反应详情

Stir 5 g of 3-(5-nitro-2-furyl)-1-phenylpyrazole-4-carboxaldehyde together with 1.29 of hydroxylamine hydrochloride and 1.52 g of anhydrous sodium acetate in 15 ml of dimethylformamide for 1.5 hours at room temperature. Then add 2.85 g of phosphorus oxychloride dropwise to the resulting reaction mixture, the temperature of which rises to 40° C. Stir for 1 hour and then confirm that the reaction is complete by a thin layer chromatograph. Allow the solution to stand overnight and then pour onto 90 ml of ice water. Stir for 30 minutes at room temperature and then for 30 minutes at 40° C. Draw off the formed precipitate by vacuum filtration, wash the precipitate well with water and dry to obtain a 98% yield of 3-(5-nitro-2-furyl)-1-phenylpyrazole-4-carbonitrile [m.p. 190° to 192° C].

1. customdropwise to the resulting reaction mixture
2. customrises to 40° C
3. waitto stand overnight
4. stirringStir for 30 minutes at room temperature
5. waitfor 30 minutes at 40° C
6. filtrationby vacuum filtration
7. washwash the precipitate well with water
8. customdry