Method for preparing isoxazoline

An isoxazoline and a selected technology, applied in the field of preparing isoxazoline, can solve problems such as limited application, and achieve the effects of good reaction, cheap and easily available raw materials, and convenient post-processing

Active Publication Date: 2020-12-04
SUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, high temperature, transition metal and alkali are required in the reaction, which limits its application in the preparation of bioactive molecules (see: Wan Xiaobing; Org.Lett.2017,19,5896, CN 107118171A)

Method used

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  • Method for preparing isoxazoline
  • Method for preparing isoxazoline
  • Method for preparing isoxazoline

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040]

[0041] Add acetonitrile (40mL), compound 1a (10mmol, 1.78g), compound 2a (20mmol, 2.40g), compound 3 (20mmol, 2.17g), catalyst boron trifluoride diethyl ether (1mmol, 263μL) into the reaction flask in sequence; Then react under the condition of 25 ℃ in the air for 12 hours; The mixed solvent of petroleum ether was subjected to column chromatography to obtain the product 4a with a yield of 80%. The main test data of the obtained product are as follows. It can be seen from the analysis that the actual synthesized product is consistent with the theoretical analysis.

[0042] 1 H NMR (400MHz, CDCl 3 )δ7.40(d, J=8.4Hz, 2H), 7.26(d, J=8.4Hz, 2H), 5.76(dd, J=11.6, 9.0Hz, 1H), 4.36(q, J=7.1Hz, 2H), 3.60(dd, J=17.8, 11.6Hz, 1H), 3.23(dd, J=17.8, 9.0Hz, 1H), 1.37(t, J=7.1Hz, 3H), 1.31(s, 9H). ; 13 C NMR (101MHz, CDCl 3 )δ160.5, 151.7, 151.1, 136.3, 125.69, 125.66, 84.9, 62.0, 41.1, 34.5, 31.2, 14.0; HRMS (ESI-TOF): Anal. Calcd. For C 16 h 21 NO 3 +H + :276.1594,Fou...

Embodiment 2

[0044]

[0045]Add acetonitrile (2.0mL), compound 1b (0.5mmol, 53.2mg), compound 2a (1.0mmol, 108μL), compound 3 (1.0mmol, 121μL), catalyst boron trifluoride diethyl ether (0.05mmol , 14 μL); then reacted for 12 hours at 25°C in the air; after the reaction was completed, it was quenched with saturated sodium chloride solution, extracted with ethyl acetate, the solvent was removed by a rotary evaporator, adsorbed on silica gel, and finally used The mixed solvent of ethyl acetate and petroleum ether was subjected to column chromatography to obtain the product 4b with a yield of 74%. The main test data of the obtained product are as follows. It can be seen from the analysis that the actual synthesized product is consistent with the theoretical analysis.

[0046] 1 H NMR (400MHz, CDCl 3 )δ7.47-7.21(m,5H),5.77(dd,J=11.6,8.9Hz,1H),4.35(q,J=7.1Hz,2H),3.63(dd,J=17.8,11.6Hz,1H ),3.21(dd,J=17.8,8.9Hz,1H),1.37(t,J=7.1Hz,3H).; 13 C NMR (101MHz, CDCl 3 )δ160.4, 151.0, 139.4, 128.7,...

Embodiment 3

[0048]

[0049] Add acetonitrile (2.0mL), compound 1c (0.5mmol, 61.1mg), compound 2a (1.0mmol, 108μL), compound 3 (1.0mmol, 121μL), catalyst boron trifluoride diethyl ether (0.05mmol , 14 μL); then reacted for 12 hours at 25°C in the air; after the reaction was completed, it was quenched with saturated sodium chloride solution, extracted with ethyl acetate, the solvent was removed by a rotary evaporator, adsorbed on silica gel, and finally used The mixed solvent of ethyl acetate and petroleum ether was subjected to column chromatography to obtain the product 4c with a yield of 67%. The main test data of the obtained product are as follows. It can be seen from the analysis that the actual synthesized product is consistent with the theoretical analysis.

[0050] 1 H NMR (400MHz, CDCl 3 )δ7.35-7.28(m,2H),7.14-7.00(m,2H),5.77(dd,J=11.6,8.9Hz,1H),4.36(q,J=7.1Hz,2H),3.64(dd ,J=17.8,11.6Hz,1H),3.18(dd,J=17.8,8.9Hz,1H),1.38(t,J=7.1Hz,3H); 13 C NMR (101MHz, CDCl 3 )δ162.7(d, J=...

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Abstract

The invention relates to a method for preparing isoxazoline, which comprises the steps of reacting olefin, a diazo compound and tert-butyl nitrite in an organic solvent at the temperature of 25-50 DEGC under the action of a Lewis acid catalyst to obtain isoxazoline after complete reaction. Lewis acid is used as a catalyst for synthesizing isoxazoline, reaction conditions are mild and can be carried out under the condition that the temperature is as low as the room temperature, use of transition metal is avoided, and the product yield is high.

Description

technical field [0001] The invention relates to the technical field of isoxazoline synthesis, in particular to a method for preparing isoxazolines. Background technique [0002] Isoxazolines are core skeletons that widely exist in natural products, drug molecules, and agrochemicals, and are also widely used as ligand molecules for transition metals. At present, although there are many methods for preparing isoxazolines, they all have obvious disadvantages, such as harsh reaction conditions, complicated preparation of raw materials, and the need for expensive and harmful transition metals. For example: [0003] (1) Xu Bin's research group reported the in situ generation of nitrile oxide intermediates from alkynes and copper nitrate and further preparation of isoxazolines by dipolar cycloaddition with alkenes, but the reaction must be performed under a nitrogen atmosphere. Higher yield, at the same time it is unavoidable to use equivalent transition metals, which has more re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D261/04C07D413/12
CPCC07D261/04C07D413/12
Inventor 万小兵马亮成雄略江港钟陶苏艳
Owner SUZHOU UNIV
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