2-Chlorobenzimidazole → 1-ethoxycarbonyl-4-(1H-benzimidazol-2-yl)[1,4]diazepane

Participants

Reaction Conditions

Reaction Steps

Combine 1-ethoxycarbonyl[1,4]diazepane (36.6 g, 212 mmol) and 2-chlorobenzimidazole (18.0 g, 106 mmol). Heat to 130° C. After 4 hours, cool to ambient temperature and add hot methanol to dissolve the reaction mixture. Partition the methanol solution between dichloromethane (700 mL) and a solution of sodium hydroxide (20 g) in water (500 mL). Separate the layers and extract the aqueous layer three times with dichloromethane. Combine the organic layers, extract with brine, dry over Na2SO4, filter, and evaporate in vacuo to give a solid. Triturate the solid with ethyl acetate (100 mL) and cool to 0° C. Collect solid by filtration and dry in vacuo to give 1-ethoxycarbonyl-4-(1H-benzimidazol-2-yl)[1,4]diazepane.

Provenance & Evidence