1-Methylimidazole → 2-Bromo-9-(4-(tert-butyl)pyridin-2-yl)-9H-carbazole

Participants

Reaction Conditions

Reaction Steps

To a pressure vessel equipped with a magnetic stir bar was added 2-bromo-9H-carbazole (2461 mg, 10.0 mmol, 1.0 eq), CuI (762 mg, 4.0 mmol, 0.4 eq), and K2CO3 (2764 mg, 20.0 mmol, 2.0 eq). Then the vessel was evacuated and back-filled with nitrogen, and the evacuation and back-fill procedure was repeated twice. Then solvent toluene (60 mL), 1-methyl-1H-imidazole (792 uL, 10.0 mmol, 1.0 eq) and 2-bromo-4-tert-butylpyridine (5353 mg, 25.0 mmol, 2.5 eq) were added under the protection of nitrogen. The mixture was stirred in an oil bath at a temperature of 115-125° C. for 4 days. Then the mixture was cooled to ambient temperature. The solvent was removed under reduced pressure and the residue was purified through column chromatography on silica gel using dichloromethane as an eluent to obtain the desired product, 2-bromo-9-(4-tert-butylpyridin-2-yl)-9H-carbazole, as a colorless sticky liquid (3635 mg in 96% yield). 1H NMR (DMSO-d6, 400 MHz): δ 1.39 (s, 9H), 7.36 (t, J=8.0 Hz, 1H), 7.48-7.55 (m, 3H), 7.71-7.73 (m, 2H), 7.94 (d, J=2.0 Hz, 1H), 8.23 (d, J=8.0 Hz, 1H), 8.28 (d, J=8.0 Hz, 1H), 8.66 (d, J=5.5 Hz, 1H).

Provenance & Evidence