises activated carbon fiber-supported nano-magnesium oxide and polyethylene glycol (PEG400) in a mass ratio of 1:1; based on a molar content of p-chlorobenzaldehyde of 1 mol, the volume of the solvent is 200 mL; the solvent comprises a mixed solvent of n-butanol and water in a mass ratio of 1:0.2.

[0070] (2) 0.05 mol of sodium p-sulfonate benzaldehyde obtained in step (1) and 8 g of o-nitrobenzoic acid (the mass ratio of o-nitrobenzoic acid to sodium p-sulfonate benzaldehyde is 0.77:1) are added to a 250 mL four-necked round-bottom flask, and then 150 mL of xylene is added thereto. After heating and reflux for 10 min under stirring conditions, 30 mL of pyrrole xylene solution (the molar content of pyrrole is 0.05 mol) is added dropwise through a constant pressure dropping funnel. The addition is completed within 0.5 h, and the reaction is continued under reflux for 2 h. When the temperature drops to 100 ° C, the reaction solution is quickly transferred to a large beaker and gradually cooled. to room temperature, add 30 mL of ethanol, cool with ice water and let stand for 10 h, filter with suction, wash the obtained solid product with anhydrous ethanol until the filtrate is colorless, then wash with 200 mL of hot water, and drain to obtain purple crystals; dry the obtained crystals in an oven at 100 ° C for 1.5 h, put them in a dryer, and after cooling to room temperature, obtain crude porphyrin sodium salt (mass 5.76 g, yield 45%); recrystallize the porphyrin sodium salt in a mixed solvent of water and ethanol (total volume 120 mL, water to ethanol volume ratio of 2: 1) to obtain 5.46 g of purple crystals, that is, obtain purified porphyrin sodium salt.

[0071] (3) mixing the porphyrin sodium salt obtained in step (2) with dilute sulfuric acid (mass concentration of 10%) and a mixed solvent of ethanol and water (volume ratio of ethanol to water of 1:2), wherein the solid-liquid mass ratio of the porphyrin sodium salt to the dilute sulfuric acid is 1:5, and the mass ratio of the porphyrin sodium salt to the mixed solvent is 1:5; then recrystallizing in a mixed solvent of water and ethanol (total volume of 120 mL; volume ratio of water to ethanol of 2:1), filtering with suction, washing with deionized water for 3 times, and vacuum drying at 80° C. for 10 h to obtain a green powder, namely, obtaining the porphyrin compound 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin.

[0072] In the present invention, the synthesis route of the 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin prepared by the preparation method provided in Example 1 is as follows:

[0073]

[0074] In the present invention, a nuclear magnetic resonance hydrogen spectrometer is used to characterize the structure of 5,10,15,20-tetrakis(4-sulfonatephenyl)porphyrin obtained in Example 1; specifically, a Mercury 300NMR nuclear magnetic resonance spectrometer from Varian, USA is used, TMS is used as an internal reference, and deuterated DMSO is used as a solvent.

[0075] The test results are: 1HNMR: δ: 8.78 for the proton on the pyrrole ring (8H); 8.69, 8.32 for the proton on the benzene ring (8H, 8H); -0.71 for the proton of NH (2H).

[0076] Example 2

[0077] This embodiment provides a method for preparing a porphyrin compound, the preparation method comprising the following steps:

[0078] (1) 0.1 mol of p-chlorobenzaldehyde, 0.18 mol of sodium sulfite, a catalyst and a solvent are mixed and reacted at normal pressure and a temperature of 90° C. for 16 hours to obtain sodium p-sulfonate benzaldehyde; the molar ratio of p-chlorobenzaldehyde to sodium sulfite is 1:1.8; the mass of the catalyst is 10% of the mass of p-chlorobenzaldehyde; the catalyst comprises activated carbon fiber-supported nano-magnesium oxide and polyethylene glycol (PEG400) in a mass ratio of 1:2; the volume of the solvent is the same as that in Example 1; the solvent comprises a mixed solvent of n-hexanol and water in a mass ratio of 1:0.1.

