In a 100 ml flask, 2-(8-bromo-[1,2,4]triazolo[1,5-a]pyridin-6-yl)-6-(6-tert-butyl-8-fluoro-1-oxophthalazin-2(1H)-yl)benzyl acetate (250 mg, 443 μmol, Eq: 1.00), (6-aminopyridin-3-yl)(morpholino)methanone (110 mg, 532 μmol, Eq: 1.2) and cesium carbonate (722 mg, 2.21 mmol, Eq: 5.0) were combined with dioxane (31.3 ml) to give an orange suspension. 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene (38.4 mg, 66.4 μmol, Eq: 0.15) and tris(dibenzylideneacetone)dipalladium(0) (20.3 mg, 22.1 μmol, Eq: 0.05) were added. The solution was degassed with Ar for 10 min. The reaction was heated at 100° C. for 18 h. The reaction mixture was diluted with 200 ml DCM. MgSO4 was added and the mixture was stirred. The solid was removed by filtration and washed several times with DCM. The combined filtrate and washes were concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, 40 g, 5% to 10% MeOH in DCM gradient). The resulting residue was triturated with Et2O. The solid was filtered, and then washed with Et2O. The solid was dried overnight at 50° C. to give acetic acid 2-(6-tert-butyl-8-fluoro-1-oxo-1H-phthalazin-2-yl)-6-{8-[5-(morpholine-4-carbonyl)-pyridin-2-ylamino]-[1,2,4]triazolo[1,5-a]pyridin-6-yl}-benzyl ester (289 mg, 95%). LC/MS-ESI observed [M+H]+ 691.
