To a mixture of methyl 4-{[(5-chloro-3-methylfuro[3,2-b]pyridin-2-yl)(cyclohexyl)methyl]amino}benzoate (1.31 g) synthesized above, ethanol (20 mL) and tetrahydrofuran (20 mL) was added 1N lithium hydroxide aqueous solution (20 mL), and the mixture was stirred with heating under reflux for 3 hr, and concentrated under reduced pressure. The residue was dissolved in water (40 mL), and 1N hydrochloric acid (20 mL) was added at 0° C. The resulting precipitate was collected by filtration and the obtained solid was dissolved in ethyl acetate. The solution was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was washed with diisopropyl ether to give the title object compound (1.21 g, 96%) as a pale-yellow solid.
