反应详情

To a mixture of ethyl 5-hydroxy-1-(2-methylphenyl)-1H-pyrazole-3-carboxylate (1.0 g, 4.06 mmol), potassium carbonate (0.84 g, 6.09 mmol) and N,N-dimethylformamide (10 mL) was added isobutyl bromide (0.49 mL, 4.47 mmol) under stirring at room temperature, and the mixture was stirred at the same temperature for 16 hr. The reaction mixture was diluted with ethyl acetate, washed with water and 5% aqueous potassium hydrogensulfate solution, dried, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=10/1-4/1) to give the title compound (1.07 g, yield 87%) as pale-yellow crystals.

1. stirringthe mixture was stirred at the same temperature for 16 hr
2. washwashed with water and 5% aqueous potassium hydrogensulfate solution
3. customdried
4. concentrationconcentrated under reduced pressure
5. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=10/1-4/1)