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,

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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