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Green catalytic preparation method of pyrano[4,3-b]pyran derivative

A technology for the preparation of pyran derivatives and catalysis, which is applied in the field of ionic liquid catalysis, can solve the problems of difficult biodegradation of ionic liquids, low utilization rate of raw materials, and complicated post-processing, etc., and achieves industrial scale production, high utilization rate, post-processing Handle simple effects

Active Publication Date: 2015-11-11
平邑现代中药产业园有限公司
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Problems solved by technology

[0005] The purpose of the present invention is to overcome the existence of ionic liquids in the process of preparing pyran[4,3-b]pyran derivatives by catalysis in the prior art, which are not easy to biodegrade, use a large amount, low raw material utilization rate, and complicated post-treatment and other shortcomings, and provide a kind of bissulfonate ionic liquid that is easy to biodegrade, has good catalyst activity, high atom economy, and simple and convenient post-treatment as a green catalyst, and catalyzes the preparation of pyran[4,3-b under the condition of water as a solvent. ] method of pyran derivative

Method used

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  • Green catalytic preparation method of pyrano[4,3-b]pyran derivative

Examples

Experimental program
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Effect test

Embodiment 1

[0021] 1mmol benzaldehyde, 1mmol malononitrile, 1mmol 4-hydroxy-6-methyl-2-pyrone and 0.04mmol bissulfonate ionic liquid were added to 25ml single port with stirring bar and condenser tube filled with 5ml water in the bottle. Heated to 65°C, reacted for 27 minutes, detected by TLC (thin plate chromatography), the raw material point disappeared, cooled to room temperature, a large amount of solids precipitated, crushed the solids, stood still, and filtered with suction, the obtained filter residue was dried and recrystallized with ethanol to obtain pure 2-amino-7-methyl-4-phenyl-5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile, the yield was 96%. The filtrate was directly added with benzaldehyde, malononitrile and 4-hydroxy-6-methyl-2-pyrone for repeated use.

[0022] 2-Amino-7-methyl-4-phenyl-5-oxo-4H, 5H-pyrano[4,3-b]pyran-3-carbonitrile: m.p.236~238℃; IR(KBr) : 3403, 3324, 3207, 3089, 2195, 1714cm -1 ; 1 HNMR (300MHz, CDCl 3 ): δ=2.27(s, 3H, CH 3 ), 4.45(s, 1H, CH), 4.58(...

Embodiment 2

[0024] 1mmol p-chlorobenzaldehyde, 1mmol malononitrile, 1mmol4-hydroxyl-6-methyl-2-pyrone and 0.05mmol bissulfonate ionic liquid were added to 8ml of water with stirring bar and condenser 25ml single mouth bottle. Heated to 70°C, reacted for 32min, detected by TLC (thin plate chromatography), the raw material point disappeared, cooled to room temperature, a large amount of solid precipitated, crushed the solid, stood still, filtered with suction, dried the obtained filter residue and recrystallized with ethanol to obtain pure 2-Amino-7-methyl-4-(4-chlorophenyl)-5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile, the yield is 90% . The filtrate was directly added with p-chlorobenzaldehyde, malononitrile and 4-hydroxy-6-methyl-2-pyrone for repeated use.

[0025] 2-Amino-7-methyl-4-(4-chlorophenyl)-5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile: m.p.231~232℃ ;IR (KBr): 3409, 3325, 3084, 2189, 1701cm -1 ; 1 HNMR (300MHz, CDCl 3 ): δ=2.26(s, 3H, CH 3 ), 4.46(s, 1H, CH), 4.57(s, 2H...

Embodiment 3

[0027] Add 1mmol p-nitrobenzaldehyde, 1mmol malononitrile, 1mmol4-hydroxyl-6-methyl-2-pyrone and 0.03mmol bissulfonate ionic liquid respectively to a stirring bar and condenser tube filled with 8ml water 25ml single mouth bottle. Heated to 60°C, reacted for 17 minutes, detected by TLC (thin plate chromatography), the raw material point disappeared, cooled to room temperature, a large amount of solids precipitated, crushed the solids, stood still, filtered with suction, dried the obtained filter residue and recrystallized with ethanol to obtain pure 2-Amino-7-methyl-4-(4-nitrophenyl)-5-oxo-4H, 5H-pyrano[4,3-b]pyran-3-carbonitrile, the yield was 92 %. The filtrate was directly added with p-nitrobenzaldehyde, malononitrile and 4-hydroxy-6-methyl-2-pyrone for repeated use.

[0028] 2-Amino-7-methyl-4-(4-nitrophenyl)-5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile: m.p.216~218 ℃; IR (KBr): 3400, 3303, 3149, 2297, 1703cm -1 ; 1 HNMR (300MHz, CDCl 3 ): δ=2.25(s, 3H, CH 3), 4.60(...

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Abstract

The invention discloses a green catalytic preparation method of a pyrano[4,3-b]pyran derivative and belongs to the technical field of ionic liquid catalysis. In the preparation reaction, the molar ratio of aromatic aldehyde, 4-hydroxy-6-methyl-2-pyrone and malononitrile is 1:1:1, the molar weight of a bissulfonate ionic liquid catalyst is 3-5% of that of aromatic aldehyde, the volume dose of reaction solvent water by milliliter is 5-8 times of the molar weight of aromatic aldehyde by millimole, the reaction temperature is 60-80 DEG C, the reaction time is 15-40 min, cooling to the room temperature is performed after finish of reaction, lots of solids are separated out and crushed, then leaving to stand and suction filtration are carried out, and the obtained filter residues are recrystallized by ethanol after being dried to obtain the target product. Compared with preparation methods adopting other acidic ionic liquid catalysts, the green catalytic preparation method has the characteristics that the catalytic activity of the catalyst, the biodegradability and the raw material utilization ratio are high, and the whole preparation process is simple and convenient to operate, and industrial large-scale application is facilitated.

Description

technical field [0001] The invention belongs to the technical field of ionic liquid catalysis, and in particular relates to a green catalytic method for preparing pyrano[4,3-b]pyran derivatives. Background technique [0002] Pyranopyran derivatives are a class of compounds with unique structures, and many of them are inhibitors of AIDS protease, and have properties such as anti-aging, anti-cytotoxic activity and inhibition of cancer cells. Such compounds are usually synthesized by a three-component one-pot reaction of aromatic aldehydes, malononitrile, and 4-hydroxy-6-methyl-2-pyrone, but the use of traditional acid catalysts generally suffers from long reaction times and high yields. The efficiency is not high enough, it is difficult to realize recycling, serious environmental pollution and other shortcomings. Therefore, developing a green, efficient, convenient and quick method for preparing pyrano[4,3-b]pyran derivatives has become a common concern of many organic synthe...

Claims

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Application Information

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IPC IPC(8): C07D493/04
CPCC07D493/04
Inventor 储昭莲岳彩波吴胜华
Owner 平邑现代中药产业园有限公司
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