Synthesis and characterization of dicoumarol substituted cyclotriphosphazenes

Abstract

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, H-1 and P-31 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. (C) 2013 Elsevier B.V. All rights reserved.