Process for the preparation of a substituted diphenylporphyrin-2-carbaldehyde
The one-step synthesis of substituted diphenylporphyrin-2-carboxaldehyde solves the problem of numerous steps in the synthesis of formylporphyrins, achieving the effects of simplified operation, reduced cost and improved purity, and expanding the functional applications of porphyrins.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUNAN UNIV OF SCI & TECH
- Filing Date
- 2024-09-03
- Publication Date
- 2026-05-19
AI Technical Summary
Existing synthetic methods for formylporphyrins involve numerous steps, complex operations, large reagent consumption, and difficult separation, which limits their subsequent applications.
A one-step method was adopted to synthesize substituted diphenylporphyrin-2-carboxaldehyde. 5-substituted phenyl dipyrrolemethane was reacted with trialkyl orthoformate in an organic solvent, followed by pH adjustment with dropwise addition of organic acid and oxidation. The resulting product was purified by silica gel column chromatography, simplifying the preparation process.
It significantly reduces the number of operation steps and reagent usage, simplifies product separation, lowers costs, provides target products with higher purity, and enhances the functionalization potential of porphyrins.
Smart Images
Figure CN119219645B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of porphyrin derivative preparation technology, and more specifically to a method for preparing substituted diphenylporphyrin-2-carboxaldehyde. Background Technology
[0002] Porphyrins are highly conjugated macrocyclic compounds with excellent photophysical properties, including good photothermal stability, large Stokes shift, and long emission wavelength. They have wide applications in photodynamic therapy, optoelectronic devices, fluorescence analysis, photoelectrocatalysis, and supramolecular chemistry. Therefore, the synthesis of porphyrins and their derivatives has always attracted widespread attention from researchers.
[0003] Traditional porphyrin synthesis methods include the Adler-Longo method, the Lindsey method, the 2-substituted pyrrole cyclization reaction method, the [2+2] method, the [3+1] method, and modification of the porphyrin's peripheral substituents. These methods can yield various types of porphyrin derivatives, such as symmetrical and asymmetrical porphyrins, and porphyrin derivatives containing one or more functional groups (e.g., aldehyde, sulfonic acid, carboxyl, halogen, hydroxyl, nitro, amino, alkyl, and aryl groups). Currently, the types and quantities of porphyrins have increased significantly, and their properties and applications have been further improved. Introducing active functional groups into the porphyrin molecule is a fundamental method for synthesizing porphyrin intermediates or improving their application properties. For example, introducing sulfonic acid or carboxyl groups can improve water solubility, introducing halogens can facilitate intermolecular C / C bond coupling, and further modifications can be made using introduced active amino and aldehyde groups. Formylation of porphyrins (introducing an aldehyde group onto the porphyrin ring) has attracted widespread attention from researchers.
[0004] Currently, the formylation reaction of porphyrins requires the following four steps: the first step is to synthesize the porphyrin parent material; the second step is to complex the porphyrin parent material with metals such as copper and nickel to obtain metal porphyrins; the third step is to introduce a formyl group at the meso or β(2) position of the metal porphyrin through the Vilsmeier formylation reaction to obtain formyl metal porphyrins; and the fourth step is to remove the metal from the formyl metal porphyrin under strongly acidic conditions to finally obtain formyl free porphyrins. Because of the many steps involved in the synthesis, there are disadvantages such as complex operation, large reagent consumption, and difficult separation, which greatly limits the subsequent application of formyl porphyrins. Therefore, how to minimize the number of steps in the synthesis of formyl porphyrins to reduce reagent consumption and lower the difficulty of operation and separation is of great practical significance.
[0005] In view of this, the present invention is proposed. Summary of the Invention
[0006] This invention provides a method for preparing substituted diphenylporphyrin-2-carboxaldehyde, which solves the problem of too many steps in the existing preparation of formylporphyrin.
[0007] In a first aspect, the present invention provides a method for preparing substituted diphenylporphyrin-2-carboxaldehyde. Exemplarily, the substituted diphenylporphyrin-2-carboxaldehyde is 5,15-diphenylporphyrin-2-carboxaldehyde, 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde, 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde, 5,15-bis(4-nitrophenyl)porphyrin-2-carboxaldehyde, 5,15-bis(4-dimethylaminophenyl)porphyrin-2-carboxaldehyde, and 5,15-bis(4-diphenylaminophenyl)porphyrin-2-carboxaldehyde. The preparation method includes the following steps: reacting 5-substituted phenyldipyrrolemethane and trialkyl orthoformate in an organic solvent system under an anaerobic environment until the system becomes transparent; adding organic acid dropwise and reacting at room temperature in the dark until the 5-substituted phenyldipyrrolemethane reacts completely; adding a pH adjuster to adjust the reaction system to alkaline, mixing until the reaction is quenched, and then oxidizing the reaction with oxygen to obtain the target product. An anaerobic environment is used to prevent the oxidation of 5-substituted phenyldipyrrolemethane.
