CN113845499A - Method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide - Google Patents

Method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide Download PDF

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CN113845499A
CN113845499A CN202111250209.XA CN202111250209A CN113845499A CN 113845499 A CN113845499 A CN 113845499A CN 202111250209 A CN202111250209 A CN 202111250209A CN 113845499 A CN113845499 A CN 113845499A
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furandicarboxylic acid
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heterocyclic carbene
acid
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张锴
刘凤洋
何伟
李玉光
沈磊
郭凯
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Nanjing Advanced Biomaterials And Process Equipment Research Institute Co ltd
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    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D307/00Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
    • C07D307/02Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
    • C07D307/34Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
    • C07D307/56Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
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Abstract

The invention discloses a method for synthesizing 2, 5-furandicarboxylic acid by using nitrogen heterocyclic carbene to catalyze carbon dioxide, which comprises the following steps: (1) dissolving furoate, N-heterocyclic carbene NHC and metal compound catalyst in a first solvent, and introducing CO2Reacting to obtain 2, 5-furandicarboxylic acid 2-formic ether; (2) dissolving 2, 5-furandicarboxylic acid 2-formic ether and alkali in a second solvent for reaction to obtain 2, 5-furandicarboxylic acid salt; (3) dissolving 2, 5-furandicarboxylic acid salt in deionized water, and acidifying with acid to obtain 2, 5-furandicarboxylic acid; compared with the prior art, the invention has simple reaction system, no accumulation of intermediate oxidation products, high yield and high industrial application potential of FDCA; with CO2Is also a carbon resource with abundant reserves, low price and easy obtaining, and converts CO by catalysis2Efficiently converting into products with high economic added value2And (4) discharging.

