Tetrahydrofuran → 1-(t-butoxycarbonyl)-4-(fur-2-ylmethyl-1H-benzimidazol-2-yl)[1,4]diazepane

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Reaction Steps

Combine 1-(t-butoxycarbonyl)-4-(1H-benzimidazol-2-yl)[1,4]diazepane (1.7 g, 5.37 mmol), tetrahydrofuran (45 mL), and dimethylformamide (5 mL). Cool in an ice-bath. Add sodium hydride (0.32 g, 60%n in oil, 8.06 mmol). After 15 minutes, warm to ambient temperature. When gas evolution ceases add 2-(chloromethyl)furan (0.94 g, 8.06 mmol). After 18 hours, cool the reaction mixture, quench by the addition of a saturated aqueous ammonium chloride solution. Evaporate to remove most of the tetrahydrofuran, dilute with ethyl acetate, and extract with water, a saturated aqueous sodium bicarbonate solution, and then brine. Dry the organic layer over MgSO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with 50% ethyl acetate/hexane to give 1-(t-butoxycarbonyl)-4-(fur-2-ylmethyl-1H-benzimidazol-2-yl)[1,4]diazepane: Rf=0.47 (silica gel, ethyl acetate) Elemental Analysis Calculated for C22H28N4O3: C, 66.66; H, 7.17; N, 14.04. Found C, 66.65; H, 7.12; N, 14.13.

Provenance & Evidence