Abstract Arylation of diethyl phosphoric acid by triphenylphosphite leading to diethylphenylphosphate was studied by NMR-spectroscopy. The mixed PIII− PIV− anhydride was proved to be an intermediate. The scope of arylation is presented. Die Arylierung von Phosphorsäure-diethylester zu Phosphorsäure-diethylester-phenylester mit Triphenylphosphit wurde NMR-spektroskopisch untersucht.(Phosphorigsäure- ...