2-Amino-6,7-dihydro-5H-cyclopenta[b]pyridine-3carboxylic acid described in Preparation Example C-5 (100 mg, 0.56 mmol), triethylamine (0.188 mL, 1.35 mmol) and benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (298 mg, 0.67 mmol) were dissolved in N,N-dimethylformamide (3 mL), C-(5-phenoxy-thiophen-2-yl)-methylamine described in Preparation Example 26 (138 mg, 0.67 mmol) was added, followed by stirring for 15 hours 20 minutes at room temperature. After the reaction was completed, the reaction solution was poured into brine, and the solution was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, then concentrated, the obtained residue was purified by silica gel column chromatography (ethyl acetate:hexane=1:1), and the title compound (77 mg, 0.21 mmol, 38%) was obtained.
