t-Butyl bromide → 3-(tert-Butyl)-6-nitro-1h-indole

Participants

Reaction Conditions

Reaction Steps

To a mixture of 6-nitroindole (1.0 g, 6.2 mmol), zinc triflate (2.1 g, 5.7 mmol), and TBAI (1.7 g, 5.2 mmol) in anhydrous toluene (11 mL) was added DIEA (1.5 g, 11 mmol) at room temperature under nitrogen. The reaction mixture was stirred for 10 min at 120° C., followed by the addition of t-butyl bromide (0.71 g, 5.2 mmol). The resulting mixture was stirred for 45 min at 120° C. The solid was filtered off and the filtrate was concentrated to dryness. The residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate=20:1) to give 3-tert-butyl-6-nitro-1H-indole (0.25 g, 19%) as a yellow solid. 1H-NMR (CDCl3) δ 8.32 (d, J=2.1 Hz, 1H), 8.00 (dd, J=2.1, 14.4 Hz, 1H), 7.85 (d, J=8.7 Hz, 1H), 7.25 (s, 1H), 1.46 (s, 9H).

Provenance & Evidence