Review of Synthesis of 2,3-Dichloro-5-Trifluoromethyl ...
Jul. 29, 2024
Review of Synthesis of 2,3-Dichloro-5-Trifluoromethyl ...
Introduction
CAS -84-7 2,3-Dichloro-5-Trifluoromethyl Pyridine is a very valuable fluorine-containing pyridine organic intermediate. It is used in the production of a series of high-efficiency insecticides such as diafenthiuron, fenflunom, the high-efficiency herbicide fenflufop and the high-efficiency fungicide fluazinam. Key Intermediates of New Pesticide Varieties
Overview of Synthetic Routes
1) Using 2,3-dichloro-5-trichloromethylpyridine as raw material
106.16 g (0.4 mol) of 2,3-dichloro-5-trichloromethylpyridine and 180 g (9 mol) of anhydrous hydrogen fluoride were added to a polyethylene reactor, and the temperature was controlled at 20 °C within 3 h Slowly add mercuric oxide, control the reaction temperature of the system not to exceed 35 , and stir the reaction for about 22 h after the addition, until the system is gray-white. Filter, neutralize the filtrate with sodium bicarbonate, extract with dichloromethane, dry with anhydrous sodium sulfate, remove the dichloromethane under reduced pressure to obtain the product 2,3-dichloro-5-trifluoromethylpyridine, the conversion rate is 100%, and the selectivity is 98%.
2) Using 3-methylpyridine as raw material
Take 50 g of 2,3-dichloro-5-trichloromethylpyridine, add catalyst, heat up to 170 °C, slowly introduce anhydrous hydrogen fluoride gas, and react for 11 h. After the reaction is completed, use 5% sodium bicarbonate solution in And, the organic phase was separated, washed with water and dried to obtain a crude product with a content of 85% and a yield of 65%.
If you are looking for more details, kindly visit huimeng.
3) Using 2-chloro-5-trifluoromethylpyridine as raw material
Take 363 g of 2-chloro-5-trifluoromethylpyridine, add 325 g of ferric chloride, pass chlorine gas, heat up to 150-170 °C and react for 18 h, add the reaction system to 1.5 L of hot water, separate out The oil layer was dried with anhydrous sodium sulfate and rectified to obtain 163 g of product.
Source
Review of Synthesis of 2,3-Dichloro-5-trifluoromethyl Pyridine [YUAN Qi-liang, SHEN De-long, LU Xin-xin, Fu Qing]
2,3-Dichloro-5-(trifluoromethyl)pyridine, 97%
Description
2,3-Dichloro-5-(trifluoromethyl)pyridine is reported as an intermediate of herbicide. Synthesis of 2,3-dichloro-5-(trifluoromethyl)pyridine has been reported. Palladium-catalyzed monoalkoxycarbonylation of 2,3-dichloro-5-(trifluoromethyl)pyridine has been reported.
Application
D (OTTO) 2,3-Dichloro-5-(trifluoromethyl)pyridine, 97% Cas -84-7 - used in pharmaceutical and bio chemical industry.
47
0
0
Previous: None
Next: None
Comments
All Comments (0)