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A kind of preparation method of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate

A technology of pyrazole sulfate and hydroxyethyl, which is applied in the field of preparation of 4,5-diamino-1-pyrazole sulfate, can solve the problems of high synthesis cost, long cycle and complicated synthesis process, and achieve Fewer by-products, reduced synthesis cycle, beneficial to expand the effect of promotion

Active Publication Date: 2015-08-12
沈阳感光化工研究院有限公司
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  • Abstract
  • Description
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  • Application Information

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Problems solved by technology

[0002] 4,5-diamino-1-(2-hydroxyethyl) pyrazole sulfate is as a kind of important intermediate, and prior art is starting raw material with cyano-3-ethoxy ethyl acrylate, and hydroxy Cyclization of ethyl hydrazine, followed by hydrolysis, acidification, decarboxylation, nitrosation, reduction, and sulfuric acid salification to obtain 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate, the synthesis method is complicated and the cycle long and expensive to synthesize

Method used

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  • A kind of preparation method of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate
  • A kind of preparation method of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate

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Effect test

Embodiment 1

[0017] Add 20g of 27% sodium methoxide and 25ml of methanol solution, 4.8g of 5-amino-1-(2-hydroxyethyl)-1H-pyrazole-4-carboxamide in a 250ml three-necked flask, stir and heat to dissolve at 40°C, and then Cool to 5°C, add 7.68g of liquid bromine dropwise, control the temperature at 10°C, react for 5 hours, then add 50ml of ethanol solution containing 10wt% sodium hydroxide to reflux for 24 hours, add 12g of 98% concentrated sulfuric acid for acidification, filter to obtain the crude product, 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate was obtained by column chromatography with a content of 98% and a yield of 55%.

[0018] 1 H NMR (300MHz ,DMSO): 9.18~9.28 ( s ,4H) ,7.21 ( s ,1H H) ,5.06~5.82 (S ,3H) ,3.91~3.95 (t ,2H ,) , 3.61~3.65 ( s , 2H , ) , see NMR spectrum figure 1 .

Embodiment 2

[0020] Add 20.5g of 27% sodium methoxide and 25.6ml of methanol solution, 4.5g of 5-amino-1-(2-hydroxyethyl)-1H-pyrazole-4-carboxamide into a 250ml three-necked flask, stir and heat at 60°C Dissolve, then cool to 5°C, add 8.1g of liquid bromine dropwise, control the temperature at 10°C, react for 5 hours, then add 60ml of ethanol solution containing 8wt% sodium hydroxide to reflux for about 24 hours, add 11.28g of 98% concentrated sulfuric acid to acidify , The crude product was obtained by filtration, and 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate was obtained by column chromatography with a content of 98.5% and a yield of 56%.

Embodiment 3

[0022] Add 19.8g 27% sodium methoxide and 24.5ml methanol solution, 3.96g 5-amino-1-(2-hydroxyethyl)-1H-pyrazole-4-carboxamide in a 250ml three-necked flask, stir and heat at 30°C Dissolve, then cool to 5°C, add dropwise 7.92g of liquid bromine, control the temperature at 10°C, react for 5 hours, then add 73.5ml of ethanol solution containing 5wt% sodium hydroxide and reflux for about 28 hours, add 11.88g of 98% concentrated sulfuric acid Acidification, filtration to obtain the crude product, and column chromatography to obtain 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate with a content of 98.2% and a yield of 53%.

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Abstract

The invention relates to a method for preparing a midbody, and in particular relates to a method for preparing a 4,5-diamido-1-(2-ethoxy) pyrazol sulfate. The invention provides the method for preparing the 4,5-diamido-1-(2-ethoxy) pyrazol sulfate with simple process and high purity. According to the method, 5-amino-1-(2-hydroxy ethyl)-1H-pyrazol-4-formamide is used as a raw material, and the 4,5-diamido-1-(2-ethoxy) pyrazol sulfate is prepared through Hoffman degradation reaction and acidification reaction in sequence. Due to adoption of the method, a prepared product is high in purity, and meanwhile, the process is simplified and the synthesis period is shortened.

Description

Technical field: [0001] The present invention relates to a kind of preparation method of intermediate, more specifically, relate to a kind of preparation method of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate. Background technique: [0002] 4,5-diamino-1-(2-hydroxyethyl) pyrazole sulfate is as a kind of important intermediate, and prior art is starting raw material with cyano-3-ethoxy ethyl acrylate, and hydroxy Cyclization of ethyl hydrazine, followed by hydrolysis, acidification, decarboxylation, nitrosation, reduction, and sulfuric acid salification to obtain 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate, the synthesis method is complicated and the cycle Long, and the synthesis cost is also high. Invention content: [0003] The present invention aims at the above problems and provides a preparation method of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfate with simple process and high purity. [0004] In order to achieve the above-mentioned purpose of the present inv...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D231/38
CPCC07D231/38
Inventor 李善柱许巍巍周兆秋李玉敏刘全群
Owner 沈阳感光化工研究院有限公司
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