A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 3-(acetoxymethyl)-2-(6-tert-butyl-8-fluoro-1-oxophthalazin-2(1H)-yl)pyridin-4-ylboronic acid 116c (438 mg, 1.06 mmol), 129a (150 mg, 0.60 mmol), Pd(dppf)Cl2 (19 mg, 0.026 mmol), K3PO4 (224 mg, 1.06 mmol), sodium acetate (87 mg, 1.06 mmol), water (5 drops), and acetonitrile (10 mL). After three cycles of vacuum/argon flush, the reaction mixture was heated at 100° C. for 1 h. Analysis of the reaction mixture by LCMS showed complete conversion to the desired product. The mixture was cooled down to room temperature and filtered. The filtrate was concentrated under reduced pressure to afford 129b (300 mg, 87%) as a dark oil, which was used in next step without further purification. MS-ESI: [M+H]+ 573.3
