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Preparation method of 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole

A technology of pyrazolidine and chlorophenyl, which is applied in the field of preparation of 1--3-pyrazolol, can solve the problems of low safety and high content of three wastes, achieve high safety, increase reaction yield, and mild reaction Effect

Inactive Publication Date: 2018-10-16
SUN SHINE CHEM
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

[0004] The object of the present invention is to overcome above-mentioned technical deficiency, propose a kind of preparation method of 1-(4-chlorophenyl)-3-pyrazol, solve existing 1-(4-chlorophenyl)-3-pyrazol The technical problem of high content of three wastes and low safety in the synthetic method

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  • Preparation method of 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole
  • Preparation method of 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole

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preparation example Construction

[0013] The present embodiment provides a kind of preparation method of 1-(4-chlorophenyl)-3-pyrazolol, which comprises the following steps:

[0014] (1) After mixing hydrazine hydrate and polar solvent at room temperature, add a basic catalyst, raise the temperature of the mixed solution to 30-40°C and add acrylate, and raise the temperature of the mixed solution to After reflux reaction at 65-80°C for 1.5-4 hours, the liquid phase method was used to detect the mixed liquid several times. When the content of the main peak remained unchanged, the reaction was stopped. At this time, the reaction was complete, and a mixed liquid containing pyrazol-3-one was obtained;

[0015] In order to achieve the purpose of less environmental pollution and high economic efficiency, methanol, ethanol or toluene is selected as the polar solvent, wherein methanol, ethanol and water form azeotrope and are difficult to separate. Preferably, methanol is selected as the polar solvent.

[0016] If the...

Embodiment 1

[0032] (1) After mixing hydrazine hydrate 12.50g (80%, 0.2mol) and methanol 91.32g uniformly at room temperature, add sodium methoxide 21.82g (99%, 0.4mol), raise the temperature of the mixture to 40°C and 20.43g (98%, 0.2mol) of ethyl acrylate was added dropwise, and the dropwise addition was completed in 1 h. After the addition, the temperature of the mixed solution was raised to 70° C., and after reflux and stirring for 2 hours, the mixed solution was repeatedly detected by the liquid phase method. When the main peak content is constant, the reaction is stopped, and the reaction is complete at this time, and a mixed solution containing pyrazol-3-one is obtained;

[0033](2) Distill the mixed solution containing pyrazol-3-one obtained in step (1) until no solvent flows out, continue to steam for 0.5h; add 250g of water to the remaining solute to dissolve, and then add hydrogen to it Sodium oxide 10.12g (99%, 0.25mol) and ferric chloride 0.9g (99%, 0.005mol), after stirring a...

Embodiment 2

[0037] (1) After mixing hydrazine hydrate 12.50g (80%, 0.2mol) and methanol 106.54g at room temperature, add sodium methoxide 21.82g (99%, 0.4mol), raise the temperature of the mixture to 30°C and 20.43g (98%, 0.2mol) of ethyl acrylate was added dropwise, and the dropwise addition was completed in 1 h. After the addition, the temperature of the mixed solution was raised to 75° C., and after reflux and stirring for 2 hours, the mixed solution was repeatedly detected by the liquid phase method. When the main peak content is constant, the reaction is stopped, and the reaction is complete at this time, and a mixed solution containing pyrazol-3-one is obtained;

[0038] (2) Distill the mixed solution containing pyrazol-3-one obtained in step (1) until no solvent flows out, continue to steam for 0.5h; add 240g of water to the remaining solute to dissolve, and then add hydrogen to it Sodium oxide 10.12g (99%, 0.25mol) and ferric chloride 0.9g (99%, 0.005mol), after stirring and mixin...

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Abstract

The invention discloses a preparation method for 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole. Hydrazine hydrate and acrylic ester are taken as raw materials to synthesize pyrazol-3-ketone, the pyrazol-3-ketone is oxidized into hydroxypyrazole, and finally, hydroxypyrazole and bromochlorobenzene react to generate the 1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole. Compared with a traditional diazotizationmethod, the preparation method disclosed by the invention is characterized in that use of a great quality of acid and sulfite can be avoided, a whole preparation process does not generate harmful gas, and the emission of exhaust gas is obviously reduced; in addition, in a reaction process, no diazotization reaction exists during the reaction, reaction is moderate, and safety is higher; before the1-(4-chlorophenyl)-3-hydroxy-1-h-pyrazole is synthesized, reaction liquid carries out water diversion through backflow to control the moisture content of the reaction liquid, and wastewater can be reduced; ferric chloride is taken as catalyst, and the ferric chloride can be returned to a reaction system through simple processing to be reused. According to the synthesis method, the emission of three wastes is reduced, reaction safety is improved, and therefore, the preparation method has a good industrial application value.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a preparation method of 1-(4-chlorophenyl)-3-pyrazolol. Background technique [0002] Pyrazole compounds are a class of nitrogen-containing heterocyclic compounds with broad-spectrum biological activity, and have good insecticidal activity. Among them, 1-(4-chlorophenyl)-3-pyrazolol is the pesticide pyraclostrobin The important intermediate of 1-(4-chlorine) was mentioned in "Pesticide Science and Management" (2012, 33(1), "1-(4-chlorophenyl)-3-pyrazolol's synthesis process") Phenyl)-3-pyrazolol is synthesized from p-chlorophenylhydrazine by cyclization and chlorination. Under optimal conditions, 1-(4-chlorophenyl)-3-pyrazolol can be The total yield of synthesis is 68.35%, and the content is 98.5%. [0003] At present, most of the synthetic methods of 1-(4-chlorophenyl)-3-pyrazolol are to first synthesize p-chlorophenylhydrazine hydrochloride by p-chloroa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D231/22
CPCC07D231/22
Inventor 孙光强陈小敏梁洁
Owner SUN SHINE CHEM