4-Bromo-1-[(2,2-dimethoxyethyl)oxy]-2-methylbenzene → 5-Bromo-7-methylbenzofuran

A solution of 4-bromo-1-[(2,2-dimethoxyethyl)oxy]-2-methylbenzene (5 g) in toluene (5 ml) was added to a mixture of polyphosphoric acid (2 g) and toluene (20 ml) at reflux, and the resulting dark mixture heated at reflux for 4 h. The solvent was decanted from the cooled mixture which was washed with further toluene (2×20 ml). The residue was dissolved in 2N sodium carbonate (20 ml) and was extracted with dichloromethane (3×20 ml). The combined, dried (MgSO4) organics were evaporated in vacuo and the dark residue purified by Kugelrohr distillation (8 mbar, 150°) to give a mixture of starting material and product as a colorless oil (4.1 g). The mixture was purified by FCC eluting with dichloromethane-hexane (1:3) to give the title compound as an oil (1.33 g).

1. temperatureat reflux
2. temperaturethe resulting dark mixture heated
3. temperatureat reflux for 4 h
4. customThe solvent was decanted from the cooled mixture which
5. washwas washed with further toluene (2×20 ml)
6. dissolutionThe residue was dissolved in 2N sodium carbonate (20 ml)
7. extractionwas extracted with dichloromethane (3×20 ml)
8. dry with materialdried (MgSO4)
9. customorganics were evaporated in vacuo
10. distillationthe dark residue purified by Kugelrohr distillation (8 mbar, 150°)
11. customto give
12. customThe mixture was purified by FCC
13. washeluting with dichloromethane-hexane (1:3)

ORD record

ord-d653a4729e294c099c291e47d640ad5c

Source dataset

uspto-grants-1999_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05935972