反应详情

3-Benzyloxy-5-bromo-1-isopropylpyrazole-4-carboxylic acid (4.6 g) was dissolved in tetrahydrofuran (30 mL), and borane-tetrahydrofuran complex, 1M tetrahydrofuran solution (21 mL) was delivered by drops into the stirred solution under ice cooling. The mixture was stirred at room temperature for 1 hour. The reaction mixture was cooled with ice bath, and water (50 mL) was delivered by drops into the mixture. Hydrochloric acid (1 mol/L, 20 mL) was delivered by drops into the mixture, 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 (3.0 g).

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