1, 3, 2-Diazaphosphetidin-4-one derivatives were synthesized. Their 'H NMR signals at ambient temperature displayed a broad doublet which eventually coalesced before becoming sharp upon warming, and the C NMR spectra also showed that the α- and β-carbons of the dialkylamino group were non-equivalent. The phenomena were ascribed to restricted rotation about the exocyclic P-N bond. © 1990,...
