Synthese von N-Di(alk-, ar-)oxyphosphoryl-tri(alk-, ar-)-oxyphosphazenen, (RO)2P(O)?NP(OR)3, durch P?N-Bindungsknüpfung

Synthesis of N-Di(alk-, ar-)oxyphosphoryl-tri(alk-, ar-)oxyphosphazenes, (RO)₂P(O)? N?P(OR)₃, by P? N-Bond Formation The title compounds can be prepared from di- and triesters of phosphorous acid, sodium azide, and carbon tetrachloride in a single step procedure and in high yields. Due to the combination of the Atherton-Todd and the Staudinger reaction toxic phosphoric acid ester azides are formed only in situ and their concentration is kept very small. As by-products trichloromethane phosphonic acid esters, (RO)₂P(O)CCl₃, esters of phosphoric acid and condensed phosphoric acids as well as N-alkylimidodiphosphoric acid esters, (RO)₂P(O)]₂NR, are formed. Their formation can be avoided or reduced by choosing suitable reaction conditions. The mechanism of the reaction is discussed.