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Preparation method of 1-(4-chlorophenyl)-3-hydroxypyrazole

A technology of chlorophenyl and pyrazol, which is applied in the field of preparation of 1--3-pyrazol, can solve the problems of uneconomical, high cost, raw material preservation and harsh operating conditions, and achieves reduction of labor and product quality. Good, stable and easy-to-preserve raw materials

Active Publication Date: 2014-02-19
JINGBO AGROCHEM TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

"Research on the Synthesis of Pyraclostrobin" [Pesticide Research and Application, 13 (2009), 1] reacted p-chlorophenylhydrazine and methyl acrylate under the catalysis of sodium ethoxide to obtain 1-(4-chlorophenyl)pyridine Oxazolidin-3-one, after being separated and dried, was oxidized by air in KOH aqueous solution under the catalysis of ferric chloride to obtain 1-(4-chlorophenyl)-3-pyrazolol with a total yield of 79.9% (in terms of p-chlorophenylhydrazine), the content is 99%, but the cost is high, uneconomical, and the raw material storage and operating conditions are very harsh, so it is necessary to improve the synthesis of this intermediate compound

Method used

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  • Preparation method of 1-(4-chlorophenyl)-3-hydroxypyrazole
  • Preparation method of 1-(4-chlorophenyl)-3-hydroxypyrazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 36.16g (99%, 0.2mol) of p-chlorophenylhydrazine hydrochloride and 216.96g of toluene at room temperature, mix well, add 21.82g (99%, 0.4mol) of sodium methoxide, and dropwise add ethyl acrylate 26.53g at 50°C g (98%, 0.26mol), the dropwise addition was completed in 1 hour; the temperature was raised to 80°C for reflux and stirred for 6 hours, and through liquid phase detection, the main raw material p-chlorophenylhydrazine hydrochloride peak disappeared, that is, the reaction was complete; Continue steaming for 0.5h until no toluene flows out, add 145g of water to dissolve, then add 5.46g (99%, 0.02mol) of ferric chloride hexahydrate, heat up to 50°C and pass air (the flow rate of air is 70L / min) to oxidize 16h until the 1-(4-chlorophenyl)pyrazolidin-3-one peak disappears through the liquid phase detection, that is, the reaction is complete; add 50g of water, cool down to 40°C, add hydrochloric acid dropwise until pH=1, cool down to 30°C , Suction filtration to obta...

Embodiment 2

[0027] Add 36.16g (99%, 0.2mol) of p-chlorophenylhydrazine hydrochloride and 216.96g ethanol at room temperature, mix well, add 99.73g (30%, 0.44mol) of 30wt% sodium ethylate in ethanol, and drop Add 24.49 g (98%, 0.24 mol) of ethyl acrylate, and drop it for 1 hour; raise the temperature to 80° C. and reflux and stir for 6 hours. Through liquid phase detection, the main raw material p-chlorophenylhydrazine hydrochloride peak disappears, that is, the reaction is complete; Distill under reduced pressure, steam until no ethanol flows out and then continue to steam for 0.5h, add 145g of water to dissolve, then add 5.46g (99%, 0.02mol) of ferric chloride hexahydrate, heat up to 60°C and ventilate the air (the flow rate of the air is 70L / min) to oxidize for 12h until the peak of 1-(4-chlorophenyl)pyrazolidin-3-one disappears through liquid phase detection, that is, the reaction is complete; add 50g of water, cool down to 42°C, add hydrochloric acid dropwise until pH=1 , cooled to 30...

Embodiment 3

[0029]Add 36.16g (99%, 0.2mol) of p-chlorophenylhydrazine hydrochloride and 216.96g of methanol at room temperature. After mixing evenly, add 26.18g (99%, 0.48mol) of sodium methoxide, and dropwise add 24.57g of methyl acrylate at 40°C. g (98%, 0.28mol), the dropwise addition was completed in 1 hour; the temperature was raised to 65°C for reflux and stirred for 6 hours, and through liquid phase detection, the peak of the main raw material p-chlorophenylhydrazine hydrochloride disappeared, that is, the reaction was complete; Continue steaming for 0.5h until no methanol flows out, add 145g of water to dissolve, then add 5.46g (99%, 0.02mol) of ferric chloride hexahydrate, heat up to 70°C and pass air (the flow rate of air is 70L / min) to oxidize 10h until the 1-(4-chlorophenyl)pyrazolidin-3-one peak disappears through the liquid phase detection, that is, the reaction is complete; add 50g of water, cool down to 44°C, add hydrochloric acid dropwise until pH=1, cool down to 30°C , S...

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Abstract

The invention provides a preparation method of 1-(4-chlorophenyl)-3-hydroxypyrazole. P-chlorophenylhydrazine hydrochloride and acrylics are taken as raw materials and subjected to cyclization reaction and oxidation reaction with a one-pot method, so that 1-(4-chlorophenyl)-3-hydroxypyrazole is obtained. According to the method, 'one-pot method' reaction is realized, loss of transformed materials is avoided, the reaction period is shortened, the labor amount is reduced, the product quality is good, the yield is high, discharge of three wastes is reduced, the requirement of the green chemical technology is met, and the method has a good industrial application value.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a preparation method of 1-(4-chlorophenyl)-3-pyrazolol. Background technique [0002] Pyraclostrobin, also known as pyraclostrobin, is a broad-spectrum methyl methoxyacrylate fungicide with a pyrazole structure discovered by BASF in 1993. Its structural formula is: [0003] [0004] The chemical name is: N-methoxy-N-2-[(N-p-chlorophenyl)-3-pyrazolyloxymethyl]phenylcarbamate. It can prevent and control plant diseases caused by almost all types of fungal pathogens such as Ascomycetes, Basidiomycetes, Deuteromycetes and Oomycetes. At the same time, it is a hormone-type fungicide, which can make crops absorb more nitrogen Promoting the growth of crops, this variety is not only low in toxicity, safe for non-target organisms, but also safe and friendly to users and the environment. [0005] 1-(4-Chlorophenyl)-3-pyrazol is an important intermediate in the synthe...

Claims

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Application Information

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IPC IPC(8): C07D231/22
CPCC07D231/22
Inventor 于金苹王宗韦能春曹同波苑敬林王建刚孙永坤王帅帅
Owner JINGBO AGROCHEM TECH CO LTD
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