Description

Method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide
Technical Field
The invention belongs to the technical field of 2, 5-furandicarboxylic acid synthesis, and particularly relates to a method for synthesizing 2, 5-furandicarboxylic acid by catalyzing carbon dioxide with azacyclo-carbene.
Background
2, 5-furandicarboxylic acid is a bio-based aromatic monomer, can be used for synthesizing high-performance polyesters, polyamides and epoxy resins, is determined by the U.S. department of energy as one of the 12 most potential bio-based platform compounds, and is also considered as "sleeping giant". At present, 2, 5-furandicarboxylic acid is mainly prepared by chemically catalyzing 5-hydroxymethylfurfural, the 2, 5-furandicarboxylic acid is synthesized by catalyzing furoate ester at the starting stage, and CO is not used in the existing reports2Catalyzing to generate 2, 5-furandicarboxylic acid.
Disclosure of Invention
The purpose of the invention is as follows: the invention provides a method for synthesizing 2, 5-furandicarboxylic acid by using nitrogen heterocyclic carbene to catalyze carbon dioxide.
The technical scheme is as follows: in order to achieve the purpose, the invention adopts the following technical scheme:
a method for synthesizing 2, 5-furandicarboxylic acid by using nitrogen heterocyclic carbene to catalyze carbon dioxide comprises the following steps:
(1) dissolving furoate, N-heterocyclic carbene NHC and metal compound catalyst in a first solvent, and introducing CO2Reacting to obtain 2, 5-furandicarboxylic acid 2-formic ether;
(2) dissolving 2, 5-furandicarboxylic acid 2-formic ether and alkali in a second solvent for reaction to obtain 2, 5-furandicarboxylic acid salt;
(3) dissolving 2, 5-furandicarboxylic acid salt in deionized water, and acidifying with acid to obtain 2, 5-furandicarboxylic acid;
Figure BDA0003322219550000011
wherein R is selected from C1-C5 alkyl.
Preferably, the method comprises the following steps:
in the step (1), the N-heterocyclic carbene is selected from imidazole N-heterocyclic carbenes.
In the step (1), the N-heterocyclic carbene is selected from the following structures:
Figure BDA0003322219550000021
in the step (1), the furoate ester is any one of methyl furoate, ethyl furoate, propyl furoate and the like; the metal compound catalyst is any one of rhodium chloride, rhodium acetate, rhodium nitrate, rhodium octanoate and the like; the first solvent is N, N-dimethylformamide; the molar ratio of the furoate to the azacyclo-carbene to the metal compound catalyst to the first solvent is 1:
(0.008-0.013):(0.015-0.025):100。
in the step (1), the reaction is carried out in CO2Reacting in the atmosphere, wherein the reaction time is 36-48h, and the temperature is 130-150 ℃.
In step (1), after the reaction is finished, the solvent is removed from the reaction mixture in vacuum, and column chromatography (SiO) is carried out2Dichloromethane/methanol, 30: 1) 2, 5-Furan dicarboxylic acid 2-carboxylate was obtained as a white solid.
In the step (2), the alkali is any one of sodium hydroxide and potassium hydroxide; the second solvent is methanol, ethanol, 2-formic ether of 2, 5-furandicarboxylic acid and alkali in a molar ratio of 1: (1-1.1); the dosage of the second solvent is 8-10 times of the total mass of the 2-formic ether of 2, 5-furandicarboxylic acid and the alkali;
in the step (2), the reaction temperature is 60-75 ℃; the reaction time is 12-16 h.
In the step (3), the acid is strong acid without oxidation, preferably concentrated hydrochloric acid.
In the step (3), acidifying to obtain a 2, 5-furandicarboxylate crude product, removing the solvent in vacuum, adding a proper amount of deionized water, and extracting with dichloromethane (preferably three times); the organic layer was acidified with concentrated hydrochloric acid until pH 2; the heterogeneous solution was extracted with ethyl acetate, the organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 2, 5-furandicarboxylic acid
Has the advantages that: compared with the prior art, the invention has simple reaction system, no accumulation of intermediate oxidation products, high yield and high industrial application potential of FDCA; with CO2Is also oneThe carbon resource with abundant reserves, low price and easy obtaining is used for catalyzing and converting CO2Efficiently converting into products with high economic added value2And (4) discharging.
Drawings
FIG. 1 is a hydrogen spectrum of N-heterocyclic carbene in step 1 of the example.
FIG. 2 is a hydrogen spectrum of the product of step 1 in example 1.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The azaheterocyclic carbenes used in the following examples are selected from the following structures:
Figure BDA0003322219550000031
example 1:
the method comprises the following steps: 1.26g of methyl furoate, 0.118g of azacyclocarbene and 44.2mg of rhodium acetate dimer are added to a dry flask, 30ml of DMF is added, vacuum is applied and CO is introduced2Reaction at 150 deg.c for 48 hr to obtain crude methyl 2, 5-furandicarboxylate product, which is subjected to column chromatography to obtain 1.47g of 2, 5-furandicarboxylate methyl 2-carboxylate in 86.41% yield.
