4-[(6,7-Dimethoxy-quinolyl)oxy]aniline (2 g) was dissolved in chloroform (100 ml) (starting compound A) to prepare a solution. Triethylamine (2 ml) was added to the solution. A solution of triphosgene (1 g) in chloroform (4 ml) was added dropwise thereto, and the mixture was stirred at room temperature for 30 min. 3,3-Dimethylbutylamine (750 mg) (starting compound B) was added thereto, and the mixture was stirred at room temperature for 5 hr. Water and chloroform were added to the reaction solution, and the mixture was extracted with chloroform. The extract was washed with saturated brine and was dried over sodium sulfate. The solvent was then removed by evaporation under the reduced pressure. The crude thus obtained was purified by chromatography on silica gel using chloroform/acetone for development to give the title compound (1.70 g, yield 59%).
