Ethyldimethylsilane → 4-[4-(Dimethylethylsilyl)butyl]-1-bromobenzene

Beteiligte Stoffe

Reaktionsschritte

About 20.0 g (95 mMol) of 4-(3-butenyl)-1-bromobenzene [which can be prepared, for example, by the method of P. E. Peterson et al, J. Org. Chem. 33, 972 (1968)] were dissolved in 40 ml of toluene, 2 ml of a platinum catalyst solution (0.5 percent solution of cyclopentadiene-platinum dichloride in dichloromethane) were added, and the mixture was added dropwise to a stirred solution containing 16 g (0.18 Mol) of commercially available dimethylethylsilane in 20 ml of toluene. The mixture was stirred at 50° to 70° C. for 3 hours and then cooled, and the solvent was removed by distillation. The residue was fractionated under reduced pressure. Approximately 19.4 g of 4-[4-(dimethylethylsilyl)butyl]-1-bromobenzene (67.9 percent yield) were obtained at a pressure of 0.05 hPa and at a temperature of 110° to 112° C. A mixture containing 18 g (0.06 Mol) of this derivative, 6.3 g (0.07 Mol) of CuCN and 10 ml of dimethylformamide was heated at 160° C. for 8 hours. The mixture, still hot at 80° C., was poured into a mixture containing 30 g of iron(III) chloride, 7.5 ml of concentrated hydrochloric acid and 90 ml of water, and the full mixture was stirred at 70° C. for 75 minutes. The product was then extracted with tert-butyl methyl ether, the extract was washed, dried and evaporated, and the residue was fractionated. About 9.9 g of 4-[4-(dimethylethylsilyl)butyl]benzonitrile were obtained at 0.02 hPa and at 114° to 116° C. (66.6 percent yield).

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