Step two: 1.47g of 2, 5-furandicarboxylic acid methyl 2-carboxylate and sodium hydroxide were dissolved in methanol and reacted at 60 ℃ for 14 hours to obtain 1.45g of crude 2, 5-furandicarboxylic acid salt with a yield of 100%.
Step three: removing the solvent from 1.45g of 2, 5-furandicarboxylate crude product in vacuum, adding a proper amount of deionized water, and extracting with a proper amount of dichloromethane for three times; acidifying the organic layer with concentrated hydrochloric acid until the pH is 2; the heterogeneous solution was extracted with 250mL of ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 1.07g of 2, 5-furandicarboxylic acid as a white powder in 99% yield.
Example 2:
the method comprises the following steps: 1.40g of furoic acid ethyl esterEster, 0.118g azacyclocarbene and 44.2mg rhodium acetate dimer were added to a dry flask, 30ml DMF was added, vacuum was applied and CO was passed through2Reaction at 150 deg.c for 48 hr to obtain crude ethyl 2, 5-furandicarboxylate product, which is subjected to column chromatography to obtain 1.53g of 2, 5-furandicarboxylate ethyl 2-carboxylate, yield 83.08%.
Step two: 1.53g of 2, 5-furandicarboxylic acid ethyl 2-carboxylate and sodium hydroxide were dissolved in methanol and reacted at 60 ℃ for 14 hours to obtain 1.396g of crude 2, 5-furandicarboxylic acid salt with a yield of 100%.
Step three: removing the solvent from 1.396g of 2, 5-furandicarboxylate crude product in vacuum, adding a proper amount of deionized water, and extracting with a proper amount of dichloromethane for three times; acidifying the organic layer with concentrated hydrochloric acid until the pH is 2; the heterogeneous solution was extracted with 250mL of ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 1.031g of 2, 5-furandicarboxylic acid as a white powder in 99% yield.
Example 3:
the method comprises the following steps: 1.54g of propyl furoate, 0.118g of azacyclocarbene and 44.2mg of rhodium acetate dimer were added to a dry flask, 30ml of DMF was added, and the flask was evacuated and charged with CO2Reaction at 150 deg.c for 48 hr to obtain 2-propyl 2, 5-furandicarboxylate, which was purified by column chromatography to obtain 2, 5-furandicarboxylate, 2-propyl 2-carboxylate, 1.47g, in 74.18% yield.
Step two: 1.47g of 2, 5-furandicarboxylic acid propyl 2-carboxylate and sodium hydroxide were dissolved in methanol and reacted at 60 ℃ for 14 hours to obtain 1.247g of crude 2, 5-furandicarboxylic acid salt with a yield of 100%.
Step three: removing the solvent from 1.247g of 2, 5-furandicarboxylate crude product in vacuum, adding a proper amount of deionized water, and extracting with a proper amount of dichloromethane for three times; acidifying the organic layer with concentrated hydrochloric acid until the pH is 2; the heterogeneous solution was extracted with 250mL of ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 0.921g of 2, 5-furandicarboxylic acid as a white powder in 99% yield.
Example 4:
the method comprises the following steps: 1.26g of methyl furoate, 0.118g of azacyclocarbene and 44.2mg of rhodium acetate dimer were charged to a dry flaskAdding 30ml of DMMF, vacuumizing and introducing CO2Reaction at 130 deg.c for 42 hr to obtain crude methyl 2, 5-furandicarboxylate product, which is subjected to column chromatography to obtain 1.40g of 2, 5-furandicarboxylate methyl 2-carboxylate in 82.29% yield.
Step two: 1.40g of 2, 5-furandicarboxylic acid methyl 2-carboxylate and sodium hydroxide were dissolved in methanol and reacted at 60 ℃ for 14 hours to obtain 1.38g of crude 2, 5-furandicarboxylic acid salt with a yield of 100%.
Step three: removing the solvent from 1.38g of 2, 5-furandicarboxylate crude product in vacuum, adding a proper amount of deionized water, and extracting with a proper amount of dichloromethane for three times; acidifying the organic layer with concentrated hydrochloric acid until the pH is 2; the heterogeneous solution was extracted with 250mL of ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 1.026g2, 5-furandicarboxylic acid as a white powder in 99% yield.
Example 5:
the method comprises the following steps: 1.26g of methyl furoate, 0.118g of azacyclocarbene and 44.2mg of rhodium acetate dimer are added to a dry flask, 30ml of DMF is added, vacuum is applied and CO is introduced2Reaction at 150 deg.c for 36 hr to obtain crude methyl 2, 5-furandicarboxylate product, which is subjected to column chromatography to obtain 1.38g of 2, 5-furandicarboxylate methyl 2-carboxylate in 81.12% yield.
Step two: 1.38g of 2, 5-furandicarboxylic acid methyl 2-carboxylate and sodium hydroxide were dissolved in methanol and reacted at 60 ℃ for 14 hours to obtain 1.36g of crude 2, 5-furandicarboxylic acid salt with a yield of 100%.
