- Preparation of acyloxysilanes
-
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° C. to 45° C.
- -
-
-
- Process for the continuous preparation of acyloxysilanes
-
Acyloxysilanes are prepared by a process of reacting an organochlorosilane with an excess of monocarboxylic anhydride at elevated temperature, thereby forming product acyloxysilane and by-product acyl chloride transferring the reaction mixture to the middle inlet of a separation tower having a still pot at its base, removing excess carboxylic anhydride by distillation at the tower top under reduced pressure, removing acyl chloride by-product from the separation tower, uniformly removing acyloxysilane from the tower still pot, and reacting virtually quantitatively the residual acid chloride present in the acyloxysilane removed from the still pot by adding a metal carboxylate to the acyloxysilane and separating the metal chlorides formed from the product.
- -
-
-
- Process for the preparation of organocarbonoyloxysilanes
-
Organocarbonoyloxysilanes are prepared by reacting an organochlorosilane with a carboxylic acid in a first step which liberates HCl, removing the HCl which is formed, reacting the reaction mixture from the first step with a carboxylic acid anhydride in a second reaction step, the first and/or second reaction steps being conducted in the presence of a catalyst, and isolating the resulting organocarbonoyloxysilane product from the reaction mixture.
- -
-
-
- Process for preparing triacetoxysilanes from tris(amino)silanes
-
Triacetoxysilanes are prepared by adding a tris(amino)silane to acetic anhydride and maintaining the reaction mix at a temperature no greater than about 50° C.
- -
-
-