JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Lateral functionalization of phosphonate quinolines

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An efficient metalation-functionalization of diethylmethylphosphonate quinolines, at low-temperature, with suitable electrophiles in the presence of n-BuLi in THF, is described herein. It constitutes a general method for the synthesis of halogenophosphonoquinolines and vinylquinolines.

N. Jelaiel, T. Saïed, M.L. Efrit

methylphosphonate, quinoline, halogenophosphonoquinoline, vinylquinoline

Pages 121-126

Synthesis and characterization of new cyano-quinazolines poly-functionalized

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Fonctionalized N-aryliminoesters are obtained from the conversion of different aromatic amines by action on orthoesters. The closing cycle or cyclisation of latter is developed by nucleophile attack through one of the two electrophile centre of the iminoesters followed by a second intermolecular development of binucleophile which is the cyanamid. A scale of generated products is functionalized cyano-quinazolines.

T. Saïed, N. Jelaiel, M.L. Efrit

aromatic amines, N-aryliminoesters, cyanamide, cyano-quinazoline

Pages 127-130

An efficient synthesis of new N-pyrazolyl benzodiazaphosphole-2-sulfides conjugates

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A series of novel N-pyrazolyl benzodiazaphosphole-2-sulfides (4a-h) were prepared via cyclocondensation reactions between different 5-(2-aminophenylamino)-3-pyrazole derivatives (3a-h) and the Lawesson’s reagent. Structural elucidations of all compounds were established by mean of 1D-NMR spectroscopy: 1H, 13C, 31P, 2D-NMR techniques and HRMS analysis.

W. Abdallah, A. Regazzetti, D. Dargère, O. Laprévote, H. Ben Jannet, R. Gharbi

1,5-benzodiazepines, pyrazoles, Lawesson’s reagent, diazaphosphole-2-sulfides

Pages 131-138

Synthesis of a new 2,4,5-triphenyl-1H-imidazolium-paratoluenesulfonic acid salt: Thermal and electrochemical stability

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A new Imidazolium salt named 2,4,5-triphenyl-1H-imidazolium-paratoluen sulfonic acid have been synthesized from 2,4,5-triphenyl-1H-imidazole and paratoluen sulfonic acid. The structure of the obtained compound has been established on the basis of FTIR, 1H NMR and 13C spectral data. The stability of this novel product was confirmed by thermal and electrochemical characterizations.

A. Dhahri, A. El Ghali, M.H.V Baouab

Imidazolium salt, Anion Tosylate, Thermal and Electrochemical stability

Pages 139-143

Silica particles with grafted UV-filter for the stabilization of pickering emulsions

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Pickering emulsions have been prepared using silica particles grafted with UV-filter as stabilizers. Such formulation contains all the ingredients of a sun protection product: organic UV-filter, inorganic particles as anti-UV screen and oil. Grafting the UV-filter is expected to prevent deep penetration of potentially harmful organic molecules inside the skin. p-methoxycinnamate has been immobilized onto to the surface of fumed silica particles. The UV-filter molecule was attached to silica by means of a short (C2) or a long (C10) alkyl spacer to study their effect on grafting degree. Better water dispersion was obtained for the two materials. The water dispersion particles remained stable for 40 days. The hydrophobically-modified silica, with different grafting degrees and linkers, were used for the formulation of o/w Pickering emulsions with various oils of cosmetic relevance: silicone oils of different viscosities and octylbenzoate. The stability and drop size distributions in the different emulsions are evaluated. Stable emulsions were obtained with oil contents in the range 10% to 60%. UV-absorbing ability was retained after immobilization of UV-filter molecules onto silica particles in all emulsion.

A. Noomane, R. Kalfat, Y. Chevalier, S. Hbaieb

Pickering emulsions, UV-filter, modified silica, sunscreen formulation

Pages 144-151

Box-Behnken design optimization of magnesium potassium phosphate cement properties using sodium chloride as retarder

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Magnesium potassium phosphate cement (MKPC) pastes based on magnesium oxide (MgO) and potassium dihydrogen phosphate (KDP) was prepared with the addition of sodium chloride (NaCl) as retarder. The experimental results demonstrate that the use of NaCl at concentrations varied from 2 to 6% found to increase the setting time and contribute to the enhancement of final compressive strength. In order to evaluate the influence of this retarder in the total mixture and its interaction between each component, a Box-Behnken design with three variables was established. The influences of MgO/KDP ratio, Water/Binder ratio and the percentage of NaCl were studied. According to the setting time and compressive strength results, an optimum operating condition was introduced. The obtained optimal conditions were examined and analysed by X-ray diffraction (XRD) and scanning Electronic Microscopic (SEM).

I. Bouaoun, H. Hammi, A. M’nif

Magnesium potassium phosphate cement (MKPC), sodium chloride, setting time, compressive strength, Box-Behnken design

Pages 152-159

Preparation and characterization of activated carbon monoliths from date stones by physical activation

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Binderless activated carbon monoliths have been prepared from date stone of the south of Tunisia (Kébeli). The activation process involved two steps. First, pyrolysis of the samples was conducted up to a temperature of 1000°C under nitrogen flow. The obtained carbon monoliths were then physically activated at 500 - 900°C under CO2 flow. All samples have been characterized by N2 adsorption, scanning electron microscopy and mercury porosimetry. The activated carbons exhibited a predominant microporosity with specific surface area from 476 m2 g-1 to 877 m2 g-1 , and microporous volumes from 0.19 cm3 g-1 to 0.33 cm3 g-1.

S. Rezma, M. Birot, A. Hafiane, H. Deleuze

Date stones; Binderless Carbon Monoliths; Physical Activation

Pages 160-165

Determination of strontium traces in highly concentrated solutions and brines using flame atomic absorption spectrometry

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The natural brines are aqueous solutions strongly concentrated in oceanic salts. The total content of salts can attain 350 g/L. The studied matrix is very complex; it includes a multitude of elements; among them (Mg2+, Ca2+, Na+, K+), other miners and constituents in the state of traces such as lithium and strontium. This latter has not been studied previously. Considering what precedes; it is evident that the determination of the strontium in the state of trace by flame atomic absorption spectrometry is unsettled by phenomena of interferences due to the matrix effect. In order to understand such phenomena, this work was undertaken. Thus, the investigation of these interferences is necessary. This study allowed us to identify, for each filed of concentration of disturbing elements, the nature of interference phenomena. The obtained results showed that these interferences, are mainly chemical and spectral (interferences of ionization, dissociation, volatilization and superposition of bands). We succeeded to reduce the matrix effect, by using an analysis based on the optimization of the flame and the use of spectroscopic buffer. The persistence of the difficulties caused by presence of magnesium led to study of its quasi-total elimination of the medium.

A. Boughalmi, H. Hammi, A. M’nif

Determination of trace elements, strontium, interference phenomena, brine, flame atomic absorption spectrometry

Pages 166-172

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