Synthesis and NMR Spectroscopic Study of New Furan-Derived Bis(Aminophosphonates)

Abstract

The synthesis of two novel furyl-containing bis(aminophosphonates) 1,5-bis[N-methyl(dimethoxyphosphonyl)-1-(2-furyl)]diaminonaphthalene (1) and 1,5-bis[N-methyl(diethoxyphosphonyl)-1-(2-furyl)]diaminonaphthalene (2) through an addition of dialkyl phosphites to N,N′-difurfurylidene-1,5-naphthalenediamine is reported. The compounds have been characterized by elemental analysis, TLC, IR and NMR (¹H, ¹C and ³¹P) spectra. Some new ³¹P NMR data of three previously described analogues (3–5) of the above bis(aminophosphonates) is also presented. The ³¹P NMR study reveals that in most of the cases (1, 3–5), the addition reaction is completely stereoselective, and only one diastereomer is formed. By the preparation of compound 2, this reaction proceeds not completely stereoselectively with the predominant formation (in 90%) of one of the two possible diastereomers.

Keywords:

• Aminophosphonic acids
• furan derivatives
• NMR spectra
• Schiff bases

Acknowledgments

Thanks are due to the UNESCO Division of Life Sciences for the financial support (GrantSC 206.579.0).