To a solution a −78° C. cooled (dry ice/acetone bath) of 5-[(phenylmethyl)oxy]-1-(phenylsulfonyl)-1H-indole (1.1 g, 0.003 mol) in THF (anhydrous, 10 mL) was added n-butyllithium (2.3 mL of a 1.6 M solution in hexanes) dropwise. The mixture was then warmed to −10° C. over 30 min and then cooled to −78° C. and 1-iodopropane (1.5 eq., 0.005 mol, 0.77 g) was added dropwise. The mixture was warmed to rt over 1 h and then stirred at rt for 20 min. Water (10 mL) and EtOAc (100 mL) was added. The organic layer was separated, dried (MgSO4), and concentrated. Purification via semipreparative reverse-phase HPLC provided the desired product: MS (ES) m/z 406 (M+1).
