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Synthesis method of 5-amidogen-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole

A technology of trifluoromethylphenyl and trifluoromethylaniline, which is applied in the field of synthesis of 5-amino-3-cyano-1-pyrazole, can solve the problem of excessive reaction temperature lag of sodium nitrite and solid material feeding speed Non-uniformity, potential safety hazards and other problems, to achieve the effect of high purity and yield, low production cost and high product quality

Active Publication Date: 2019-09-17
HAIZHENG CHEM NANTONG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Therefore, the process of preparing a large amount of 2,6-dichloro-4-trifluoromethylaniline diazonium salt and reacting with ethyl 2,3-dicyanopropionate itself has potential safety hazards
And this patent needs to add solid sodium nitrite, there is a problem of uneven feeding speed of solid material in the actual operation of the workshop, it is easy to cause local excess sodium nitrite reaction temperature lag, thus causing safety hazards such as fire and explosion accidents

Method used

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  • Synthesis method of 5-amidogen-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole
  • Synthesis method of 5-amidogen-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole
  • Synthesis method of 5-amidogen-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] Add 52g of 2,6-dichloro-4-trifluoromethylaniline, 52g of ethanol, and 19.4g of 30% hydrochloric acid into a 250mL flask, and stir at 30-35°C for 1h to form 2,6-dichloro-4- Ethanol solution of trifluoromethylaniline salt;

[0052] At room temperature, add 34.4 g of ethyl 2,3-dicyanopropionate, 100 g of ethanol, and 20.6 g of 30% hydrochloric acid into a 1000 mL four-necked flask, and stir to obtain ethyl 2,3-dicyanopropionate hydrochloric acid Ethanol solution 155g;

[0053] Controlled at 0-5°C, add dropwise the ethanol solution of 2,6-dichloro-4-trifluoromethylaniline salt and 43g of 40% sodium nitrite aqueous solution to a 1000mL four-necked flask at the same time, drop as much as possible at the same time After the addition is completed, continue to incubate at 0-5°C for 4 hours, and after sampling and detecting 2,6-dichloro-4-trifluoromethylaniline ≤ 0.5% by HPLC, add 40% aqueous urea solution to the reaction solution dropwise until the starch Potassium iodide test...

Embodiment 2

[0074] Add 78g of 2,6-dichloro-4-trifluoromethylaniline, 78g of ethanol, and 20g of 35% hydrochloric acid into a 250mL flask, and stir at 30-35°C for 1.5h to form 2,6-dichloro-4- Ethanol solution of trifluoromethylaniline salt;

[0075] At room temperature, add 51.6 g of ethyl 2,3-dicyanopropionate, 150 g of ethanol, and 22.4 g of 35% hydrochloric acid into a 1000 mL four-necked flask, and stir to obtain ethyl 2,3-dicyanopropionate hydrochloric acid Ethanol solution 224g;

[0076] Controlled at 0-5°C, add dropwise the ethanol solution of 2,6-dichloro-4-trifluoromethylaniline salt and 62.4g of 45% sodium nitrite aqueous solution to a 1000mL four-necked flask at the same time. After the dropwise addition, continue to incubate at 0-5°C for 2 hours, take a sample and detect 2,6-dichloro-4-trifluoromethylaniline ≤ 0.5% by HPLC, then add ammonium sulfite with a concentration of 35% to the reaction solution Water solution to starch potassium iodide test paper test does not change c...

Embodiment 3

[0082] Add 156g of 2,6-dichloro-4-trifluoromethylaniline, 104g of ethanol, and 38.8g of 32% hydrochloric acid into a 500mL flask, and stir at 30-35°C for 1h to form 2,6-dichloro-4- Ethanol solution of trifluoromethylaniline salt;

[0083] At room temperature, add 103.2 g of ethyl 2,3-dicyanopropionate, 200 g of ethanol, and 38.8 g of 32% hydrochloric acid into a 2000 mL four-necked flask, and stir to obtain ethyl 2,3-dicyanopropionate hydrochloric acid Ethanol solution 342g;

[0084] Controlled at 0-5°C, add dropwise the ethanol solution of 2,6-dichloro-4-trifluoromethylaniline salt and 122.6g of 42% sodium nitrite aqueous solution to a 2000mL four-necked flask at the same time. After the dropwise addition, continue to keep warm at 0-5°C for 12 hours, and after sampling and detecting 2,6-dichloro-4-trifluoromethylaniline ≤ 0.5% by HPLC, add hydrogen sulfite with a concentration of 38% to the reaction solution Sodium aqueous solution to starch potassium iodide test paper test...

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Abstract

The invention discloses a synthesis method of 5-amidogen-3-cyano-1-(2,6-dichloro-4-trifluoromethyl phenyl) pyrazole. The synthesis method comprises the following steps that at 0 to 5 DEG C, an ethanol solution of 2,6-dichloro-4-trifluoromethyl aniline salt and a sodium nitrite solution with the mass concentration being 40 to 45 percent are simultaneously and dropwise added into a hydrochloric acid ethanol solution of 2,3-dicyan ethyl propionate; reaction liquid is subjected to heat insulation for 2 to 12h at 0 to 5 DEG C until the concentration of 2,6-dichloro-4-trifluoromethyl aniline in the reaction liquid is smaller than or equal to 0.5 percent; reducing reagents are dropwise added into the reaction liquid to remove excessive nitrous acid in the reaction liquid until the nitrous acid in the reaction liquid is completely removed; at 10 to 15 DEG C, ammonium hydroxide and ethanol are added into the reaction liquid, so that the pH of the reaction liquid is greater than or equal to 11; heat insulation is performed for 8 to 24h. The synthesis method has the advantages that the technology prejudice of technicians in the field is broken; the cost is reduced; the generation of three wastes is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of preparation of fine chemical products, in particular to a synthesis method of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole. Background technique [0002] 5-Amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole, referred to as pyrazole ring, is an important intermediate in the synthesis of insecticides fipronil and ethiprole body. The pure product is a white crystalline solid, and the industrial product is a light yellow-brown solid with a melting point of 141-142°C. It is soluble in methanol, ethanol, acetone, dichloroethane and ethyl acetate. The quality of the finished product and the level of synthesis efficiency will have a major impact on the insecticidal effects of fipronil and ethiprole. [0003] Fipronil is a phenylpyrazole insecticide with a wide insecticidal spectrum. It mainly has gastric toxicity to pests, and also has contact killing and certain systemic effects...

Claims

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Application Information

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IPC IPC(8): C07D231/38
CPCC07D231/38
Inventor 王建忠包如胜金晓东孙仁标柯林刚
Owner HAIZHENG CHEM NANTONG CO LTD
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