A solution of 4-isopropoxypiperidine hydrochloride (120 mg, 0.67 mmol) and triethylamine (0.206 mL, 1.48 mmol), in N,N dimethylformamide (2 mL) was added in one portion to a stirred solution of 2-fluoro-5-((4-oxo-3,4-dihydrophthalazin-1-yl)methyl)benzoic acid (1) (200 mg, 0.67 mmol), triethylamine (0.206 mL, 1.48 mmol) and O-Benzotriazol-1-yl-N,N,N′,N′-tetra-methyluronium hexafluorophosphate (381 mg, 1.01 mmol) in N,N dimethylformamide (2 mL) at 25° C. The resulting solution was stirred at 25° C. for 4 hours. The crude product was purified by preparative HPLC (Waters XBridge Prep C18 OBD column, 5μ silica, 30 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% NH3) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to afford the desired compound (172 mg, 60.6% yield); 1H NMR (399.902 MHz, DMSO) δ 1.06-1.11 (6H, m), 1.21-1.46 (2H, m), 1.61-1.87 (2H, m), 3.04 (1H, t), 3.62 (2H, td), 3.70 (1H, quintet), 3.92-4.01 (1H, m), 4.07 (1H, q), 4.33 (2H, s), 7.19-7.25 (1H, m), 7.32-7.37 (1H, m), 7.38-7.44 (1H, m), 7.81-7.92 (2H, m), 7.96-8.00 (1H, m), 8.26-8.29 (1H, m), 12.58 (1H, s); m/z (LC-MS, ESI+), RT=1.98 (M+H 424.6).
