Nucleophilic substitution of 3-chloropropyltrialkoxysilane with aniline or benzylamine was studied in relation to temperature (90-165degreesC), solvent type, reactant ratio, addition mode, and additives. Petroleum ether as solvent and 18-crown-6 ether as additive were favorable (rapid precipitation, less dark reaction mixture). Reaction temperature and time, 100-120degreesC and 2.5-3 h and amine excess (step one: 1:1; step two: 1:3) gave N-phenyl- and N-benzoyl-3-aminopropylotrimethoxy-silane in 90+% yields. 38 refs.