4-[1-[3-(Isopropylamino)-2-pyridyl]piperazin-4-yl-carbonyl]benzoic acid methyl ester (1.2 g) was dissolved in a co-solvent of ethanol (10 ml) and acetonitrile (20 ml), and 4-(2-aminoethyl)morpholine (0.82 g) was added. The reaction mixture was heated to reflux for 15 hours and cooled. After excess of water was added to the solution at 30° C. to precipitate the crystals, the solution was stirred for 1 hour. Then, the solution was again cooled slowly, stirred at 10~15° C. for 2 hours and filtered. The filtered crystal was washed with preheated water(40° C.) and was recrystallized using isopropanol and ether, filtered and dried to give 1.22 g (yield: 81%) of the desired compound.
