Trifluoroacetic acid → 3-Bromo-2,6-difluorobenzenamine

To a round bottom flask containing tert-butyl 3-bromo-2,6-difluorophenylcarbamate (1 g, 3.3 mmol) was added DCM (3 mL) and TFA (3 mL). The reaction was stirred for 2 hours at room temperature. The volatiles were removed in vacuo, and the resulting residue was neutralized with saturated aqueous NaHCO3 solution to pH 8. The aqueous mixture was extracted with EtOAc. Organic phase was washed with water, brine, dried (Na2SO4), filtered and concentrated onto silica. Purification by flash chromatography (SiO2; 0-50% EtOAc in heptane) afforded 425 mg (63%) of 3-bromo-2,6-difluoroaniline: LCMS(m/z) 208.0 (MH+); tR=0.80 minute; 1H NMR (400 MHz, DMSO-d6) δ 5.54 (s, 2H) 6.78 (ddd, J=9.0, 7.4, 5.5 Hz, 1H) 6.85-6.95 (m, 1H).

1. customThe volatiles were removed in vacuo
2. extractionThe aqueous mixture was extracted with EtOAc
3. washOrganic phase was washed with water, brine
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated onto silica
7. customPurification by flash chromatography (SiO2; 0-50% EtOAc in heptane)

ORD record

ord-729f86fb790946cbad6fb51bbf40b048

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08242260B2