[0079] (2) 0.05 mol of p-chlorobenzaldehyde obtained in step (1) and 12 g of o-nitrobenzoic acid (the mass ratio of o-nitrobenzoic acid to p-chlorobenzaldehyde is 1.15:1) are added to a 250 mL four-necked round-bottom flask, and then 150 mL of xylene is added thereto. After heating and reflux for 10 min under stirring conditions, 30 mL of pyrrole xylene solution (the molar content of pyrrole is 0.08 mol) is added dropwise through a constant pressure dropping funnel. The addition is completed within 0.5 h, and the reaction is continued under reflux for 4 h. When the temperature drops to 100 ° C, the reaction solution is quickly transferred to The mixture was gradually cooled to room temperature in a large beaker, 30 mL of ethanol was added, the mixture was cooled with ice water and allowed to stand for 10 h, and then filtered. The solid product was first washed with anhydrous ethanol until the filtrate was colorless, and then washed with 200 mL of hot water, and dried to obtain purple crystals; the obtained crystals were dried in an oven at 100 ° C for 1.5 h, placed in a dryer, and cooled to room temperature to obtain crude porphyrin sodium salt; the porphyrin sodium salt was recrystallized in a mixed solvent of water and ethanol (the total volume and volume ratio of the solvent used for recrystallization were the same as those in Example 1) to obtain purple crystals, i.e., the purified porphyrin sodium salt was obtained.

[0080] (3) The porphyrin sodium salt obtained in step (2) is mixed with dilute sulfuric acid (mass concentration is 10%) and a mixed solvent of ethanol and water, wherein the solid-liquid mass ratio of the porphyrin sodium salt to the dilute sulfuric acid is 1:4, and the mass ratio of the porphyrin sodium salt to the mixed solvent is the same as that in Example 1; then, the mixture is recrystallized in a mixed solvent of water and ethanol (the total volume and volume ratio of the solvent used for recrystallization are the same as those in Example 1), filtered, washed with deionized water for 3 times, and vacuum dried at 80° C. for 10 h to obtain a green powder, i.e., the porphyrin compound 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin is obtained.

[0081] Example 3

[0082] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that the total mass of the activated carbon fiber-supported nano-magnesium oxide and polyethylene glycol in step (1) remains unchanged, with a mass ratio of 1:0.5, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0083] Example 4

[0084] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that the total mass of the activated carbon fiber-supported nano-magnesium oxide and polyethylene glycol in step (1) remains unchanged, with a mass ratio of 1:2.8, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0085] Example 5

[0086] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that PEG400 is replaced with PEG200 of equal mass in step (1), and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0087] Example 6

[0088] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that PEG400 is replaced with PEG600 of equal mass in step (1), and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0089] Example 7

[0090] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that PEG400 is replaced with PEG4000 of equal mass in step (1), and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0091] Example 8

[0092] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that the total amount of the solvent in step (1) remains unchanged, including a mixed solvent of n-butanol and water in a mass ratio of 1:0.4, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0093] Example 9

[0094] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that n-butanol is replaced with ethanol of equal mass in step (1), and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0095] Example 10

[0096] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that in step (1), sodium sulfite is replaced by an equimolar amount of sulfur trioxide, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0097] Embodiment 11

[0098] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that the reaction temperature in step (1) is 100° C., and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0099] Example 12

[0100] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that the reaction temperature in step (1) is 65° C., and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0101] Embodiment 13

[0102] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that in step (2), o-nitrobenzoic acid is replaced by an equal mass of m-nitrobenzoic acid, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0103] Embodiment 14

[0104] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that in step (2), o-nitrobenzoic acid is replaced by an equal mass of p-nitrobenzoic acid, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0105] Embodiment 15

[0106] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that in step (2), o-nitrobenzoic acid is replaced by propionic acid of equal mass, and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0107] Example 16

[0108] This embodiment provides a method for preparing a porphyrin compound, which differs from Embodiment 1 only in that ethanol is replaced by an equal mass of n-butanol in step (3), and other raw materials, amounts and step parameters are the same as those in Embodiment 1.

[0109] Comparative Example 1

[0110] This comparative example provides a method for preparing a porphyrin compound, which differs from Example 1 only in that in step (1), the activated carbon fiber-supported magnesium oxide is replaced with magnesium oxide of equal mass, and other raw materials, amounts and step parameters are the same as those in Example 1.

[0111] Comparative Example 2

[0112] This comparative example provides a method for preparing a porphyrin compound, which differs from Example 1 only in that the total amount of catalyst in step (1) remains unchanged, polyethylene glycol is not present, and other raw materials, amounts and step parameters are the same as those in Example 1.

[0113] Comparative Example 3

[0114] This comparative example provides a method for preparing a porphyrin compound, which differs from Example 1 only in that there is no o-nitrobenzoic acid in step (2), and the other raw materials, amounts and step parameters are the same as those in Example 1.

