The invention relates to a 5, 10, 15, 20-tetra (4apos; preparation method of porphyrin (-acetic acid pyridine halide salt)

Abstract

The invention belongs to the technical field of porphyrin compounds, and discloses a preparation method of 5, 10, 15, 20-tetra (4 '-acetoxypyridine halide salt) porphyrin, which comprises the following steps: uniformly dispersing 5, 10, 15, 20-tetra (4'-pyridyl) porphyrin serving as a raw material in an organic solvent, then adding halogenated ethyl acetate to react at 115-125 DEG C, and after the reaction is finished, separating and purifying to obtain the 5, 10, 15, 20-tetra (4 '-pyridyl) porphyrin. Washing, filtering and drying a product obtained after the reaction is finished to obtain an intermediate product; and uniformly mixing the intermediate product with a hydrochloric acid aqueous solution, carrying out a reaction at 100-105 DEG C, and carrying out rotary evaporation and drying on the product after the reaction is finished to obtain the 5, 10, 15, 20-tetra (4 '-acetic acid pyridine halide salt) porphyrin. The preparation process is simple, only the dosage of raw materials needs to be regulated and controlled, the operability is high, the preparation method is suitable for mass production, the oil bath reaction condition is mild, the production process is safe, and the industrial application prospect is good.

Description

Technical Field

[0001] The invention relates to the technical field of porphyrin compounds, and in particular to a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin. Background Art

[0002] Porphyrin is an important compound that is widely present in nature and living organisms, such as heme (ferroporphyrin), chlorophyll (magnesium porphyrin) and vitamin B 12 (Cobalt porphyrin) The core part is the metal complex of porphyrin, which plays a vital role in the metabolism of organisms. In addition, porphyrin and metalloporphyrin are dark solids with high melting points. Most of them are insoluble in water and alkali, but soluble in inorganic acids. The solution has fluorescence and other characteristics. Therefore, the research on porphyrin has always attracted much attention. Porphyrin is a compound with a conjugated macrocyclic structure composed of 20 carbon atoms and 4 nitrogen atoms. It contains 4 pyrrole molecules. The 4 nitrogen atoms in the center all contain lone pairs of electrons, which can combine with metal ions to form a macrocyclic conjugated system with 18 p electrons, which makes it have a unique cyclic conjugated structure and good photosensitivity, stable performance and easy modification. In view of the excellent properties of porphyrin and metalloporphyrin, it has shown attractive application prospects in bionic systems, molecular recognition, catalysis, materials, organic synthesis and medicine, which has made many researchers turn their attention to porphyrin and metalloporphyrin.

[0003] However, the prior art has the following defects in the preparation of porphyrin compounds: complex processing technology, low product yield, and many by-products resulting in low product purity, which is not suitable for large-scale production and also limits the further application of porphyrin compounds.

[0004] To this end, the present invention provides a 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin and a preparation method thereof. Summary of the invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a 5,10,15,20-tetrakis (4'-acetoxypyridinium halide) porphyrin and a preparation method thereof. Porphyrin and porphyrin-like compounds can be used as catalysts for visible light catalytic CO2 reduction, artificial development of solar cells, high-density molecular storage, cancer diagnosis and treatment, and molecular recognition and molecular applications similar to supramolecular functions.

[0006] The preparation method of 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin of the present invention is achieved by the following technical scheme:

[0007] A method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin comprises the following steps:

[0008] Step 1, using 5,10,15,20-tetrakis(4'-pyridyl)porphyrin as a raw material, uniformly dispersing it in an organic solvent, then adding ethyl halide, and reacting under reflux stirring at 115-125° C., washing, filtering, and drying the product obtained after the reaction to obtain an intermediate product;

[0009] Step 2, mixing the intermediate product with a hydrochloric acid aqueous solution, reacting at 100-105° C., and rotary evaporating and drying the product after the reaction to obtain the 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin.

