6-Hydroxy-1-oxo-3-phenyl-1H-indene-2-carboxylic acid ethyl ester (2 g, 6.79 mmol) prepared in Preparation Example 2, potassium carbonate (1.40 g, 10.19 mmol) and sodium iodide (0.2 g, 1.39 mmol) were dissolved in N,N-dimethyl formamide, and 1-bromo-3-phenyl propane (2.066 ml, 13.592 mmol) was added thereto, followed by stirring for 8 hrs at room temperature. The resulting mixture washed with saturated ammonium chloride and extracted with ethyl acetate. The organic layer was separated, dried over anhydrous MgSO4, and concentrated under a reduced pressure. Then, the resulting residue was purified by flash chromatography to obtain 2.37 g of the titled compound (yield: 85%) as a dark red solid.
