Nitric Acid → 3-(2,5-difluoro-4-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole

Participants

Reaction Steps

To an ice cooled solution of 50 ml of fuming nitric acid (90%) was added slowly 8.29 g of 3-(2,5-difluorophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole. After addition, the mixture was allowed to warm to room temperature and then gently heated to 52° C. Heated for 2.5 hours, then cooled and poured onto ice. The resulting mixture was extracted with ether and the ether then washed twice with water, dried with anhydrous magnesium sulfate, filtered and the solvent removed by concentration in vacuo. The residue was purified utilizing a combination of chromatography and crystallization to give 5.62 g of 3-(2,5-difluoro-4-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole, mp 80°-81° C.

Provenance & Evidence