Br[C:2]1[C:7]([F:8])=[CH:6][C:5]([OH:9])=[C:4]([Cl:10])[CH:3]=1.C([Li])CCC.Cl[Si](C)(C)CC[Si](Cl)(C)C.C([Li])(C)(C)C.CN(C)[CH:33]=[O:34].Cl>O1CCCC1.O>[Cl:10][C:4]1[C:5]([OH:9])=[CH:6][C:7]([F:8])=[C:2]([CH:3]=1)[CH:33]=[O:34]To 4-bromo-2-chloro-5-fluoro-phenol (104, 2.25 g, 9.98 mmol) in tetrahydrofuran (50 mL), cooled to −78° C. under an atmosphere of nitrogen, was added n-butyllithium (2.50 M in hexane, 4.21 mL) and 1,2-bis-(chloro-dimethyl-silanyl)-ethane (1.08 g, 5.01 mmol). The reaction was stirred at room temperature for 2 hours. The reaction was cooled to −78° C., followed by adding tert-butyllithium (1.70 M in hexane, 12.4 mL). After 30 minutes, N,N-dimethylformamide (0.97 mL, 0.0125 mol) was added to the reaction. After 30 minutes, the reaction was warmed to room temperature for 10 minutes. 5N HCl (20 mL) was added to the reaction. After 30 minutes, the reaction was poured into water and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated and purified by silica gel column chromatography eluting with 20% to 100% ethyl acetate in hexane to give the desired compound (105, 0.50 g, 28.7). 1H NMR consistent with structure.
Wird geladen…