Step three: removing the solvent from 1.45g of 2, 5-furandicarboxylate crude product in vacuum, adding a proper amount of deionized water, and extracting with a proper amount of dichloromethane for three times; acidifying the organic layer with concentrated hydrochloric acid until the pH is 2; the heterogeneous solution was extracted with 250mL of ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the solvent was removed in vacuo to give 1.00g of 2, 5-furandicarboxylic acid as a white powder in 99% yield. .
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A method for synthesizing 2, 5-furandicarboxylic acid by using nitrogen heterocyclic carbene to catalyze carbon dioxide is characterized by comprising the following steps:
(1) dissolving furoate, N-heterocyclic carbene NHC and metal compound catalyst in a first solvent, and introducing CO2Reacting to obtain 2, 5-furandicarboxylic acid 2-formic ether;
(2) dissolving 2, 5-furandicarboxylic acid 2-formic ether and alkali in a second solvent for reaction to obtain 2, 5-furandicarboxylic acid salt;
(3) dissolving 2, 5-furandicarboxylic acid salt in deionized water, and acidifying with acid to obtain 2, 5-furandicarboxylic acid;
Figure FDA0003322219540000011
wherein R is selected from C1-C5 alkyl.
2. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (1), the N-heterocyclic carbene is selected from imidazole N-heterocyclic carbenes.
3. The method for synthesizing 2, 5-furandicarboxylic acid by using azacyclo-carbene to catalyze carbon dioxide as claimed in claim 1, wherein in step (1), the azacyclo-carbene is selected from the following structures:
Figure FDA0003322219540000012
4. the method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene as a catalyst, according to claim 1, wherein in the step (1), the furoate is any one of methyl furoate, ethyl furoate and propyl furoate; the metal compound catalyst is any one of rhodium chloride, rhodium acetate, rhodium nitrate and rhodium octanoate; the first solvent is N, N-dimethylformamide; the molar ratio of the furoate to the azacyclo-carbene to the metal compound catalyst to the first solvent is 1: (0.008-0.013): (0.015-0.025): 100.
5. the method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (1), the reaction is carried out in CO2Reacting in the atmosphere, wherein the reaction time is 36-48h, and the temperature is 130-150 ℃.
6. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene as a catalyst according to claim 1, wherein in the step (1), after the reaction is finished, the solvent is removed from the reaction mixture in vacuum, and the reaction mixture is subjected to column chromatography to obtain white solid 2, 5-furandicarboxylic acid 2-formate.
7. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (2), the base is any one of sodium hydroxide and potassium hydroxide; the second solvent is methanol, ethanol, 2-formic ether of 2, 5-furandicarboxylic acid and alkali in a molar ratio of 1: (1-1.1); the dosage of the second solvent is 8-10 times of the total mass of the 2-formic ether of 2, 5-furandicarboxylic acid and the alkali.
8. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (2), the reaction temperature is 60-75 ℃; the reaction time is 12-16 h.
9. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (3), the acid is strong non-oxidizing acid, preferably concentrated hydrochloric acid.
10. The method for synthesizing 2, 5-furandicarboxylic acid by using N-heterocyclic carbene to catalyze carbon dioxide according to claim 1, wherein in the step (3), a crude product of 2, 5-furandicarboxylic acid salt is obtained after acidification, the solvent is removed in vacuum, a proper amount of deionized water is added, and dichloromethane is used for extraction; the organic layer was acidified with concentrated hydrochloric acid until pH 2; the heterogeneous solution was extracted with ethyl acetate, the organic layer was dried over anhydrous sodium sulfate, and the solvent was removed in vacuo to give 2, 5-furandicarboxylic acid.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115260390A (en) * 2022-07-26 2022-11-01 合肥工业大学 Preparation of novel polymerized N-heterocyclic carbene catalyst and application of catalyst in furoic acid synthesis process

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108299353A (en) * 2017-01-12 2018-07-20 中国科学院宁波材料技术与工程研究所 A kind of preparation method of 5- formic acid ester group furan compound
CN108299355A (en) * 2017-01-12 2018-07-20 中国科学院宁波材料技术与工程研究所 A kind of preparation method of the disubstituted furan compounds of 2,5-

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108299353A (en) * 2017-01-12 2018-07-20 中国科学院宁波材料技术与工程研究所 A kind of preparation method of 5- formic acid ester group furan compound
CN108299355A (en) * 2017-01-12 2018-07-20 中国科学院宁波材料技术与工程研究所 A kind of preparation method of the disubstituted furan compounds of 2,5-

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SCHMALZBAUER, M: "Redox-neutral Photocatalytic CH Carboxylation of Arenes and Styrenes with CO2", CHEM, 31 October 2020 (2020-10-31) *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115260390A (en) * 2022-07-26 2022-11-01 合肥工业大学 Preparation of novel polymerized N-heterocyclic carbene catalyst and application of catalyst in furoic acid synthesis process

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