Improved synthesis of functionalized 5,6-dihydro-pyrimido[4,5-b][1,4]oxazepines

Novel synthetic approaches toward 5,6-dihydro-pyrimido[4,5-b][1,4]oxazepines were reported that led to successful introduction of poorly reactive anilines and various 2-hydroxybenzaldehydes to this therapeutically relevant scaffold. More extensive SAR studies on this scaffold hence became possible.