Condensation of 2‐aminophenols and α‐dicarbonyl compounds. Part 3. Benzoxazines substituted with heterocycles

Abstract A series of 1,4‐benzoxazines (I) and 2,2′‐dibenzoxazolines (II) were obtained by condensation of 2‐aminophenol and 2‐amino‐5‐nitrophenol with glyoxal derivatives of the heterocyclic series. The structure of compounds (I) was investigated by uv, pmr and mass spectroscopy.