A mixture of intermediate 48 (110 mg, 0.39 mmol) and NaI (117 mg, 0.78 mmol) in CH3CN was heated to reflux for 30 min and then cooled to rt. Intermediate 41 (156 mg, 0.59 mmol) and anhydrous K2CO3 (215 mg, 1.56 mmol) were added to the mixture. The resulting mixture was heated to reflux and stirred overnight. Precipitated crystals were filtered off and the filtrate was evaporated under reduced pressure. The residue was extracted with EtOAc. The combined EtOAc layers were washed with brine, dried over anhydrous Na2SO4, concentrated in vacuo and purified by flash chromatography on silica gel column (elution with DCM/MeOH=15:1) to give 5-(3-(4-(2,3-dichlorophenyl)piperazin-1-yl)propoxy)-1H-benzo[d]imidazol-2(3H)-one (compound 35) (54 mg, 32%). 1H NMR (300 MHz, CDCl3): δ 9.53 (s, 1H), 9.24 (s, 1H), 7.17-7.13 (m, 2H), 6.97-6.91 (m, 2H), 6.66-6.60 (m, 2H), 3.95 (t, J=5.7 Hz, 2H), 3.20-3.01 (m, 4H), 2.80-2.61 (m, 4H), 2.52 (t, J=7.5 Hz, 2H), 1.82-1.73 (m, 4H). HPLC: 99%, RT 2.325 min. MS (ESI) m/z 435.1 [M+H]+.
