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A kind of preparation method and application of pyrazole derivative

A technology of pyrazole derivatives and reaction, which is applied in the field of industrial synthesis of pyrazole derivatives, can solve the problems that ethyl propiolate is expensive, unsuitable for industrial production, and difficult to separate isomers, etc., and achieves easy preparation, The effect of high product quality and easy purification

Active Publication Date: 2022-02-08
SUQIAN KEYLAB BIOCHEMICAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although there are certain advantages in cost control, the reaction conditions are relatively harsh, in which dichloroacetyl chloride and vinyl ether compounds need to react at -40~-20°C; The temperature is 150°C, and the pressure in the kettle must be constantly changed during the process, which is inconvenient to operate, and the isomers are not easy to separate; 2) WO2009000442 reported that ethyl difluoroacetate was used as a raw material to react with hydrazine hydrate to form hydrazide, which was methylated and then 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (DFMMP) is obtained by ring closure with ethyl propiolate, the yield of this method is not high, and ethyl propiolate Esters are more expensive and not suitable for industrial production

Method used

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  • A kind of preparation method and application of pyrazole derivative
  • A kind of preparation method and application of pyrazole derivative
  • A kind of preparation method and application of pyrazole derivative

Examples

Experimental program
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Embodiment 1

[0043]The preparation method of pyrazole derivatives in this example suspends 74.1g (1mol) of acetylhydrazide in 200g of toluene, stirs and raises the temperature to 90ºC, adds 132g (1.05mol) of dimethyl sulfate dropwise, after the addition is completed, keep the temperature for 4 hours for reaction , the generated acetylmethylhydrazine methylsulfate was cooled to room temperature for use.

[0044] Add 68g of sodium ethylate, 70g of absolute ethanol, and 200g of toluene into another pressure reactor, raise the temperature to 70°C and feed carbon monoxide, keep the pressure at 20 atmospheres, then slowly pump in ethyl acetate with a high-pressure pump, keep the temperature and pressure to continue React for 3 hours.

[0045] Cool to room temperature, and gradually press the generated sodium salt into the previously prepared acetylmethylhydrazine methylsulfate. React at 30ºC to 40ºC for 2 hours, and filter to remove the generated sodium methyl sulfate. The filtrate was concent...

Embodiment 2

[0050] The preparation method of pyrazole derivatives in this example suspends 74.1g (1mol) of acetylhydrazide in 200g of toluene, stirs and raises the temperature to 90ºC, adds 132g (1.05mol) of dimethyl sulfate dropwise, after the addition is completed, keep the temperature for 4 hours for reaction , the generated acetylmethylhydrazine methylsulfate was cooled to room temperature for use.

[0051] Add 68g of sodium ethylate, 70g of absolute ethanol, and 200g of toluene into another pressure reactor, raise the temperature to 70°C and feed carbon monoxide, keep the pressure at 20 atmospheres, then slowly pump in ethyl acetate with a high-pressure pump, keep the temperature and pressure to continue React for 3 hours.

[0052] Cool to room temperature, and gradually press the generated sodium salt into the previously prepared acetylmethylhydrazine methylsulfate. React at 30ºC to 40ºC for 2 hours, and filter to remove the generated sodium methyl sulfate. The filtrate was concen...

Embodiment 3

[0056] The preparation method of pyrazole derivatives in this example suspends 74.1g (1mol) of acetylhydrazide in 200g of toluene, stirs and raises the temperature to 90ºC, adds 132g (1.05mol) of dimethyl sulfate dropwise, after the addition is completed, keep the temperature for 4 hours for reaction , the generated acetylmethylhydrazine methylsulfate was cooled to room temperature for use.

[0057] Add 54g of sodium methylate, 70g of methanol, and 200g of toluene into another pressure reactor, raise the temperature to 70°C and feed carbon monoxide, keep the pressure at 20 atmospheres, then slowly pump in methyl acetate with a high-pressure pump, keep the temperature and pressure to continue the reaction 3 Hour.

[0058] Cool to room temperature, and gradually press the generated sodium salt into the previously prepared acetylmethylhydrazine methylsulfate. React at 30ºC to 40ºC for 2 hours, and filter to remove the generated sodium methyl sulfate. Concentrate the filtrate un...

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Abstract

The invention relates to a preparation method of pyrazole derivatives. The compound shown in formula I reacts with the silylating agent shown in formula II to generate the intermediate product shown in formula III, and the intermediate product shown in formula III and the compound shown in formula IV The halogenated acid derivatives are reacted to generate halogenated compounds shown in formula V, and the halogenated compounds shown in formula V are reacted under acidic conditions to generate pyrazole derivatives shown in formula VI. The preparation method of the pyrazole derivatives of the present invention is suitable for industrial production.

Description

technical field [0001] The invention relates to an industrial synthesis method of pyrazole derivatives, belonging to the technical field of chemical synthesis. Background technique [0002] Halogen-substituted pyrazole derivatives, especially fluorine-containing pyrazole derivatives are intermediates of many medicines or pesticides. Among these fluorine-containing pyrazole derivatives, 3-difluoromethyl-1-methylpyrazole-4-carboxylic acid is an important pesticide intermediate, and plays a very important role as an intermediate in many new pesticide varieties , such as the cereal fungicide Bixafen (Bixafen) launched by Bayer CropScience, the new fungicide Fluxapyroxad (Fluxapyroxad) launched by BASF, the pyrazapyrazam (Isopyrazam) launched by Syngenta, Fluxapyrox Sedaxane, etc. [0003] [0004] International Patent WO 1992 / 12970 discloses 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid and its use as fungicides. This method converts 3-(difluoromethyl)-1-methyl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D231/14
CPCC07D231/14
Inventor 王明春李庆毅
Owner SUQIAN KEYLAB BIOCHEMICAL CO LTD
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