N-bromobutanimide → 3-bromo-9-(2-(2-methoxyethoxy)ethyl)-9H-carbazole

Participants

Reaction Steps

To a solution of 1a (2 g, 7.4 mmol) in dichloromethane (60 mL) was added NBS (1.3 g, 7.4 mmol) portionwise in an ice-water bath. After complete addition, the solution mixture was warmed to room temperature and stirred overnight. The resulting solution was washed with water and brine. The organic phase was dried over anhydrous sodium sulfate and the solvent was removed. The residue was purified by silica gel chromatography using ethyl acetate and petroleum ether (EA:PE=1:5) as eluent to afford 2a (1.75 g) in 68% yield as an oil that can turn into solid after standing. NMR (400 MHz, CDCl3) δ 8.16 (d, J=2.0 Hz, 1H), 8.01 (d, J=8.0 Hz, 1H), 7.51 (dd, J=8.0 Hz, 2.0 Hz, 1H), 7.44 (m, 2H), 7.34 (d, J=8.4 Hz, 1H), 7.22 (m, 1H), 4.46 (t, J=6.0 Hz, 2H), 3.83 (t, J=6.0 Hz, 2H), 3.48 (m, 2H), 3.39 (m, 2H), 3.28 (s, 3H). 13C NMR (400 MHz, CDCl3) δ 140.7, 139.2, 128.2, 126.3, 124.5, 122.8, 121.8, 120.4, 119.3, 111.7, 110.4, 109.0, 71.8, 70.7, 69.1, 59.0, 43.2. MS (FAB) m/z Calcd for C17H18BrNO2 347.0. Found 347.3 [M]+.

Provenance & Evidence