A method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride

Abstract

The invention discloses a method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride, wherein the method comprises the following steps: adding anhydrous aluminum chloride, aromatic aldehyde, pyrrole and nickel salt to DMF solvent in a step of refluxing under the catalysis of anhydrous aluminum chloride, stopping the reaction after heating and refluxing for a certain period of time, cooling, placing at about 273K overnight, and filtering to obtain nickel porphyrin crystals. The method directly uses aromatic aldehyde, pyrrole and nickel salt as raw materials, does not require the use of porphyrin, does not use highly corrosive organic acids as solvents, obtains high-purity tetraaryl nickel porphyrins in high yield without the need for complex separation means, and is easy to realize industrial production.

Description

Technical Field

[0001] The invention relates to a method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride, and in particular to a method for synthesizing tetraaryl nickel porphyrin in a DMF solvent in one step by using aromatic aldehyde, pyrrole and nickel salt as raw materials under the catalysis of anhydrous aluminum chloride, and belongs to the field of organic synthesis. Background Art

[0002] Nickel porphyrin is a metal organic compound with a macrocyclic conjugated structure. The ligand porphin of nickel porphyrin is a large cyclic molecule composed of 20 carbon atoms and 4 nitrogen atoms, with a stable conjugated system of 4n+2 electrons and aromaticity. In industrial production and life, nickel porphyrin is mainly used as a catalyst for chemical oxidation and electrical and photooxidation. The nickel porphyrin commonly used as a catalyst is tetraaryl nickel porphyrin. The chemical synthesis method of tetraaryl nickel porphyrin reported in the literature and patents is generally based on the basic reaction of tetraaryl porphyrin as raw material and nickel salt reported by Adler et al. (J. Inorg. Nucl. Chem., 1970, 32, 2443). The chemical process involved is:

[0003]

[0004] During the reaction, divalent nickel ions coordinate with tetraarylporphine to form stable divalent nickel porphyrin. Patent CN103880851B discloses a method for producing nickel porphyrin on an industrial scale by reacting the above tetraarylporphine as a raw material with a nickel salt through a continuous process. The biggest disadvantage of this reaction is that the raw material tetraarylporphine used in the synthesis of nickel porphyrin is expensive, and in a neutral or slightly alkaline environment, the instability of nickel porphyrin is prone to nickel ion shedding, which affects the product purity of divalent nickel porphyrin.

[0005] From the existing literature, there are also reports on the one-step synthesis of zinc porphyrin using aromatic aldehydes, pyrrole and zinc salts as raw materials. Badger et al. reported the one-step synthesis of zinc porphyrin using aromatic aldehydes, pyrrole and zinc salts as raw materials in an autoclave (Australian J Chem, 1964, 19, 1028).

[0006]

[0007] However, this reaction condition cannot be used to prepare nickel porphyrin. In propionic acid solvent, nickel salt cannot react with porphyrin to form nickel porphyrin with poor stability.

[0008] In view of the fact that zinc porphyrin can be replaced with nickel salt to obtain nickel porphyrin (Chemical Technology, 2000, 8, 1; Journal of Shenyang University of Technology, 2010, 60; Chemical Research and Application, 2012, 24, 154), patent CN1238355C discloses a reaction in which a mixture of zinc porphyrin and porphine is obtained by using aromatic aldehyde, pyrrole and zinc salt as raw materials without using an autoclave, and then the mixture of zinc porphyrin and porphine is reacted with nickel acetate to synthesize nickel porphyrin.

[0009]

[0010] In the above process, the intermediate products porphyrin zinc and porphine need to be obtained through a separation process, and the propionic acid solvent used in the first step is an organic acid with strong corrosiveness. In addition, if nickel salt is directly added to the propionic acid system, divalent nickel ions cannot coordinate with porphine to obtain nickel porphyrin. Summary of the invention

[0011] In view of the defect that tetraaryl nickel porphyrins need to be synthesized from the metalation reaction of expensive tetraaryl porphyrins and nickel salts or from the metal replacement reaction of expensive tetraaryl zinc porphyrins and nickel salts, the present invention aims to provide a method for synthesizing tetraaryl nickel porphyrins in one step with basic chemical raw materials aryl aldehydes, pyrrole and nickel salts as reactants under the catalysis of anhydrous aluminum trichloride, and obtaining high-purity tetraaryl nickel porphyrins in high yield without using complex separation means, and the method is easy to realize industrial production.

