Patent ID: 6872845

Claim:
A process for preparing a haloorganoalkoxysilane of the formula (R 1 ) x (R 2 O) 3-x SiCH 2 CHR 3 CR 4 R 5 X wherein R 1 in an alkyl of from 1 to 6 carbon atoms, R 2 is an alkyl of from 1 to 6 carbon atoms, R 3 is an alkyl group of 1 to 6 carbon atoms or hydrogen, R 4 is an alkyl of from 1 to 6 carbon atoms, hydrogen or halogen, R 5 is hydrogen or an alkyl of from 1 to 6 carbon atoms, X is a halogen, x is 0, 1 or 2, which comprises reacting an olefinic halide of the general formula: H 2 C═CR 3 CR 4 R 5 X wherein R 3 , R 4 , R 5 and X have the aforestated meanings, with a molar excess of alkoxysilane of the general formula: (R 1 ) x (R 2 O) 3-x SiH wherein R 1 and R 2 and x have the aforestated meanings, in a reaction medium to which has been added a catalytically effective amount of ruthenium-containing catalyst and an electron-donating aromatic compound in an amount of about 1 to about 100 mole equivalents versus the moles of ruthenium metal; wherein the yield of the haloorganoalkoxysilane exceeds 87 mole percent, based upon the total reaction products.