A Convenient Cascade Strategy Towards the Synthesis of Novel Substituted Morpholinopyrimidines and Pyrimidooxazapines

A simple and novel protocol for the facile synthesis of bicyclic hybrid molecular framework of morpholinopyrimidines having six-membered pyrimidine ring fused with the morpholine unit is established. The method has been successfully employed to synthesize both regioisomers of the morpholinopyrimidine derivatives in good to high yields. The strategy is further extended successfully to synthesize bicyclic pyrimidooxazapine derivatives bearing the six-membered aromatic pyrimidine unit fused with seven-membered aliphatic oxazapine fragment.