6-Hydroxy-1-oxo-3-phenyl-1H-indene-2-carboxylate ethyl ester (2 g, 6.80 mmol), potassium carbonate (1.41 g, 10.194 mmol), and sodium iodide (200 mg, 1.359 mmol) were dissolved in dimethylformamide (100 ml). 1-Bromo-3-phenylpropane (2.01 ml, 13.59 mmol) was added thereto at room temperature, was stirred for 12 hours at 60° C., and washed with saturated ammonium chloride. The organic layer obtained by extracting the reaction mixture with ethyl acetate was dried over anhydrous magnesium sulfate, concentrated, and the residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:4) to obtain the title compound (yield 85%) as a dark red solid.
