SYNTHESIS OF 1,3,4-DIAZAPHOSPHOLIDIN-2-ONE-4-OXIDES BY MANNICH-TYPE REACTION AND STRUCTURE-ANALYSIS OF PRODUCTS

The Mannich-type reaction of phenylurea with phenyl dichlorophosphine and aldehydes (or ketones) is studied in this paper. It is found that straight chain and cyclic products are obtained respectively, when dif ferent solvents are used. The ways of cyclization are affected by the substituents of ketones. There exist two geometrical isomers for each of the title compounds which are proved by their H-1 NMR and P-31 NMR spectra, and the configuration of each isomer is confirmed by means of X-ray diffraction and H-1 NMR spectra. Besides, it is found that the five-membered phosphorus heterocycle is of a plane conformation with a dpi-ppi bond between P and N.