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Method for preparing 1,2-tetrahydron isoxazole hydrochloride

A technology of isoxazole hydrochloride and tetrahydroisoxazole, which is applied in the field of preparation of 1,2-tetrahydroisoxazole hydrochloride, can solve the problems of expensive raw materials, high synthesis cost and complicated operation, etc. Achieve the effect of simple operation, easy enlargement and cost reduction

Inactive Publication Date: 2017-11-28
湖南华腾制药有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

It mainly solves the problems of expensive raw materials, complicated operation and high synthesis cost

Method used

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  • Method for preparing 1,2-tetrahydron isoxazole hydrochloride
  • Method for preparing 1,2-tetrahydron isoxazole hydrochloride
  • Method for preparing 1,2-tetrahydron isoxazole hydrochloride

Examples

Experimental program
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Effect test

Embodiment 1

[0011] Preparation of N-Boc-tetrahydroisoxazole:

[0012]

[0013] Dissolve 20 g of N-tert-butoxycarbonyl-hydroxylamine in 300 ml of tetrahydrofuran, add 8.2 g of sodium methoxide, and stir at room temperature for 0.5 hours. Then, 36 g of 1,3-dibromobutane was added dropwise to the reaction solution, heated to reflux and stirred for 6 hours. Cool, add saturated ammonium chloride solution, extract with ethyl acetate, wash the organic phase with saturated brine, combine the organic phase, dry over anhydrous sodium sulfate, filter, and concentrate the filtrate under reduced pressure to obtain N-Boc-tetrahydroisoxazole Crude product 29g.

Embodiment 2

[0015] Preparation of 1,2-tetrahydroisoxazole hydrochloride:

[0016]

[0017] Add 29g of N-Boc-tetrahydroisoxazole crude product to 200ml hydrogen chloride isopropanol solution, stir at room temperature for 4 hours, filter the reaction solution, wash the filter cake with isopropanol to obtain 14.9g 1,2-tetrahydroisoxazole Azole hydrochloride, total yield: 91.2%.

Embodiment 3

[0019]

[0020] Dissolve 20 g of N-tert-butoxycarbonyl-hydroxylamine in 280 ml of tetrahydrofuran, add 7.6 g of sodium methoxide, and stir at room temperature for 0.5 hours. Then, 32 g of 1,3-dibromobutane was added dropwise to the reaction liquid, and heated to reflux and stirred for 6 hours. Cool, add saturated ammonium chloride solution, extract with ethyl acetate, wash the organic phase with saturated brine, combine the organic phase, dry over anhydrous sodium sulfate, filter, and concentrate the filtrate under reduced pressure to obtain N-Boc-tetrahydroisoxazole Crude product 27.8g.

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Abstract

The invention provides a method for preparing 1,2-tetrahydron isoxazole hydrochloride, and mainly aims to solve the technical problems that a conventional synthesis process is low in yield, not easy in reaction control, inconvenient in experiment operation and the like. The method comprises the following steps: by taking N-t-butyloxycarboryl-hydroxylamine hydrochloride and 1,3-dibromopropane as initial raw materials, sodium alkoxide as an alkali, and tetrahydrofuran as a solvent, performing heating reflux for 6 hours so as to prepare N-Boc-tetrahydron isoxazole, and performing Boc protection removal, thereby obtaining 1,2-tetrahydron isoxazole hydrochloride. The 1,2-tetrahydron isoxazole hydrochloride is a useful intermediate for synthesizing multiple medicines.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a preparation method of 1,2-tetrahydroisoxazole hydrochloride. Background technique [0002] 1,2-Tetrahydroisoxazole hydrochloride and its derivatives have important applications in medicinal chemistry and organic synthesis. At present, the synthesis method of 1,2-tetrahydroisoxazole hydrochloride (Journal of Organic Chemistry, 1985, vol.50, #21p.3972–3979) is mainly through 1-aminocarbamic acid ethyl ester and 1,4- After the reaction of dibromobutane, the ethoxycarbonyl group is removed to obtain 1,2-tetrahydroisoxazole hydrochloride. The synthesis method mainly has the following problems: (1) the raw material is expensive; (2) the operation is complicated. Concrete reaction formula is as follows: [0003] [0004] Therefore, it is necessary to develop a synthetic method with low raw material price, convenient operation and easy control of reaction. Contents of the inven...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D261/02
CPCC07D261/02
Inventor 不公告发明人
Owner 湖南华腾制药有限公司
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