Imidazole → 5-(tert-Butyldimethylsilyloxy)-1H-indole

Participants

Reaction Steps

A solution of 5-hydroxyindole 1-3 (5.50 g, 41.3 mmol, 1 equiv), tert-butyldimethylsilyl chloride (7.47 g, 49.6 mmol, 1.20 equiv), and imidazole (7.03 g, 103 mmol, 2.50 equiv) in N,N-dimethylformamide (20 mL) was stirred at 23° C. for 20 hours. The reaction mixture was concentrated, and the residue was partitioned between ethyl acetate and water. The organic layer was washed with water (3×), then dried over magnesium sulfate and concentrated. The residue was purified by flash column chromatography (40% dichloromethane in hexanes, then 60% dichloromethane in hexanes) to give 5-(tert-butyl-dimethyl-silanyloxy)-1H-indole as a colorless oil which solidified upon standing. 1H NMR (400 MHz, CDCl3) δ 8.00 (br s, 1H), 7.22 (d, 1H, J=8.7 Hz), 7.17 (t, 1H, J=2.8 Hz), 7.06 (d, 1H, J=2.3 Hz), 6.76 (dd, 1H, J=8.6, 2.3 Hz), 6.44 (m, 1H), 1.00 (s, 9H), 0.19 (s, 6H).

Provenance & Evidence