反应详情

温度

-5 °C

To a stirred solution of 8-fluoro-3,4-dihydroquinolin-2(1H)-one (see Example 41 for details), (5 g, 30.3 mmol) in sulfuric acid, cooled to −5° C. was added nitric acid, fuming (1.413 ml, 30.3 mmol) as a 1:1 mixture in water. The resulting mixture was stirred at −5° C. for 20 min. After 20 min the reaction was quenched via addition of ice, precipitating the product which was collected by filtration. The filter cake was dissolved in dichloromethane and a minimal amount of methanol, dried, filtered and concentrated onto silica gel then chromatographed using 0-10% ethyl acetate in dichloromethane to give the desired 8-fluoro-6-nitro-3,4-dihydroquinolin-2(1H)-one (5.9 g, 28.1 mmol, 93% yield). 1H NMR (DMSO-d6) δ 10.73 (brs, 1H), 8.03 (m, 1H), 8.02 (m, 1H), 3.08 (t, J=7.5 Hz, 2H), 2.57 (t, J=7.5 Hz, 1H).

1. customAfter 20 min the reaction was quenched via addition of ice
2. customprecipitating the product which
3. filtrationwas collected by filtration
4. dissolutionThe filter cake was dissolved in dichloromethane
5. dry with materiala minimal amount of methanol, dried
6. filtrationfiltered
7. concentrationconcentrated onto silica gel
8. customthen chromatographed