Oily sodium hydride (60%,0.323 g) was added to a solution of 1H-1,2,4-triazole (0.558 g) in N,N-dimethylformamide (30 ml), followed by stirring at room temperature for 15 minutes. Then 2-chloromethyl-6,7-dimethoxy-4-(3,4-dimethoxyphenyl)quinoline-3-carboxylic acid ethyl ester (3.0 g) was added. After stirring at 80° C. for 1 hour, the reaction mixture was poured over water and extracted with ethyl acetate. The ethyl acetate layer was washed with water and then dried (MgSO4), after which the solvent was distilled off. The residue was subjected to silica gel column chromatography and eluted with chloroform-methanol (40:1, v/v) to yield 6,7-dimethoxy-4-(3,4-dimethoxyphenyl)-2-(1,2,4-triazol-1-ylmethyl)quinoline-3-carboxylic acid ethyl ester (1.7 g, 53%), which was then recrystallized from ethyl acetate-hexane to yield a colorless prismatic crystal having a melting point of 176° to 177° C.
