反应详情

温度

3.5 °C

A 500 mL 3-neck round-bottom flask was charged with 6-bromo-1H-indole (5.95 g, 30.4 mmol) and THF (60 ml) to give a deep red solution. The flask was fitted with a N2 sweep, then cooled in an ice bath until an internal temperature of 2 to 5° C. was reached. At this time, sodium hydride (1.457 g, 36.4 mmol) was added portion-wise over 2 to 3 minutes such that the internal temperature was maintained below 10° C. The resulting mixture was stirred at this temperature for 20 minutes before triisopropylsilyl chloride (8.12 ml, 37.9 mmol) was added over 1 min. The cooling bath was removed, and the mixture was stirred for 15 min at room temperature. The volatiles were evaporated in vacuo, and the residue was taken up in saturated aq. sodium bicarbonate solution (150 mL). The mixture was extracted with DCM (2×250 mL), and the combined organic extracts were dried over sodium sulfate, filtered, and concentrated. The crude product was purified by chromatography on silica gel (0 to 10% EtOAc/Heptane) to give 6-bromo-1-(triisopropylsilyl)-1H-indole (7.33 g, 20.80 mmol, 68.5% yield) as a clear oil. 1H NMR (400 MHz, CDCl3) δ=8.22 (td, J=0.8, 1.5 Hz, 1 H), 7.85-7.70 (m, 2 H), 7.58 (d, J=3.1 Hz, 1 H), 6.78 (dd, J=1.0, 3.1 Hz, 1 H), 1.84-1.65 (m, 3 H), 1.17 (d, J=7.5 Hz, 18 H).

1. customto give a deep red solution
2. temperaturewas maintained below 10° C
3. additionwas added over 1 min
4. customThe cooling bath was removed
5. customThe volatiles were evaporated in vacuo
6. extractionThe mixture was extracted with DCM (2×250 mL)
7. dry with materialthe combined organic extracts were dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude product was purified by chromatography on silica gel (0 to 10% EtOAc/Heptane)