[0012] The reaction raw materials used to realize the present invention are simple organic raw materials, aromatic aldehyde and pyrrole, and inorganic nickel salt, the reaction solvent is DMF, and the catalyst is a non-protonic inorganic acid, anhydrous aluminum chloride.

[0013] The chemical reaction on which the present invention is based is as follows:

[0014]

[0015] The aromatic group Ar can be a benzene ring or an aromatic heterocycle such as pyridine, pyrrole, furan, naphthalene, quinoline, etc.;

[0016] The substituent R on the aryl group Ar may be an alkyl substituent such as methyl, ethyl, propyl or a halogen substituent such as chlorine, bromine or iodine, or an oxygen-containing substituent such as methoxy, ethoxy, hydroxyl or carboxyl or a nitrogen-containing substituent such as amino, dimethylamino or nitro;

[0017] The nickel salt used in the reaction can be nickel acetate, nickel chloride, nickel bromide, nickel nitrate, or nickel sulfate.

[0018] The operation process of the present invention is as follows: DMF is added to a commonly used reflux stirring reactor and added until boiling, anhydrous aluminum chloride, aromatic aldehyde, pyrrole and nickel salt are added in sequence under stirring, the reaction is stopped after a certain reaction time, the temperature is lowered to below 373K, ethanol in an amount equal to the volume of DMF is added, and the reaction is continued to be cooled, the reaction is placed at about 273K overnight, and nickel porphyrin crystals are obtained by suction filtration.

[0019] The input ratio (molar ratio) of aromatic aldehyde, pyrrole, nickel salt and anhydrous AlCl3 is: 1-1.5:1-1.5:1-5:1-5, and the preferred ratio is 1:1:3:1.5;

[0020] The molar ratio of pyrrole to DMF is 1:500-2000, preferably 1:1000;

[0021] The reaction time is 0.5-4 hours, preferably 2 hours.

[0022] The reaction requires that all reactants are added at room temperature and then heated to reflux. If reactants are added after reflux, or nickel salt is added after reflux, the desired product cannot be obtained or the product yield is reduced.

[0023] According to the technical scheme of the present invention, the condensation of aromatic aldehyde and pyrrole and the metallization of the condensation product and divalent nickel ions occur simultaneously, so that the two-step reaction of the prior art of synthesizing tetraaryl nickel porphyrin with aromatic aldehyde and pyrrole as raw materials is changed into a one-step reaction. Meanwhile, the divalent nickel ions also play a template role in the condensation process of aromatic aldehyde and pyrrole to improve the condensation yield; non-protonic acid anhydrous AlCl3 is used as an acidic catalyst, which can not only promote the condensation of aromatic aldehyde and pyrrole, but also accelerate the metallization reaction of porphyrin and nickel ions and reduce the shedding of nickel ions in nickel porphyrin; the use of DMF as a solvent can dissolve anhydrous AlCl3, which is beneficial to exerting the catalytic performance of AlCl3 on the condensation of aromatic aldehyde and pyrrole, and the difference in the solubility of DMF on organic hydrocarbon substances and metal compounds. After the reaction is completed, an equal volume of ethanol is added, so that the tetraaryl nickel porphyrin is crystallized and precipitated at low temperature, and various intermediate impurities formed by the condensation of aromatic aldehyde and pyrrole in the reaction process will not be precipitated with the product, so that the product tetraaryl nickel porphyrin is easy to separate.

[0024] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0025] 1) Compared with the prior art of synthesizing tetraaryl nickel porphyrin using porphyrin as raw material, the raw materials aromatic aldehyde and pyrrole used in the present invention are more economical and readily available than porphyrin, and can effectively avoid the shedding of nickel ions in the product tetraaryl nickel porphyrin to reduce by-products, improve product purity, and simplify the separation process;

[0026] 2) Compared with the prior art of synthesizing tetraaryl nickel porphyrin using aromatic aldehyde and pyrrole as raw materials, the present invention only requires one step of reaction and does not require the use of special equipment, thus reducing the number of reaction steps. The product yield under optimal conditions can reach up to 52%. At the same time, the large-scale use of corrosive organic acids can be avoided, thus having good environmental benefits.

