Reaction Steps
To a suspension of N-(5-(pyrrolidin-1-yl)-2-(3,4,5-trimethoxybenzylamino)phenyl)benzamide in ethanol (20 mL) was added 4 N HCl. The reaction mixture was heated at 50° C. for 5 h, then cooled to room temperature. Excess acid was neutralized with ammonia hydroxide, and the resulting mixture was extracted with ethyl acetate (50 mL×3). The combined organics were washed with brine, dried over anhydrous MgSO4, and concentrated in vacuum. The residue was subjected to flash chromatography on silica gel to obtain 2-phenyl-5-(pyrrolidin-1-yl)-1-(3,4,5-trimethoxybenzyl)-1H-benzo[d]imidazole as a solid. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 7.75-7.72 (m, 2H, 2′,6′-H), 7.55-7.50 (m, 3H, 3′, 4′, 5′-H), 7.34 (d, J=8 Hz, 1H, 7-H), 7.75 (d, J=2 Hz, 1H, 4-H), 6.60 (dd, J=8, 2 Hz, 1H, 6-H), 6.29 (s, 2H, 2″, 6″-H), 5.38 (s, 2H, CH2), 3.56 (s, 9H, OCH3), 3.25-3.22 (m, 4H, 2′,5′-H), 1.97-1.94 (m, 4H, 3′,4′-H); 13C NMR (100 MHz, DMSO-d6) δ (ppm): 152.9, 152.9, 152.5, 144.8, 144.0, 136.6, 132.7, 130.7, 129.4, 128.9, 128.9, 128.7, 128.7, 127.9, 111.1, 109.9, 103.7, 103.7, 99.9, 59.8, 55.7, 55.7, 47.9, 47.9, 47.7, 24.8, 24.8; EIMS: m/z 443 (M+).
