Tetrahydrofuran → 8-Fluoro-6-nitro-1,2,3,4-tetrahydroquinoline

Temperature

60 °C

8-Fluoro-6-nitro-3,4-dihydroquinolin-2(1H)-one (5.9 g, 28.1 mmol) was stirred in borane-THF complex, 1M in THF (140 ml, 140 mmol). The solution was heated to 60° C. and stirred overnight. The mixture was then cooled in an ice bath and quenched via addition of methanol (30 mL). The quenched solution was concentrated, then dissolved in methanol and refluxed for 1 h. The solution was then concentrated onto silica gel and chromatographed using 5-30% ethyl acetate in hexanes to give the desired 8-fluoro-6-nitro-1,2,3,4-tetrahydroquinoline (4.34 g, 22.12 mmol, 79% yield). 1H NMR (DMSO-d6) δ 7.77-7.71 (m, 1H), 7.73 (m, 1H), 7.31 (brs, 1H), 3.35-3.28 (m, 2H), 2.77 (t, J=6.2 Hz, 2H), 1.85-1.77 (m, 2H).

1. temperatureThe mixture was then cooled in an ice bath
2. customquenched via addition of methanol (30 mL)
3. concentrationThe quenched solution was concentrated
4. dissolutiondissolved in methanol
5. temperaturerefluxed for 1 h
6. concentrationThe solution was then concentrated onto silica gel
7. customchromatographed

ORD record

ord-904c2d76e18c423cba4b819bd189807b

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08173813B2