Abstract
A series of novel benzo [e][1,3,2]diazaphosphinino[1,6-c][1,3,2]-oxazaphosphinine derivatives (3a-f) were synthesized by cyclization reactions of 6-(2-hydroxyphenyl)-2-phenyl-1H-2-oxido-1,3,2-diazaphosphinine (2) with some phosphorus dichlorides in the presence of triethylamine in dry dioxane under reflux. The structures of all the synthesized compounds were established by IR, H-1-, C-13- and P-31-NMR spectra as well as by elemental analysis and mass spectral analysis.