SYNTHESIS, NMR INVESTIGATION AND FAB-MS CHARACTERIZATION OF 1-AMINO-2-ARYLMETHYL-DIPHOSPHONATE ESTERS

Variously substituted amino aryl-methyl-diphosphonate ethyl esters have been prepared in good yields by adding diethyl phosphonate to the corresponding Schiff bases. All compounds were characterized by NMR and MS-FAB techniques, which reveal the presence of peaks or fragmentation patterns very useful and diagnostic for constitutional assignment. Evidences for a stereospecific addition of diethyl phosphonate to the two-CH=N-sites in diaryl diimines have been observed. The presence of heteroaromatic rings such as pyridine or azo-groups renders such compounds also very attractive for complexation studies towards metals: thus, these molecules are for potential uses in agrochemistry and biodiagnostic medicine.