[0008] Exemplarily, the synthetic route for the substituted diphenylporphyrin-2-carboxaldehyde is shown in Formula I.
[0009]
[0010] In Formula I, R is any one of -H, -OCOCH3, -OCH3, -NO2, -N(CH3)2 and -N(C6H5)2.
[0011] As one possible implementation, the 5-substituted phenyl dipyrrolemethane is any one of 5-phenyl dipyrrolemethane, 5-(4-acetoxyphenyl) dipyrrolemethane, 5-(4-methoxyphenyl) dipyrrolemethane, 5-(4-nitrophenyl) dipyrrolemethane, 5-(4-N,N-dimethylaminophenyl) dipyrrolemethane, and 5-(4-N,N-diphenylaminophenyl) dipyrrolemethane; and / or, the trialkyl orthoformate is one of triethyl orthoformate and trimethyl orthoformate; and / or, the organic acid is one of trifluoroacetic acid and trichloroacetic acid. Among these, considering electronic effects, the 5-substituted phenyldipyrrolemethanes selected are those mentioned above. Methoxy, 4-N,N-dimethylaminophenyl, and 4-N,N-diphenylaminophenyl are electron-donating groups, while nitro is an electron-withdrawing group. 5-Phenylated dipyrrolemethane, however, contains only hydrogen, meaning it lacks both electron-donating and electron-withdrawing groups. Therefore, the selectivity of substituents on the benzene ring of 5-phenyldipyrrolemethane is broad. Trialkyl orthoformate has two functions: firstly, as a reaction reagent (i.e., a cyclizing agent) in the synthesis of diphenylporphyrins; and secondly, as a formylation reagent (i.e., introducing an aldehyde group) for diphenylporphyrins.
[0012] As one possible implementation, the reaction of 5-substituted phenyl dipyrrolemethane and trialkyl orthoformate in an organic solvent system under anaerobic conditions until the system becomes transparent, wherein the molar ratio of 5-substituted phenyl dipyrrolemethane to trialkyl orthoformate is 1:40-80; and / or, the ratio of 5-substituted phenyl dipyrrolemethane to the organic solvent is 1 mmol:230-300 mL; and / or, the addition of an organic acid, wherein the molar ratio of 5-substituted phenyl dipyrrolemethane to the organic acid is 1:23-26.
[0013] As one possible implementation, the organic solvent system contains dichloromethane or chloroform as the organic solvent; and / or the oxygen-free environment is a sealed, light-proof, nitrogen-filled environment.
[0014] As one possible implementation, the organic acid is a solution of an organic acid, and the solvent is one of dichloromethane and chloroform; the concentration of the organic acid in the solution is 0.17 to 0.25 mol / L.
[0015] As one possible implementation, the pH adjuster is any one of triethylamine, pyridine, and ammonia; and / or, adjusting the reaction system to alkalinity means adjusting the pH of the reaction system to 8-10.
[0016] As one possible implementation, the method further includes: sequentially evaporating and drying the product of the oxidation reaction to obtain a crude product; separating and purifying the crude product using silica gel column chromatography, collecting the second band to obtain the substituted diphenylporphyrin-2-carboxaldehyde; and removing dichloromethane and triethylamine by rotary evaporation under reduced pressure.
[0017] As one possible implementation, the evaporation is reduced-pressure rotary evaporation; and / or, the drying is vacuum drying; and / or, in the silica gel column chromatography, a mixture of dichloromethane and petroleum ether is used as the eluent; and / or, in the mixture of dichloromethane and petroleum ether, the volume ratio of dichloromethane to petroleum ether is 1:1 to 3.
[0018] In a second aspect, the present invention provides a substituted diphenylporphyrin-2-carboxaldehyde prepared by the preparation method described in any possible implementation of the first aspect.
[0019] Thirdly, the present invention provides the application of the substituted diphenylporphyrin-2-carboxaldehyde described in the second aspect in the preparation of a drug.
[0020] The preparation method provided by this invention uses 5-substituted phenyl dipyrrolemethane as a precursor and trialkyl orthoformate as a cyclizing and formylating agent. Under acid catalysis, a one-pot method involving cyclization, formylation, quenching, and oxidation is used to obtain substituted diphenylporphyrin-2-carboxaldehyde. This invention reduces the four steps of the prior art to one step, significantly reducing the number of steps in the preparation process, significantly reducing the amount of reagents used, simplifying the operation, and making the product easier to separate and purify.
