Dimethylformamide → 1-t-butoxycarbonyl-4-(1-pentyl-1H-benzimidazol-2-yl)[1,4]diazepane

Participants

Reaction Conditions

Reaction Steps

Treat a solution of 1-(t-butoxycarbonyl)-4-(1H-benzimidazol-2-yl)[1,4]diazepan (0.59 g, 1.86 mmol, Preparation 9) and dimethylformamide (10 mL) with sodium hydride (0.11 g, 2.75 mmol, 60% dispersion in oil) at room temperature. After 15 minutes, add pentyl bromide (0.34 mL, 2.74 mmol, Aldrich Chemical Company) and heat overnight at 80° C. Cool the reaction and dilute with dichloromethane (150 mL). Extract the organic phase with brine, dry (Na2SO4), filter and concentrate the filtrate to afford 4-(1-pentyl-1H-benzoimidazol-2-yl)-[1,4]diazepane-1-carboxylic acid tert-butyl ester (0.71 g, Rf=0.87, silica gel, 95:5:0.5 dichloromethane:methanol:ammonium hydroxide).

Provenance & Evidence