During our studies on the RuO4-mediated oxidation of tertiary amines, 1a-b the NMR spectroscopy was successfully used to identify the various reaction products. Small amounts of the expected, pure compounds were added to the respective reaction mixtures and their NMR spectra compared to those formerly registered. Working with 1, 4-dibenzyl-and 1- benzylpiperazine as substrates, 1c the acyclic derivatives 1-6 (formulae in Chart 1) with an ...