[0021] The preparation method provided by this invention uses trialkyl orthoformate as the cyclizing and formylating agent, resulting in low reagent cost and small dosage. It employs organic acid as a catalyst, making the reagents widely available, low in cost, and requiring small dosage. This significantly reduces the reagent dosage and preparation cost for substituted diphenylporphyrin-2-carboxaldehyde. The preparation method uses vacuum rotary evaporation to remove impurities such as dichloromethane and triethylamine, and vacuum drying to obtain the crude product; the purification method is simple and easy to operate. This invention uses silica gel column chromatography to separate the crude product to obtain the target product with higher purity; the separation method is simple and easy to operate.
[0022] The preparation method provided by this invention introduces multiple functional groups simultaneously, which has potential application value in the further functionalization modification of porphyrins. The aldehyde group is a highly chemically reactive functional group; reducing the aldehyde group to a carboxyl group yields carboxyl-containing diphenylporphyrins, enhancing water solubility. Through Schiff base reactions, amino compounds are bonded, forming Schiff base porphyrins with amines. Schiff bases possess antibacterial activity, and porphyrins can generate singlet states, thereby enhancing the application of porphyrins in biomedicine. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 Mass spectrometry [M+H] of 5,15-diphenylporphyrin-2-carboxaldehyde provided in this embodiment of the invention. + picture.
[0025] Figure 2 The 1H NMR spectrum of 5,15-diphenylporphyrin-2-carboxaldehyde provided in this embodiment of the invention.
[0026] Figure 3 Mass spectrometry [M+H] of 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde provided in this embodiment of the invention. + picture.
[0027] Figure 4The 1H NMR spectrum of 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde provided in an embodiment of the present invention.
[0028] Figure 5 Mass spectrometry [M+H] of 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde provided in this embodiment of the invention. + picture.
[0029] Figure 6 The 1H NMR spectrum of 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde provided in the embodiments of the present invention. Detailed Implementation
[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] To address the problem of excessive steps in existing methods for preparing formylporphyrins, this invention provides a method for preparing substituted diphenylporphyrin-2-carboxaldehyde.
[0032] The preparation method of substituted diphenylporphyrin-2-carboxaldehyde provided in this invention includes the following steps: reacting 5-substituted phenyldipyrrolemethane and trialkyl orthoformate in an organic solvent system under an oxygen-free environment until the system becomes transparent; adding organic acid dropwise and reacting at room temperature in the dark until the 5-substituted phenyldipyrrolemethane reacts completely; adding a pH adjuster to adjust the reaction system to alkaline, mixing until the reaction is quenched, and then introducing oxygen to oxidize the reaction to obtain substituted diphenylporphyrin-2-carboxaldehyde.
[0033] Furthermore, in the embodiments of the present invention, 5,15-diphenylporphyrin-2-carboxaldehyde, 5,15-di(4-acetoxyphenyl)porphyrin-2-carboxaldehyde, 5,15-di(4-methoxyphenyl)porphyrin-2-carboxaldehyde, 5,15-di(4-nitrophenyl)porphyrin-2-carboxaldehyde, 5,15-di(4-dimethylaminophenyl)porphyrin-2-carboxaldehyde and 5,15-di(4-diphenylaminophenyl)porphyrin-2-carboxaldehyde were prepared using the preparation method provided by the present invention.
[0034] The method provided by this invention reduces the preparation process of substituted diphenylporphyrin-2-carboxaldehyde from four steps to one step, significantly reducing the amount of reagents used, making the operation simpler, and making the product easier to separate and purify.
[0035] The technical solution of the present invention will be further described below with reference to specific embodiments.
[0036] Example 1
[0037] This embodiment provides a method for preparing 5,15-diphenylporphyrin-2-carboxaldehyde.
[0038]
[0039] Following the synthetic route shown in Formula II, 252 mg of 5-phenyldipyrrolemethane (Compound 1, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the system became transparent. The mixed solution in the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 5 hours until it turned dark green. Triethylamine (TEA) was added to adjust the pH of the reaction system to 8. The mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours until it emitted a strong red fluorescence under 365 nm ultraviolet light. The reaction solution was subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine. The solution was then dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether in a volume ratio of 1:1. The second band was collected to obtain pure purple 5,15-diphenylporphyrin-2-carboxaldehyde (compound 2); its mass spectrum is shown below. Figure 1 1H NMR spectrum (solvent: CD2Cl2) Figure 2 ,Depend on Figure 1 and Figure 2 As can be seen, 5,15-diphenylporphyrin-2-carboxaldehyde was prepared in this embodiment.
