Nitric Acid → 1-Bromo-2,4-difluoro-5-nitrobenzene

Temperature

0 °C

To a suspension of 1-bromo-2,4-difluorobenzene (53.0 mmol, 6.00 mL) in concentrated H2SO4 (38.5 mL) at 0° C. was added dropwise concentrated HNO3 (34.0 mL) maintaining internal temperature below 20° C. The resulting mixture was stirred for 10 min at 0° C., then poured into ice/water with vigorous stirring. The mixture was extracted with Et2O (3×100 mL). The combined organic extracts were washed with aqueous NaHCO3 solution (3×100 mL) and brine, dried over MgSO4, filtered and concentrated in vacuo. The crude product was purified by flash chromatography (EtOAc:hexanes 1:9) to afford 5-bromo-2,4-difluoronitrobenzene as a yellow oil (12.2 g, 97%). 1H NMR (400 MHz, CDCl3) δ 8.45 (t, 1H, J=7.5 Hz), 7.16 (dd, 1H, J=11.0, 8.6 Hz); ESMS m/e: 240, 238, 223, 221, 112

1. temperaturemaintaining internal temperature below 20° C
2. extractionThe mixture was extracted with Et2O (3×100 mL)
3. washThe combined organic extracts were washed with aqueous NaHCO3 solution (3×100 mL) and brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude product was purified by flash chromatography (EtOAc:hexanes 1:9)

ORD record

ord-2375ded1b46a4feb88b78b130e32d65d

Source dataset

uspto-grants-2009_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07473698B2