Formic Acid → 1H-Benzimidazol-6-ol,1-methyl-(9CI)

Participants

Reaction Conditions

Reaction Steps

To a suspension of 3-methylamino-4-nitro-phenol (300 mg, 1.786 mmol) in formic acid (4 mL) was added iron powder (1.0 g, 17.86 mmol). The reaction mixture was stirred at 100° C. overnight, then it was cooled to room temperature and diluted with methanol. The insolubles were filtered and washed with methanol. The filtrate was concentrated in vacuo and adsorbed on silica gel. Purification by flash chromatography on silica gel using a gradient of 0-15% methanol/dichloromethane afforded 249 mg of 3-methyl-3H-benzoimidazol-5-ol as a light brown solid (94% yield): 1H NMR (DMSO-d6) δ 3.71 (s, 3H), 6.69 (dd, 1H), 6.81 (d, 1H), 7.40 (d, 1H), 7.94 (s, 1H), 9.3 (broad s, 1H); MS (m/z) 149 [M+H]+.

Provenance & Evidence