One-pot synthesis of phosphoramidates from dibenzo[1,3,2]dioxaphosphepine-6-oxide

Flame retardants play a crucial role in mitigating the hazards associated with fires by impeding their ignition and spread. However, conventional halogen-based flame retardants have encountered environmental and health concerns due to their persistence, bioaccumulation, and potential toxicity. In light of these concerns, the present study aimed to develop innovative compounds with potential application as flame retardant system that mitigates the drawbacks associated with halogen-based compounds. Several phosphoramidates were synthesized in a single step under mild conditions from the H-phosphonate dibenzo[1,3,2]dioxaphosphepine-6-oxide (BPPO), following a method based on the oxidation of the reactant in the presence of a suitable aliphatic or aromatic amine. The compounds were isolated with high purity and the formulations were confirmed by multinuclear NMR spectroscopy.