[0010] Furthermore, the ethyl halide is any one of ethyl bromoacetate, ethyl fluoroacetate and ethyl chloroacetate.

[0011] Furthermore, the usage ratio of the 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to the ethyl halide acetate is 360-430 mg:0.08-0.09 mol.

[0012] Furthermore, the organic solvent is DMF.

[0013] Furthermore, the usage ratio of the 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to the organic solvent is 360-430 mg:35-45 mL.

[0014] Furthermore, in step 2, the concentration of the hydrochloric acid is 0.4 to 1 mol / L.

[0015] Furthermore, in step 1, the stirring rate of the reflux stirring reaction is 500-600 r / min, and the reaction time is 68-76 h.

[0016] Furthermore, in step 2, the reaction time is 72 to 78 hours.

[0017] Furthermore, in step 1, the washing solvent for washing is DMF.

[0018] Furthermore, in step 2, during the rotary evaporation, methanol solution is used for rotary evaporation.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses 5,10,15,20-tetrakis(4'-pyridyl)porphyrin as a raw material, and the inventors consider that the nitrogen atom on the pyridine ring in 5,10,15,20-tetrakis(4'-pyridyl)porphyrin has a sp 2The hybrid orbital does not participate in bonding, and is occupied by a pair of lone electrons, making it have a strong affinity. Therefore, the present invention adds ethyl halide to make it react with ethyl halide to undergo a nucleophilic reaction, thereby converting 5,10,15,20-tetrakis(4'-pyridyl)porphyrin into an intermediate product in the form of an inner salt. Then, by fully hydrolyzing the ester group in the intermediate product under heating and acidic conditions, a high yield of 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin can be obtained.

[0021] The carboxylic acid formed after hydrolysis can form a P-π conjugation with the pyridine ring on the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin, thereby improving the stability of the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin, and the carboxylic acid functional groups on the four pyridine rings in the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin can all be coordinated with metal ions, thereby facilitating the coordination of the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin prepared by the present invention with metal ions according to actual needs to obtain the corresponding single crystal metal porphyrin, thereby facilitating the technical personnel in the field to further study the performance of the porphyrin complex.

[0022] The preparation process of the invention is simple, and only needs to adjust the amount of raw materials, has strong operability, is suitable for mass production, has mild oil bath reaction conditions below 120° C., has a safe production process, and has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The reaction flow chart of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1;

[0024] Figure 2 The infrared spectra of the raw material 5,10,15,20-tetrakis(4'-pyridyl)porphyrin in Example 1 and the 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1;

[0025] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0027] The present invention provides a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin, comprising the following steps:

[0028] Step 1, using 5,10,15,20-tetrakis(4'-pyridyl)porphyrin as a raw material, uniformly dispersing it in an organic solvent, then adding ethyl halide and reacting at 115-125° C., washing, filtering and drying the product obtained after the reaction to obtain an intermediate product;

[0029] It should be noted that the present invention uses 5,10,15,20-tetra(4'-pyridyl)porphyrin as a raw material, which has a very mature synthesis technology and high yield, high purity and low raw material cost. It can not only improve the purity of the product from the source, but also the nitrogen atom on the pyridine ring in 5,10,15,20-tetra(4'-pyridyl)porphyrin has an sp 2 The hybrid orbital does not participate in bonding, and is occupied by a pair of lone pairs of electrons, which makes it have a strong affinity, and is convenient for nucleophilic reaction with ethyl halide, and converts 5,10,15,20-tetra(4'-pyridyl)porphyrin to form an intermediate product in the form of an inner salt, so that in the subsequent treatment process, the ester group in the intermediate product is fully hydrolyzed under heating and acidic conditions, and then a high yield of 5,10,15,20-tetra(4'-acetylpyridinium halide)porphyrin can be obtained. Therefore, the present invention can obtain 5,10,15,20-tetra(4'-acetylpyridinium halide)porphyrin in only two steps, and the prepared 5,10,15,20-tetra(4'-acetylpyridinium halide)porphyrin has a high yield and is suitable for large-scale production.

