A facile method for the synthesis of 3,1-benzooxazines from N-acyl-2-(alk-2-enyl)anilines
Electrophilic addition of HCl or Br2 to N-acyl-2-(alk-2-enyl)anilines is accompanied by intramolecular cyclization of these amides to give 3,1-benzooxazine hydrochlorides or hydrobromides in high yields.