Ethyl 6-nitro-1H-benzimidazole-2-carboxylate → 1H-Benzimidazole-2-carboxylic acid, 6-amino-, ethyl ester

Participants

Reaction Steps

A solution of 1.9 g (8.1 mmol) of ethyl 6-nitro-1H-benzimidazole-2-carboxylate in 30 ml of ethanol was hydrogenated in the presence of 190 mg of palladium (10% on activated carbon) at RT and standard pressure for 3 h. The reaction mixture was then filtered through kieselguhr and the residue was washed with ethanol. The combined filtrates were concentrated under reduced pressure. The residue was dried under reduced pressure and then purified by flash chromatography (silica gel 50, mobile phase: dichloromethane/methanol 3-5%). Yield: 640 mg (39% of theory)

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