Benzyl Chloride → 2-Amino-1-benzylbenzimidazole

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.

1. temperaturethe brown solution was refluxed for 3 days under N2 gas
2. filtrationthe reaction mixture was filtered through celite and
3. concentrationconcentrated in vacuo
4. filtrationThe resulting brown solid was filtered hot in 300 mL acetone
5. customcrystallized from approximately 100 mL of acetone

ORD record

ord-a1bb42c2b1844d15a110df80e4d73138

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07868028B2