反应详情

温度

0 °C

Under a nitrogen atmosphere, sodium borohydride (36 mg, 0.95 mmol) was added portionwise to a solution of methyl 2-[3-bromo-4-(3,4-dihydro-2H-1-benzopyran-6-yl)-1-methyl-1H-pyrazol-5-yl]-2-oxoacetate (11g) (300 mg, 0.79 mmol) in anhydrous tetrahydrofuran (8 mL) at 0° C. After 30 minutes stirring at 0° C., water was added (5 mL) and the mixture was concentrated in vacuo. The crude was dissolved in ethyl acetate (10 mL) then successively washed with water (10 mL), and brine (10 mL). The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC (dichloromethane/ethyl acetate 80/20) to provide methyl 2-[3-bromo-4-(3,4-dihydro-2H-1-benzopyran-6-yl)-1-methyl-1H-pyrazol-5-yl]-2-hydroxyacetate (11h) (204 mg, 0.54 mmol, 68%).

1. concentrationthe mixture was concentrated in vacuo
2. dissolutionThe crude was dissolved in ethyl acetate (10 mL)
3. washthen successively washed with water (10 mL), and brine (10 mL)
4. dry with materialThe organic layer was dried over sodium sulfate
5. concentrationconcentrated in vacuo
6. customThe residue was purified by preparative TLC (dichloromethane/ethyl acetate 80/20)