Sulfuric Acid → 3-Bromo-4-(trifluoromethoxy)aniline

Temperatur

80 °C

4-Trifluoromethoxynitrobenzene (4.1 g) was suspended in water (16 ml) and concentrated sulfuric acid (16 ml) and warmed to 80° C. with stirring. Potassium bromate (3.7 g) was added portionwise over 3 h., and the mixture was heated at 80° C. for a further 2 h. The mixture was cooled to room temperature and poured onto ice (100 g). The mixture was extracted with ethyl acetate and the combined organic fractions were dried (MgSO4) and the solvent was evaporated under reduced pressure. The residue) was dissolved in acetic acid (2.5 ml) and water (10 ml) and iron powder (2.0 g) was added. The mixture was heated under reflux for 2 h., cooled to room temperature and filtered through Celite™. The filtrate was extracted with ethyl acetate and the combined organic fractions were dried (MgSO4) and the solvent was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with hexane/EtOAc (3:1) to give the title compound as a yellow oil. 1H NMR (CDCl3) δ6.57 (1H, dd), 6.9 (1H, d), 7.06 (1H, dd).

1. temperatureThe mixture was cooled to room temperature
2. additionpoured onto ice (100 g)
3. extractionThe mixture was extracted with ethyl acetate
4. dry with materialthe combined organic fractions were dried (MgSO4)
5. customthe solvent was evaporated under reduced pressure
6. dissolutionThe residue) was dissolved in acetic acid (2.5 ml)
7. additionwater (10 ml) and iron powder (2.0 g) was added
8. temperatureThe mixture was heated
9. temperatureunder reflux for 2 h.
10. temperaturecooled to room temperature
11. filtrationfiltered through Celite™
12. extractionThe filtrate was extracted with ethyl acetate
13. dry with materialthe combined organic fractions were dried (MgSO4)
14. customthe solvent was evaporated under reduced pressure
15. customThe residue was purified by column chromatography on silica gel
16. washeluting with hexane/EtOAc (3:1)

ORD-Eintrag

ord-98298d36b6314c6bb4c94699381b5099

Quelldatensatz

uspto-grants-2000_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06071927