反应详情

1-Phenyl-1H-pyrazole-3-carbaldehyde (779 mg, 4.53 mmol) was dissolved in anhydrous THF (9 mL) and chilled in an ice bath. EtMgBr (3.0 M in Et2O, 4.5 mL) was added dropwise. After 1.5 hours, the reaction mixture was allowed to warm to ambient temperature. TLC (2:1 hexanes:EtOAc indicated complete consumption of aldehyde starting material. The reaction mixture was quenched with water and extracted with EtOAc (2×). The EtOAc layers were washed with brine (1×), dried over Na2SO4 and concentrated. The residue was purified by silica gel chromatography (2:1 hexanes:EtOAc) to provide the title compound (631 mg, 69%) as a yellow oil. 1H NMR (400 MHz, CDCl3) δ 7.85 (d, 1H, J=2.4 Hz), 7.65 (d, 2H, J=7.6 Hz), 7.42 (t, 2H, J=7.6 Hz), 7.27 (d, 1H, J=7.2 Hz), 6.38 (d, 1H, J=2.4 Hz), 4.79 (dd, 1H, J=12, 5.6 Hz), 2.38 (d, 1H, J=4.8 Hz), 1.98-1.81 (m, 2H), 1.01 (t, 3H, J=7.2 Hz). MS (ES) m/z 203.1 (M+H+).

1. temperaturechilled in an ice bath
2. customTLC (2:1 hexanes:EtOAc indicated complete consumption of aldehyde starting material
3. customThe reaction mixture was quenched with water
4. extractionextracted with EtOAc (2×)
5. washThe EtOAc layers were washed with brine (1×)
6. dry with materialdried over Na2SO4
7. concentrationconcentrated
8. customThe residue was purified by silica gel chromatography (2:1 hexanes:EtOAc)