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Preparation method of diastereoisomer 4-position substituted isoxazoline

A technology of diastereoisomers and isoxazolines, applied in the field of preparation of 4-position substituted isoxazolines, can solve the problem of simultaneously preparing diastereomer 4-position substituted isoxazolines and other issues to achieve the effect of broadening the scope of application

Active Publication Date: 2019-03-22
HARBIN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The present invention aims to solve the problem that it is difficult to simultaneously prepare two diastereomer 4-position substituted isoxazolines with completely opposite configurations in existing methods, and provides a diastereoisomer 4-position substituted isoxazoline The preparation method of oxazoline

Method used

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  • Preparation method of diastereoisomer 4-position substituted isoxazoline
  • Preparation method of diastereoisomer 4-position substituted isoxazoline
  • Preparation method of diastereoisomer 4-position substituted isoxazoline

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specific Embodiment approach 1

[0052] Specific embodiment one: the preparation method of diastereoisomer 4-position substituted isoxazoline in this embodiment is to use chiral bisoxazoline as catalyst ligand, respectively use Cu(OTf) 2 or Ni(OTf) 2 As a chiral metal catalyst, it catalyzes the reaction of acryloyl oxazolidinone and acryloyl-3,5-dimethylpyrazole with diaryl nitrone to prepare diastereomer 4-substituted isoxazolines, That is, the 4-position substituted isoxazoline in the cis configuration and the 4-position substituted isoxazoline in the trans configuration.

[0053] Among them, chiral bisoxazoline is used as catalyst ligand, and Cu(OTf) 2 As a chiral metal catalyst, it catalyzes the reaction of acryloyl oxazolidinone and diaryl nitrone to obtain a 4-position substituted isoxazoline with 100% cis configuration;

[0054] Using chiral bisoxazoline as catalyst ligand, Ni(OTf) 2 As a chiral metal catalyst, it catalyzes the reaction of acryloyl-3,5-dimethylpyrazole and diphenylnitrone to obtain ...

specific Embodiment approach 2

[0055] Specific embodiment two: the difference between this embodiment and specific embodiment one is: the preparation method of the 4-position substituted isoxazoline in the cis configuration specifically includes the following steps:

[0056] Step 1: Under the protection of nitrogen, add the chiral metal catalyst and 4ÅMS into the round bottom flask, and then add CH 2 Cl 2 Inject the reaction system, replace the nitrogen three times, and then take the chiral catalyst ligand with CH 2 Cl 2 After dissolving, inject into the reaction system, stir at room temperature for 30~40min; wherein the chiral metal catalyst is Cu(OTf) 2 , the chiral catalyst ligand is chiral bisoxazoline;

[0057] Step 2: Take acryloyl oxazolidinone and use CH 2 Cl 2 After dissolving, inject into the system, stir at room temperature for 1~1.5h,

[0058] Adjust the reaction temperature to 0°C, take a certain amount of dipolar nitrone, and use CH 2 Cl 2 After dissolving, add dropwise to the reaction...

specific Embodiment approach 3

[0061] Embodiment 3: This embodiment is different from Embodiment 2 in that the molar ratio of the chiral metal catalyst to the chiral catalyst ligand in step 1 is 1:1. Others are the same as in the second embodiment.

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Abstract

The invention discloses a preparation method of diastereoisomer 4-position substituted isoxazoline, relates to a preparation method of 4-position substituted isoxazoline, and aims to solve the problemthat two types of diastereoisomer 4-position substituted isoxazoline with completely opposite configurations are hard to prepare simultaneously in the conventional method. The method comprises the following steps: by taking chiral bioxazoline as a catalyst ligand, taking Cu(OTf)2 or Ni(OTf)2 as a metal center and taking bioxazoline derived from indene ammonia alcohol as a chiral ligand, catalyzing reaction of acryloyl oxazolanone, acryloyl-3,5-dimethylpyrazole and diaryl nitrone to prepare the 4-position substituted isoxazoline having a completely opposite configuration. Cis isoxazoline and trans isoxazoline which have 100 percent of optical activity are obtained, and the enantioselectivities of the products are at least 92 percent and 91 percent, respectively. A pair of optically pure diastereomers can be obtained through alcoholysis of the cis-4-substituted product and the trans-4-substituted product, respectively. The preparation method is used for the preparation of the diastereoisomer 4-position substituted isoxazoline.

Description

technical field [0001] The invention relates to a preparation method of a 4-position substituted isoxazoline. Background technique [0002] Isoxazole five-membered heterocyclic ring is an important class of pharmaceutical intermediates. Acryloyloxazolidinone 2a and acryloylpyrazole 2b are two excellent latent chiral compounds, and both electron-withdrawing alkenes can combine with diarylnitrones in 1,3-dipolar cycloaddition reactions reaction to prepare isoxazole five-membered heterocyclic compound. Since the reaction generates 2 chiral centers, involving regioselectivity, diastereoselectivity and enantioselectivity, 8 isomers will be produced, and the use of chiral catalysts can greatly improve the ring Regioselectivity, diastereoselectivity and enantioselectivity of addition reactions. [0003] At present, the asymmetric catalytic reaction of these two types of alkenes with nitrones reported in the literature only obtains an optical isomer in a single configuration (tra...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D413/06C07D261/02
CPCC07D261/02C07D413/06C07B2200/07
Inventor 由君李明龙曹茜娴喻艳超武文菊
Owner HARBIN UNIV OF SCI & TECH
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