Reaction system and method for generating flavanone by cyclization of 2'-hydroxy chalcone

Abstract

The invention discloses a reaction system for generating flavanone by the cyclization of 2'-hydroxy chalcone, mainly comprising naphthyridine and water. The reaction can be carried out by adopting a heating or irradiation method. The reaction system has high yield and easy recovery of a solvent.

Description

technical field

[0001] The present invention relates to preparation of flavanones by cyclization of 2'-hydroxychalcones, and in particular to a reaction system and a method for cyclization under the reaction system. Background technique

[0002] Flavanones are one of the active ingredients of various medicinal plants. Due to its remarkable biological and pharmacological activities and unique plastic structure, it has attracted strong research interest of chemists for nearly a hundred years. According to relevant literature reports, many flavanone compounds have many biological activities such as antibacterial, anti-inflammatory, anti-HIV virus, anti-tumor, anti-mutagenesis, and anti-oxidation. They are a class of compounds with high research value and broad application prospects. Flavanone derivatives are mostly extracted from natural plants, and the substituents are mostly hydroxyl, methoxy, benzyloxy, isopentenyl, geranyl, etc. Although flavanone compounds widely exist i...

Examples

Embodiment 1

[0029] Example 1: 2'-hydroxychalcone heating cyclization

[0030] Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, add it to a 250ml three-neck round bottom flask, add 60ml of distilled water, stir mechanically, condense and reflux, control the temperature at 90°C, and react for 1h; concentrate under reduced pressure; Column chromatography separation (eluent is benzene: ethyl acetate=30: 1), distillation under reduced pressure; Concentrate is constant volume with methanol, adopts ultraviolet-visible spectrophotometer to measure absorbance at 251nm place of characteristic peak of flavanone, The flavanone content was calculated, and the yield was 91.1%; and the melting point, IR, H-NMR, and HRMS analyzes were carried out.

[0031] Other solvent systems (volume ratio is 1: 1.5), are shown in Table 1 to the action effect of heating cyclization of 2'-hydroxychalcone under the above-mentioned same conditions.

[0032] Table 1 Effect of different solvent systems...

Embodiment 2

[0039] Example 2: cyclization of 2'-hydroxychalcone with visible light

[0040] Visible light photocyclization of 2'-hydroxychalcone was studied in pyridine-water system. Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, pour it into a quartz glass photoreactor, add 60ml of distilled water, fix the quartz glass photoreactor on a shaker, irradiate with a 500W xenon lamp, and react 4h, the reaction mixture was concentrated under reduced pressure, separated by column chromatography (eluent: benzene:ethyl acetate=30:1), and distilled under reduced pressure; The absorbance was measured at a fixed wavelength at 251nm, the characteristic peak of alkanone, and the content of flavanone was calculated. The yield was 99.6%; and analyzed by melting point, IR, H-NMR, HRMS and so on.

[0041] The effects of different reaction systems on the visible light photocyclization of 2'-hydroxychalcone to generate flavanones under the same conditions above are shown in Table 3. ...

Embodiment 3

[0045] Example 3: Photocyclization of 2'-hydroxychalcone under natural light

[0046] The natural light photocyclization reaction of 2'-hydroxychalcone was studied in pyridine-water system. Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, add it to a 250ml three-necked round-bottomed flask, then add 60ml of distilled water, stir mechanically, and react for 4 hours under natural light in the room, concentrate the reaction mixture under reduced pressure, and perform column chromatography Separation (eluent is benzene: ethyl acetate = 30: 1), distillation under reduced pressure; Concentrate is distilled to volume with methanol, adopts ultraviolet-visible spectrophotometer to measure absorbance at fixed wavelength at 251nm place of flavanone characteristic peak, calculates Flavanone content, the yield is 89.7%; and analyzed by melting point, IR, H-NMR, HRMS and so on.

technical field

[0001] The present invention relates to preparation of flavanones by cyclization of 2'-hydroxychalcones, and in particular to a reaction system and a method for cyclization under the reaction system. Background technique

[0002] Flavanones are one of the active ingredients of various medicinal plants. Due to its remarkable biological and pharmacological activities and unique plastic structure, it has attracted strong research interest of chemists for nearly a hundred years. According to relevant literature reports, many flavanone compounds have many biological activities such as antibacterial, anti-inflammatory, anti-HIV virus, anti-tumor, anti-mutagenesis, and anti-oxidation. They are a class of compounds with high research value and broad application prospects. Flavanone derivatives are mostly extracted from natural plants, and the substituents are mostly hydroxyl, methoxy, benzyloxy, isopentenyl, geranyl, etc. Although flavanone compounds widely exist i...

Examples

Embodiment 1

[0029] Example 1: 2'-hydroxychalcone heating cyclization

[0030] Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, add it to a 250ml three-neck round bottom flask, add 60ml of distilled water, stir mechanically, condense and reflux, control the temperature at 90°C, and react for 1h; concentrate under reduced pressure; Column chromatography separation (eluent is benzene: ethyl acetate=30: 1), distillation under reduced pressure; Concentrate is constant volume with methanol, adopts ultraviolet-visible spectrophotometer to measure absorbance at 251nm place of characteristic peak of flavanone, The flavanone content was calculated, and the yield was 91.1%; and the melting point, IR, H-NMR, and HRMS analyzes were carried out.

[0031] Other solvent systems (volume ratio is 1: 1.5), are shown in Table 1 to the action effect of heating cyclization of 2'-hydroxychalcone under the above-mentioned same conditions.

[0032] Table 1 Effect of different solvent systems...

Embodiment 2

[0039] Example 2: cyclization of 2'-hydroxychalcone with visible light

[0040] Visible light photocyclization of 2'-hydroxychalcone was studied in pyridine-water system. Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, pour it into a quartz glass photoreactor, add 60ml of distilled water, fix the quartz glass photoreactor on a shaker, irradiate with a 500W xenon lamp, and react 4h, the reaction mixture was concentrated under reduced pressure, separated by column chromatography (eluent: benzene:ethyl acetate=30:1), and distilled under reduced pressure; The absorbance was measured at a fixed wavelength at 251nm, the characteristic peak of alkanone, and the content of flavanone was calculated. The yield was 99.6%; and analyzed by melting point, IR, H-NMR, HRMS and so on.

[0041] The effects of different reaction systems on the visible light photocyclization of 2'-hydroxychalcone to generate flavanones under the same conditions above are shown in Table 3. ...

Embodiment 3

[0045] Example 3: Photocyclization of 2'-hydroxychalcone under natural light

[0046] The natural light photocyclization reaction of 2'-hydroxychalcone was studied in pyridine-water system. Weigh 1mmol of 2'-hydroxychalcone, dissolve it with 40ml of pyridine, add it to a 250ml three-necked round-bottomed flask, then add 60ml of distilled water, stir mechanically, and react for 4 hours under natural light in the room, concentrate the reaction mixture under reduced pressure, and perform column chromatography Separation (eluent is benzene: ethyl acetate = 30: 1), distillation under reduced pressure; Concentrate is distilled to volume with methanol, adopts ultraviolet-visible spectrophotometer to measure absorbance at fixed wavelength at 251nm place of flavanone characteristic peak, calculates Flavanone content, the yield is 89.7%; and analyzed by melting point, IR, H-NMR, HRMS and so on.

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