Efficient and convenient one-pot synthesis of dioxadiazaphophepines

The reaction of vicinal dioxime with sodium hydride in dry THF followed by addition of dichlorophosphates or dichlorothiophosphates yields 2-oxo-1,3,4 ,7-dioxadiazaphosphepines and 2-thioxo-1,3,4,7-dioxodiazaphosphepines in mo derate to good overall yields. The products are characterized by elemental analyses, molecular weights and spectral (IR, H-1, C-13 and P-31 NMR) studi es. A salt elimination route is used for the synthesis of titled heterocycl es.