Methyl iodide → N-Methylcarbazole

Participants

Reaction Conditions

Reaction Steps

To a solution of carbazole (3.34 g, 20 mmol) in DMF (80 mL) at 0° C. was added NaH (0.72 g, 30 mmol). After heating at 80° C. for 1.5 h, iodomethane (3.4 g, 24 mmol) was added dropwise. The resulting mixture was kept at 80° C. overnight. After cooling down to 0° C., the reaction mixture was carefully quenched with water and extracted with ethyl acetate three times. The combined organic phase was washed with water and brine. Then the organic layer was dried over anhydrous sodium sulfate and the solvent was removed. The residue was purified by silica gel chromatography using petroleum ether and ethyl acetate as eluent (EA:PE=1:5) to afford methylated carbazole 1b (2.78 g) as yellow oil in 77% yield. 1H NMR (400 MHz, CDCl3) δ 8.08 (d, J=8.0 Hz, 2H), 7.46 (t, J=8.0 Hz, 2H), 7.36 (d, J=8.0 Hz, 2H), 7.22 (t, J=8.0 Hz, 2H), 3.79 (s, 3H).13C NMR (400 MHz, CDCl3) δ 140.9, 125.6, 122.7, 120.2, 118.8, 108.4, 28.9.

Provenance & Evidence