Methyl 5-bromo-2-iodobenzoate → Methyl 5-bromo-2-ethylbenzoate
Reaktionsgleichung
C([Zn][CH2:4][CH3:5])C.[Br:6][C:7]1[CH:8]=[CH:9][C:10](I)=[C:11]([CH:16]=1)[C:12]([O:14][CH3:15])=[O:13]>Cl>[Br:6][C:7]1[CH:8]=[CH:9][C:10]([CH2:4][CH3:5])=[C:11]([CH:16]=1)[C:12]([O:14][CH3:15])=[O:13]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Reaktionsbedingungen
- Temperatur
- 62.5 °C
Versuchsvorschrift
Add diethyl zinc (3050 mL, 3.05 mol, 1 M hexane) over 3 hours to a 5° C. solution of methyl 5-bromo-2-iodobenzoate (1876 g, 5.50 mol) and (1,1′-bis(diphenylphosphino)ferrocene)palladium(II) chloride (40 g, 0.05 mol). Heat the mixture to 60-65° C. over 2 hours and stir for an additional 2 hours, then cool to 10-15° C. and pour into ice cold aqueous 1 M HCl (10 L). Separate the phases, extract the aqueous layer with methyl-tert-butyl ether (2×10 L), combine the organic phases, wash with saturated aqueous sodium chloride, dry over sodium sulfate, filter, and evaporate under reduced pressure. Dissolve in ethyl acetate (400 mL) and add petroleum ether (8 L), then let stand at 15-20° C. for 16 hours and filter through a pad of silica gel, wash with ethyl acetate/petroleum ether (1:20, 8 L) and evaporate the filtrate under reduced pressure to provide the title compound as a pale yellow oil (1306 g, 96%). ES/MS m/e: (79Br/81Br) 243/245 (M+H).