A 100-mL flask equipped with a reflux condensor was charged with 4-chloro-2-(10-fluoro-1-oxo-3,4,6,7,8,9-hexahydropyrazino[1,2-a]indol-2(1H)-yl)nicotinaldehyde 134c (297 mg, 0.57 mmol), 1-methyl-3-(pyridin-2-ylamino)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2(1H)-one 178b (186 mg, 0.57 mmol), sodium acetate (90 mg, 1.1 mmol), K3PO4 (234 mg, 1.1 mmol), PdCl2(dppf) (50 mg, 0.057 mmol), acetonitrile (25 mL), and water (1 mL). After bubbling nitrogen through the mixture for 30 minutes, it was heated at 100° C. under nitrogen atmosphere for 3 hours. It was then cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 20:1 methylene chloride/methanol to afford 183a (178 mg, 61%) as a brown solid. MS-ESI: [M+H]+ 513.3.
