Toluene → ethyl 8-carbamoyl-6-(3-methoxyphenyl)-9H-carbazole-2-carboxylate

Participants

Reaction Steps

To a suspension of ethyl 6-bromo-8-carbamoyl-9H-carbazole-2-carboxylate (3.5 g, 6.85 mmol, Example 58C), tetrakis(triphenylphosphine)palladium (0)(0.317 g, 0.274 mmol), toluene (30 mL), and 2 M aqueous sodium carbonate (6.85 mL, 13.70 mmol) under nitrogen were added a solution of 3-methoxyphenylboronic acid (1.457 g, 9.59 mmol) in MeOH (4 mL). The resulting reaction mixture was heated at reflux for 5 h. After cooling to room temperature, it was diluted with a mixture of water (250 mL) and ethyl acetate (250 mL) and the two phases were separated. The aqueous phase was extracted with ethyl acetate (2×200 mL), and the combined organic phases were washed with water (2×200 mL), 5% aqueous NH4OH solution (120 mL), and brine (100 mL). The organic phase was dried over Na2SO4 and the solvent removed. The crude material was suspended in a mixture of DCM and ethyl acetate. The solid was collected by filtration, washed with DCM, and air dried to afford 1.31 g product 82A. The filtrate was mixtured with silica gel and the solvent removed. This was loaded onto a silica gel column and eluted with hexane containing 10 to 50% ethyl acetate to afford additional 1.01 g of product for a total of 2.32 g of crude. MS (ESI) m/z 389.2 (M+H). 1H NMR (DMSO-d6) δ ppm 11.73 (1H, s), 8.78 (1H, s), 8.30-8.51 (4H, m), 7.83 (1H, d, J=8.24 Hz), 7.55-7.67 (1H, m), 7.37-7.54 (3H, m), 6.96 (1H, d, J=8.24 Hz), 4.38 (2H, q, J=6.92 Hz), 3.90 (3H, s), 1.39 (3H, t, J=7.02 Hz).

Provenance & Evidence