Abstract: Alkyl(amino)dialkoxysilanes are prepared by anhydrously reacting stoichiometric amounts of an alkoxysilane and an alkylaminomagnesium chloride in a reverse addition process. The alkylamino magnesium chloride is preferably prepared in situ by the reaction of a Grignard reagent (RMX) and an alkylamine in a suitable aprotic solvent, such as tetrahydrofuran. The "alkyl" substituent can be alkyl, arylalkyl or aryl. The reaction can be conducted in the temperature range of from 25.degree. C. to 75 .degree. C., without a catalyst, and the aprotic solvent is recovered for re-use in the process.

Abstract: Acyloxysilanes are prepared by the anhydrous reaction of stoichiometric amounts of a carboxylic acid with a mixture of a halosilane and a silazane in an aprotic solvent, such as diethyl ether, acetonitrile, tetrahydrofuran or toluene, in an inert gas atmosphere. In a preferred embodiment the silazane is prepared in situ by the reaction of the corresponding halosilane and ammonia. No catalyst is necessary and the reaction preferably is performed at a temperature of -5.degree. C. to 45.degree. C.