反应详情

250 ml (0.26 mol) of acetic anhydride are added to 60 g (0.20 mol) of 5-amino-1-(2,3,5,6-tetrafluoro-4-trifluoromethyl-phenyl)-pyrazole in 170 ml glacial acetic acid, whereupon the reaction temperature rises from 20° C. to about 35° C. The mixture is stirred at room temperature for 16 hours and then poured onto 800 ml of water. The crystalline solid which has precipitated out is filtered off with suction, washed freely with water and acetic acid and dried in vacuo. 59.8 g (87.7% of theory) of 5-acetamido-1-(2,3,5,6-tetrafluoro-4-trifluoromethyl-phenyl)-pyrazole of melting point 102° C. -104° C. are obtained.

1. customrises from 20° C. to about 35° C
2. customThe crystalline solid which has precipitated out
3. filtrationis filtered off with suction
4. washwashed freely with water and acetic acid
5. customdried in vacuo