Bogdan Boduszek

The acidic cleavage of pyridylmethyl(amino)phosphonates. Formation of the corresponding amines

Abstract Hydrolysis of 3-pyridylmethyl(amino)phosphonates by means of 20% aq. hydrochloric acid gave corresponding 3-pyridylmethyl(amino)phosphonic acids, as expected. However, hydrolysis of 2- and 4-pyridylmethyl(amino)phosphonates led to decomposition of the phosphonates with a cleavage of CP bond and formation of the corresponding amines. The leaving phosphorus moiety was identified as phosphoric acid. The scope of the reaction is limited to 2- and 4-pyridylmethyl derivatives of aminophosphonic acids and their esters, as well as to the derivatives possessing similar structure. In the contrary, the basic hydrolysis of 2- and 4-pyridylmethyl(amino)phosphonates led to the corresponding monoalkyl esters of the aminophosphonates, and no a cleavage of CP bond was observed in those cases.

FT-IR and FT-Raman study of selected pyridinephosphonocarboxylic acids

In this work we present FT-IR and FT-Raman spectra of three acids: pyridine-2-phosphono-4-carboxylic (MC1), pyridine-2phosphono-5-carboxylic (MC2), and pyridine-2-phosphono-6-carboxylic (MC3) that possess potential neuroactive abilities. Their molecular structures and vibrational frequencies are calculated with ab initio Hartree–Fock and density functional theory methods (DFT) using the local (SVWN) and hybrid (B3LYP, B3PW91) exchange functionals. Here we discuss and compare differences in geometrical structures and vibrational patterns obtained by ab initio and DFT methods used in this work. The best agreement between the experimental and calculated spectra was obtained at the B3PW91/6-31G �� level. Assignments of Raman and IR bands for all studied acids are made on the basis of potential energy distribution (PED). We also show how the arrangements of phosphonato and carboxylic substituents on the pyridine ring change the vibrational structure of pyridine. # 2003 Elsevier Science B.V. All rights reserved.

Coordination abilities of amino-phosphonate derivatives of pyridine

Abstract Potentiometric and spectroscopic methods were used to evaluate the binding ability of the series of amino-phosphonates containing pyridine as a side-chain. The involvement of pyridine nitrogen in the Cu(II) binding results in very effective chelation of the metal ion. The binding ability of some pyridine-containing ligands is comparable to powerful imidazole amino-phosphonates.

1-AMINOPHOSPHONIC ACIDS AND ESTERS BEARING HETEROCYCLIC MOIETY. PART 2.1PYRIDINE, PYRROLE AND IMIDAZOLE DERIVATIVES

Abstract The benzylic amines (benzylamine, benzhydrylamine and benzyl carbamate) were applied in the synthesis of aminophosphonates derived from pyridine, pyrrole and imidazole. The Schiff bases obtained from corresponding heterocyclic aldehydes and benzylic amines were caused to react with diphenyl phosphonate or dibenzyl phosphonate to form corresponding heterocyclic aminophosphonates in good yields. The N-(benzylamino)-phosphonates were deblocked by catalytic hydrogenolysis. The benzhydryl group from the phosphonates was removed by acidic hydrolysis, and the carbobenzyloxy group from the phosphonates can be easy removed by treatment with a solution of 30% HBr in acetic acid, as well. It was found that during acidic hydrolysis of 2- and 4-pyridylmethylaminophosphonates a rearrangement occurred. combined with a cleavage of C—P bond in the phosphonate molecules and subsequent formation of the corresponding amines.

AN EFFICIENT SYNTHESIS OF 1-AMINOPHOSPHONIC ACIDS AND ESTERS BEARING HETEROCYCLIC MOIETY

Abstract New α-aminophosphonic esters and acids derived from furan, thiophene and pyrazole were prepared in high yield, in the reactions of benzylamine, benzhydrylaraine or benzyl carbamate with heterocyclic aldehydes and diethyl or diphenyl phosphonates. The protecting groups at amine (benzyl or benzhydryl) were removed by hydrogenolysis or hydrolysis, respectively. The N-benzyloxycarbonyl (Z-group) was removed by treatment with 45% HBr in acetic acid.

Methylphosphonate, hydroxymethylphosphonate and aminomethylphosphonate ligands containing pyridine, pyrazole or imidazole side chains: the coordination abilities towards Cu(II) ions

Abstract Potentiometric and spectroscopic study on coordination abilities of phosphonic acid derivatives with pyridine, imidazole and pyrazole towards Cu(II) ions have shown that involvement of heterocyclic amines increases considerably the chelating power of phosphonates. The most effective ligand was found to be the imidazole amino-phosphonate derivative, which may compete with histidine the most effective natural amino acid chelator.

Mode of action of herbicidal derivatives of aminomethylenebisphosphonic acid. I. Physiologic activity and inhibition of anthocyanin biosynthesis

N-Pyridylaminomethylenebisphosphonic acids constitute a class of promising herbicides. Since their mode of action at the cellular level is still poorly understood, we studied the influence of N-pyridylaminomethylenebisphosphonic acids on plant growth, at the whole plant and undifferentiated tissue levels, using seedlings and cell suspension cultures of mono- and dicotyledonous species. These compounds exhibited strong herbicidal properties, being equipotent with the popular herbicide glyphosate. Since they also depressed buckweed anthocyanin biosynthesis, the shikimate pathway could represent a site of action of N-pyridylaminomethylenebisphosphonic acids.

The cleavage of 1-amino-2′-nitrobenzylphosphonates in a basic medium. Formation of the 3-amino-2,1-benzisoxazole derivatives

Abstract Treatment of 1-amino-2′-nitrobenzylphosphonic acids with aqueous sodium hydroxide caused a C-P bond cleavage, with formation of 3-amino-2,1-benzisoxazole derivatives ( 3 ). The leaving phosphorus moiety was identified here as phosphoric acid. In the case of basic hydrolysis of corresponding esters, new cyclic phosphorus compounds (derivatives of benzoxazaphosphorin-3,1,2 P v -one-2) were obtained. The cyclic products were formed as a result of the subsequent reaction of anthranil derivatives with leaving phosphorus fragment, presumably metaphosphate. These benzoxazaphosphorins (compounds 4 ) were converted by means of aqueous hydrochloric acid to 3-amino-2,1-benzisoxazole derivatives.

Adsorbed States of Phosphonate Derivatives of N-Heterocyclic Aromatic Compounds, Imidazole, Thiazole, and Pyridine on Colloidal Silver: Comparison with a Silver Electrode

Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

Experimental and calculated 1H, 13C and 31P NMR spectra of pyridine-2-phosphono-4-carboxylic acid

Pyridine-2-phosphono-4-carboxylic acid (MC1) is a compound that possesses potential neuroactivity. In this work the 1 H, 13 C and 31 P NMR spectra of MC1 dissolved in D2O in solution, in the 1.5 –9.0 pD range, are presented. Theoretical calculations of the NMR spectra, as well as structural parameters of expected compounds, were performed at the B3PW91/6-311G** and B3PW91/6-31G** level, respectively, for all five possible forms of MC1 (cation, zwitteranion and three anions). Consecutive deprotonation of MC1 and its influence on the structure of the ligand are discussed in detail. q 2003 Elsevier Science B.V. All rights reserved.