[0115] Comparative Example 4

[0116] This comparative example provides a method for preparing a porphyrin compound, which differs from Example 1 only in that the preparation method comprises first subjecting benzaldehyde to an addition reaction with pyrrole, and then subjecting the obtained product to a sulfonation reaction with a sulfonation reagent to obtain a porphyrin compound 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin; the specific method comprises:

[0117] (1) 0.05 mol of benzaldehyde and 12 g of o-nitrobenzoic acid (the mass ratio of o-nitrobenzoic acid to benzaldehyde is 1.15:1) are added to a 250 mL four-necked round-bottom flask, and then 150 mL of xylene is added thereto. Under stirring conditions, the mixture is heated to reflux for 10 min, and then 30 mL of a xylene solution of pyrrole (the molar content of pyrrole is 0.08 mol) is added dropwise through a constant pressure dropping funnel. The addition is completed within 0.5 h, and the reaction is continued under reflux for 4 h. When the temperature drops to 100 ° C, the reaction solution is quickly transferred to a large beaker, gradually cooled to room temperature, 30 mL of ethanol is added, and the mixture is cooled with ice water and allowed to stand for 10 h. The solid product is first washed with anhydrous ethanol until the filtrate is colorless, and then washed with 200 mL of hot water, and dried to obtain purple crystals; the obtained crystals are dried in an oven at 100 ° C for 1.5 h, placed in a dryer, and cooled to room temperature to obtain porphyrin;

[0118] (2) 0.1 mol of porphyrin and 0.18 mol of concentrated sulfuric acid were reacted at normal pressure and 90° C. for 16 h to obtain a porphyrin compound 5,10,15,20-tetrakis(4-sulfonate phenyl)porphyrin. The porphyrin compound was recrystallized twice in a mixed solvent of water and ethanol (the total volume and volume ratio of the solvent used for recrystallization were the same as those in Example 1), then filtered, washed with deionized water three times, and vacuum dried at 80° C. for 10 h to obtain a green powder, i.e., a porphyrin compound 5,10,15,20-tetrakis(4-sulfonate phenyl)porphyrin.

[0119] The purity of the porphyrin compound was tested by high performance liquid chromatography; the instrument was a Shimadzu high performance liquid chromatograph, including an SPD-10Atvp infusion pump, an SPD-10Avp ultraviolet spectrophotometer, a Rheodyne7721 injection valve, a column pressure of 2.5 MPa, and a column temperature of 25°C.

[0120] The specific operating conditions are as follows: the chromatographic column is a Hypseil ODS2 chromatographic column (250mm×4.6id, particle size 5μm); the mobile phase is methanol-buffer solution (volume ratio 15:85, buffer solution pH=3); the flow rate is 0.8mL / min; the maximum absorption wavelength of the SPD-10Avp ultraviolet spectrophotometer is 412~416nm.

[0121] The yields of the products of each step of step (1) and step (2) and the purity of the product obtained in step (2) are shown in Table 1; wherein, the yield of step (2) is the yield of the product calculated before recrystallization of step (2); the purity is the purity of the product after recrystallization of step (2); wherein, "-" means that the yield is not calculated, and only the effect of the different processes of step (1) on the product yield is compared, so no calculation is required.

[0122] Table 1

[0123]

[0124]

[0125] As can be seen from Table 1, the preparation method provided by the present invention adopts a nonionic surfactant and a supported magnesium oxide dual-phase catalysis; at the same time, a synthetic route of sulfonation followed by addition is adopted, and the obtained porphyrin compound 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin has a high yield and high purity; wherein, the yield of the sulfonated benzaldehyde obtained in step (1) is ≥75%, and can even reach more than 90%; the yield of the porphyrin salt obtained in step (2) is ≥35%, and can even reach 45% and above, and the purity is ≥92%, and can even reach 95% and above; and the preparation method does not need to use a strong acid catalyst, and does not need to introduce a strongly acidic sulfonation reagent, thereby avoiding the corrosion of the equipment by the strongly acidic substance, and the reaction conditions are mild, thereby improving the production safety, and facilitating the large-scale production of the porphyrin compound.

[0126] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a porphyrin compound, characterized in that: The preparation method comprises the following steps: (1) reacting a benzaldehyde derivative with a sulfonating agent in the presence of a catalyst to obtain a sulfonated benzaldehyde; (2) reacting the sulfonated benzaldehyde obtained in step (1) with pyrrole in the presence of an acid catalyst to obtain a porphyrin compound; The benzaldehyde derivative in step (1) has a structure shown in Formula I: In formula I, X is selected from halogen; The catalyst in step (1) comprises supported magnesium oxide and a nonionic surfactant; The porphyrin compound contains a sulfonic acid group in its molecular structure.

