C[Si](C)(C)N[Si](C)(C)C.[Li].[C:11]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])(=[O:13])[CH3:12].Br[C:20]1[CH:25]=[C:24]([Br:26])[N:23]=[C:22]([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][C:28]=2[Cl:33])[C:21]=1[CH2:34]Br>C1COCC1>[Br:26][C:24]1[N:23]=[C:22]([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][C:28]=2[Cl:33])[C:21]([CH2:34][CH2:12][C:11]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])=[CH:20][CH:25]=1To 25 mL of THF at −78° C. was added 26.6 mL of a 1.0M solution of lithium hexamethyldisilazane in THF. t-Butyl acetate (4.47 mL) was added dropwise to the cold solution, and the mixture was stirred for 10 min at −78° C. 4,6-Dibromo-3-(bromomethyl)-2-(2-chlorophenyl)pyridine (9.74 g) in 25 mL of THF was added dropwise over 15 min. The mixture was stirred 20 min at −78° C., then quenched by addition of 5 mL of saturated aqueous NaHCO3. The mixture was warmed to rt, diluted with 200 mL of saturated aqueous NaHCO3, and extracted with 3×100 mL of EtOAc. The combined organics were washed with 100 mL of brine, and dried over MgSO4. The residue was purified by flash chromatography on a Biotage 65M column, eluting with a gradient system of 95:5 to 90:10 hexanes-Et2O to yield the title compound as a white solid. Mass spectrum (ESI) 476 (M+1).
読み込み中…