[0030] In addition, the present invention takes into account the solubility of 5,10,15,20-tetrakis (4'-pyridyl) porphyrin, so DMF (N,N-dimethylformamide) is preferably used as an organic solvent, and the 5,10,15,20-tetrakis (4'-pyridyl) porphyrin and DMF are mixed uniformly in a ratio of 360-430 mg: 35-45 mL. Then, according to the ratio of 5,10,15,20-tetrakis (4'-pyridyl) porphyrin and ethyl halide ester 360-430 mg: 0.08-0.09 mol, ethyl halide ester is added and mixed uniformly, and then placed in an oil bath temperature of 115-125° C. for reaction for 68-76 hours, so that the ethyl halide ester modifies 5,10,15,20-tetrakis (4'-pyridyl) porphyrin in the environment of DMF to obtain an intermediate product. In order to reduce the influence of impurities, the product obtained after the reaction in this step is washed three times with DMF, then filtered, and the solid component obtained is dried to obtain an intermediate product. Wherein, the ethyl halide is any one of ethyl bromoacetate, ethyl fluoroacetate, and ethyl chloroacetate.

[0031] Step 2, mixing the intermediate product with an aqueous hydrochloric acid solution, reacting at 100-105° C., and rotary evaporating and drying the product after the reaction to obtain the 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin;

[0032] It should be noted that, in the present invention, the intermediate product obtained above is placed in a hydrochloric acid aqueous solution and placed in an oil bath temperature of 100 to 105° C. for reaction, so that the ester group in the intermediate product is fully hydrolyzed, thereby obtaining 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin, and the carboxylic acid formed after hydrolysis can form a P-π conjugation with the pyridine ring on the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin, thereby improving the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin. The stability of 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin is improved, and the carboxylic acid functional groups on the four pyridine rings in 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin can all be coordinated with metal ions, which helps to coordinate the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin prepared by the present invention with metal ions according to actual needs to obtain the corresponding single crystal metal porphyrin, which can help those skilled in the art to further study the performance of porphyrin complexes.

[0033] Example 1

[0034] Figure 1 For the reaction flow chart of 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin prepared in Example 1, please refer to Figure 1 This embodiment provides a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin:

[0035] 1) Add 360 mg of 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to a round-bottom flask containing 35 mL of DMF (N,N-dimethylformamide) and stir to mix, then add 0.08 mol of ethyl bromoacetate and stir to mix to obtain a mixed solution in the round-bottom flask;

[0036] 2) The round-bottom flask containing the mixed solution was heated in an oil bath at 115° C. for 68 h. After the reaction was completed, it was washed three times with DMF and then filtered to obtain an intermediate product after preliminary modification of ethyl bromoacetate;

[0037] 3) 2 mol / L HCl was mixed with water in a volume ratio of 1:3.5 to obtain a total volume of 18 mL of hydrochloric acid aqueous solution, and then the above intermediate product was added and mixed, and then the mixture was stirred in an oil bath at 100° C. for 72 h. After the reaction was completed, the mixture was cooled to room temperature and rotary evaporated with methanol solution to remove the water remaining in the round-bottom flask. The mixture was then placed in an oven at 75° C. and dried for 1.5 h to obtain 605 mg of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin, and the yield was calculated to be as high as 88%.

[0038] Example 2

[0039] This embodiment provides a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin as follows:

[0040] 1) Add 400 mg of 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to a round-bottom flask containing 40 mL of DMF and stir to mix, then add 0.085 mol of ethyl bromoacetate and stir to mix to obtain a mixed solution in the round-bottom flask;

[0041] 2) The round-bottom flask containing the mixed solution was heated in an oil bath at 120° C. for 72 h. After the reaction was completed, it was washed three times with DMF and then filtered to obtain an intermediate product after preliminary modification of ethyl bromoacetate;

[0042] 3) 3 mol / L HCl and water were mixed in a volume ratio of 1:4 to obtain a total volume of 15 mL of hydrochloric acid aqueous solution, and then the above intermediate product was added and mixed, and then the mixture was stirred in an oil bath at 105° C. for 72 h. After the reaction was completed, the mixture was cooled to room temperature, and a methanol solution was used for rotary evaporation to remove the water remaining in the round-bottom flask, and then the mixture was placed in an oven at 75° C. and dried for 2 h to obtain 680 mg of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin, and the yield was calculated to be as high as 90%.

