Hydrochloric Acid → 3-fluoro-7-methoxyquinolin-2(1H)-one

Participants

Reaction Steps

To a solution of 3-methoxyaniline (1.718 mL, 15.29 mmol) in THF (12 mL) was added 2.5 N n-BuLi (5.965 mL, 14.91 mmol) in hexane at 0 C. The reaction mixture was stirred at 0 C for 5 minutes. (E)-methyl 3-fluoro-3-methoxyacrylate (1.00 g, 7.457 mmol) in THF (10 mL) was added. The mixture was stirred at 0° C. for one hour. 1 N HCl (20 mL) and ether (30 mL) were added. The organic layer was separated, washed with water, saturated sodium bicarbonate and brine, dried (sodium sulfate), filtered and concentrated under reduced pressure to give an oil. Sulfuric acid (70%; 8 mL) was added. The mixture was stirred at 56° C. (bath) for 2 hours. After cooling to ambient temperature, ice (20 g) and water (50 mL) were added. The mixture was stirred at ambient temperature for 10 minutes. The solid was collected by filtration and washed with water to give 3-fluoro-7-methoxyquinolin-2(1H)-one (1.40 g, 7.247 mmol, 97.19% yield) as a solid.

Provenance & Evidence