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Method for preparing alpha-hydroxyl-beta-dicarbonyl compound through activating oxygen in air by using hydrazine

A technology for dicarbonyl compounds and compounds, applied in the preparation of organic compounds, organic chemistry methods, chemical instruments and methods, etc., can solve the problems of harsh requirements and low catalytic activity, and achieve the effect of mild reaction conditions and high yields

Inactive Publication Date: 2014-12-10
DALIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the relatively low catalytic activity of the triethyl phosphite / oxygen system and the harsh environmental requirements for substrates and solvents, the application of this method is limited.
Although scientists have done a lot of fruitful work on the α-hydroxylation of β-dicarbonyl compounds, it is still a great challenge to use molecular oxygen as an oxidant in this reaction to realize the reaction process.

Method used

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  • Method for preparing alpha-hydroxyl-beta-dicarbonyl compound through activating oxygen in air by using hydrazine
  • Method for preparing alpha-hydroxyl-beta-dicarbonyl compound through activating oxygen in air by using hydrazine
  • Method for preparing alpha-hydroxyl-beta-dicarbonyl compound through activating oxygen in air by using hydrazine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] Example 1 Preparation of 5-chloro-2-hydroxyl-1-indanone-2-carboxylic acid methyl ester

[0049] Weigh the substrate (22.4mg, 0.1mmol), cesium carbonate (32.5mg, 0.1mmol) and methylhydrazine (12.0mg, 0.26mmol), add 4mL of chloroform, and stir the reaction in air at room temperature. During the reaction, the conversion of the substrate was observed by TLC (thin layer chromatography). After reacting for 12 hours, the solvent was spin-dried and prepared by medium pressure (silica gel column, PE / EtOAc=5 / 1) to obtain the target product as a white solid (21.0 mg, 88% yield).

Embodiment 2

[0050] Example 2 Preparation of 5-chloro-2-hydroxyl-1-indanone-2-carboxylic acid methyl ester

[0051] Weigh the substrate (22.4mg, 0.1mmol), tetramethylguanidine (11.5mg, 0.1mmol) and methylhydrazine (12.0mg, 0.26mmol), add 4mL of chloroform, and stir the reaction in air at room temperature. During the reaction, the conversion of the substrate was observed by TLC (thin layer chromatography). After reacting for 6 hours, the solvent was spin-dried and prepared by medium pressure (silica gel column, PE / EtOAc=5 / 1) to obtain the target product as a white solid (20.3 mg, 88% yield).

Embodiment 3

[0052] Example 3 Preparation of (S)-5-chloro-2-hydroxyl-1-indanone-2-carboxylic acid methyl ester

[0053] Weigh the substrate (22.4mg, 0.1mmol), cinchonine (11.7mg, 0.04mmol) and methylhydrazine (6.0mg, 0.13mmol) into a reaction flask, and add 4mL of chloroform. The reaction temperature was controlled at 15°C, and the reaction was stirred in the open air. During the reaction, the conversion of the substrate was observed by TLC (thin layer chromatography). After 24 hours of reaction, the solvent was spin-dried and prepared by medium pressure (silica gel column, PE / EtOAc=5 / 1) to obtain the target product as a white solid (19.4 mg, 81% yield, 51% ee).

[0054] Example 3: Preparation of (S)-5-chloro-2-hydroxyl-1-indanone-2-carboxylic acid methyl ester

[0055] Weigh the substrate (22.4mg, 0.1mmol), dihydrocinchonine (11.7mg, 0.04mmol) and methylhydrazine (6.0mg, 0.13mmol) into a reaction flask, and add 4mL of chloroform. The reaction temperature was controlled at 15°C, and the...

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Abstract

The invention relates to a method for preparing a compound I (the compound is achiral, racemized or enantiomer-enriched in the indicated hydroxylation center). The method comprises the steps of adding organic hydrazine and a compound II under the condition that alkali is used as a catalyst, and enabling the organic hydrazine and the compound II to be in contact with a gas containing oxygen molecules to obtain the compound I with the highest yield of 98%. The product obtained by carrying out mixed reaction in a solvent by taking chiral alkali such as cinchona alkaloid as a catalyst and the compound II as a substrate is used as the enantiomer-enriched compound I with the highest yield of 95% and the ee value of 85%. The solvent comprises halogenated hydrocarbon, aromatic hydrocarbon, alkane, ether solvents and the like. Molecular oxygen is activated by using organic hydrazine compounds to realize the alpha-hydroxylation reaction of a beta-dicarbonyl compound, so that the method is relatively high in atom economy and environment-friendly. The method is a novel method for preparing various chiral or achiral alpha-hydroxyl-beta-dicarbonyl compounds through activating molecular oxygen by using organic hydrazine compounds.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis and relates to a method for preparing chiral and achiral α-hydroxyl-β-dicarbonyl compounds by activating air oxygen with hydrazine. technical background [0002] Optically active ɑ-hydroxy-β-dicarbonyl compounds are a very important structural unit, which widely exist in natural products, chiral pharmaceuticals and pesticide intermediates. It is worth mentioning that (S)-5-chloro-1-oxoindene-2-hydroxy-2-carboxylic acid methyl ester is an important intermediate of the pesticide indoxacarb. Direct asymmetric α-hydroxylation of 1,3-dicarbonyl compounds is the simplest and most direct method to obtain such structural units. In recent years, researchers have reported a large number of methods for the asymmetric synthesis of chiral α-hydroxy β-dicarbonyl compounds, which can be divided into two categories: a) metal complexes / active oxygen systems. b) Organic catalyst / active oxygen system. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/31C07C69/757
CPCC07C67/31C07B2200/07C07C2602/08
Inventor 孟庆伟王亚坤熊婷房金海杨帆刘广志
Owner DALIAN UNIV OF TECH
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