A solution of 1-{4-[2-(2-methoxycarbonylphenyl)benzoylamino]benzoyl}-1,2,3,4-tetrahydroquinoline (300 mg) and dry tetrahydrofuran (15 ml) was cooled to 0° C., and lithium aluminum hydride (46 mg) was added. The reaction mixture was maintained at 0° C. for 1 hour, and then was quenched by adding 1N hydrochloric acid. The resulting mixture was filtered through a bed of celite, diluted with ethyl acetate, washed with brine, dried over magnesium sulfate, and concentrated. Purification of the residue by column chromatography (silica gel, 15 g; ethyl acetate-n-hexane, 1:2) gave 1-{4-[2-(2-hydroxymethylphenyl)benzoylamino]benzoyl}-1,2,3,4-tetrahydroquinoline (80 mg) as a amorphous.
