Benzyl Chloride → 2-Amino-1-benzylbenzimidazole

Participants

Reaction Steps

To a solution of 2-aminobenzimidazole (2) (Aldrich, 6 g., 45 mmol) in EtOH (10 mL) was added EtONa (21% in EtOH, 16.83 mL, 45 mmol) and benzyl chloride (5.70 mL, 50 mmol) and the brown solution was refluxed for 3 days under N2 gas. After cooling to room temperature, the reaction mixture was filtered through celite and concentrated in vacuo. The resulting brown solid was filtered hot in 300 mL acetone and crystallized from approximately 100 mL of acetone, and gave 3 as brown crystals (3.91 g., 39%). Recrystallization of the mother liquor afforded additional 3 as brown crystals (0.70 g., 7%). 1H-NMR (DMSO-d6) δ 5.27 (s, 2H), 6.61 (s, 2H), 6.82 (t, J=8.8 Hz, 1H), 6.93 (t, J=6.4 Hz, 1H), 7.05 (d, J=8.0 Hz, 1H), 7.15 (d, 7.2 Hz, 1H), 7.20 (d, 6.8 Hz, 2H), 7.24 (d, 7.6 Hz, 1H), 7.31 (t, 7.6 Hz, 2H); 13C-NMR (DMSO-d6) 45.11, 108.30, 115.19, 118.49, 120.88, 127.39, 127.66, 128.91, 134.60, 137.64, 143.34, 155.46.

Provenance & Evidence