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Preparation method of polysubstituted [alpha]-ketoester

A multi-substituted, ketoester technology, applied in the field of preparation of multi-substituted α-ketoesters, can solve problems such as low conversion rate and reaction yield, harsh reaction conditions, and poor substrate universality

Active Publication Date: 2021-04-20
YANGTZE NORMAL UNIVERSITY
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In view of the above-mentioned deficiencies or defects, the purpose of the present invention is to provide a method for preparing multi-substituted α-ketoesters, which can effectively solve the problems of harsh reaction conditions, poor substrate universality, low conversion rate and reaction yield in the prior art. The problem

Method used

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  • Preparation method of polysubstituted [alpha]-ketoester
  • Preparation method of polysubstituted [alpha]-ketoester
  • Preparation method of polysubstituted [alpha]-ketoester

Examples

Experimental program
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Effect test

Embodiment 1

[0022] This Example 1 provides a method for preparing a multi-substituted α-ketoester C1, the reaction formula is as follows:

[0023]

[0024] The specific preparation process of Example 1 is as follows: into a dry 10mL reaction tube, dissolve A1 (0.12mmol, 29.6mg) in 1,4-dioxane (1mL), and add accurately weighed Cesium carbonate (0.15mmol, 48.9mg) and B1 (0.1mmol, 20.2mg), then the reaction tube was placed at room temperature and stirred for 2 hours, and thin layer chromatography (TLC) was detected. After the reaction was over, the reaction solution was transferred to the chicken heart bottle The pure target product C1 can be obtained after column chromatography (petroleum ether:ethyl acetate=15-5:1, volume ratio) with a yield of 92%.

[0025] Characterization data of C1: m.p.167-169℃. 1 H NMR (400MHz, CDCl 3 )δ7.58(d,J=7.2Hz,2H),7.49(s,1H),7.46–7.35(m,6H),7.35–7.25(m,7H),3.76(q,J=7.1Hz,2H ),0.91(t,J=7.1Hz,3H). 13 C NMR (101MHz, CDCl 3 )δ188.2, 161.3, 147.9, 146.1, 1...

Embodiment 2

[0027] This Example 2 provides a method for preparing a multi-substituted α-ketoester C2, the reaction formula is as follows:

[0028]

[0029] The specific preparation process of Example 2 is as follows: in a dry 10mL reaction tube, dissolve A2 (0.12mmol, 33.8mg) in 1,4-dioxane (1mL), and add accurately weighed Cesium carbonate (0.15mmol, 48.9mg) and B1 (0.1mmol, 20.2mg), then the reaction tube was placed at room temperature and stirred for 2 hours, detected by TLC. Chromatography (petroleum ether: ethyl acetate = 15-5:1, volume ratio) can obtain the pure target product C2 with a yield of 82%.

[0030] Characterization data of C2: m.p.173-175℃. 1 H NMR (500MHz, Chloroform-d) δ7.74–7.69(m,2H),7.67(s,1H),7.59–7.50(m,4H),7.49–7.40(m,6H),7.40–7.34(m ,2H),3.90–3.81(m,2H),1.03(t,J=7.1Hz,3H). 13 C NMR (126MHz, CDCl 3 )δ187.2,160.8,147.9,145.6,143.9,137.8,137.3,135.4,134.5,133.7,131.5,131.3,130.9,129.9,129.5,129.3,129.2,129.1,129.0,128.9,127.0,116.2,112.4,62.6,13.7 .

Embodiment 3

[0032] This embodiment 3 provides a kind of preparation method of multi-substituted α-ketoester C3, and the reaction formula is as follows:

[0033]

[0034] The specific preparation process of Example 3 is as follows: into a dry 10mL reaction tube, dissolve A3 (0.12mmol, 33.8mg) in 1,4-dioxane (1mL), and then add accurately weighed Cesium carbonate (0.15mmol, 48.9mg) and B1 (0.1mmol, 20.2mg), then the reaction tube was placed at room temperature and stirred for 2 hours, detected by TLC. Chromatography (petroleum ether:ethyl acetate=15-5:1, volume ratio) can obtain the pure target product C3 with a yield of 85%.

[0035] Characterization data of C3: m.p.153-155℃. 1 H NMR (400MHz, Chloroform-d) δ7.69–7.62(m,2H),7.59(s,1H),7.56–7.48(m,3H),7.48–7.37(m,6H),7.37–7.27(m ,3H),3.88(q,J=7.1Hz,2H),1.03(t,J=7.1Hz,3H). 13C NMR (101MHz, CDCl 3 )δ187.9,161.2,148.0,145.3,144.7,137.6,137.3,137.2,135.8,134.6,131.3,130.0,129.9,129.5,129.5,129.2,129.1,129.0,128.9,128.8,128.2,116.4,111.7,6...

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Abstract

The invention discloses a preparation method of polysubstituted [alpha]-ketoester, which belongs to the field of organic synthesis, and comprises the following steps: adding [alpha]-cyano-[beta]-methyl substituted ketene compound, [beta], [gamma]-alkyne ketone ester and inorganic base into a reaction container according to the molar ratio of (1-2):1:(1-3) at room temperature, adding a solvent, and stirring to react for 2-4 hours, and after the reaction is finished, separating, purifying and drying to obtain the polysubstituted [alpha]-ketoester. The invention provides the method for synthesizing the polysubstituted [alpha]-ketoester derivative through [4+2] benzene cyclization, the whole process is simple and convenient to operate, environment-friendly, mild in condition and pollution-free, a target product is synthesized through one step of benzene cyclization, no by-product is generated, and the method has the characteristics of high atom utilization rate, high yield and high conversion rate.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of a multi-substituted α-ketoester. Background technique [0002] Polysubstituted α-ketoesters are widely found in many natural products, bioactive molecules, and functional organic materials. The carbonyl adjacent to the ester group in the structure of α-keto esters has very high reactivity and has been successfully used in the synthesis of many heterocyclic compounds. Therefore, developing a green and efficient method for the synthesis of multi-substituted α-ketoesters has always been a research hotspot and challenge for organic synthetic chemists. [0003] As early as 1985, it was reported that palladium catalyzed the secondary carbonylation of aryl iodides to realize the synthesis of α-ketoesters, but the reaction required harsh conditions and long reaction times; The addition of diethyl esters is a method for the synthesis of α-ketoesters, but harsh re...

Claims

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Application Information

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IPC IPC(8): C07C253/30C07C253/34C07C255/57C07D333/24C07D307/80C07C391/02C07C255/56
Inventor 贾乾发王文秀林银河
Owner YANGTZE NORMAL UNIVERSITY
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