(6-(1,4-diazepan-1-yl)pyridin-2-yl)(2-amino-5-bromopyridin-3-yl)methanone (650 mg, 1.36 mmol) was added to a stirred suspension of 3,3,3-trifluoropropionic acid (0.13 ml, 1.50 mmol), 1-hydroxybenzotriazole (184 mg, 1.36 mmol), triethylamine (1.33 ml, 9.52 mmol) and PS-carbodiimide (2.08 g, 2.72 mmol) in dichloromethane (20 ml). The resulting mixture was stirred at room temperature for 18 hours. The crude mixture was filtered and concentrated in vacuo. The residue was purified on silica gel by flash column chromatography (ISCO Companion|, 40 g column, 0-50% EtOAc/Petroleum ether) to afford the title compound as an orange solid (355 mg, 54% yield).
