301 mg of the crude product obtained in Example 28 and 95 mg of 3-phenylpropyl bromide were dissolved in 5 ml of dimethylformamide, and to the solution were added 66 mg of potassium carbonate and 72 mg of sodium iodide. After stirring at 80° C. for 7 hours, 30 ml of saturated sodium chloride was added to the reaction mixture, which was then extracted with 40 ml of ethyl acetate, and the extract was washed with 30 ml of saturated sodium chloride aqueous solution, dried over magnesium sulfate, and concentrated under a reduced pressure. The resulting residue was applied to a silica gel column and eluted with chloroform/methanol (40:1) to obtain 216 mg of the title compound in a yellow amorphous form.
