反应详情

温度

0 °C

nBuLi (1.6 M solution in hexane, 25 mL, 40 mmol) was added dropwise at −78° C. to a solution of 4-bromo-3-phenyl-1-trityl-1H-pyrazole (7.96 g, 20.6 mmol) and B(OiPr)3 (6.92 mL, 30 mmol) in THF (75 mL). After stirring for 1 h, the reaction mixture was allowed to warm to 0° C., quenched with saturated NH4Cl aqueous solution, and extracted with AcOEt. The extract was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography eluting with hexane/AcOEt (2/1-0/1) and crystallized from MeOH to give crude (3-phenyl-1-trityl-1H-pyrazol-4-yl)boronic acid (5.73 g) as a white solid.

1. customquenched with saturated NH4Cl aqueous solution
2. extractionextracted with AcOEt
3. washThe extract was washed with brine
4. dry with materialdried over MgSO4
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by silica gel column chromatography
7. washeluting with hexane/AcOEt (2/1-0/1)
8. customcrystallized from MeOH