A preparation method of porphyrin compound

Abstract

The present invention provides a method for preparing a porphyrin compound, 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; wherein the benzaldehyde derivative in step (1) has a structure shown in Formula I; 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. In the present invention, the preparation method has mild reaction conditions, high selectivity, greatly reduces the probability of side reactions, and has a high yield and purity of the obtained porphyrin compound. Furthermore, the method does not corrode equipment, reduces costs, simplifies post-processing, and 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 preparation method of a porphyrin compound. Background Art

[0002] Porphyrin compounds are a class of macromolecular heterocyclic compounds formed by the interconnection of the α-carbon atoms of four pyrrole subunits through a methine bridge. 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 functionalized porous organic polymers. Secondly, porphyrin compounds can form ordered nanostructures through controllable self-assembly under the action of non-covalent bonds, and effectively regulate the photoelectric properties through intermolecular synergy. Porphyrins also 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 the design of their macrocyclic mother ring, obtaining porphyrin compounds with more unique structures and outstanding properties, 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 a 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, electrochemical oxidation, chlorination hydrolysis and MnO2 method. The chemical oxidation method is to use a strong oxidant such as KMnO4 to oxidize the derivatives of toluene into derivatives of benzoic acid under the combined action of air, and then react with thionyl chloride to form derivatives of benzoyl chloride, 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 electrochemically convert Mn into benzoic acid in an acidic medium. 2+ Oxidation to Mn 3+ , and then use Mn 3+ Oxidation of toluene derivatives produces benzaldehyde derivatives, but electrochemical oxidation requires complex equipment and consumes high power. Chlorination hydrolysis is more cost-effective than oxidation hydrolysis, but it also has more side reactions and product quality cannot be guaranteed. The MnO2 method is simple, but requires high MnO2 activity, resulting in low utilization and limited industrial application value.

[0005] Low-temperature liquid-phase oxidation methods, such as those disclosed in the prior art, use manganese trioxide as a catalyst to selectively oxidize p-tert-butyltoluene in an acidic solution under low-temperature liquid-phase conditions to produce p-tert-butylbenzaldehyde; p-tert-butylbenzaldehyde is then used as a raw material to prepare porphyrin compounds. Manganese trioxide is soluble in sulfuric acid and is stable in moderate concentrations of sulfuric acid, not disproportionating to divalent manganese or manganese dioxide. Furthermore, it has oxidizing properties similar to trivalent ion salts in acidic solutions. During the reaction, manganese trioxide and sulfuric acid form a suspension. After the addition of p-tert-butyltoluene, an oil-water-solid three-phase reaction system is formed. The reaction ends when the purple color of the aqueous phase fades, and the reaction product dissolves in the oil phase and is distilled to obtain the product. However, the method uses a strong liquid acid, which is easily corrosive to equipment and poses significant 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 the catalyst carrier) as a catalyst to produce benzaldehyde through a hydrogenation reaction. This method can produce highly selective benzaldehyde derivatives. However, due to the difficulty in vaporizing salt substances, it is difficult to directly obtain sodium p-sulfonate benzaldehyde through hydrogenation.

[0007] The intermediate sulfonation method uses benzaldehyde and pyrrole as raw materials to prepare tetraphenylporphyrin. The tetraphenylporphyrin is then sulfonated to obtain a porphyrin compound containing a sulfonic acid group. While this method can improve yields to a certain extent when using strong acid homogeneous catalysis, the selectivity of the sulfonation reaction is low, the liquid strong acid is easily corrosive to equipment, and recovery and separation are also difficult. Using anhydrous aluminum chloride as a catalyst and chlorosulfonic acid as a sulfonation reagent, while anhydrous aluminum chloride improves yields and eliminates byproducts, it reacts readily with water, making product isolation difficult. Using chlorosulfonic acid as a sulfonation reagent offers significantly higher yields than sulfonation in a concentrated sulfuric acid environment, and the operating conditions are relatively simple and time-consuming, but chlorosulfonic acid is more corrosive, making it unsuitable for production.

