Combine imidazole (0.08 g, 1.2 mmol) and dimethylformamide (2 mL). Cool in an ice bath and add sodium hydride (0.04 g, 60% i oil, 1.2 mmol). After 30 minutes, warm to ambient temperature. Add a solution of 1-(t-butoxycarbonyl)-4-(1-(2-methanesulfonyloxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane (0.35 g, 0.80 mmol) in dimethylformamide (2 mL). Heat to 75° C. After 12 hours, partition the reaction mixture between water and dichloromethane. Extract the organic layer twice with water, dry over Na2SO4, filter, and concentrate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with 5% methanol/dichloromethane/0.5% concentrated aqueous ammonia to give 1-(t-butoxycarbonyl)-4-(1-(2-(1H-imidazol-1-yl)ethyl)-1H-benzimidazol-2-yl)[1,4]diazepane: Rf=0.44 (silica gel, 5% methanol/dichloromethane/0.5% concentrated aqueous ammonia).
