Bromine → 1-Bromo-4-methoxy-2,5-dimethylbenzene

Bromine (291.5 g, 1835 mmol) was added dropwise to a mixture of 2,5-dimethylanisole (250 g, 1835 mmol) and Fe powder (3.25 g) while stirring. The commencement of the reaction could be observed by means of the evolution of gas. The remaining bromine was then added dropwise over a period of 30-40 minutes at room temperature while cooling on a water bath. The reaction mixture was stirred further for about 4 hours. The solution was subsequently separated from the Fe powder, a little chloroform was added and the mixture was shaken with water, leading to the solution becoming lighter in color. After shaking with 50 ml of saturated aqueous Na2SO3 solution, the solution had become completely decolorized. It was shaken once more with dilute aqueous NaOH and twice with H2O and, after drying, the solvent was taken off. The crude product was fractionally distilled under reduced pressure.

1. customThe commencement of the reaction
2. temperaturewhile cooling on a water bath
3. stirringThe reaction mixture was stirred further for about 4 hours
4. customThe solution was subsequently separated from the Fe powder
5. additiona little chloroform was added
6. stirringthe mixture was shaken with water
7. stirringAfter shaking with 50 ml of saturated aqueous Na2SO3 solution
8. stirringIt was shaken once more with dilute aqueous NaOH and twice with H2O
9. customafter drying
10. distillationThe crude product was fractionally distilled under reduced pressure

ORD record

ord-d4b50471ef714a8482afa45feb6c926a

Source dataset

uspto-grants-2003_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06509507B2