[0043] Example 3

[0044] This embodiment provides a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin as follows:

[0045] 1) Add 430 mg of 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to a round-bottom flask containing 45 mL of DMF and stir to mix, then add 0.09 mol of ethyl bromoacetate and stir to mix to obtain a mixed solution in the round-bottom flask;

[0046] 2) The round-bottom flask containing the mixed solution was heated in an oil bath at 125° C. for 72 h. After the reaction was completed, it was washed three times with DMF and then filtered to obtain an intermediate product after preliminary modification of ethyl bromoacetate;

[0047] 3) 4 mol / L HCl was mixed with water in a volume ratio of 1:4.5 to obtain a total volume of 22 mL of hydrochloric acid aqueous solution, and then the above intermediate product was added and mixed, and then the mixture was stirred in an oil bath at 105° C. for 76 h. After the reaction was completed, the mixture was cooled to room temperature, and a methanol solution was used for rotary evaporation to remove the water remaining in the round-bottom flask, and then the mixture was placed in an oven at 80° C. and dried for 2 h to obtain 740 mg of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin, and the yield was still as high as 91% after calculation.

[0048] Example 4

[0049] The difference between this embodiment and embodiment 1 is only that:

[0050] The ethyl halide used in this example is ethyl fluoroacetate, and the yield of 5,10,15,20-tetrakis(4'-acetoxypyridinium fluoride)porphyrin prepared in this example is 89%.

[0051] Example 5

[0052] The difference between this embodiment and embodiment 1 is only that:

[0053] The ethyl halide used in this example is ethyl chloroacetate, and the yield of 5,10,15,20-tetrakis(4'-acetoxypyridinium chloride)porphyrin prepared in this example is 88.7%.

[0054] Comparative Example 1

[0055] This comparative example provides a method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin:

[0056] 1) Add 500 mg of 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to 40 mL of DMF and stir to mix, then add 0.085 mol of ethyl bromoacetate and stir to mix to obtain a mixed solution;

[0057] 2) The mixed solution was heated in an oil bath at 120° C. for 72 h. After the reaction was completed, it was washed three times with DMF and then filtered to obtain an intermediate product after preliminary modification of ethyl bromoacetate;

[0058] 3) 6 mol / L HCl and water were mixed in a volume ratio of 1:4 to obtain a total volume of 15 mL of hydrochloric acid aqueous solution, and then the above intermediate product was added and mixed, and then the mixture was stirred in an oil bath at 105° C. for 72 h. After the reaction was completed, the mixture was cooled to room temperature, rotary evaporated using a methanol solution, and then dried in an oven at 75° C. for 2 h. The yield of the obtained 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin was greatly reduced to only 37%.

[0059] Comparative Example 2

[0060] This comparative example provides a 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin, and its preparation method is as follows:

[0061] 1) Add 430 mg of 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to 45 mL of DMF and stir to mix, then add 0.09 mol of ethyl bromoacetate to obtain a mixed solution;

[0062] 2) The mixed solution was controlled to be heated in an oil bath at 120° C. for 72 h. After the reaction was completed, it was washed three times with DMF and then filtered to obtain an intermediate product after preliminary modification of ethyl bromoacetate;

[0063] 3) 1 mol / L HCl was mixed with water in a volume ratio of 1:4.5 to obtain a total volume of 22 mL of hydrochloric acid aqueous solution, and then the above intermediate product was added and mixed, and then the mixture was stirred in an oil bath at 105° C. for 76 h. After the reaction was completed, the mixture was cooled to room temperature, and a methanol solution was used for rotary evaporation to remove the water remaining in the round-bottom flask, and then the mixture was placed in an oven at 80° C. and dried for 2 h to obtain 320 mg of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin, and the yield was greatly reduced to only 39%.

