Potassium hydride → 5-Bromo-3-(1-Methylpiperidin-4-yl)-1-Triisopropylsilylindole

Participants

Reaction Conditions

Reaction Steps

To a 10° C. slurry of potassium hydride (1.6 g, 14.3 mmol, 35% in mineral oil) in tetrahydrofuran (40 mL) was added neat 5-bromo-3-(1-methyl-4-piperidinyl)indole (2.8 g, 9.5 mmol) portionwise over 30 minutes. The resulting reaction mixture was stirred at 0° C. for 1 hour. Triisopropylsilyl trifluoromethanesulfonate (3.1 mL, 11.4 mmol) was added dropwise over 20 minutes and a slight exotherm was observed. After stirring 2 hours at 0° C., the reaction was quenched with ice chips then diluted with water and methylene chloride. The layers were separated and the aqueous layer was extracted with methylene chloride. The organic extracts were combined, washed with brine, dried over sodium sulfate, and concentrated in vacuo to give 7.4 g of a clear colorless oil. Purification by chromatography (florisil, 50:50 methylene chloride:hexanes, then 100% methylene chloride, then 95:5 methylene chloride:methanol) provided 3.6 g (84.1%) of the title compound. MS(FD) 448, 450 (M+).

Provenance & Evidence