The reaction between triethyl phosphite and some aromatic amines

Abstract : According to a recent review, triethyl phosphite and o-phenylenediamine give a heterocyclic compound. This statement appears to be based on a misreading of the original literature. Triethyl phosphite and o-phenylenediamine were found to give a mixture of all possible N-ethylated phenylenediamines in which the diethyl compounds predominated. The reaction mixture exhibited an intense blue colour which became red immediately on acidification or red-brown slowly on standing. These colours are thought to be associated with the Wurster salt-like oxidation product of the unsymmetrical N,N-diethylphenylenediamine. (Author)