[0064] By comparing the yields of Comparative Example 1 and Example 2, and the yields of Comparative Example 2 and Example 3, it can be seen that the ratio of 5,10,15,20-tetra(4'-pyridyl)porphyrin to ethyl bromoacetate, and the acid concentration of the hydrolysis treatment will affect the purity and yield of 5,10,15,20-tetra(4'-acetylpyridinium bromide)porphyrin. This may be due to the fact that if the ratio of 5,10,15,20-tetra(4'-pyridyl)porphyrin to ethyl bromoacetate is not appropriate, excessive or insufficient ethyl bromoacetate usage will affect the modification effect of ethyl bromoacetate on 5,10,15,20-tetra(4'-pyridyl)porphyrin, which may result in only one, two or three pyridine rings on the four pyridine rings. Ethyl bromoacetate is introduced, which will reduce the yield of the intermediate product while also introducing more by-products, thereby affecting the effect of the subsequent hydrolysis treatment. Moreover, during the hydrolysis treatment process, the acid concentration of the system will also seriously affect the yield of the product. Too high or too low an acid concentration will result in the ester groups connected to the four pyridines on the intermediate product not being completely hydrolyzed, resulting in only one ester group being hydrolyzed, or two or three ester groups being hydrolyzed. This will not only lead to a low yield of the product, but will also introduce more by-products, thereby causing a low yield of the prepared target product 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin.

[0065] In summary, the key to obtaining 5,10,15,20-tetrakis(4'-pyridinium bromide)porphyrin with high yield and high purity in the present invention is to control the dosage ratio of 5,10,15,20-tetrakis(4'-pyridinyl)porphyrin to ethyl halide to 360-430 mg:0.08-0.09 mol, the oil bath reaction temperature to 115-125° C., and the reaction time to 68-76 h, so that ethyl halide can fully modify 5,10,15,20-tetrakis(4'-pyridinyl)porphyrin to obtain an intermediate product with high yield; and then, by limiting the concentration of the hydrochloric acid aqueous solution in the hydrolysis treatment step (i.e., step 2) to 0.4-1 mol / L, the ester group in the intermediate product can be fully hydrolyzed, thereby greatly improving the yield of 5,10,15,20-tetrakis(4'-pyridinium halide)porphyrin.

[0066] Experimental part

[0067] (I) Infrared spectrum test

[0068] The present invention takes the preparation raw material 5,10,15,20-tetrakis(4'-pyridyl)porphyrin in Example 1 and the 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1 as examples, and performs infrared spectrum tests on them respectively, and the test results are as follows: Figure 2 shown.

[0069] Depend on Figure 2It can be seen that compared with 5,10,15,20-tetrakis(4'-pyridyl)porphyrin, the infrared spectrum of 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1 has a peak at 1681 cm -1 C=O stretching vibration appears at 2920cm -1 The CH2 (methylene) symmetric stretching vibration appears around 2850cm -1 The antisymmetric stretching vibration of CH2 (methylene) occurs. However, the initial raw material 5,10,15,20-tetrakis(4'-pyridyl)porphyrin does not contain a carboxyl group, that is, it does not contain C=O stretching vibration, that is, the present invention has successfully synthesized 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin.

[0070] (II) Hydrogen Nuclear Magnetic Resonance Test

[0071] The present invention takes the 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin prepared in Example 1 as an example, and performs a hydrogen nuclear magnetic resonance test on it. The test results are as follows: Figure 3 shown.

