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Preparation method of 3-aminoisoxazole

A technology of aminoisoxazole and hydroxyurea, applied in the field of medicine, can solve the problems of high cost, high process risk, easy filling and the like, and achieves the effects of improved yield, simple process steps, safe operation and environmental protection

Inactive Publication Date: 2020-12-08
YANGZHOU TIANHE PHARM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The object of the present invention provides a kind of preparation method of 3-aminoisoxazole, to solve existing 3-aminoisoxazole preparation and adopt 2,3-dibromopropionitrile intermediate to cause extremely easy punching, process risk is big , technical problems with high cost

Method used

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  • Preparation method of 3-aminoisoxazole
  • Preparation method of 3-aminoisoxazole

Examples

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preparation example Construction

[0030] A preparation method of 3-aminoisoxazole, the reaction scheme is as follows:

[0031]

[0032] Specific steps are as follows:

[0033] Put liquid caustic soda, hydroxyurea, and N,N-dimethylformamide into the reaction kettle; add 2,3-dichloropropionitrile dropwise under temperature control at 10-20°C; after the dropwise addition, stir at 10-30°C for 4 hours. After the reaction, pass in carbon dioxide, adjust the pH to 8-9, and filter with suction; extract the mother liquor with methyl isobutyl ketone, dry the extract with anhydrous sodium sulfate, decolorize and filter it with activated carbon, and desolventize the extract to obtain a light yellow oil and then distilled under reduced pressure to obtain a colorless oil.

[0034] The molar ratio of hydroxyurea, 2,3-dichloropropionitrile and sodium hydroxide is 1:1:3~4.

[0035] The weight ratio of hydroxyurea to N,N-dimethylformamide is: 1:0.05-0.10.

[0036] After the dropwise addition of 2,3-dichloropropionitrile i...

Embodiment 1

[0039] Preparation of 2,3-dichloropropionitrile: put 130g of acrylonitrile into a 500ml reactor, start stirring; then put in 1.3g of N,N-dimethylformamide and 0.13g of pyridine in turn; cool the contents of the reaction bottle to 5~15°C, slowly feed chlorine gas into the reaction bottle, keep the reaction temperature not exceeding 20°C; weigh, the molar amount of the gas introduced is 1.05~1.1 times the molar amount of acrylonitrile, and the aeration is completed; the temperature is controlled at 15~25°C Stir for more than 5 hours.

[0040] Nitrogen blows out excess chlorine until the reaction solution is slightly yellow or colorless and transparent.

[0041] Preparation of 3-aminoisoxazole: put 600g of liquid caustic soda with a mass concentration of 20% into a 2L reactor, start stirring; then put in 76g of hydroxyurea and 7.6g of N,N-dimethylformamide in sequence, and cool down; 15°C Thereafter, 126.7 g of 2,3-dichloropropionitrile was started to be added dropwise; during t...

Embodiment 2

[0044] Preparation of 2,3-dichloropropionitrile: put 1.30kg of acrylonitrile into a 2000ml reactor, start stirring; then put in 13g of N,N-dimethylformamide and 1.3g of pyridine in turn; cool the contents of the reaction bottle to 5~15°C, slowly feed chlorine gas into the reaction bottle, keep the reaction temperature not exceeding 20°C; weigh, the molar amount of the gas introduced is 1.05~1.1 times the molar amount of acrylonitrile, and the aeration is completed; the temperature is controlled at 15~25°C Stir for more than 5 hours.

[0045] Preparation of 3-aminoisoxazole: put 6.0kg of liquid caustic soda with a mass concentration of 20% into a 20L reactor, start stirring; then put in 760g of hydroxyurea and 57g of N,N-dimethylformamide in sequence, and cool down; 15°C Next, start to add 1.27kg of 2,3-dichloropropionitrile dropwise; keep the temperature at 10-20°C during the dropwise addition, and the dropwise addition time is about 2 hours. After the dropwise addition, keep...

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Abstract

The invention belongs to the technical field of medicines, and particularly relates to a preparation method of 3aminoisoxazole, which comprises the following steps: (1) preparing 2, 3dichloropropionitrile: adding acrylonitrile, N, Ndimethylformamide and pyridine into a reaction vessel, cooling to 5-15 DEG C, introducing chlorine into the reaction vessel, and keeping the reaction temperature at 1020 DEG C; controlling the temperature to be 15-25 DEG C and stirring for 5 hours after the chlorine gas is introduced; blowing excessive chlorine until the reaction liquid is yellowish or colorless andtransparent to obtain 2, 3dichloropropionitrile; and (2) preparation of 3amino isoxazole: under an alkaline condition, synthesizing 3amino isoxazole by taking hydroxyurea and 2, 3dichloropropionitrile as raw materials and N, Ndimethylformamide as a catalyst. The preparation method is used for solving the technical problems of extremely easy material punching and high process risk caused by the adoption of a 2, 3dibromopropionitrile intermediate in the existing 3amino isoxazole preparation.

Description

technical field [0001] The invention belongs to the technical field of medicine and relates to a preparation method of 3-aminoisoxazole. Background technique [0002] The preparation of 3-aminoisoxazole by traditional process requires the use of 2,3-dibromopropionitrile, and the preparation of 2,3-dibromopropionitrile has the following problems: [0003] First, in the process of dropping bromine, aggregation will occur, rapid exothermic phenomenon, very easy to wash materials, and the process is dangerous, which is not conducive to industrialized production. [0004] Second, the price of liquid bromine is high, and the molecular weight is large, and the consumption of raw materials is large, which further increases the cost of raw materials. [0005] Third, use 2,3-dibromopropionitrile to prepare 3-aminoisoxazole. The product contains liquid bromine. The product needs to be added to pyridine and heated to reflux. The pyridine is evaporated and then distilled to obtain a col...

Claims

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Application Information

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IPC IPC(8): C07D261/14
CPCC07D261/14
Inventor 张来平赵云德朱林飞薛晨金蕾
Owner YANGZHOU TIANHE PHARM CO LTD
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