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A kind of preparation method of fipronil intermediate

An intermediate, the technology of fipronil, which is applied in the field of preparation of fipronil intermediates, can solve problems such as undisclosed, and achieve the effect of improving safety

Active Publication Date: 2016-06-15
安徽美诺华药物化学有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a 5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazole using a new reaction mechanism -The preparation method of 3-nitrile, this preparation method is not disclosed in the prior art

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] In a three-necked flask equipped with a magnetic stirrer, a thermometer and a reflux condenser, add 5g of 5-amino-3cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-pyrazole, A mixture of 5 g of dimethylammonium p-toluenesulfonate, 3 g of sodium trifluoromethanesulfinate, 12 mL of toluene and 12 mL of DMF was stirred for 5 min and the mixture in the reactor was cooled to 0°C in an ice bath; 2.1 mL of phosphorus oxychloride and 5 mL of toluene solution were slowly added dropwise to the above reactor, stirred and heated to 45° C. After the reaction for 20 h, the reaction was quenched with ice water; the product obtained by the above reaction was extracted with dichloromethane as the extract, and Washed with saturated sodium bicarbonate and water in turn, and concentrated to obtain 8.1g of product A. After testing, the HPLC purity of product A was 65%, and then the product A was recrystallized or treated with column chromatography with toluene to obtain 4.95g of product B, ...

Embodiment 2

[0019] In a three-necked flask equipped with a magnetic stirrer, a thermometer and a reflux condenser, add 5g of 5-amino-3cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-pyrazole, 5g dimethylamine hydrochloride, 3g potassium trifluoromethanesulfinate, 24mL DMF, after stirring for 10min, the mixture in the above reactor was cooled to 5°C in an ice bath; mL of phosphorus oxychloride and 5 mL of DMF solution, stirred and heated to 40°C, reacted for 18 h, quenched with ice water; extracted the product obtained by the above reaction with dichloromethane, and successively used saturated sodium bicarbonate and water to carry out After washing and concentration, 8.5g of product A was obtained. After testing, the HPLC purity of product A was 30%, and then the product A was recrystallized with toluene or subjected to column chromatography to obtain 2.1g of product B. After identification, product B was 5 -Amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyraz...

Embodiment 3

[0021] In a three-necked flask equipped with a magnetic stirrer, a thermometer and a reflux condenser, add 5g of 5-amino-3cyano-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-pyrazole, 5g of dimethylammonium p-toluenesulfonate, 1.5g of sodium trifluoromethanesulfinate, 1.5g of potassium trifluoromethanesulfinate, 14mL of toluene and 11mL of DMF mixed solution, after stirring for 8min, the mixture in the above-mentioned reactor The ice bath was cooled to -5 °C; 2.1 mL of phosphorus oxychloride, 3 mL of toluene and 2 mL of DMF solution were slowly added dropwise to the above reactor under stirring, stirred and heated to 50 °C, and the reaction was quenched with ice water after the reaction for 21 h; The product obtained by the above reaction was extracted with dichloromethane as the extract, and washed with saturated sodium bicarbonate and water in turn. After concentration, 8.35 g of product A was obtained. After testing, the HPLC purity of product A was 55%, and then toluene was us...

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Abstract

The invention relates to a preparation method of a fipronil intermediate-5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazoles-3-nitrile. According to the invention, a brand new reaction mechanism is used for using 5-amino-3cyan-1-(2,6-dichloro4-(trifluoromethyl)phenyl)-pyrazolidine sulfenyl to prepare 5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazoles-3-nitrile. In the reaction process, usage of severe toxic substances such as PCI can be avoided, phosphorous oxychloride with little toxicity is taken as a chloridizing agent, security of the preparation process is greatly increased, and the purity of the products can reach more than 95%.

Description

technical field [0001] The present invention relates to a preparation method of a fipronil intermediate, in particular to a kind of 5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethyl) Process for the preparation of thio)-1H-pyrazole-3-carbonitrile. Background technique [0002] 5-Amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazole-3-carbonitrile is an important fluorine Phronil intermediates can be used as antiparasitic drugs. In the prior art, 5-amino-1-(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazole-3-carbonitrile is generally It is prepared by alkylthiolation of pyrazole compounds. For example, in European patents EP0295117, EP0460940, EP0484165 and EP1374061, RSX (X=Cl or Br) or R-S-S-R and pyrazole compounds have been disclosed in detail to prepare 5-amino-1 -(2,6-dichloro-4-(trifluoromethyl)phenyl)-4-(trifluoromethylthio)-1H-pyrazole-3-carbonitrile process, but the above preparation met...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D231/44
CPCC07D231/44
Inventor 周赛冬任海豪沈芩陈海荣姚成志
Owner 安徽美诺华药物化学有限公司
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