Tetraethoxysilane → Cyclopentyltriethoxysilane

Reaktionsgleichung

C(O[Si:4]([O:11][CH2:12][CH3:13])([O:8][CH2:9][CH3:10])[O:5][CH2:6][CH3:7])C.[CH:14]1([Mg]Br)[CH2:18][CH2:17][CH2:16][CH2:15]1.[Cl-].[NH4+]>COC(C)(C)C>[CH:14]1([Si:4]([O:5][CH2:6][CH3:7])([O:8][CH2:9][CH3:10])[O:11][CH2:12][CH3:13])[CH2:18][CH2:17][CH2:16][CH2:15]1

Komponenten

Versuchsvorschrift

60 ml of dry t-butyl methyl ether and 14.0 gram (0.067 mole) of tetraethoxysilane were charged in a 250 ml flask equipped with a reflux condenser and a stirring apparatus in an atmosphere of nitrogen and the solution of cyclopentyl magnesium bromide prepared above under (a) was slowly added while keeping the internal temperature below 10° C. After completion of addition stirring was carried out at room temperature for 6 hours and at reflux temperature for 2 hours. To the resulting reaction mass 10-20 ml of saturated aqueous ammonium chloride solution was added drop wise to dissolve magnesium salt. The organic layer was separated from the aqueous layer, dried and evaporated to give crude cyclopentyltriethoxysilane. The crude was purified by fractional distillation under reduced pressure, yielding 12 gram of pure cyclopentyltriethoxysilane (76% of the theoretical maximum yield based on the amount of tetraethoxysilane).