[C:1]([Si:5]([O:8][C:9]1[CH:14]=[C:13]([CH3:15])[CH:12]=[C:11]([F:16])[CH:10]=1)([CH3:7])[CH3:6])([CH3:4])([CH3:3])[CH3:2].[Br:17]N1C(=O)CCC1=O.C(OCC)(=O)C.O>C1COCC1>[Br:17][C:12]1[C:13]([CH3:15])=[CH:14][C:9]([O:8][Si:5]([C:1]([CH3:4])([CH3:3])[CH3:2])([CH3:7])[CH3:6])=[CH:10][C:11]=1[F:16].[Br:17][C:14]1[C:13]([CH3:15])=[CH:12][C:11]([F:16])=[CH:10][C:9]=1[O:8][Si:5]([C:1]([CH3:4])([CH3:3])[CH3:2])([CH3:7])[CH3:6]To a solution of tert-butyl(3-fluoro-5-methylphenoxy)dimethylsilane (17.0 g, 70.8 mmol) in THF (300 mL) as added N-bromosuccinimide (18.9 g, 106 mmol) at room temperature, and the mixture was stirred for 1 h. The mixture was poured into ethyl acetate and water. The organic layer was washed with brine and dried on anhydrous sodium sulfate. The solvent was removed in vacuo, and the residue was purified by silica gel chromatography (98:2 hexane/ethyl acetate) to give a mixture (ca. 4:1) of (4-bromo-3-fluoro-5-methylphenoxy)(tert-butyl)dimethylsilane and (2-bromo-5-fluoro-3-methylphenoxy)(tert-butyl)dimethylsilane (20.9 g).
Wird geladen…
