A novel series of Diphenyl (aryl) (4-oxo-quinazolin-4(3H)-ylamino) methyl phosphonates (1-4)is
obtained in high yields from the reactions of 3-amino-4(3H)-quinazolinone with different aromatic aldehydes
and triphenylphosphite in the presence of cupper trifillate as a Lewis acid catalyst. The structures of the
synthesized compounds are confirmed by IR, 1H NMR, and El-mass spectral data. The synthesized compounds
show high antimicrobial activities against Gram-negative, Gram-positive bacteria and fungi at low
concentrations (2.5-10mg/mL). Also, they show significant cytotoxicity anticancer activities against liver
carcinoma cell line (HepG2). The quantum chemical calculations are performed using density functional theory
(DFT), with the B3LYP hybrid functional with 6-31G + (d) basis set to study the effect of the molecular and
electronic structure changes on the biological activity of the investigated compounds. The calculations show
that the electron-withdrawing substituent increase the biological activity of the α-aminophosphonate
compounds more than the electron donating group which is in a good agreement with the experimental results.
Finally, the quantum chemical parameters confirmed with MEPs are able to describe the biological activity of
the investigated compounds.