Phosphorus tribromide → 5-(2-Bromoethyl)-2,3-dihydro-1-benzofuran
Reaktionsgleichung
P(Br)(Br)[Br:2].O[CH2:6][CH2:7][C:8]1[CH:9]=[CH:10][C:11]2[O:15][CH2:14][CH2:13][C:12]=2[CH:16]=1>C(Cl)(Cl)(Cl)Cl>[Br:2][CH2:6][CH2:7][C:8]1[CH:9]=[CH:10][C:11]2[O:15][CH2:14][CH2:13][C:12]=2[CH:16]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
Phosphorus tribromide (0.37 g) was added to a solution of 5-(2-hydroxyethyl)-2,3-dihydrobenzofuran (0.612 g--see Preparation 16) in carbon tetrachloride (3 ml) and the mixture was heated under reflux for 3 hours. On cooling to room temperature, the mixture was partitioned between 10% aqueous sodium carbonate (20 ml) and dichloromethane (20 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (2×10 ml). The combined dichloromethane extracts were dried (MgSO4) and concentrated in vacuo to give the title compound as an oil which crystallised on standing, yield 0.584 g, m.p. 60°-62° C.