Benzimidazole → 3-(1H-1,3-benzodiazol-1-yl)propan-1-amine

Participants

Reaction Steps

Prepare a suspension of sodium hydride (812 mg, 20 mmol) in tetrahydrofuran (50 mL). Add benzimidazole (2 g, 16.9 mmol) under nitrogen. Reflux the mixture for 1 hour. At the same time, add 3-bromopropylamine hydrobromide (3.7 g, 16.9 mmol) to a suspension of sodium hydride (676 mg, 16.9 mmol) under nitrogen and reflux the mixture for 1 hour. Combine the two mixtures and reflux for 2 hours. Filter the reaction mixture, concentrate the filtrate to an oil, basify with sodium hydroxide and extract with ethyl acetate (3×50 mL). Concentrate the combined organic layers to an oil. Perform chromatography (silica gel, 9:1 methylene chloride/MeOH) to afford the title compound (780 mg) MS: m/e=176 (MH+)

Provenance & Evidence