[0027] 3) The technical solution of the present invention has simple steps and strong operability, and meets the requirements of industrial production. Example

[0028] The following examples are intended to further illustrate the present invention rather than to limit the scope of protection of the claims. The raw materials involved in the examples are all commercially available conventional raw materials unless otherwise specified.

[0029] Embodiment 1:

[0030] 500 mL of DMF was added to a stirred reactor with a reflux condenser, and 0.75 mol of anhydrous aluminum chloride, 0.5 mol of benzaldehyde, 0.5 mol of pyrrole and 1.5 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and maintained for 2 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 500 mL of ethanol was added and continued to cool, and the mixture was placed at 273 K overnight. Purple crystals of tetraphenylnickel porphyrin were obtained by suction filtration with a yield of 52%.

[0031] Embodiment 2:

[0032] 1800 mL of DMF was added to a stirred reactor with a reflux condenser, and 1 mol of anhydrous aluminum chloride, 0.8 mol of 3-bromopyridinecarboxaldehyde, 0.6 mol of pyrrole and 1.5 mol of nickel chloride were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 1 hour before stopping the reaction. The temperature was lowered to below 373 K, 1800 mL of ethanol was added and continued to cool. The mixture was placed at 273 K overnight and filtered to obtain purple crystals of tetrakis(3-bromopyridine)nickelporphyrin with a yield of 43%.

[0033] Embodiment three:

[0034] 2800 mL of DMF was added to a stirred reactor with a reflux condenser, and 1.2 mol of anhydrous aluminum chloride, 0.8 mol of 2-ethylpyrrole carboxaldehyde, 0.7 mol of pyrrole and 2 mol of nickel bromide were added in sequence under stirring. The reaction mixture was heated to reflux and maintained for 2 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 2800 mL of ethanol was added and continued to cool, and the mixture was allowed to stand at 273 K overnight. Purple crystals of tetrakis(2-ethylpyrrole)nickelporphyrin were obtained by suction filtration with a yield of 38%.

[0035] Embodiment 4:

[0036] 1500 mL of DMF was added to a stirred reactor with a reflux condenser, and 0.75 mol of anhydrous aluminum chloride, 0.75 mol of 5-hydroxy-1-naphthaldehyde, 0.75 mol of pyrrole and 2 mol of nickel nitrate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 1.5 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 1500 mL of ethanol was added and continued to cool, and the mixture was allowed to stand at 273 K overnight. Light green crystals of tetrakis(5-hydroxy-1-naphthylpyridine)nickelporphyrin were obtained by suction filtration with a yield of 32%.

[0037] Embodiment five:

[0038] 1000 mL of DMF was added to a stirred reactor with a reflux condenser, and 1 mol of anhydrous aluminum chloride, 0.6 mol of 3-methylfurfural, 0.5 mol of pyrrole and 1.8 mol of nickel sulfate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 1.8 hours before stopping the reaction. The temperature was lowered to below 373 K, 1000 mL of ethanol was added and continued to cool. The mixture was placed at 273 K overnight and filtered to obtain purple crystals of tetrakis(3-methylfuran)nickelporphyrin with a yield of 35%.

[0039] Embodiment six:

[0040] 1500 mL of DMF was added to a stirred reactor with a reflux condenser, and 0.5 mol of anhydrous aluminum chloride, 0.7 mol of 5-methoxy-2-quinolinecarboxaldehyde, 0.5 mol of pyrrole and 1.2 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 3 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 1500 mL of ethanol was added and continued to cool, and the mixture was allowed to stand at 273 K overnight. Purple crystals of tetrakis(5-methoxy-2-quinoline)nickelporphyrin were obtained by suction filtration with a yield of 28%.

