[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[CH:4][CH:3]=1.[Li]CCCC.Cl[Si:15]([CH3:26])([CH3:25])[CH:16]1[C:20]([CH3:21])=[C:19]([CH3:22])[C:18]([CH3:23])=[C:17]1[CH3:24]>C1COCC1>[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH:6][Si:15]([CH3:25])([CH3:26])[CH:16]2[C:20]([CH3:21])=[C:19]([CH3:22])[C:18]([CH3:23])=[C:17]2[CH3:24])=[CH:4][CH:3]=1Under an argon atmosphere, to a solution of 14.8 g (86.0 mmol) of 4-bromoaniline in 250 ml of THF, 34.0 ml of 2.5 M (86.0 mmol) nBuLi in hexanes were added at −80° C. This mixture was stirred for 30 minutes at this temperature and then warmed for ca. 1 hour to ambient temperature. The resulting solution was added dropwise over ca. 1 hour, while vigorous stirring, to a solution of 18.4 g (86.0 mmol) of chloro(dimethyl)(2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)silane in 100 ml of THF. The resulting mixture was stirred overnight at ambient temperature, then, evaporated to dryness. To the residue 100 ml of toluene were added. This mixture was filtered through a glass frit (G4). The filtrate was evaporated to dryness. Fractional distillation gave a yellow liquid, bp 170° C./0.4 mm Hg. The product crystallizes slowly at ambient temperature. Yield 21.3 g (70%).
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