[0040] Example 2
[0041] This embodiment provides a method for preparing 5,15-diphenylporphyrin-2-carboxaldehyde.
[0042]
[0043] Following the synthetic route shown in Formula III, 252 mg of 5-phenyldipyrrolemethane (Compound 1, 1.0 mmol), 8.8 mL of trimethyl orthoformate (CH(MeO)3, 80 mmol), and 300 mL of dichloromethane were added to a three-necked flask. A mixture of 156 mL of dichloromethane and 1.9 mL of trifluoroacetic acid (TFA, 26 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 10 hours. Pyridine was added to adjust the pH of the reaction system to 10, and the mixture was stirred for 4 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 24 hours. The reaction solution was subjected to rotary evaporation under reduced pressure to remove dichloromethane and pyridine, and then dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether in a volume ratio of 1:3. The second band was collected, ultimately yielding pure purple 5,15-diphenylporphyrin-2-carboxaldehyde (compound 2); its mass spectrum is shown below. Figure 1 1H NMR spectrum (solvent: CD2Cl2) Figure 2 ,Depend on Figure 1 and Figure 2 As can be seen, 5,15-diphenylporphyrin-2-carboxaldehyde was prepared in this embodiment.
[0044] Example 3
[0045] This embodiment provides a method for preparing 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde.
[0046]
[0047] Following the synthetic route shown in Formula IV, 280 mg of 5-(4-acetoxyphenyl)dipyrrolemethane (compound 3, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 5 hours. Triethylamine (TEA) was added to adjust the pH of the reaction system to 8, and the mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours. The reaction solution was then subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine, and dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and petroleum ether as the eluent, with a volume ratio of dichloromethane:petroleum ether = 1:1. The second band was collected, ultimately yielding pure 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde (compound 4) in purple; its mass spectrum is shown below. Figure 3 1H NMR spectrum (solvent: CD2Cl2) Figure 4 ,Depend on Figure 3 and Figure 4 As can be seen, 5,15-bis(4-acetoxyphenyl)porphyrin-2-carboxaldehyde was prepared in this embodiment.
[0048] Example 4
[0049] This embodiment provides a method for preparing 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde.
[0050]
[0051] Following the synthetic route shown in Formula V, 252 mg of 5-(4-methoxyphenyl)dipyrrolemethane (compound 5, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 10 hours. Then, triethylamine (TEA) was added to adjust the pH of the reaction system to 8, and the mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours. The reaction solution was then subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine, and dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixed solvent of dichloromethane and petroleum ether in a volume ratio of 1:1. The second band was collected, ultimately yielding pure purple 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde (compound 6); its mass spectrum is shown below. Figure 5 1H NMR spectrum (solvent: CD2Cl2) Figure 6 ,Depend on Figure 5 and Figure 6 As can be seen, 5,15-bis(4-methoxyphenyl)porphyrin-2-carboxaldehyde was prepared in this embodiment.
[0052] Example 5
[0053] This embodiment provides a method for preparing 5,15-bis(4-nitrophenyl)porphyrin-2-carboxaldehyde.
[0054]
[0055] Following the synthetic route shown in Formula VI, 267 mg of 5-(4-nitrophenyl)dipyrrolemethane (compound 7, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 5 hours. Triethylamine (TEA) was added to adjust the pH of the reaction system to 8, and the mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours. The reaction solution was then subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine. The solution was dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and petroleum ether as the eluent, with a volume ratio of dichloromethane:petroleum ether = 1:1. The second band was collected, ultimately yielding pure purple 5,15-bis(4-nitrophenyl)porphyrin-2-carboxaldehyde (compound 8).
[0056] Example 6
[0057] This embodiment provides a method for preparing 5,15-bis(4-dimethylaminophenyl)porphyrin-2-carboxaldehyde.
[0058]
[0059] Following the synthetic route shown in Formula VII, 265 mg of 5-(4-N,N-dimethylaminophenyl)dipyrrolemethane (compound 9, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 5 hours. Triethylamine (TEA) was added to adjust the pH of the reaction system to 8, and the mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours. The reaction solution was then subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine, and dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and petroleum ether as the eluent, with a volume ratio of dichloromethane:petroleum ether = 1:1. The second band was collected, ultimately yielding pure purple 5,15-bis(4-dimethylaminophenyl)porphyrin-2-carboxaldehyde (compound 10).
