A Facile and Convenient Synthesis of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide Derivatives under Mild Conditions

A novel heterocyclic compound with pendent spiro-cyclotriphosphazene group was designed and synthesized via a convenient synthetic pathway. The structure was characterized by Fourier transform infrared spectroscopy(FTIR), Nuclear magnetic resonance (H-1 NMR), Liquid chromatograph mass spectrometer (LC-MS). The incorporation of phosphazene rings into the molecular backbone imparts flame retardancy on the compound. This may result from a unique combination of phosphorus and nitrogen in the phosphazene ring. The compound synthesized in this study is a green functional monomer and may become a potential candidate for fire- and heat-resistant applications in polymer fields.