3-Phenyl-6-(3-phenyl-propoxy)-indene-1-one (200 mg, 0.586 mmol) obtained in Step 1 was dissolved in carbon tetrachloride, and N-bromosuccinimide (313 mg, 1.75 mmol) and 2,2′-azobisisobutyronitrile (9.7 mg) were added thereto. The mixture was refluxed for 1 hr under the irradiation of a 375 W tungsten lamp. Upon the completion of the reaction, the mixture washed with saturated saline and extracted with dichloromethane. The organic layer was separated, dried over anhydrous MgSO4 and concentrated under a reduced pressure. The resulting residue was purified by flash chromatography (ethyl acetate:hexane=1:5) to obtain 147 mg of the titled compound (yield: 60%) as a red solid.