[0041] Embodiment seven:

[0042] 2500 mL of DMF was added to a stirred reactor with a reflux condenser, and 2 mol of anhydrous aluminum chloride, 0.75 mol of 4-chlorobenzaldehyde, 0.5 mol of pyrrole and 2 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 2.5 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 2500 mL of ethanol was added and continued to cool, and the mixture was allowed to stand at 273 K overnight. Purple crystals of tetrakis(4-chlorophenyl)nickelporphyrin were obtained by suction filtration with a yield of 50%.

[0043] Embodiment eight:

[0044] 2000 mL of DMF was added to a stirred reactor with a reflux condenser, and 2.5 mol of anhydrous aluminum chloride, 0.5 mol of 3-aminobenzaldehyde, 0.5 mol of pyrrole and 1.5 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 2 hours, then the reaction was stopped, the temperature was lowered to below 373 K, 2000 mL of ethanol was added and continued to cool, and the mixture was placed at 273 K overnight. Blue crystals of tetrakis(3-aminophenyl)nickelporphyrin were obtained by suction filtration with a yield of 25%.

[0045] Embodiment nine:

[0046] 2000 mL of DMF was added to a stirred reactor with a reflux condenser, and 2 mol of anhydrous aluminum chloride, 0.6 mol of 4-carboxybenzaldehyde, 0.5 mol of pyrrole and 2.2 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 1.5 hours before stopping the reaction. The temperature was lowered to below 373 K, 2000 mL of ethanol was added and continued to cool. The mixture was allowed to stand at 273 K overnight and filtered to obtain purple crystals of tetrakis(4-carboxyphenyl)nickelporphyrin with a yield of 22%.

[0047] Embodiment ten:

[0048] 1500 mL of DMF was added to a stirred reactor with a reflux condenser, and 0.8 mol of anhydrous aluminum chloride, 0.6 mol of 4-nitrobenzaldehyde, 0.5 mol of pyrrole and 2.5 mol of nickel acetate were added in sequence under stirring. The reaction mixture was heated to reflux and the reaction was maintained for 0.5 hours before stopping the reaction. The temperature was lowered to below 373 K, 1500 mL of ethanol was added and continued to cool. The mixture was placed at 273 K overnight and filtered to obtain purple crystals of tetrakis(4-nitrophenyl)nickelporphyrin with a yield of 21%.

Claims

1. A method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride, characterized in that: Under the catalysis of anhydrous aluminum chloride, in DMF solvent, condensation of aromatic aldehyde and pyrrole and metalation reaction with nickel salt occur simultaneously to generate tetraaryl nickel porphyrin; the reaction process is: add DMF to a reflux stirring reactor at room temperature, start stirring, and add anhydrous aluminum chloride, aromatic aldehyde, pyrrole and nickel salt in sequence; heat the reaction mixture to reflux, continue the reaction for a certain period of time and then stop the reaction; cool to below 373K, add ethanol equal to the volume of DMF and continue cooling, place it at about 273K overnight, and filter to obtain porphyrin nickel crystals; wherein, the input molar ratio of aromatic aldehyde, pyrrole, nickel salt and anhydrous AlCl3 is: 1-1.5:1-1.5:1-5:1-5; the molar concentration of pyrrole in DMF is 1 / 500-1 / 2000; The structure of the aromatic aldehyde is as follows: ； The tetraaryl nickel porphyrin has the following structure: ； Ar is a phenyl ring group, a pyridyl group, a pyrrolyl group, a furyl group, a naphthyl group or a quinolyl group; The substituent R on Ar is methyl, ethyl, propyl, chloro, bromo, iodo, methoxy, ethoxy, hydroxy, carboxyl, amino, dimethylamino or nitro.

2. The method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride according to claim 1, characterized in that: The reaction time is 0.5-4 hours.

3. The method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride according to claim 1, characterized in that: The reaction was carried out under refluxing DMF.

4. The method for synthesizing tetraaryl nickel porphyrin catalyzed by anhydrous aluminum chloride according to claim 1, characterized in that: The nickel salt used in the reaction is selected from nickel acetate, nickel chloride, nickel bromide, nickel nitrate or nickel sulfate.

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