140380-55-8Relevant articles and documents
Characterization of oxidation products of TNT metabolism in aquatic phytoremediation systems of Myriophyllum aquaticum
Bhadra,Spanggord,Wayment,Hughes,Shanks
, p. 3354 - 3361 (1999)
TNT transformation processes in sediment-free, 'natural', aquatic phytoremediation systems of Myriophyllum aquaticum were investigated with specific interest in oxidation products. Extraction procedures combining liquid-liquid extractions and solid-phase extractions were developed for the isolation of the mostly acidic, oxidized TNT metabolites. Six compounds unique from the reduction products of TNT were isolated and characterized by UV-vis, 1H, and 13C NMR spectroscopy, by mass spectroscopy, and by chemical synthesis where feasible. These compounds include 2-amino-4,6- dinitrobenzoic acid, 2,4-dinitro-6-hydroxy-benzyl alcohol, 2-N-acetoxyamino- 4,6-dinitrobenzaldehyde, 2,4-dinitro-6-hydroxytoluene, and two binuclear metabolites unique from the customary azoxytetranitrotoluenes. The monoaryl compounds show clear evidence of oxidative transformations, methyl oxidation and/or aromatic hydroxylation. It is possible that oxidative transformation(s) preceded nitro reduction since studies on exposure of M. aquaticum to either 2-amino-4,6-dinitrotoluene or 4-amino-2,6-dinitrotoluene did not yield any of the oxidation products identified here. The accumulation of oxidation products was significant: 2-amino-4,6-dinitrobenzoic acid, 4.4%; 2,4-dinitro-6-hydroxy-benzyl alcohol, 8.1%; 2-N-acetoxyamino-4,6- dinitrobenzaldehyde, 7.8%; and, 2,4-dinitro-6-hydroxytoluene, 15.6%. The binuclear metabolites accounted for an estimated 5.6%. This study is the first direct evidence for oxidative transformations in aquatic phytoremediation systems. TNT transformation processes in sediment-free, `natural', aquatic phytoremediation systems of Myriophyllum aquaticum were investigated with specific interest in oxidation products. Extraction procedures combining liquid-liquid extractions and solid-phase extractions were developed for the isolation of the mostly acidic, oxidized TNT metabolites. Six compounds unique from the reduction products of TNT were isolated and characterized by UV-vis, 1H, and 13C NMR spectroscopy, by mass spectroscopy, and by chemical synthesis where feasible. These compounds include 2-amino-4,6-dinitrobenzoic acid, 2,4-dinitro-6-hydroxy-benzyl alcohol, 2-N-acetoxyamino-4,6-dinitrobenzaldehyde, 2,4-dinitro-6-hydroxytoluene, and two binuclear metabolites unique from the customary azoxytetranitrotoluenes. The monoaryl compounds show clear evidence of oxidative transformations, methyl oxidation and/or aromatic hydroxylation. It is possible that oxidative transformation(s) preceded nitro reduction since studies on exposure of M. aquaticum to either 2-amino-4,6-dinitrotoluene or 4-amino-2,6-dinitrotoluene did not yield any of the oxidation products identified here. The accumulation of oxidation products was significant: 2-amino-4,6-dinitrobenzoic acid, 4.4%; 2,4-dinitro-6-hydroxy-benzyl alcohol, 8.1%; 2-N-acetoxyamino-4,6-dinitrobenzaldehyde, 7.8%; and, 2,4-dinitro-6-hydroxytoluene, 15.6%. The binuclear metabolites accounted for an estimated 5.6%. This study is the first direct evidence for oxidative transformations in aquatic phytoremediation systems.
Synthetic utilization of polynitroaromatic compounds. 6. Remarkable regioselectivity in nucleophilic displacement of aromatic nitro groups with amines
Kislyi, Konstantine A.,Samet, Alexander V.,Strelenko, Yuri A.,Semenov, Victor V.
, p. 2285 - 2291 (2008/09/18)
(Chemical Equation Presented) 5,7-Dinitroquinazoline-4-ones undergo nucleophilic displacement of a nitro group with N-, S-, and O-nucleophiles. In contrast to previously studied dinitro-substituted benzoannulated five- and seven-membered heterocycles (where a high degree of selectivity was observed), these quinazolines mostly yield mixtures of regioisomeric substitution products. At the same time, primary and secondary amines react selectively to afford 5-aminoquinazolones (peri-substitution). A similar effect is observed for some other polynitroaromatic compounds with adjacent nitro and carbonyl groups. This phenomenon is attributed to a stabilization of the intermediate peri-σ-complex by intramolecular hydrogen bond N+-H...O=C.
Synthesis of reference substances for highly polar metabolites of nitroaromatic compounds
Schmidt, Torsten C.,Steinbach, Klaus,Buetehorn, Ulf,Heck, Kerstin,Volkwein, Ute,Stork, Gottfried
, p. 3119 - 3130 (2007/10/03)
Transformation processes of nitroaromatic compounds (NAC) lead to polar and highly hydrophilic metabolites. For the unequivocal identification of proposed metabolites reference substances are needed. Since most of them are not commercially available, their synthesis was done in our group. In many cases no satisfying synthesis schemes were found in the literature. In this communication, we therefore describe the preparation, structural elucidation and separation of 17 compounds. Many of the newly synthesized analytes were found in various water samples from a former ammunition plant.
Thermal Stability Studies on a Homologous Series of Nitroarenes
Oxley, Jimmie C.,Smith, James L.,Ye, Hong,McKenney, Robert L.,Bolduc, Paul R.
, p. 9593 - 9602 (2007/10/02)
The thermal stabilities of a number of nitroarenes were examined in solution and in condensed phase.In general, increasing the number of nitro groups decreased thermal stability.Changing the substituent on 1-X-2,4,6-trinitrobenzene from X = H to NH2 to CH3 to OH accelerated decomposition; this effect was attributed to increased ease of intramolecular proton transfer to an ortho nitro group, thus weakening the carbon-nitrogen bond.In solution, the effect of increasing substitution from n = 1 to n = 3 on Xn(NO2)3C6H3-n was uniformly that of decreasing the thermal stability of the species.However, in condensed phase, results suggested that crystal habit may be more important than molecular structure; for X = Br, CH3, and NH2, the more substituted species was the more stable.
RADICAL ANIONS OF AROMATIC COMPOUNDS XIX. INFLUENCE OF SALTS OF MULTIPLY CHARGED CATIONS ON THE STRUCTURE OF RADICAL ANIONS AND THE ORIENTATION OF PARTIAL REDUCTION IN SOME DI- AND TRI-NITROBENZENES
Bil'kis, I. I.,Uskov, S. I.,Shteingarts, V. D.
, p. 1694 - 1699 (2007/10/02)
Addition of Ba2+ and Al3+ salts in the partial reduction of a number of 1-substituted 2,4-di- and 2,4,6-tri-nitrobenzenes (substituents: CO2H, Cl) with the Ti3+-EDTA complex leads to a substantial increase in the formation of the orthoamino derivative relative to that of the para compound.This fact is in keeping with the character of the influence of additions of barium chloride on the proportions of the isomeric forms of the 2,4-dinitrobenzoic acid radical anion, which differ in the localization of the unpaired electron on the ortho- or para-nitro group respectively.An analogous effect of change in the orientation of the partial reduction can be obtained when titanium trichloride is used as reductant and no chelating agent is added.
