To a solution of 3-(3,5-dichloro-phenyl)-1-[4-(4-iodo-phenyl)-piperidin-4-ylmethyl]-1-methyl-urea (˜0.10 g, 0.17 mmol) in ClCH2CH2Cl (1 mL) was added cyclopropanecarboxaldehyde (0.016 mL, 0.204 mmol, 1.2 eq.). The mixture was stirred at room temperature for 15 min and then HOAc (0.01 mL, 1% v/v) was added. The reaction was stirred for a further 1 h. Na(OAc)3BH (0.054 g, 0.255 mmol, 1.5 eq.) was added and the reaction was stirred at room temperature for 12 h. It was diluted with EtOAc (10 mL) and washed with saturated NaHCO3 (10 mL) and saturated brine (10 mL). The combined organic extracts were dried over anhydrous Na2SO4, filtered and concentrated by rotary evaporation to give 1-[1-cyclopropylmethyl-4-(4-iodo-phenyl)-piperidin-4-ylmethyl]-3-(3,5-dichloro-phenyl)-1-methyl-urea (0.094 g, 95%). Crude 1H NMR (CDCl3): δ 7.83 (d, 2H), 7.22 (m, 4H), 7.05 (s, 1H), 6.01 (br.s, 1H), 3.50 (s, 2H), 2.97 (d, 2H), 2.83 (s, 3H), 2.36 (m, 2H), 2.27 (m, 2H), 2.09 (m, 2H), 0.91 (br.m, 1H), 0.58 (d, 2H), 0.15 (d, 2H).
