A mixture of tert-butyl 5-iodo-2,3-dihydropyrido[3,4-b][1,4]oxazine-1-carboxylate (5 g, 13.8 mmol), benzylamine (1.776 g, 16.6 mmol), bis(dibenzylideneacetone)palladium (397 mg, 0.79 mmol), (+/−)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (858 mg, 1.38 mmol), and sodium tert-butoxide (2.65 g, 27.6 mmol) in dioxane (50 mL) was heated to 120° C. for 16 h under nitrogen. The mixture was filtered. The filtrate was concentrated. The residue was purified by silica gel column chromatography (PE/EtOAc v/v 1:1) to give tert-butyl 5-(benzylamino)-2,3-dihydropyrido[3,4-b][1,4]oxazine-1-carboxylate (3.6 g, 76% yield) as a yellow solid. ESI MS: m/z 342 [M+H]+.