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

[0009] In response to the shortcomings of the prior art, the present invention provides a method for preparing a porphyrin compound. The method has mild reaction conditions, high selectivity, greatly reduces the probability of side reactions, and produces a high yield and purity of the porphyrin. Furthermore, the method is non-corrosive to equipment, reduces costs, simplifies post-processing, 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, 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; wherein 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 relates to a Lewis acidic site, which is a stable adsorption site for aldehyde groups. The magnesium in the magnesium oxide combines with the aldehyde groups in the benzaldehyde derivative to activate the halogen on the benzene ring, and then obtains sulfonated benzaldehyde through a substitution reaction. The supported magnesium oxide is used to improve the catalyst utilization rate and catalytic efficiency. The non-ionic surfactant is a phase transfer catalyst. The non-ionic 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 facilitating the improvement of product yield and purity. The magnesium oxide is a lipophilic catalyst, and the product is easy to separate. At the same time, the preparation method adopts the steps of sulfonation followed by addition, which further improves the selectivity of the sulfonation reaction and improves the yield and purity of the product. The corrosion of equipment by strong acidic substances is avoided, the reaction conditions are mild, production safety is improved, and the requirements of green chemistry are met.

[0013] In the present invention, the halogen includes F, Cl, Br, and 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 values ​​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 loaded 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 of (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.; more 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 the aggregation of magnesium oxide, increase the contact area between the catalyst and the reactants, realize nano-catalysis, and improve the catalytic efficiency; and loading the nano-magnesium oxide on the 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 comprises: 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 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, the mass of which is 1 to 8% of the total mass of the activated carbon fiber and the nano-magnesium oxide; the solvent includes water, the mass of which 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 200-20,000, for example, 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, fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, aminosulfonic acid, sulfite or bisulfite, 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 of (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 reactants, water is used to dissolve the sulfonation reagent, and the alcohol compound and water form a mutually soluble state, providing a transfer channel for the reactants 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 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 header tank into the reactor by a metering pump, and the dropping speed of the reaction raw materials is controlled. After the dropwise addition 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. On the one hand, it can provide a weak acid environment to improve the solubility of pyrrole in the reaction system; on the other hand, it can catalyze the addition reaction to 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 of (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 in sequence.

[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 dropwise adding a pyrrole solution thereto for 20 to 40 minutes. After the dropwise addition is completed, heating and refluxing for 2 hours or more to stop 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 sulfonation reagent 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 of (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, an alcohol compound, and a mixed solvent of 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 includes not only the point values ​​listed above, but also 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 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 way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely 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 nanomagnesium oxide: The mass ratio of activated carbon fiber to nanomagnesium oxide (average particle size of 50 nm) was 1:1.5; the activated carbon fiber and nanomagnesium oxide (average particle size of 50 nm) were 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 the activated carbon fiber, nanomagnesium oxide, a dispersant, and a solvent at room temperature with stirring for 1 hour to obtain a dispersion; then filtering the dispersion and calcining the resulting solid at 600°C under a nitrogen atmosphere for 2 hours to obtain the activated carbon fiber-supported nanomagnesium oxide; wherein the dispersant is PEG200, the mass of which is 4% of the total mass of the activated carbon fiber and nanomagnesium 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, which comprises 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 70°C for 12 hours to obtain white crystals of sodium p-sulfonate benzaldehyde (yield: 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; the volume of the solvent is 200 mL based on a molar content of p-chlorobenzaldehyde of 1 mol; 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, 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, 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; the obtained crystals are dried in an oven at 100 ° C for 1.5 h, placed in a desiccator, and after cooling to room temperature, crude porphyrin sodium salt (mass 5.76 g, yield 45%) is obtained; the porphyrin sodium salt is recrystallized 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, i.e., purified porphyrin sodium salt.

