Hydrogen Bromide → 4-Bromo-2-iodo-1-methylbenzene

Temperature

90 °C

A mixture of 3-iodo-4-methyl-phenylamine (5.0 g, 21 mmol) and 48% hydrobromic acid (30 ml) was heated at 90° C. for 30 minutes. After cooling in an ice bath, a solution of sodium nitrite (1.7 g, 25.2 mmol) in water (5 ml) was added and stirred for 15 minute. This mixture was added to a mixture of copper bromide (I) (3.6 g, 25.2 mmol), 48% hydrobromic acid (20 ml) and ice (50 g) cooled in an ice bath. After stirring for 20 minutes, the mixture was heated at 90° C. for 1 hour. After stirring at room temperature for 16 hours, the mixture was treated with water (350 ml) and extracted with dichloromethane (100 ml). The organic layer was washed with saturated aqueous sodium bicarbonate solution (100 ml), washed with saturated aqueous sodium chloride solution (100 ml), dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by flash chromatography eluting with hexane to give 5-bromo-2-methyl-1-iodo-benzene (4.4 g, 71% yield). 1H NMR (acetone-d6) δ 2.40 (s, 3H, CH3), 7.30 (d, 1H, J=8.2 Hz, Ar), 7.50 (dd, 1H, J=8.2 Hz, J=2.0 Hz, Ar), 8.00 (d, 1H, J=2.0 Hz, Ar).

1. temperatureAfter cooling in an ice bath
2. temperaturecooled in an ice bath
3. stirringAfter stirring for 20 minutes
4. temperaturethe mixture was heated at 90° C. for 1 hour
5. stirringAfter stirring at room temperature for 16 hours
6. extractionextracted with dichloromethane (100 ml)
7. washThe organic layer was washed with saturated aqueous sodium bicarbonate solution (100 ml)
8. washwashed with saturated aqueous sodium chloride solution (100 ml)
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by flash chromatography
12. washeluting with hexane

ORD record

ord-ad06025d2155485499bc7d8dc4f3f193

Source dataset

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07419984B2