反应详情

To a stirred solution of 4-ethyl-2-methylpyridine (0.458 9, 3.79 mmol) in THF (4mL) at −50 degrees Celsius, add butyl lithium (1.5 mL, 2.5 M, 3.79 mmol) slowly and stir for 10 minutes. To the reaction, slowly add a solution of 6-Chloro-1H-indazole-3-carbaldehyde (0.5 g, 1.89 mmol) in THF (4 mL). After stirring for 10 minutes, the reaction was quenched with 1 N citric acid (10 mL). The mixture was diluted with EtOAc (50 mL), water (20 mL), and saturated NaCl (10 mL). The layers were separated, and the aqueous was extracted with EtOAc (3×15 mL). The organics were combined and washed with saturated NaCl (20 mL). After drying the organic layer over Na2SO4, the solids were removed by filtration and the liquid was concentrated to an oil by rotary evaporation. Chromatography (40 g silica gel, 60–100% EtOAc/hex) yields the desired product (142 mg, 32%) and recovered 6-Chloro-1H-indazole-3-carbaldehyde (348 mg).

1. customTo the reaction
2. stirringAfter stirring for 10 minutes
3. customthe reaction was quenched with 1 N citric acid (10 mL)
4. additionThe mixture was diluted with EtOAc (50 mL), water (20 mL), and saturated NaCl (10 mL)
5. customThe layers were separated
6. extractionthe aqueous was extracted with EtOAc (3×15 mL)
7. washwashed with saturated NaCl (20 mL)
8. dry with materialAfter drying the organic layer over Na2SO4
9. customthe solids were removed by filtration
10. concentrationthe liquid was concentrated to an oil by rotary evaporation