The Synthesis of Hexaphenylcyclotriphosphazene in Improved Yield

The reaction between phenylmagnesium bromide and hexachlorocyclotriphophazene (N ₃ P ₃ Cl ₆ ) ( 1 ) was reinvestigated for the synthesis of hexaphenylcyclotriphosphazene (N ₃ P ₃ Ph ₆ ) ( 2 ) in high yield. The reaction is complete within two weeks at room temperature using toluene as solvent. When the reactants (PhMgBr and N ₃ P ₃ Cl ₆ ) were employed in a 6:1, 36:1 and 72:1 molar ratio, compound 2 was obtained in 2.6%, 14%, and 33.4% yield, respectively. The formation of N ₃ P ₃ Cl ₆ ( 2 ) during the reaction was followed by thin-layer chromatography. Compound 2 was characterized by elemental analysis, IR, UV-VIS, ¹ H, ¹³ C, and ³¹ P NMR spectroscopy as well as by mass spectrometry.