Under an argon atmosphere, 1-{2-[(6,7-dimethoxy-4-quinolyl)oxy]-5-methoxyphenyl}-1-propanol (compound 11) (65.9 mg) was dissolved in methylene chloride (2 ml) to prepare a solution. 1,8-Diazabicyclo[5.4.0]-7-undecene (72 mg) was then added to the solution, and the mixture was cooled to −78° C. N-Tert-butylbenzenesulfineimidoyl chloride (71.4 mg) was dissolved in methylene chloride to prepare a solution, and the solution was added to the reaction solution. The mixture was stirred at −78° C. for 30 min and at 0° C. for 30 min. Water was added to the reaction solution, and the mixture was extracted with chloroform. The chloroform layer was then washed with saturated brine and was dried over anhydrous magnesium sulfate. The solvent was removed therefrom by distillation under the reduced pressure, and the residue was purified by thin layer chromatography using acetone-hexane to give the title compound (56.2 mg, yield 86%).
