A tandem coupling/smiles rearrangement/cyclization approach to 1,4-benzooxazinones or 1,4-pyridooxazinones under mild conditions

A facile and efficient approach to 1,4-benzooxazinone or 1,4-pyridooxazinone scaffolds is developed via Smiles rearrangement tandem reaction. 1,4-Benzooxazinones or 1,4-pyridooxazinones with diversity at two substituents on their scaffolds were synthesized conveniently in the presence of cesium carbonate at room temperature in good to excellent yields. The reaction mechanism is assumed by a tandem coupling/Smiles rearrangement/cyclization process.