[0071] (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 (the volume ratio of ethanol to water is 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 recrystallized in a mixed solvent of water and ethanol (total volume is 120 mL; the volume ratio of water to ethanol is 2:1), filtered, washed with deionized water 3 times, and vacuum dried at 80° C. for 10 h to obtain a green powder, namely, 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, the structure of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin obtained in Example 1 was characterized by hydrogen nuclear magnetic resonance spectrometry; specifically, a Mercury 300 NMR nuclear magnetic resonance spectrometer from Varian, USA was used, TMS was used as the internal reference, and deuterated DMSO was used as the 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, which comprises 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 under 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 In a large beaker, the mixture was gradually cooled to room temperature, 30 mL of ethanol was added, the mixture was cooled with ice water and allowed to stand for 10 h, and filtered. The obtained 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 desiccator, 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., 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%), 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 3 times, and vacuum dried at 80° C. for 10 h to obtain a green powder, namely, the porphyrin compound 5,10,15,20-tetrakis(4-sulfonylphenyl)porphyrin.

[0081] Example 3

[0082] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0083] Example 4

[0084] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0085] Example 5

[0086] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0087] Example 6

[0088] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0089] Example 7

[0090] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0091] Example 8

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

[0093] Example 9

[0094] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0095] Example 10

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

[0097] Example 11

[0098] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 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 Example 1.

[0099] Example 12

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

[0101] Example 13

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

[0103] Example 14

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

[0105] Example 15

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

[0107] Example 16

[0108] This embodiment provides a method for preparing a porphyrin compound, which differs from Example 1 only in that ethanol is replaced with an equal mass of n-butanol in step (3), and other raw materials, amounts, and step parameters are the same as those in Example 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 the 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 omitted, 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 preparation method of 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 the porphyrin compound 5,10,15,20-tetrakis(4-sulfonatophenyl)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 under 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 desiccator, 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 three times with deionized water, and vacuum dried at 80°C for 10 h to obtain a green powder, namely, the 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 (250 mm×4.6 id, particle size 5 μm); the mobile phase is methanol-buffer solution (volume ratio 15:85, buffer solution pH = 3); the flow rate is 0.8 mL / min; the maximum absorption wavelength of the SPD-10Avp ultraviolet spectrophotometer is 412~416 nm.

[0121] The yields of the products of each 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 before recrystallization of step (2) calculated; 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 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-sulfonatophenyl)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% or more, and the purity is ≥92%, and can even reach 95% or more; and the preparation method does not require the use of a strong acid catalyst, and does not require the introduction of a strongly acidic sulfonation reagent, thereby avoiding the corrosion of equipment by strongly acidic substances, and the reaction conditions are mild, thereby improving production safety and facilitating the large-scale production of porphyrin compounds.

[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 are only specific embodiments of the present invention and are 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 scope of protection of the present invention.

Claims

1. A method for preparing a porphyrin compound, characterized in that: The preparation method comprises the following steps: (1) In the presence of a catalyst, a benzaldehyde derivative is reacted with a sulfonating reagent at 70-90°C to obtain 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: Formula I; In formula I, X is selected from halogen; The catalyst in step (1) comprises supported magnesium oxide and a nonionic surfactant; The nonionic surfactant includes polyethylene glycol with a number average molecular weight of 200 to 1000; The reaction in step (1) is carried out in a solvent; the solvent comprises a mixed solvent of an alcohol compound having ≥4 carbon atoms and water; The molecular structure of the porphyrin compound contains a sulfonic acid group.

2. The preparation method according to claim 1, characterized in that The mass of the catalyst in step (1) is 5-15% of the mass of the benzaldehyde derivative.

3. The preparation method according to claim 1, characterized in that The mass ratio of the supported magnesium oxide to the nonionic surfactant is 1:(0.5-3).

4. The preparation method according to claim 3, characterized in that The mass ratio of the supported magnesium oxide to the nonionic surfactant is 1: (1-2).

5. The preparation method according to claim 1, characterized in that The supported magnesium oxide includes supported nano magnesium oxide.

