To a suspension of sodium diphenylphosphide prepared, under nitrogen in dry toluene (100 ml), from sodium (4.6, 0.2 g atom) and diphenylphosphinous chloride (22.0 g, 0.1 mol), vinyl triethoxysilane (19.0 g, 0.1 mol) is added during 45 minutes. A slight temperature rise occurs. The temperature is held at 30° C by adjusting the feed rate of the vinyl silane. After 3 hours, 5 ml anhydrous ethanol is added. The yellow color of the anion is instantly discharged. The solution is filtered to remove inorganic salts. Gas chromatographic analysis confirms the presence of diphenyl phosphine and 2-(dipenylphosphinyl)ethyl triethoxysilane. After neutralization with carbon dioxide, the liquid is distilled giving 6.3 g (16.7 percent yield) of 2-(diphenylphosphinyl) ethyl triethoxysilane and 3.0 g (16.3 percent yield) of diphenylphosphine. The H'NMR spectrum of the silane is identical to that of the product of addition of diphenylphosphine to vinyl triethoxysilane with a radical initiator.
