Acetic Anhydride → 1-(2,3,5,6-Tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole

Participants

Reaction Steps

A mixture of 7.48 grams (0.0250 mole) of 5-amino-1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)pyrazole, 21.0 mL of glacial acetic acid, and 3.1 mL of acetic anhydride was stirred at room temperature for approximately 18 hours. The reaction mixture was poured into 100 mL of ice-water, forming a white precipitate. This solid was collected by filtration and washed in succession with dilute acetic acid and water. The washed solid was dried to yield 8.1 grams of 1-(2,3,5,6-tetrafluoro-4-trifluoromethylphenyl)-5-methylcarbonylaminopyrazole, m.p. 103°-105° C. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence