Sodium hydride → 4-Bromo-1-(triisopropylsilyl)-7-azaindole

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Reaction Steps

Sodium hydride (8.37 g, 209 mmol; 60% oil dispersion) was slowly added to 4-bromo-1H-pyrrolo[2,3-b]pyridine (33.0 g, 167 mmol) in THF (500 mL) at 0° C. The reaction was stirred for 15 minutes. Chlorotriisopropylsilane (38.7 g, 201 mmol) was then added in one portion. The suspension was warmed to room temperature and stirred for 30 minutes. The suspension was then cooled to about 0-5° C. and quenched with saturated aqueous NH4Cl (about 200 mL). The aqueous phase was extracted with hexanes (3×300 mL), and the combined organic phases were dried (MgSO4) and concentrated in vacuo. The residue was purified by flash chromatography on silica gel eluting with hexanes to yield 4-bromo-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (50 g, 84% yield) as an oil, which solidified upon standing. 1H NMR (400 MHz, CDCl3) δ 8.05 (d, 1H), 7.34 (d, 1H), 7.22 (d, Hz, 2H), 6.59 (d, 1H), 1.88-1.80 (m, 3H), 1.11 (d, 18H).

Provenance & Evidence