反应详情

5-Bromo-3-hydroxy-1-isopropylpyrazole-4-carboxylic acid ethyl ester (5.8 g) and potassium carbonate (3.5 g) were suspended in N,N-dimethylformamide (50 mL), and benzyl bromide (2.76 mL) was added to the suspension under ice cooling. The mixture was stirred at room temperature for 6 hours. The reaction mixture was poured into 1 mol/L hydrochloric acid (100 mL), and the mixture was extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the obtained residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane=1/5) to give the title compound (7.7 g)

1. extractionthe mixture was extracted with ethyl acetate
2. washThe organic layer was washed with brine
3. dry with materialdried over anhydrous magnesium sulfate
4. customThe solvent was removed under reduced pressure
5. customthe obtained residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane=1/5)