[5-(2-Benzyloxy-ethoxy)-2-nitro-phenyl]-methyl-carbamic acid methyl ester → 6-(2-Benzyloxy-ethoxy)-1-methyl-1,3-dihydro-benzoimidazol-2-one

Participants

Reaction Steps

To a solution of [5-(2-benzyloxy-ethoxy)-2-nitro-phenyl]-methyl-carbamic acid methyl ester (0.93 g, 2.58 mmol) in methanol (50 ml) and tetrahydofuran (50 ml) was added Raney Ni and the mixture was stirred under a hydrogen atmosphere (1 atm) until all starting material was consumed as indicated by TLC. The catalyst was filtered, washed generously with tetrahydofuran, and the filtrate evaporated. The residue was washed with anhydrous tetrahydofuran and evaporated (2×15 ml). The oil was dissolved in anhydrous tetrahydofuran (30 ml) and NaH was added (0.31 g, 60%, 7.75 mmol), and the reaction mixture was heated to reflux under nitrogen for 3.5 h. The reaction was quenched with NH4Cl (sat) (20 ml), water (20 ml) and ethyl acetate (20 ml). The layers were separated, and the aqueous layer was extracted with ethyl acetate (2×25 ml). The combined organics were washed with brine (25 ml), dried over MgSO4, filtered, and evaporated to give 6-(2-benzyloxy-ethoxy)-1-methyl-1,3-dihydro-benzoimidazol-2-one (0.75 g, 97%) as a solid. Analysis calculated for C17H18N2O3 : C, 68.44; H, 6.08; N, 9.39. Found: C, 68.64; H, 6.13; N, 8.96.

Provenance & Evidence