[0072] Depend on Figure 3 It can be seen that the hydrogen atom number integral and chemical shift values ​​are as follows, 1H NMR (600 MHz, DMSO) (δ / ppm) 9.61 (d, 4H), 9.60 (d, 4H), 9.16 (d, 8H), 9.15 (d, 8H), 6.00 (s, 8H), 3.03 (s, 2H), indicating that the present invention successfully synthesized 5,10,15,20-tetrakis(4'-acetoxypyridinium bromide)porphyrin.

[0073] The prior art discloses that porphyrin and its derivatives can be used as catalysts for visible light catalytic CO2 reduction, and the prior art also discloses that porphyrin compounds with a structure similar to the 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin of the present application are chemically doped with molecule Re(I) to form a novel porphyrin-organic framework (MOF)-Re(I) hybrid visible light catalytic CO2 reduction catalyst; and the catalyst, in the case where the volume of water accounts for 3% and the volume of DMF (N,N-dimethylformamide) accounts for 97%, reduces CO2 to CO with a turnover number of ≥1893 [1070±80μmolh-1] in 59 hours. -1 (gMOF) -1]. Compared with traditional porphyrin compounds, the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin prepared by the present invention has more coordination sites and can be coordinated with multiple metals to obtain complexes with more complex structures, which provides more selection basis for people to further explore the performance of porphyrin complexes, such as its application in catalysts for visible light catalytic CO2 reduction: 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin is a structurally symmetrical conjugated molecule, which is relatively stable and has the properties of acid, alkali and sunlight resistance. At the same time, due to the construction of the 5,10,15,20-tetrakis(4'-acetylpyridinium halide)porphyrin molecular array, its structure remains unchanged after energy or electron transfer occurs, which is a prerequisite for sustainable light harvesters. Moreover, the 5,10,15,20-tetrakis(4'-acetoxypyridinium halide) porphyrin prepared in the present application has become an inner salt-type pyridine ring compared with the porphyrin compounds previously used as catalysts for visible light catalytic CO2 reduction, which will be more conducive to the transfer of electrons and provide a better basis for the preparation of catalysts for visible light catalytic CO2 reduction. Moreover, the preparation method of this new porphyrin compound is simple to operate, has a high yield, and is suitable for large-scale production.

[0074] Obviously, the above embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for preparing 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin, characterized in that: The following steps are involved: Step 1, using 5,10,15,20-tetrakis(4'-pyridyl)porphyrin as a raw material, uniformly dispersing it in an organic solvent, then adding ethyl halide, and reacting under reflux stirring at 115-125° C., washing, filtering, and drying the product obtained after the reaction to obtain an intermediate product; Step 2, mixing the intermediate product with a hydrochloric acid aqueous solution, reacting at 100-105° C., and rotary evaporating and drying the product after the reaction to obtain the 5,10,15,20-tetrakis(4'-acetoxypyridinium halide)porphyrin.

2. The preparation method according to claim 1, characterized in that The ethyl halide is any one of ethyl bromoacetate, ethyl fluoroacetate and ethyl chloroacetate.

3. The preparation method according to claim 1, characterized in that: The usage ratio of the 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to the ethyl halide acetate is 360-430 mg:0.08-0.09 mol.

4. The preparation method according to claim 1, characterized in that: The organic solvent is DMF.

5. The preparation method according to claim 1, characterized in that: The usage ratio of the 5,10,15,20-tetrakis(4'-pyridyl)porphyrin to the organic solvent is 360-430 mg:35-45 mL.

6. The preparation method according to claim 1, characterized in that: In step 2, the concentration of the hydrochloric acid aqueous solution is 0.4 to 1 mol / L.

7. The preparation method according to claim 1, characterized in that: The stirring rate of the reflux stirring reaction is 500-600 r / min, and the reaction time is 68-76 h.

8. The preparation method according to claim 1, characterized in that: In step 2, the reaction time is 72 to 78 hours.

9. The preparation method according to claim 1, characterized in that: In step 1, the washing solvent used in the washing is DMF.

10. The preparation method according to claim 1, characterized in that: In step 2, during the rotary evaporation, methanol solution is used for rotary evaporation to remove residual water.

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