Phosphonylhydrazones are considered as valuable intermediates in heterocyclic synthesis, In the present work, we study the reaction of hydrazines with γ-ketophosphonates 1, which lead to γ-phosphonylhydrazones 2. The stereochemistry of products 2 is determined by NMR spectroscopy.
S. Touil, H. Zantour
hydrazones γ-phosphonatées, cétones γ-phosphonatées, RMN 1H, RMN 31P, RMN 13C
Iminoesters 1 and orthoesters 2 react with phenylhydrazine in solid/liquid environment to give hydrazonates 3 with good yield. Treatment of hydrazonate N-1-ethoxycarbonylated 4 with primary amines yields to 1,2,4-triazol-5-ones 5.
F. Chabchoub, M. Trabelsi, M. Salem
Two known compounds have been isolated for the first time from the leaves of Ajuga iva (Labiatae) : (24S)-28-methyl-25-methylene cholest-5-en-3-ol (clerosterol) and 3- hydroxy-hexadecanoic acid methyl ester This study involves the structural elucidation of Clerosterol by one and two-dimensional NMR techniques.
H. Ben Jannet, A. Chaari, M. T. Martin, Z. Mighri
Ajuga iva, Labiatae, steroid, ester of fatty acid
α,β-insaturated iminoesters 1 react with thiols, secondary amines and dialkylphosphites to lead to the formation of β-mercaptoimidates, β-aminoimidates and β-phosphonoimidates respectively with good yields. Furthermore, compounds 1 constitute good precursors for synthesis of new bis-(N-aryl β-mercaptoethylimidates).
M.L. El Efrit, B. Baccar, H. Zantour
imidates, mercaptoimidates, aminoimidates, phosphonoimidates
The extraction of the couple Zn2+ - Cd2+ from sulfate medium by mixture of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HPMBP) and methyl isobutyl ketone (MIBK) in toluene has been studied. The theoretical approach of separation of couple metals appears in certain conditions the existence of mixed metals complexes. The results showed that mixed metals complexes have not been formed but showed a better Zn/Cd extraction selectivity.
D. Barkat, A. Tayeb, Z. Derriche
extraction, zinc, cadmium, mixed complexes, 1-phenyl-3-methyl-4-benzoylpyrazol-5-one, methyl isobutyl ketone
The thermal field-flow fractionation technique is well suited to fractionate polymers and may be applied to the case of copolymers. The measurement of thermal diffusion coefficients from retention data allowed to study the effect of the composition of copolymers on thermal diffusion. We have shown that thermal diffusion depends both on the nature and composition of copolymers. The thermal FFF technique hence appears as a valuable fractionation and characterization tool for copolymers.
Thermal FFF, copolymers, thermal diffusion
The carnallite salt obtained by solar evaporation of « Sebkha El Melah of Zarzis » brine, contains some sulfate ions under Kaïnite or Kieserite form. The recovery of KCl by decomposing the carnallitic raw material may be affected by the presence of the sulfated salts. The aim of this study is to determine the effect of the sulfate ion on the process used for decomposing sulfated carnallite.
A. M'nif, R. Rokbani
carnallite salt, solar evaporation, brine, effect of the sulphate ion
Some brines, coming from south Tunisian «sebkhat and chatt» are relatively concentrated in magnesium witch causes difficulties during industrial exploitation. A study concerning the treatment of these natural solutions and then the isotherm evaporation of resulting mother liquors show that there is a possible solution for the above-mentioned problem.
C. Djebali, L. Zayani, A. M'nif, R. Rokbani
Brines, solubility diagram, magnesium
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