Hydrogen Bromide → 2-bromo-1-fluoro-3-iodobenzene

Participants

Reaction Conditions

Reaction Steps

A solution of (2-fluoro-6-iodo-phenyl)-carbamic acid tert-butyl ester (22.5 g, 67 mmol) in ethanol (100 mL) and 48% aqueous hydrobromic acid (100 mL) was stirred at RT. After 1 h the solvent was removed under reduced pressure and the residue was resuspended in 48% aqueous hydrobromic acid (100 mL). The suspension was heated to 60° C. for 10 min followed by cooling to 0° C. in an ice-water bath. A solution of sodium nitrite (4.9 g, 70 mmol) in water (25 mL) was added dropwise keeping the internal temperature below 5° C. The resulting suspension was stirred for 15 min at 0° C. followed by addition of copper (I) bromide (2.93 g, 20 mmol). The mixture was heated to 80° C. for 1 h and subsequently cooled to RT. The mixture was extracted with dichloromethane (2×250 mL) and the organic layer was washed with brine (150 mL), 10% aqueous sodium hydroxide solution (250 mL), brine (250 mL), dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by flash column chromatography (5% ethyl acetate:hexanes) to afford 10.5 g (50%) of the title compound. 1H NMR (300 MHz, CDCl3): δ 7.01-7.05 (m, 1H), 7.08-7.12 (m, 1H), 7.67 (d, J=4.8 Hz); 13C NMR (100 MHz, CDCl3): δ 102.5, 115.9 (d, J=22 Hz), 117.6 (d, J=21 Hz), 129.8 (d, J=14 Hz), 135.4 (d, J=21 Hz), 158.7 (d, J=250 Hz); 19F NMR (282 MHz, CDCl3): δ−96.3 (m, 1F).

Provenance & Evidence