Methyl 10-[2-(6,7-dimethoxy-quinolin-4-yloxy)-5-methyl-phenyl]-10-oxo-decanoate (40 mg) was dissolved in tetrahydrofuran (3 ml), 0.93 M diisobutylaluminum hydride (1 ml) was added to the solution at 0° C., and the mixture was stirred at room temperature for 5 hr. Water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was then washed with water and was dried over anhydrous sodium sulfate. The solvent was removed by distillation under the reduced pressure, and the residue was purified by thin layer chromatography using methanol-chloroform to give the title compound (4.9 mg, yield 13%).
