反应详情

温度

50 °C

To a mixture of 382 mg (1.2 mmol) of ethyl trifluoroacetoacetate 4-nitrophenylhydrazone in 10 ml of THF was added 53 mg (60%; 1.32 mmol) of NaH and the resulting mixture was stirred at room temperature for 4 hours and at 50° C. for 16 hours. The reaction mixture was quenched with ammonium chloride solution, the aqueous layer was extracted with ethyl acetate (3×), and the combined organic layer was dried and concentrated in vacuo. The residue was purified by column chromatography (silica gel; 50% ethyl acetate in hexane) and recrystallized from methylene chloride/hexane to afford 1-(4-nitrophenyl)-3-trifluoromethyl-5-hydroxypyrazole as a white solid.

1. customThe reaction mixture was quenched with ammonium chloride solution
2. extractionthe aqueous layer was extracted with ethyl acetate (3×)
3. customthe combined organic layer was dried
4. concentrationconcentrated in vacuo
5. customThe residue was purified by column chromatography (silica gel; 50% ethyl acetate in hexane)
6. customrecrystallized from methylene chloride/hexane