2. The preparation method according to claim 1, characterized in that: The mass of the catalyst in step (1) is 5 to 15% of the mass of the benzaldehyde derivative; Preferably, the mass ratio of the supported magnesium oxide to the nonionic surfactant is 1:(0.5-3), more preferably 1:(1-2).

3. The preparation method according to claim 1 or 2, characterized in that: The supported magnesium oxide includes supported nano magnesium oxide; Preferably, the carrier of the supported magnesium oxide comprises activated carbon fiber; Preferably, the mass ratio of the activated carbon fiber to magnesium oxide is 1:(0.05-0.4), more preferably 1:(0.1-0.2); Preferably, the nonionic surfactant comprises polyethylene glycol; Preferably, the number average molecular weight of the polyethylene glycol is 200-20,000, more preferably 200-1,000.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The molar ratio of the benzaldehyde derivative to the sulfonating agent in step (1) is 1:(1-2); Preferably, the sulfonating agent in step (1) comprises at least one of concentrated sulfuric acid, oleum, chlorosulfonic acid, sulfur trioxide, aminosulfonic acid, sulfite or bisulfite, more preferably sulfite; Preferably, the sulfite comprises sodium sulfite.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The reaction in step (1) is carried out in a solvent; Preferably, the solvent comprises a mixed solvent of an alcohol compound and water; Preferably, the mass ratio of the alcohol compound to water is 1:(0.1-0.5), more preferably 1:(0.1-0.2); Preferably, the number of carbon atoms in the alcohol compound is ≥4; Preferably, the alcohol compound includes at least one of n-butanol, n-pentanol, n-hexanol or polyethylene glycol; Preferably, the reaction temperature in step (1) is 70-90°C; Preferably, the reaction time in step (1) is 8 to 24 hours.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The acid catalyst in step (2) comprises at least one of acetic acid, propionic acid, m-nitrobenzoic acid, o-nitrobenzoic acid or p-nitrobenzoic acid, preferably o-nitrobenzoic acid; Preferably, the mass ratio of the acid catalyst to the sulfonated benzaldehyde in step (2) is (0.4-2):1; Preferably, the molar ratio of the sulfonated benzaldehyde to pyrrole in step (2) is 1:(1-2).

7. The preparation method according to any one of claims 1 to 6, characterized in that: The reaction in step (2) is carried out in an organic solvent; Preferably, the organic solvent comprises xylene; Preferably, the reaction in step (2) comprises a heating reflux reaction; Preferably, the heating reflux time is ≥ 2h; Preferably, the reaction in step (2) further includes a post-treatment step; Preferably, the post-treatment comprises cooling crystallization, washing and a first recrystallization performed sequentially.

8. The preparation method according to claim 7, characterized in that: The post-treatment also includes a desalination step; Preferably, the desalting treatment comprises acidification and a second recrystallization performed sequentially; Preferably, the acidification comprises mixing the product obtained by post-treatment with an acidic liquid and a solvent for acidification.

9. The preparation method according to claim 8, characterized in that: The solid-liquid mass ratio of the product obtained by the post-treatment to the acidic liquid is 1:(4-6); Preferably, the acidic liquid comprises dilute sulfuric acid; Preferably, the solvent in the acidification comprises a mixed solvent of alcohol and water; the alcohol comprises at least one of methanol, ethanol, isopropanol, n-butanol, n-pentanol, n-hexanol or polyethylene glycol.

10. A preparation method according to any one of claims 1 to 9, characterized in that: The preparation method comprises the following steps: (1) in the presence of supported magnesium oxide and a nonionic surfactant, a benzaldehyde derivative is mixed with a sulfonating agent, a mixed solvent of an alcohol compound and water, and the mixture is reacted at 70 to 90° C. for 8 to 24 hours to obtain a sulfonated benzaldehyde; (2) in the presence of an acid catalyst, mixing the sulfonated benzaldehyde obtained in step (1) with pyrrole and an organic solvent, heating and refluxing for 2 hours or more, and then cooling and crystallizing, washing, and performing a first recrystallization to obtain a porphyrin salt compound; (3) The porphyrin salt compound obtained in step (2) is mixed with an acidic liquid, a mixed solvent of alcohol and water for acidification, and then subjected to a second recrystallization to obtain the porphyrin compound.

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