Furfural → 2-(2,2-Dibromovinyl)furan

To a stirred solution of 9.6 g (29 mmol) of carbon tetrabromide in 120 mL of dry methylene chloride at 0° was added 15.2 g (58 mmol) of triphenylphosphine. After 15 min 3.0 mL (22.5 mmol) of triethylamine was added, and after stirring another 5 min at 0°, the reaction mixture was cooled to −78°. At this temperature 1.50 mL (22.5 mmol) of 2-furaldehyde was added quickly dropwise, and after addition was complete, the mixture was stirred a −70° for 30 min. The reaction mixture was poured onto a rapidly stirring saturated solution of sodium bicarbonate in water. The methylene chloride phase was removed and the aqueous layer was extracted with additional methylene chloride. The combined extracts were evaporated to a solid which was stirred in 500 mL of hexanes for 2 h. After filtration, the filtrate was concentrated to a volume of 50 mL and the filtered again to remove precipitated solid. Final evaporation of the filtrate afforded 3.1 g (58%) of the title compound.

1. temperaturethe reaction mixture was cooled to −78°
2. additionafter addition
3. stirringthe mixture was stirred a −70° for 30 min
4. customThe methylene chloride phase was removed
5. extractionthe aqueous layer was extracted with additional methylene chloride
6. customThe combined extracts were evaporated to a solid which
7. stirringwas stirred in 500 mL of hexanes for 2 h
8. filtrationAfter filtration
9. concentrationthe filtrate was concentrated to a volume of 50 mL
10. filtrationthe filtered again
11. customto remove
12. customprecipitated solid
13. customFinal evaporation of the filtrate

ORD record

ord-050e15467c854de594a4c4400c6f0f8a

Source dataset

uspto-grants-2002_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06489320B1