To a solution of 6-(5-{1-[4-(cyclopropylsulfonyl)phenyl]-2-(tetrahydro-2H-pyran-4-yl)ethyl}-1H-pyrrol-2-yl)pyridine-3-carboxylic acid (0.155 g) in N,N-dimethylformamide (5 mL) were added morpholine (0.056 mL), triethylamine (0.135 mL), N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride (93 mg) and 1-hydroxybenzotriazole (74 mg), and the mixture was stirred at room temperature for 16 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The extract was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography (ethyl acetate:hexane=40:60-100:0, volume ratio) and recrystallized from hexane-ethyl acetate to give the title compound (0.106 g, yield 60%) as colorless crystals. MS: 550 (MH+). melting point 114-116° C.
