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 h. The reaction mixture was concentrated, and the residue was partitioned between ethyl acetate and water. The organic layer was washed with water (3x), 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) δ8.00 (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