反应详情

1300 mg of 2-Bromo-1-(4-bromo-3-methyl-phenyl)-ethanone (VIIa) (Journal of Organic Chemistry (1947), 12, 617-703) was stirred with 1300 mg of triphenylphosphine in 20 ml of dichloromethane at ambient temperature for 18 hours. The mixture was diluted with toluene and the separated phosphonium salt was filtered off. It was then suspended in 20 ml of dichloromethane and 20 ml of water. 800 mg (7.55 mmol) of sodium bicarbonate was then added in 20 ml of water and the mixture was stirred overnight. The organic layer was separated, dried and evaporated under reduced pressure. The residue was triturated with hexane giving 1.6 g (86%) of 1-(4-Bromo-3-methyl-phenyl)-2-(triphenylphosphanylidene)-ethanone (Va) as a solid. 1H-NMR (CDCl3, δ in ppm): 7.40-7.90 (m, 18H), 4.40 (m, 1H).

1. filtrationthe separated phosphonium salt was filtered off
2. customThe organic layer was separated
3. customdried
4. customevaporated under reduced pressure
5. customThe residue was triturated with hexane giving 1.6 g (86%) of 1-(4-Bromo-3-methyl-phenyl)-2-(triphenylphosphanylidene)-ethanone (Va) as a solid