A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 142b, (1.37 g, 4.38 mmol, 1.0 eq.), 3-(acetoxymethyl)-2-(6-tert-butyl-8-fluoro-1-oxophthalazin-2(1H)-yl)pyridine-4-ylboronic acid 116c (2.07 mg, 5.0 mmol), Pd(dppf)Cl2 (179 mg, 0.219 mmol, 0.050 eq.), sodium acetate (718 mg, 8.76 mmol, 2.0 eq.), K3PO4 (1.86 g, 8.76 mmol, 2.0 eq.), acetonitrile (20 mL), and water (1 mL). After three cycles of vacuum/argon flush, the mixture was heated at 30° C. for 2 h. It was then cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by silica-gel column chromatography eluting with 100:1 dichloromethane/ethanol to afford 142c (800 mg, 32%) as a yellow solid. MS-ESI: [M+H]+ 555.2. 1H NMR (500 MHz, DMSO-d6) δ 8.66 (d, J=5.0 Hz, 1H), 8.56 (d, J=2.5 Hz, 1H), 8.14 (d, J=2.5 Hz, 1H), 8.08 (d, J=2.0 Hz, 1H), 7.91 (d, J=1.5 Hz, 1H), 7.82-7.79 (m, 1H), 7.62 (d, J=6.5 Hz, 1H), 5.02 (s, 2H), 3.59 (s, 3H), 1.78 (s, 3H), 1.40 (s, 9H).
