Synthesis and characterization of dicoumarol substituted cyclotriphosphazenes

In the present work, coumarin substituted cyclotriphosphazenes were designed, synthesized and characterized for the first time. The reactions of sodium derivative of 3,3′-methylenebis(4-hydroxycoumarin), (dicoumarol, 1), with cyclotriphosphazene, (N3P3Cl6, 2), in a THF solution gave mono-spiro (3), bis-spiro (4) and tris-spiro (5) dicoumaroxy- substituted compounds. All dicoumaroxy-substituted cyclotriphosphazene compounds (3–5) were fully characterized by elemental analysis, IR, ESI mass spectrometry, 1H and 31P NMR spectroscopies. Generally, bulky diol derivatives prefer ansa- or bridged products by reacting with cyclotriphosphazene. But, surprisingly, dicoumarol which is also bulky diol derivative gave only spiro products in this study. The molecular structures of compounds (3–5) were also determined by X-ray crystallography. The crystal structures of these compounds were solved by direct methods and refined by full-matrix least squares.

Graphical abstractIn this study, coumarin substituted cyclotriphosphazenes were designed, synthesized and characterized for the first time. Only spiro compounds were obtained by the reaction of sodium derivative of 3,3′-methylenebis(4-hydroxycoumarin), (dicoumarol), with cyclotriphosphazene, (N3P3Cl6). All cyclotriphosphazene compounds have been fully characterized by elemental analysis, IR, ESI mass spectrometry, 1H, 31P NMR spectroscopies and X-ray crystallography.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The first coumarin substituted cyclotriphosphazenes were designed, synthesized and characterized. ► Dicoumarol substituted cyclotriphosphazenes. ► The reaction of dicoumarol and cyclotriphosphazene gave only spiro products.