Condensation of dithioanilin with β-ketoesters in xylol, gave 2-acetyl (benzoyl)-3-oxo- l,4-benzothiazines and 2-ethoxycarbonyl-3-methyl (phenyl)-1,4-benzothiazines. In the case of ethyl acetoacetate, two others products have been isolated: 2-methyl benzothiazole and 2-dihydro-3-oxo-1,4-benzothiazine. The sulfurization of 2-acetyl (benzoyl) 3-oxo-1,4-benzothiazines by phosphorus pentasulfide or lawesson reagent, lead to 1-methyl (phenyl)-2,3-dithiolo[4,3-b]-1,4-benzothiazines .
A. Keita, E.M. Essassi, M. Salem
dithioanilin, β-ketoesters, 1,4-benzothiazine, sulfurization 1,2-dithiols
This research is a contribution to the synthesis of multifunctionalized dibenzo-16-crown-5. The functions bromo, nitro and nitrile were fixed on the aromatic rings. A new series of mono, di, tri and tetra substituted derivatives of the DB-16-C-5 were synthesized. Aromatic rings were substituted with one or two different functions. This has led to the following derivatives : dibromo, dinitro, tetranitro, dicyano, dibromodinitro and bromo dinitrodibenzo-16-crown-5. The substituted crowns were characterized by 1H-NMR, IR, UV, MS and elemental analysis. Likewise, we have tested these crowns for their complexing properties and the extraction of alkali cations.
F. Ammari, T. Mhamdi, G. Jaouen, F. Meganem
dibenzo-16-crown-5, synthesis, functionalization, extraction
Synthesis and characterization of new derivatives derived of benzimidazole and quinoxaline have been studied. All the products have been isolated with a good yield.
R. Zniber, A. J. El Hajji, R. Achour, M. Z. Cherkaoui, A. Harrata
benzimidazole, quinoxaline, aminoacid, serine, o-phenylenediamine
Wood powder was completely dissolved in acidified phenol or phenol tetralin mixture. The oil obtained, so called "solvolysis oil" was hydrogenated in presence of different catalysts NiMoS, CoMoS, NiW, zeolite, at temperature of 330-410°C and 30 bar. The NiMoS favorizes the production of light fractions. The hydrogenation was also performed on the residue of distillation of the solvolysis oil in presence of NiMoS and tetralin as carrier solvent, at 350°C with hydrogen pressure in the range 30-90 bar. The hydrogenated oil is free flowing at room temperature, it is also rich in aromatic and phenolic compounds. Its oxygen content is around 1% and the HHV 43 MJ/kg when to the initial pressure of hydrogen is 90 bar.
S. Ammar, R. Capart, M. Benzina
Study of sediments can provide valuable data to assess the degree of sea water pollution. Herein, we investigate two toxic elements: cadmium and lead. Their analysis requires a highly-sensitive analytical method. ETAAS, with a thermal program adapted to the nature of the sample, has been used. The determination of the total amount of metals does not provide data to indicate the risk of toxicity, or even to understand the various geochemical processes. For these reasons, chemical fractionating (or speciation) is now widely used. It is important to determinate the sediment fractions with which the metals are associated. In this study, a comparison of three and five-step sequential extraction schemes has been established. For ETAAS, the use of calibration curves and thermal programs for each fraction is necessary to give satisfactory results. The procedures of analysis is applied to Pb and Cd in two reference sediments with certified total Pb and Cd content and to different sediments from ports of the Gulf of Tunis. The results show that the three step sequential extraction gives better recoveries.
N. Mzoughi, A. El Abed, M.S. Medimagh
Sequential extraction, ETAAS, lead, cadmium, marine sediments
Zeolites type A and faujasites have been prepared from aluminosilicate gel obtained by alkalin attack of tunisian sand and aluminium scraps. The influence of several physicochemical parameters such as temperature, crystallisation time and alkalinity on the nature and quality of the obtained products has been investigated.
H. Tounsi, S. Mseddi, S. Djemel
Sand and aluminium scraps, hydrothermal synthesis, zeolite
Etude des complexes du cuivre(l) et de l’argent(I) avec l’orthophénantroline dans l’acétonitrile par potentiométrie à courant nul
A. Cherni, M. Dachraoui
Zeolite Na-P1 obtained by hydrothermal treatment from Aidoudi clay (south of Tunisia) has been used to adsorb Pb2+, Cd2+ and Cu2+ from aqueous solutions. Isothermal exchange curves have been determined at 25°C and pH 2, 3.5 and 5. They have been interpreted by the Langmuir model. Equilibrium constants related to the exchange of H+, Na+ and the different cations have been determined.
A. Baccouche, E. Srasra, M. El Maaoui
Na-P1 zeolite, isothermal exchange, heavy metals, Aidoudi clay
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