Method for catalytic synthesis of 4H-benzo[b]pyran derivative with basic ionic liquid

A technology of pyran derivatives and basic ions, which is applied in organic chemistry and other fields, can solve the problems of difficult biodegradation of ionic liquids, complicated preparation process, cumbersome handling, etc., and achieves convenience for large-scale production, simple preparation process, high yield and The effect of high purity

Active Publication Date: 2015-11-18
山东润耀环保科技有限公司
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  • Abstract
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  • Application Information

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the ionic liquids existing in the process of catalytic synthesis of 4H-benzo[b]pyran derivatives using alkaline ionic liquids in the prior art, which are not easy to biodegrade, complicated preparation process, high price, and pretreatment before recycling. cumbersome and other shortcomings, and provide a kind of alkaline ionic liquid which is easy to biodegrade, the preparation process is simple, cheap, and the recycling process is simple as a green catalyst, and the aqueous ethanol solution is used as a solvent to catalyze the synthesis of 4H-benzo [b] pyran derivatives Methods

Method used

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  • Method for catalytic synthesis of 4H-benzo[b]pyran derivative with basic ionic liquid
  • Method for catalytic synthesis of 4H-benzo[b]pyran derivative with basic ionic liquid
  • Method for catalytic synthesis of 4H-benzo[b]pyran derivative with basic ionic liquid

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Experimental program
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Effect test

Embodiment 1

[0025] Add 3mmol of benzaldehyde, 3mmol of malononitrile, 3mmol of 1,3-cyclohexanedione and 0.15mmol of alkaline ionic liquid to 12ml of water and ethanol mixture (V (water): V (ethanol) = 1:9 ) In a 50ml single-neck bottle with a stir bar and a condenser tube. The reaction was refluxed for 13 minutes, detected by TLC (Thin Plate Chromatography), the raw material point disappeared. After the reaction was cooled to room temperature, a large amount of solids precipitated. The solids were crushed, left standing, and suction filtered. The resulting filter residue was vacuum dried to obtain pure 2-amino-3- Cyano-4-phenyl-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran, the yield was 91%. The filtrate was repeatedly used after adding benzaldehyde, malononitrile and 1,3-cyclohexanedione.

[0026] 2-Amino-3-cyano-4-phenyl-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran: m.p.218~220℃; 1 HNMR(400MHz, DMSO-d 6 ):δ=1.80~1.96(m, 2H, CH 2 ), 2.17~2.31(m, 2H, CH 2 ), 2.54~2.62(m, 2H, CH 2 ), 4.15(s, 1H, C...

Embodiment 2

[0028] Add 3mmol of p-chlorobenzaldehyde, 3mmol of malononitrile, 3mmol of 1,3-cyclohexanedione and 0.12mmol of alkaline ionic liquid to a mixture containing 18ml of water and ethanol (V (water): V (ethanol) = 1 : 9) in a 50ml single-necked bottle with a stir bar and a condenser tube. The reaction was refluxed for 9 minutes, detected by TLC (Thin Plate Chromatography), the raw material point disappeared, a large amount of solids precipitated after the reaction was cooled to room temperature, the solids were crushed, stood still, and filtered with suction. The resulting filter residue was vacuum dried to obtain pure 2-amino-3- Cyano-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran, the yield was 92%. After adding p-chlorobenzaldehyde, malononitrile and 1,3-cyclohexanedione to the filtrate, it is reused.

[0029] 2-Amino-3-cyano-4-(4-chlorophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran: mp226~228℃ ; 1 HNMR(400MHz, DMSO-d 6 ):δ=1.81~1.99(m, 2H, CH 2 ), 2.19~2.32(m, ...

Embodiment 3

[0031] Add 3mmol of m-nitrobenzaldehyde, 3mmol of malononitrile, 3mmol of 1,3-cyclohexanedione and 0.12mmol of alkaline ionic liquid to 15ml of water and ethanol mixture (V (water): V (ethanol) = 1:9) in a 50ml single-neck bottle with a stir bar and a condenser tube. The reaction was refluxed for 11 minutes, detected by TLC (Thin Plate Chromatography), the raw material point disappeared. After the reaction was cooled to room temperature, a large amount of solids precipitated. The solids were crushed, allowed to stand, and filtered with suction. The resulting residue was vacuum dried to obtain pure 2-amino-3- Cyano-4-(3-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran, the yield was 91%. After adding m-nitrobenzaldehyde, malononitrile and 1,3-cyclohexanedione to the filtrate, it is reused.

[0032] 2-Amino-3-cyano-4-(3-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4H-benzo[b]pyran: mp200~202 ℃; 1 HNMR(400MHz, DMSO-d 6 ):δ=1.87~1.97(m, 2H, CH 2 ), 2.21~2.32(m, 2H, CH 2 ), 2.61~2.67...

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Abstract

The invention discloses a method for catalytic synthesis of a 4H-benzo[b]pyran derivative with a basic ionic liquid and belongs to the technical field of organic synthesis. The molar ratio of aromatic aldehyde to malononitrile to a 1,3-cyclohexanedione compound in a synthetic reaction is 1:1:1, the molar weight of a basic ionic liquid catalyst is 4%-7% of that of the used aromatic aldehyde, the volume dose of a reaction solvent ethanol aqueous solution in terms of milliliters is 4-6 times the molar weight of the aromatic aldehyde in terms of millimoles, the reaction pressure is one atmosphere, the reflux reaction is performed for 5-30 min, the mixture is cooled to the room temperature after the reaction is finished, a large quantity of solids are separated out, suction filtration is performed, filter residues are subjected to vacuum drying, and the pure 4H-benzo[b]pyran derivative is obtained. Compared with synthetic methods in which other basic ionic liquids are adopted as catalysts, the method has the characteristics that the catalyst is easy to biodegrade, simple to prepare, low in cost and easy to obtain, the utilization rate of raw materials is high in the whole synthetic process, the operation is simple and convenient and the like, and industrial mass production is facilitated.

Description

Technical field [0001] The invention belongs to the technical field of organic synthesis, and specifically relates to a method for catalyzing and synthesizing 4H-benzo[b]pyran derivatives with a basic ionic liquid. Background technique [0002] 4H-benzo[b]pyran derivatives are a very important class of natural compounds, which have very important biological activities and a wide range of medicinal values, such as diuretic and antispasmodic effects, and can be used as anticoagulants. It also has a certain therapeutic effect on cancer. In addition, they can also be used as cognitive enhancers to treat neurodegenerative diseases, including Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease, Parkinson's disease, etc. At present, the synthesis of such compounds is mainly through the three-component "one-pot" reaction of aldehydes, active methylene compounds and 1,3-cyclohexanedione compounds. However, this method usually uses a strong base and a strong acid as ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D311/74
CPCC07D311/74
Inventor 储昭莲岳彩波吴胜华
Owner 山东润耀环保科技有限公司
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