[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:10])=[C:6]([CH:9]=1)[CH:7]=[O:8].[CH3:11][Mg]Br>CCOCC>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:10])=[C:6]([CH:7]([OH:8])[CH3:11])[CH:9]=1To a solution of 5-bromo-2-fluorobenzaldehyde 101 (100 g, 0.492 mol.) in ether (500 mL), cooled in an ice bath, was added a 3 M solution of methyl magnesium bromide in ether (i.e., diethyl ether) (173 mL, 0.516 mol.) in a dropwise manner. The reaction mixture was stirred for 30 minutes in the ice bath. The reaction mixture was allowed to warm to room temperature and was stirred for 15 minutes. The reaction mixture was cooled in an ice bath and the reaction was quenched by addition of water in a dropwise manner. The reaction mixture was acidified with dilute hydrochloric acid. The organic layer was separated. The aqueous layer was extracted with ether for two times. The combined organic layer was dried over magnesium sulfate and evaporated under reduced pressure to afford 1-(5-bromo-2-fluoro-phenyl)-ethanol 102 (106 g, 0.484 mol.) which was used in the next step without further purification.
Wird geladen…