Specially prepared 2-arylquinolin-4(1H)-ones and their 2-aryl-1-methyl-4-quinolone derivatives were converted in high yield and purity to the corresponding C-3 brominated products using pyridinium tribromide in acetic acid at room temperature. The 2-arylquinolin-4(1H)-ones were reacted with iodine and Na2CO3 mixture in THF at room temperature to produce the 3-iodo-2-arylquinolin-4(1H)-one derivatives. The latter were, in turn, N-methylated using NaH-MeI mixture in dry THF to afford the corresponding 2-aryl-3-iodo-1-methyl-4-quinolone derivatives. The 3-iodo-2-arylquinolin-4(1H)-one and 2-aryl-3-iodo-1-methyl-4-quinolones were converted to 2,3-diarylquinolin-4(1H)-one and 2,3-diaryl-1-methyl-4-quinolones following Suzuki cross-coupling reaction method, respectively. The 2-aryl-3-bromoquinolin-4(1H)-ones, on the other hand, were converted to 2-aryl-3-bromo-4-chloroquinoline derivatives using phosphorus oxychloride under reflux. The 2-aryl-3-bromo-4-chloroquinoline were then transformed to the corresponding 2-aryl-3-bromo-4-N-(4'-chloroaryl)-4-aminoquinolines derivatives using 4-chloroaniline in ethanol under reflux. The products synthesized in this investigation were characterised using a combination of 1H NMR, 13C NMR, IR and mass spectroscopic techniques. / Chemistry / Chemistry / MSC (CHEMISTRY) / MSC (Chemistry)

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Face à  la menace croissante du terrorisme, il est essentiel de mettre en place des mesures de précaution et des moyens de surveillance permettant d'assurer la sécurité dans les lieux publics. Dans ce cadre, le CEA Le Ripault développe des systèmes de détection portatifs et autonomes dédiés à la détection d'explosifs en phase gazeuse. Cette thèse s'inscrit dans ce projet. L'objectif de cette étude est de concevoir et d'étudier les propriétés de matériaux sensibles fluorescents dédiés à la détection de composés nitroaromatiques tel que le TNT. Ainsi, les propriétés de mise en forme et de détection de différents matériaux, sensibles aux composés nitroaromatiques, ont été étudiées. Après identification du matériau le plus efficace pour cette application, nous avons étudié sa stabilité et nous avons cherché à comprendre le mécanisme de détection associé à ce matériau fluorescent. Les performances du détecteur de composés nitroaromatiques, intégrant ce matériau, ont ensuite été évaluées. / In order to overcome the growing threat of terrorism, it is essential to put into operation preventive measures and means of monitoring to ensure security in public areas. In this context, the CEA Le Ripault develops portable and self-contained detection systems dedicated to the detection of explosives in the gas phase. This PhD work is part of this project. The objective of this study is to design and to assess the properties of fluorescent sensitive materials dedicated to the detection of nitroaromatic compounds such as TNT. Consequently, the ease of deposition, thin films properties and detection performances of several sensitive materials have been considered. After identification of the most effective material for this application, we studied its stability and we searched to understand the detection mechanism associated with this fluorescent material. Then, the performances of the device which incorporate this sensitive material have been evaluated for the detection of nitroaromatic compounds.

L'usage industriel ou militaire de composés aromatiques nitrés toxiques, tels que le TNT, a entraîné des contaminations environnementales. Les capteurs électrochimiques sont intéressants pour identifier les sites contaminés car ils permettent des analyses rapides, sensibles, peu coûteuses et peuvent être portables. Deux exemples de modification de surface sont abordés dans cette étude pour fabriquer des capteurs sensibles et sélectifs. La première étude concerne l'utilisation d'un catalyseur électroactif, le titanocène, qui permet la réduction sélective des composés aromatiques nitrés. Le suivi de l'évolution du signal du catalyseur immobilisé dans du Nafion en surface d'électrode a permis d'atteindre des limites de détection de l'ordre de 10-6 mol/L pour une série de polluants. D'autres protocoles d'immobilisation ont également été envisagés pour améliorer la stabilité du capteur. La synthèse par électropolymérisation d'un polymère à empreintes moléculaires à base de polyaniline, permettant une préconcentration sélective à l'électrode, a également été optimisée pour des analogues du TNT. Après avoir évalué les performances du capteur sur une électrode unique (limite de détection, stabilité, reproductibilité), la méthode de modification a été appliquée à un réseau d'électrodes, permettant une voltammétrie par échantillonnage adaptée à l'analyse de molécules à l'état de traces en matrice complexe. Les premiers résultats montrent une limite de détection de 10-7 mol/L et une augmentation de la stabilité. Le capteur pourra être encore amélioré en optimisant le réseau et en reprenant le protocole d'analyse pour aboutir à un capteur sensible, spécifique et portable. / The military and industrial use of toxic nitroaromatic compounds, such as TNT, led to environmental contaminations. Electrochemical sensors are interesting to identify contaminated sites since they enable fast, cheap and sensitive analyses and can be portable. Two examples of surface modification are approached in this study with a view to making sensitive and selective sensors. The first study deals with the use of an electroactive catalyst, a titanocene, which enables selective reduction of nitroaromatic compounds. The catalyst was firstly immobilized in Nafion at the electrode surface. The monitoring of the evolution of its signal allowed for limit of detection down to about 10-6 mol/L for an array of pollutants. Other immobilization protocols were also considered to improve the stability of the sensor. The synthesis by electropolymerization of a polyaniline-based molecularly imprinted polymer, allowing a selective preconcentration on the electrode, was also optimized for TNT analogues. After the evaluation of the sensor performances on a single electrode (limit of detection, stability, reproducibility), the modification method was applied on an electrode array, that enables sampled current voltammetry suitable for trace detection in complex matrices. The first results showed limit of detection around 10-7 mol/L and improved stability. This sensor could be further improved by optimizing the array and reviewing the analysis protocol with a view to end with a sensitive and specific portable sensor.

No description available.

Evolution of strategies for biodegradation of synthetic organic pollutants relies on recruitment of genes from catabolic pathways for natural compounds. Investigation of metabolic diversity in nature can provide insight into biochemical strategies that could be recruited for bioremediation of pollutants. As part of a search for novel metabolic diversity we isolated soil bacteria able to degrade 2-nitroimidazole (2NI) and 5-nitroanthranilic acid (5NAA), and determined the biochemistry and molecular biology of their biodegradation pathways. 2NI and its analogs are increasingly used as prodrugs for the treatment of both tuberculosis and cancer. The biodegradation of 2NI by a soil Mycobacterium sp. is initiated by an unusual hydrolytic denitration. The reaction is catalyzed by a novel nitrohydrolase with a divergent sequence and represents the discovery of a previously unreported drug resistance mechanism in soil prior to its identification in clinical situations. 5NAA is the starting material for various nitroaromatic compounds and dyes. The biodegradation pathway of 5NAA is initiated by an unusual hydrolytic deamination. The corresponding gene is very distantly related to biochemically characterized genes in the NCBI database. The nitro group of 5NAA is eliminated as nitrite during the spontaneous formation of lactones from a ring fission product, a previously unreported mechanism. Degradation pathways of 5NAA and 2NI serve as precedents for those of nitroaniline and nitroimidazole pollutants. The work supports the hypothesis that the study of the metabolism of natural organic compounds selected on the basis of unusual structural features and ecological roles can reveal new metabolic diversity.

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Thesis (Ph.D.)--Tufts University, 2001. / Adviser: David R. Walt. Submitted to the Dept. of Chemistry. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 119-127).

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