[0060] Example 7
[0061] This embodiment provides a method for preparing 5,15-bis(4-diphenylaminophenyl)porphyrin-2-carboxaldehyde.
[0062]
[0063] Following the synthetic route shown in Formula VIII, 389 mg of 5-(4-N,N-diphenylaminophenyl)dipyrrolemethane (compound 11, 1.0 mmol), 6.7 mL of triethyl orthoformate (CH(EtO)3, 40 mmol), and 230 mL of dichloromethane were added to a three-necked flask. A mixture of 92 mL of dichloromethane and 2.3 mL of trichloroacetic acid (TCA, 23 mmol) was added to a dropping funnel under constant pressure and shaken well. The reaction apparatus was sealed, protected from light, and nitrogen was introduced. A magnetic stirrer was turned on. After purging with nitrogen for 30 minutes, the mixture from the dropping funnel was added dropwise. After the addition was complete, the mixture was stirred at room temperature in the dark for 5 hours. Triethylamine (TEA) was added to adjust the pH of the reaction system to 8, and the mixture was stirred for 2 hours to quench the reaction. Finally, air was introduced and the mixture was stirred for 12 hours. The reaction solution was then subjected to rotary evaporation under reduced pressure to remove dichloromethane and triethylamine. The solution was dried under vacuum to obtain a solid crude product. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and petroleum ether as the eluent, with a volume ratio of dichloromethane:petroleum ether = 1:1. The second band was collected, ultimately yielding pure purple 5,15-bis(4-diphenylaminophenyl)porphyrin-2-carboxaldehyde (compound 12).
[0064] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.
[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A method for preparing substituted diphenylporphyrin-2-carboxaldehyde, characterized in that, Includes the following steps: 5-substituted phenyl dipyrrolemethane and trialkyl orthoformate were reacted in an organic solvent system under an anaerobic environment until the system became transparent; Add organic acid dropwise and react at room temperature in the dark until the 5-substituted phenyl dipyrrolemethane has completely reacted. Add a pH adjuster to adjust the reaction system to alkaline, mix until the reaction is quenched, and then introduce oxygen to oxidize the reaction to obtain the substituted diphenylporphyrin-2-carboxaldehyde; The 5-substituted phenyl dipyrrolemethane is one of 5-phenyl dipyrrolemethane, 5-(4-acetoxyphenyl) dipyrrolemethane, 5-(4-methoxyphenyl) dipyrrolemethane, 5-(4-nitrophenyl) dipyrrolemethane, 5-(4-N,N-dimethylaminophenyl) dipyrrolemethane, and 5-(4-N,N-diphenylaminophenyl) dipyrrolemethane; The trialkyl orthoformate is one of triethyl orthoformate and trimethyl orthoformate; The organic acid is one of trifluoroacetic acid and trichloroacetic acid; The reaction of 5-substituted phenyl dipyrrolemethane and trialkyl orthoformate in an organic solvent system under an anaerobic environment until the system becomes transparent, wherein the molar ratio of 5-substituted phenyl dipyrrolemethane to trialkyl orthoformate is 1:40 to 80. The ratio of the 5-substituted phenyl dipyrrolemethane to the organic solvent is 1 mmol: 230-300 mL; The organic acid is added dropwise, wherein the molar ratio of the 5-substituted phenyl dipyrrolemethane to the organic acid is 1:23-26; In the organic solvent system, the organic solvent is one of dichloromethane and chloroform; The oxygen-free environment is a sealed, light-proof, nitrogen-filled environment; The organic acid is a solution of an organic acid, and the solvent is one of dichloromethane and chloroform; The organic acid solution has a concentration of 0.17–0.25 mol / L. The pH adjuster is any one of triethylamine, pyridine, and ammonia. Adjusting the reaction system to alkalinity means adjusting the pH of the reaction system to 8-10.
2. The method according to claim 1, characterized in that, Also includes: The products of the oxidation reaction were successively evaporated and dried to obtain a crude product; The crude product was separated and purified by silica gel column chromatography, and the second band was collected to obtain the substituted diphenylporphyrin-2-carboxaldehyde.
3. The method according to claim 2, characterized in that, The evaporation is vacuum rotary evaporation; And / or, the drying is vacuum drying.
4. The method according to claim 2, characterized in that, In the silica gel column chromatography, a mixture of dichloromethane and petroleum ether is used as the eluent.
5. The method according to claim 4, characterized in that, In the mixture of dichloromethane and petroleum ether, the volume ratio of dichloromethane to petroleum ether is 1:1 to 3.