[CH2:1]([O:3][C:4](=[O:15])[CH2:5][C:6]1[CH:11]=[C:10]([OH:12])[C:9]([F:13])=[CH:8][C:7]=1[Br:14])[CH3:2].C(=O)([O-])[O-].[Cs+].[Cs+].[I-].[Na+].Br[CH2:25][CH2:26][O:27][Si:28]([C:31]([CH3:34])([CH3:33])[CH3:32])([CH3:30])[CH3:29]>CN1C(=O)CCC1.O>[CH2:1]([O:3][C:4](=[O:15])[CH2:5][C:6]1[CH:11]=[C:10]([O:12][CH2:25][CH2:26][O:27][Si:28]([C:31]([CH3:34])([CH3:33])[CH3:32])([CH3:30])[CH3:29])[C:9]([F:13])=[CH:8][C:7]=1[Br:14])[CH3:2]
To a solution of (2-bromo-4-fluoro-5-hydroxy-phenyl)-acetic acid ethyl ester (0.42 1 g, 1.52 mmol) in NMP (5 ml) was added cesium carbonate (0.644 g, 1.97 mmol), sodium iodide (0.228 g, 1.52 mmol) and 2-bromoethoxy tert-butyldimethylsilane (0.424 g, 1.97 mmol). The mixture was heated at 100° C. for two hours. After cooling to room temperature, water was added and the product was extracted with EtOAc. The combined extracts were washed with water and brine, dried over MgSO4, filtered and concentrated to dryness under reduced pressure. Purification of the residue by flash chromatography (hexanes:EtOAc/8:2) gave {2-bromo-5-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-4-fluoro-phenyl}-acetic acid ethyl ester (0.508 g, 77%) as a white solid.
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