30465-68-0

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.

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.

First, 5-methoxy-8-nitroquinoline (0.4 g, 2.33 mmol) was placed in a two-necked eggplant flask and the reaction mixture was prepared under nitrogen protection. Subsequently, 50 ml of anhydrous ethanol was added to the flask. Under hydrogen atmosphere, palladium carbon catalyst (0.04 g) was added and the reaction was stirred at room temperature. After 6 hours of reaction, the reaction mixture was filtered through diatomaceous earth and the filtrate was concentrated using a rotary evaporator to give the final yellow solid product 5-methoxy-8-quinolinamine (0.333 g, 83% yield).

[1] Chemistry - A European Journal, 2013, vol. 19, # 43, p. 14697 - 14701
[2] Advanced Synthesis and Catalysis, 2016, vol. 358, # 10, p. 1679 - 1688
[3] Patent: JP5659191, 2015, B2. Location in patent: Paragraph 0081; 0082; 0083; 0084
[4] Patent: WO2010/66832, 2010, A1. Location in patent: Page/Page column 31-32
[5] Journal of the American Chemical Society, 1946, vol. 68, p. 1524,1526