8-Amino-5-methoxyquinoline is a substituted quinoline derivative that can be prepared using 5-chloro-2-nitroaniline as a starting material. It can act as an easily removable directing group and also mediate C-H activation. These properties have been useful for synthesizing isomeric dibenzoxazepinones and complex pyrrolidinones from compounds containing 8-amino-5-methoxyquinoline moiety. Application： The Chen auxiliary was reported to be an effective directing group in the synthesis of pyrrolidones from assisting in the activation of C(sp3)-H bonds and can be readily installed through amide bond formation and removed through mild conditions using CAN at room temperature.