Reaction Steps
To a mixture 1-[1-(cyclopropylmethyl)-2-(4-ethoxybenzyl)-1H-benzimidazol-5-yl]ethanol (1.35 g, 3.86 mmol), N-methylmorpholine-N-oxide (0.497 g, 4.24 mmol) and 4 Å molecular sieves (2.0 g) in CH2Cl2 (10 mL) was added tetrapropylammonium perruthenate (0.068 g, 0.193 mmol) and the resulting mixture was stirred at room temperature for 90 minutes. N-methylmorpholine-N-oxide (0.124 g, 1.06 mmol) and acetonitrile (1 mL) were added and the mixture was stirred at room temperature overnight. The solvent was concentrated in vacuo and the crude product was purified by silica gel column chromatography (30% EtOAc/hexanes to 60% EtOAc/hexanes) to provide the title compound (0.880 g, 65%) as a white solid. 1H NMR (CDCl3): δ 8.34 (s, 1H), 7.94 (dd, J=8.4 Hz, J=2.0 Hz, 1H), 7.35 (d, J=8.4 Hz, 1H), 7.15 (d, J=8.4 Hz, 2H), 6.91 (dd, J=6.4 Hz, J=2.0 Hz, 2H), 4.29 (s, 2H), 3.98 (q, J=7.2 Hz, 2H) 3.41 (d, J=6.8 Hz, 2H), 2.67 (s, 3H), 1.38 (t, J=7.0 Hz, 3H), 1.07–1.00 (m, 1H), 0.55–0.51 (m, 2H), 0.29–0.26 (m, 2H). 13C NMR (CDCl3): δ 198.71, 159.01, 156.43, 143.29, 140.01, 132.68, 130.44, 128.67, 123.50, 121.95, 115.83, 110.73, 64.38, 49.23, 34.63, 27.63, 15.76, 11.99, 5.20. MS (ESI) (M+H)+=349. Anal. Calcd for C22H24N2O2+0.1H2O: C, 75.44, H, 6.96; N, 8.00. Found: C, 75.48; H, 7.13; N, 8.01.
