Preparation method of p-chlorophenylhydrazine sulfate

A technology of p-chlorophenylhydrazine and sulfate, which is applied in the field of preparation of p-chlorophenylhydrazine sulfate, can solve the problems of high catalyst cost, multi-salt wastewater, complicated three-stage suction filtration process, etc., and achieve the effect of less three wastes

Inactive Publication Date: 2021-06-11
JIANGSU YOUJIA CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, phenylhydrazine hydrochloride is used as an intermediate for the synthesis of pyraclostrobin, and most of the methods for synthesizing phenylhydrazine hydrochloride introduce sodium nitrite and sodium sulfite. Acidic wastewater, which contains miscellaneous salts, is difficult to treat;
[0004] U.S. Patent (US0047023) adopted p-chloroaniline, hydrochloric acid and sodium nitrite to react to generate diazonium liquid, then react with suitable reducing agent (sodium sulfite, sodium thiosulfate, etc.), and obtain phenylhydrazine hydrochloric acid after the reaction Salt; after the reaction, there will be more miscellaneous salt wastewater, which is more difficult to deal with
[0005] European patent (EP0959067) adopts p-chloroaniline, hydrochloric acid and n-butanol as solvents to synthesize p-chlorophenylhydrazine hydrochloride, and obtain the collection of p-chlorophenylhydrazine hydrochloride, which is as low as 36.2%, and the post-treatment is complicated
[0006] The Chinese patent (CN106187811A) uses p-chloroaniline, hydrochloric

Method used

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  • Preparation method of p-chlorophenylhydrazine sulfate
  • Preparation method of p-chlorophenylhydrazine sulfate

Examples

Experimental program
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Effect test

Embodiment 1

[0027] A preparation method of p-chlorophenylhydrazine sulfate: put 3075KG of 50% sulfuric acid into a 1000L reactor equipped with stirring, heat up to 65°C, add 1000KG of p-chloroaniline, and react for 2hr after adding, cool to 3°C, add dropwise 1195KG of 100% nitrosylsulfuric acid, the temperature was raised to 35°C after 2 hours of reaction after the dropwise addition, and kept for 2 hours, and 5270KG of diazo solution was obtained after passing through the filter press tank; the normalization of diazo solution was greater than 99%.

[0028] Put the diazo solution into the reduction autoclave, keep the reaction temperature at 20°C, pour in sulfur dioxide to 0.5MPa, keep the temperature and pressure to react for 6 hours, and keep feeding sulfur dioxide in the process, and a total of about 1305KG of sulfur dioxide is fed in; Reduction of intermediates>99%, after the reaction is qualified, release the pressure and raise the temperature to reflux for 1hr, take a sample and contr...

Embodiment 2

[0030] A preparation method of p-chlorophenylhydrazine sulfate: put 5125KG of 30% sulfuric acid into a 1000L reactor equipped with stirring, heat up to 80°C, add 1000KG of p-chloroaniline, and react for 2hr after adding, cool down to 0°C, add dropwise 1494KG of 80% nitrosyl sulfuric acid, the temperature is raised to 35°C after 1 hour of reaction after the dropwise addition, and the temperature is kept for 0.5 hours. After passing through the filter press tank, 7619KG of diazo solution is obtained; the normalization of diazo solution is greater than 99%.

[0031] Put the diazo solution into the reduction autoclave, keep the reaction temperature at 0°C, pour in sulfur dioxide to 0.5MPa, keep the temperature and pressure to react for 8 hours, and keep feeding sulfur dioxide in the process, and a total of about 1250KG of sulfur dioxide is fed in; Reduction of intermediates>99%, after the reaction is qualified, release the pressure and raise the temperature to reflux for 1hr, take ...

Embodiment 3

[0033] A preparation method of p-chlorophenylhydrazine sulfate: put 5125KG of 30% sulfuric acid into a 1000L reactor equipped with stirring, heat up to 80°C, add 1000KG of p-chloroaniline, and react for 2hr after adding, cool down to 0°C, add dropwise 1195KG of 100% nitrosyl sulfuric acid, the temperature was raised to 35°C after 1 hour of reaction after the dropwise addition, and kept for 1 hour, and 7320KG of diazo solution was obtained after passing through the filter press tank; the normalization of diazo solution was greater than 99%.

[0034] Put the diazo solution into the reduction autoclave, keep the reaction temperature at -5°C, pour in sulfur dioxide to 0.8MPa, keep the temperature and pressure to react for 10 hours, and keep feeding sulfur dioxide in the process, and a total of about 1280KG of sulfur dioxide is fed in; sampling is controlled in the reaction The reduced intermediate of the reaction is >99%, after the reaction is qualified, the pressure is released an...

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PUM

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Abstract

The invention discloses a preparation method of p-chlorophenylhydrazine sulfate, which comprises the following steps of by taking p-chloroaniline as a raw material, carrying out diazotization, reduction, acidolysis and crystallization centrifugation to obtain the p-chlorophenylhydrazine sulfate. According to diazotization, sulfate reacts with aniline, and then reacts with nitrososulfuric acid at low temperature to generate diazonium liquid; the obtained diazonium liquid reacts with sulfur dioxide under a certain pressure to generate an intermediate, then pressure is released, heating and refluxing are conducted for 1 hour, cooling, crystallizing and centrifuging are conducted to obtain p-chlorophenylhydrazine sulfate, the centrifuged mother liquor isadsorbed by carbon fibers, and the mother liquor is reused in diazotization synthesis; the purity of the p-chlorobenzene phenylhydrazine sulfate is more than 97%, the yield is more than 85%, compared with the prior art, the process has the advantages that no other metal cations are introduced, the centrifuged mother liquor can be applied to diazotization synthesis after being treated, no wastewater is generated, clean production is realized, and the requirements of safe production of current industrial production are met.

Description

technical field [0001] The invention relates to a production method of a compound, in particular to a preparation method of p-chlorophenylhydrazine sulfate. Background technique [0002] Pyraclostrobin is a new type of spectrum fungicide with broad-spectrum and high-efficiency bactericidal properties. What is more prominent is its low toxicity to non-target organisms, the environment and the safety of users. It is mainly used for spraying stems and leaves, which can effectively control Crop diseases caused by almost all types of fungal pathogens, such as Cysticomycetes, Basidiomycetes, Deuteromycetes and Oomycetes. Among them, phenylhydrazine salt is an important intermediate in the synthesis of pyraclostrobin. [0003] At present, phenylhydrazine hydrochloride is used as an intermediate for the synthesis of pyraclostrobin, and most of the methods for synthesizing phenylhydrazine hydrochloride introduce sodium nitrite and sodium sulfite. Acidic wastewater, which contains m...

Claims

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Application Information

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IPC IPC(8): C07C241/02C07C243/22
CPCC07C241/02
Inventor 吴孝举孔勇葛桂冬谢邦伟段宁涛沈阳旭赵鹏
Owner JIANGSU YOUJIA CHEM
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