Following Example 112a, tert-butyl 4-(6-aminopyridin-3-yl)piperidine-1-carboxylate (1.9 g, 5.5 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1.47 g, 5.5 mmol), cesium carbonate (5.36 g, 16.5 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.53 g, 0.55 mmol), Xantphos (0.63 g, 1.1 mmol) and 1,4-dioxane (50 mL) were heated at 100° C. for 8 hours. Work-up and concentrated to dryness. Wash the resulting solid with diethyl ether, filtered and give 56% yield (1.4 g) of 264a as a grey solid: MS (ESI+) m/z 465.2 (M+H).
