Nitric Acid → 1-(2,3,5,6-Tetrafluoro-4-trifluoromethyl phenyl)-5-methylcarbonylamino-4-nitropyrazole

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Reaction Steps

A stirred solution of 7.86 grams (0.0230 mole) of 1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole in 20 mL of glacial acetic acid was cooled in an ice-water bath. Acetic anhydride (2.9 mL, 0.031 mole) was added dropwise, and the mixture was stirred briefly. Concentrated nitric acid (1.05 mL, 0.0245 mole) was added dropwise, and the reaction mixture was allowed to warm to room temperature and was stirred for four hours. The mixture was poured into 60 mL of ice-water and stirred, forming a granular yellow solid. This solid was collected by filtration and washed with water. The solid was purified by recrystallization from ethanol and water to yield 5.63 grams of 1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl) -5-methylcarbonylamino-4-nitropyrazole, m.p. 136.5-138.5° C. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence