Synthesis method of 3-difluoromethyl-1-methylpyrazole-4-formic acid

A technology of methylpyrazole and difluoromethyl, which is applied in the field of synthesis of difluoromethylpyrazole compounds, can solve the problems of unobtainable raw materials, low yield and the like

Inactive Publication Date: 2017-04-05
陈旭
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The synthesis of related 3-difluoromethyl-1-methylpyrazole-4-carboxylic acid lipid compounds mostly adopts a one-pot method. This synthesis method has its advantages, but 3-difluoromethyl will not be separated during the process. Base-1-methylpyrazole-4-ca

Method used

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  • Synthesis method of 3-difluoromethyl-1-methylpyrazole-4-formic acid
  • Synthesis method of 3-difluoromethyl-1-methylpyrazole-4-formic acid

Examples

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Embodiment 1

[0050] 102ml of 0.87mol 1-dimethylamino-1-buten-3-one was added to a solution of 500ml of dichloromethane and 254ml of triethylamine, the mixture was cooled to -10°C, and 86 ml of 1.29 mol of difluoroacetyl fluoride. After the addition was complete, the temperature of the reactants was kept at 0°C, and the mixture was continued to react for half an hour. Extract with 500ml of water, then extract the organic matter in the water with 500ml of dichloromethane, combine the organic phases, distill off the dichloromethane organic solvent under reduced pressure, and obtain 139g of 0.73mol 3-dimethylaminomethylene-1,1 difluoro- 2,4-pentanedione, yield 80%.

[0051] Add 10ml of methylhydrazine to 85ml of dichloromethane and 14ml of distilled aqueous solution, cool the mixture to -20°C, control the temperature within the range of -25°C to -17.6°C, and add 33g of 0.17mol 3- Dimethylaminomethylene-1,1-difluoro-2,4-pentanedione with 90 ml of dichloromethane. After the addition, 170 mL o...

Embodiment 2

[0054] 102 ml of 1-dimethylamino-1-buten-3-one was added to a solution of 500 ml of dichloromethane and 254 ml of triethylamine, the mixture was cooled to -5°C, and then 86 ml of difluoroethylene was added to the mixture within 90 minutes Acetyl fluoride. After the addition was complete, the temperature of the reactants was kept at 5°C, and the mixture was continued to react for half an hour. Extract with 500ml of water, then extract the organic matter in the water with 500ml of dichloromethane, combine the organic phases, distill off the dichloromethane organic solvent under reduced pressure, and distill to obtain 122g of 3-dimethylaminomethylene-1,1 difluoro-2,4 -Pentanedione, yield 70%.

[0055] Add 10ml of methylhydrazine to 85ml of dichloromethane and 14ml of distilled aqueous solution, cool the mixture to -10°C, control the temperature within the range of -15°C to -5°C, and add 33ml of 3-dimethylamino to the mixture within 20 minutes Methylene-1,1-difluoro-2,4-pentaned...

Embodiment 3

[0058] 102ml of 1-dimethylamino-1-buten-3-one was added to 500ml of dichloromethane and 254ml of triethylamine solution, the mixture was cooled to -10°C, and then 100ml of difluoroethylene was added to the mixture within 90 minutes Acetyl fluoride. After the addition was complete, the temperature of the reactants was kept at 0°C, and the mixture was continued to react for half an hour. Extract with 500ml of water, then extract the organic matter in the water with 500ml of dichloromethane, combine the organic phases, distill off the dichloromethane organic solvent under reduced pressure, and distill to obtain 138g of 3-dimethylaminomethylene-1,1 difluoro-2,4 -Pentanedione, yield 79%.

[0059]Add 20ml of methylhydrazine to 85ml of dichloromethane and 14ml of distilled aqueous solution, cool the mixture to -20°C, control the temperature within the range of -25°C to -17.6°C, add 33ml of 3-dimethylamino to the mixture within 30 minutes Methylene-1,1-difluoro-2,4-pentanedione with...

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Abstract

The invention discloses a synthesis method of 3-difluoromethyl-1-methylpyrazole-4-formic acid, and belongs to the technical field of difluoromethyl pyrazole synthesis. According to the synthesis method, 3-difluoromethyl-1-methylpyrazole-4-formic acid is prepared from 1-dimethylamino-1-butylene-3-one, difluoroacetyl fluoride, and methyl hydrazine through a series of reactions. The provided synthesis method has the advantages of easily available raw materials and high yield, can be applied to industry, and has a comprehensive yield more than 65%.

Description

technical field [0001] The invention relates to a synthesis method of difluoromethylpyrazole compounds, in particular to a synthesis method of 3-difluoromethyl-1-methylpyrazole-4-carboxylic acid. Background technique [0002] 3-Difluoromethyl-1-methylpyrazole-4-carboxylic acid, the English name is 3-difluoromethyl-1-methylpyrazole-4-carboxylic Acid. The structural formula is as follows: [0003] [0004] 3-Difluoromethyl-1-methylpyrazole-4-carboxylic acid ethyl ester is a kind of difluoromethylpyrazole compound, which is mainly used in the synthesis of pyrazole carboxylic acid amide fungicides. Pyrazole carboxylic acid amide fungicide is a novel high-efficiency fungicide with high activity against a wide range of phytopathogenic fungi and is used in various cultivated plants such as cotton, vegetables, barley, corn, rice, soybean, wheat and fungal control in bulk seeds. The synthesis of related 3-difluoromethyl-1-methylpyrazole-4-carboxylic acid lipid compounds mostly ...

Claims

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Application Information

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IPC IPC(8): C07D231/14
CPCC07D231/14
Inventor 陈旭
Owner 陈旭
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