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A method for synthesizing pyraclostrobin intermediate 1-(4-chlorophenyl)-3-pyrazolol

A technology for synthesizing pyrazole ethers and intermediates, which is applied in the field of synthesizing pesticide organic compounds, can solve the problems of potential safety hazards, incapable of high concentration of diazonium salts, huge amount of waste water and the like, achieves reduction of water consumption, simple synthesis method, The effect of raw material cleaning

Active Publication Date: 2019-04-19
SICHUAN FOURSTAR BIOTECH RANDD CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The disadvantages of using the above method include: in the production process, due to the use of a large amount of acid and sulfite, a huge amount of wastewater will be generated; there are safety hazards in the diazotization and reduction process, and the concentration of diazonium salts cannot be high, otherwise it will increase production. Dangerous performance, the sulfite used in the reduction process (such as CN103848752A) will produce sulfur dioxide gas as a by-product

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] The synthesis steps of p-chlorophenylhydrazine hydrochloride in this example are as follows:

[0049] (1.1) Using p-bromochlorobenzene and hydrazine hydrate with an equivalent ratio of 1:1 as raw materials, adding phase transfer catalyst (tetrabutylammonium hydrogen sulfate), solvent (ethylene glycol aqueous solution with a concentration of 85%), catalyst ( The weight ratio of copper sulfate and cobalt chloride is 1:1). The concentration of hydrazine hydrate is 100%, and the weight ratio of p-bromochlorobenzene to phase transfer catalyst and catalyst is 1:0.15:0.2. The weight ratio of benzene to solvent is 1:1;

[0050] The reaction process includes: slowly raising the temperature and controlling the temperature to 100°C, refluxing reaction under normal pressure, keeping the temperature for 1 hour, sampling HPLC and detecting that the p-chlorophenylhydrazine no longer increases, that is, stopping the reaction.

[0051] (1.2) After the reaction is over, the solid is separated ...

Embodiment 2

[0056] The synthesis steps of p-chlorophenylhydrazine hydrochloride in this example are as follows:

[0057] (1.1) Using p-bromochlorobenzene and hydrazine hydrate with an equivalent ratio of 1:3 as raw materials, adding phase transfer catalyst (tetrabutylammonium bromide and tetrabutylammonium hydrogen sulfate with a mass ratio of 2:1), solvent (Ethylene glycol dimethyl ether) and a catalyst (copper bromide), in which the concentration of hydrazine hydrate is 55%, the weight ratio of p-bromochlorobenzene to phase transfer catalyst and catalyst is 1:0.08:0.12, The weight ratio of chlorobenzene to solvent is 1:12;

[0058] The reaction process includes: slowly raising the temperature and controlling the temperature to 150° C., holding the pressure reaction, keeping the temperature for 10 hours, sampling HPLC and detecting that the p-chlorophenylhydrazine does not increase anymore, that is, stopping the reaction.

[0059] (1.2) After the reaction is over, the solid is separated by fil...

Embodiment 3

[0064] The synthesis steps of p-chlorophenylhydrazine hydrochloride in this example are as follows:

[0065] (1.1) Using p-bromochlorobenzene and hydrazine hydrate with an equivalent ratio of 1:4.5 as raw materials, adding phase transfer catalyst (mass ratio of 2:1:3 trioctyl methyl ammonium chloride, 15-crown-5 And PEG400), solvent (85% aqueous solution of propylene glycol ether), and catalyst (cuprous chloride). Among them, the concentration of hydrazine hydrate is 88%, and the weight ratio of p-bromochlorobenzene to phase transfer catalyst and catalyst is 1:0.11:0.09, the weight ratio of p-bromochlorobenzene to solvent is 1:8.6;

[0066] The reaction process includes: slowly raising the temperature and controlling the temperature to 120°C, refluxing reaction under normal pressure, keeping the temperature for 9h, sampling HPLC and detecting that p-chlorophenylhydrazine no longer increases, that is, stopping the reaction.

[0067] (1.2) After the reaction is over, the solid is sepa...

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PUM

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Abstract

The invention discloses a method for synthesizing a pyraclostrobin intermediate 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole. The method comprises the steps that p-bromochlorobenzene and hydrazine hydrate are used as reaction raw materials, a phase transfer catalyst, a solvent and a catalyst are added for a reaction, and p-chlorobenzene hydrazine hydrochloride is prepared; the p-chlorobenzene hydrazine hydrochloride reacts with alkali, sodium alkoxide and acrylate, and a toluene solution of an intermediate pyrazolone is prepared in the presence of toluene; toluene in the toluene solution is removed, alkali and hydrogen peroxide are added for oxidization, and the 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole solution is prepared. According to the synthesizing method, p-bromochlorobenzene and hydrazine hydrate are reacted for preparing the p-chlorobenzene hydrazine hydrochloride, so that the amount of wastewater produced in the synthesis process can be greatly reduced, usage of sulfite reducing agent and a large amount of acid is avoided, hazardous substance is prevented from being produced in the whole technological process, environment-friendly production is achieved, the HPLC content of 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole is larger than or equal to 98%, and the yield is larger than or equal to 90%.

Description

Technical field [0001] The present invention is a method for synthesizing pyraclostrobin intermediate 1-(4-chlorophenyl)-3-pyrazole alcohol, and specifically relates to the synthesis of pyraclostrobin intermediate 1-(4) from p-chlorophenylhydrazine -Chlorophenyl)-3-pyrazole alcohol method belongs to the technical field of the synthesis of pesticide organic compounds. Background technique [0002] Pyrazole compounds are a class of nitrogen-containing heterocyclic compounds with broad-spectrum biological activity and good insecticidal activity. Among them, 1-(4-chlorophenyl)-3-pyrazole is the pesticide pyraclostrobin It is mentioned in "Pesticide Science and Management" (2012, 33(1), "Synthetic process of 1-(4-chlorophenyl)-3-pyrazolone"). Phenyl)-3-pyrazol is synthesized from p-chlorophenylhydrazine through cyclization and chlorination. Under optimal conditions, 1-(4-chlorophenyl)-3-pyrazol can be realized The total yield of synthesis is 68.35%, and the content is 98.5%. [0003]...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D231/22
CPCC07D231/22
Inventor 王文马青伟刘虎陈熙李舟王蕾张华
Owner SICHUAN FOURSTAR BIOTECH RANDD CORP