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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

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