反应详情

温度

-20 °C

Vinylmagnesium bromide (0.85 M in THF, 97.7 mL, 83.0 mmol) was added over 30 min. to a stirring solution of 2,6-dibromo-3-methoxy-5-nitropyridine (7.4 g, 23.7 mmol) in THF (160 mL) at −75° C. The sol tion was stirred 1 h at −75° C., overnight at −20° C. recooled to −75° C. and quenched with saturated aqueous NH4Cl (˜100 mL). The reaction mixture was allowed to warm to rt, washed with brine (˜100 mL) and extracted with Et2O (150 mL) and CH2Cl2 (2×100 mL). The combined organi were dried (MgSO4), filtered and concentrated. The residue was purified by flash column chromatography (SiO2, 3:1 hexanes/EtOAc) to yield 5,7-dibromo-4-methoxy-6-azaindole 36 (1.10 g, 3.60 mmol, 15%) as a pale yellow solid.

1. customrecooled to −75° C.
2. customquenched with saturated aqueous NH4Cl (˜100 mL)
3. temperatureto warm to rt
4. washwashed with brine (˜100 mL)
5. extractionextracted with Et2O (150 mL) and CH2Cl2 (2×100 mL)
6. dry with materialThe combined organi were dried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by flash column chromatography (SiO2, 3:1 hexanes/EtOAc)