6. The preparation method according to claim 1, characterized in that The carrier of the supported magnesium oxide includes activated carbon fiber.

7. The preparation method according to claim 6, characterized in that The mass ratio of the activated carbon fiber to magnesium oxide is 1:(0.05-0.4).

8. The preparation method according to claim 7, characterized in that The mass ratio of the activated carbon fiber to magnesium oxide is 1:(0.1-0.2).

9. The preparation method according to claim 1, characterized in that The molar ratio of the benzaldehyde derivative to the sulfonation reagent in step (1) is 1:(1-2).

10. The preparation method according to claim 1, characterized in that The sulfonating agent in step (1) includes at least one of concentrated sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, aminosulfonic acid, sulfite or bisulfite.

11. The preparation method according to claim 10, characterized in that: The sulfonating agent is sulfite.

12. The preparation method according to claim 11, characterized in that The sulfite includes sodium sulfite.

13. The preparation method according to claim 1, characterized in that The mass ratio of the alcohol compound to water is 1:(0.1~0.5).

14. The preparation method according to claim 13, characterized in that The mass ratio of the alcohol compound to water is 1:(0.1~0.2).

15. The preparation method according to claim 1, characterized in that The alcohol compound includes at least one of n-butanol, n-pentanol, n-hexanol or polyethylene glycol.

16. The preparation method according to claim 1, characterized in that The reaction time of step (1) is 8 to 24 hours.

17. The preparation method according to claim 1, characterized in that The acid catalyst in step (2) includes at least one of acetic acid, propionic acid, m-nitrobenzoic acid, o-nitrobenzoic acid or p-nitrobenzoic acid.

18. The preparation method according to claim 17, characterized in that: The acid catalyst is o-nitrobenzoic acid.

19. The preparation method according to claim 1, characterized in that The mass ratio of the acid catalyst to the sulfonated benzaldehyde in step (2) is (0.4-2):

1.

20. The preparation method according to claim 1, characterized in that The molar ratio of the sulfonated benzaldehyde to pyrrole in step (2) is 1:(1-2).

21. The preparation method according to claim 1, characterized in that The reaction in step (2) is carried out in an organic solvent.

22. The preparation method according to claim 21, characterized in that The organic solvent includes xylene.

23. The preparation method according to claim 1, characterized in that The reaction in step (2) includes heating under reflux.

24. The preparation method according to claim 23, characterized in that The heating reflux time is ≥2h.

25. The preparation method according to claim 1, characterized in that The reaction in step (2) also includes a post-treatment step.

26. The preparation method according to claim 25, characterized in that The post-treatment includes cooling crystallization, washing and first recrystallization performed in sequence.

27. The preparation method according to claim 25, characterized in that The post-treatment further includes a desalination step.

28. The preparation method according to claim 27, characterized in that The desalting treatment includes acidification and a second recrystallization performed sequentially.

29. The preparation method according to claim 28, characterized in that The acidification includes mixing the product obtained by post-treatment with an acidic liquid and a solvent for acidification.

30. The preparation method according to claim 29, characterized in that The solid-liquid mass ratio of the product obtained by the post-treatment to the acidic liquid is 1:(4-6).

31. The preparation method according to claim 29, characterized in that The acidic liquid includes dilute sulfuric acid.

32. The preparation method according to claim 29, characterized in that 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.

33. A preparation method according to claim 1, 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, an alcohol compound, and a mixed solvent of water, and the mixture is reacted at 70-90°C for 8-24 hours to obtain a sulfonated benzaldehyde; (2) In the presence of an acid catalyst, the sulfonated benzaldehyde obtained in step (1) is mixed with pyrrole and an organic solvent, heated under reflux for 2 hours or more, and then cooled for crystallization, washed, and subjected to a first recrystallization to obtain a porphyrin salt compound; (3) The porphyrin salt compound obtained in step (2) is mixed with an acidic liquid and 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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