4590-52-7

7-Fluoro-3,4-dihydroquinolin-2(1H)-one is a useful reagent in the multicomponent one-pot synthesis of 3,4-dihydroquinolinones.

General procedure for the synthesis of 7-fluoro-3,4-dihydroquinolin-2(1H)-one from 3-chloro-N-(3-fluorophenyl)propanamide: 3-chloro-N-(3-fluorophenyl)propanamide (10 g, 49.6 mmol) and AlCl3 (23.1 g, 173.6 mmol) were added to a flame-dried 50 mL flask equipped with a magnetic stir bar. The flask was placed in a preheated oil bath, heated to 120-125 °C and kept for 2 h until LC-MS analysis showed that the reaction was complete. After completion of the reaction, the mixture was cooled to room temperature and the reaction was quenched by the slow addition of ice water. The reaction mixture was extracted with EtOAc and the organic phases were combined and washed sequentially with water and saturated brine. The organic layer was dried with anhydrous Na2SO4, filtered and concentrated under reduced pressure to afford the white solid product 7-fluoro-3,4-dihydroquinolin-2(1H)-one (7.63 g, 93.2% yield).

[1] Patent: WO2016/66597, 2016, A1. Location in patent: Page/Page column 39
[2] Patent: WO2016/86200, 2016, A1. Location in patent: Page/Page column 273; 274
[3] Patent: WO2012/94462, 2012, A2. Location in patent: Page/Page column 86
[4] Patent: CN106349241, 2017, A. Location in patent: Paragraph 0488; 0492; 0493; 0494; 0495
[5] Patent: WO2008/42735, 2008, A1. Location in patent: Page/Page column 59