Imidazole (310 mg, 4.40 mmol), iodine (440 mg, 3.5 mmol), and a solution of 2 (1 g, 2.98 mmol) in CH2Cl2 (2 mL) were added sequentially to a 0° C. solution of PPh3 (450 mg, 3.5 mmol) in CH2Cl2 (15 mL) and kept in the dark. After 2 h, the reaction mixture was quenched by adding 20% aq. Na2S2O3 (5 mL). The aqueous layer was extracted with CH2Cl2 (2×50 mL). The combined organic extracts were washed with brine (30 mL), dried over anhydrous Na2SO4, and the solvent was removed in vacuo. The residue was purified by careful column chromatography using 5% EtOAC/hexane to afford iodide 3 (1.25 mg, 92%). TLC: 10% EtOAc/hexane, Rf˜0.85; 1H NMR (CDCl3, 400 MHz) δ 7.67-7.62 (m, 4H), 7.45-7.35 (m, 6H), 3.67 (t, 2H, J=6.0 Hz), 3.41 (t, 2H, J=6.7 Hz), 2.03-1.93 (m, 2H), 1.72-1.64 (m, 4H), 1.04 (s, 9H).
