The organophosphorous analogues 2–7 of aminoacyl-5'-adenilic acid 1 have been synthesized by substitution of the anhydride oxygen atom with a methylene group, and of the hydroxyphosphinyl group with a methyl one. A new synthetic method has been developed for obtaining organophosphorous acids by condensation of the acidic chlorides of glycine, L- alanine and L-phenylalanine (N-acetyl derivatives, containing EtOCOCH2PO (OEt) R, ...