Description
2,3-Difluoro-5-(trifluoromethyl)pyridine is a useful research chemical.
Uses
2,3-Difluoro-5-(trifluoroMethyl)pyridine is a heterocyclic compound and can be used as a pharmaceutical intermediate.
Synthesis
The general procedure for the synthesis of 2,3-dichloro-5-trifluoromethylpyridine from 2,3-dichloro-5-trifluoromethylpyridine is as follows: 1500 mL of DMSO, 363 g of cesium fluoride, and 8 g of potassium carbonate were added to a 5000 mL reaction flask and heated in an oil bath. Concentrate and cool 600 mL of DMSO under reduced pressure to below 80 °C. Under nitrogen protection, 318 g (1.58 mol) of 2,3-dichloro-5-trifluoromethylpyridine was added to the reaction system and the reaction was carried out at about 110 °C for 48 hours. After completion of the reaction, 600 mL of water was added to the yellow liquid for liquid-liquid separation. The organic phase was dried with anhydrous magnesium sulfate and filtered to give a crude product of 188 g. The 100-102 °C fractions were collected by distillation to give 139 g of 2,3-difluoro-5-trifluoromethylpyridine in 47.6% yield.
References
[1] Patent: CN104628679, 2018, B. Location in patent: Paragraph 0061; 0064; 0065
[2] Patent: US2008/221327, 2008, A1. Location in patent: Page/Page column 6; 9
