The enamines constitute the one of the most important classes of reactionnal intermediates and are used often as synthons in some chemical multisteps syntheses. The ways of access to these amino olefines are numerous. We present the different modes of their obtention.
M. Hamadouche, D. El Abed
A variety of ketoaldehydphosphonates 2 have been prepared by reaction of γ-ketophosphonates 1 with ethylformate in basic conditions. On reaction with hydrazines, compounds 2 lead to β-phosphocycloalcanepyrazoles 3. The structure of all obtained products was determined on the basis of their IR and NMR data.
S. Touil, H. Zantour
Ketones γ-phosphonates, ketoaldehydephosphonates, β-phosphocycloalcanepyrazoles, RMN 1H, RMN 31P, RMN 13C
The present work is a contribution to the synthesis of polyfunctionalized dibenzo-14-crown-4. Functions such as bromo, nitro and nitrile were linked to the benzenic cycles. A new series of DB-14C-4 derivatives has been synthesized with mono, di, tri, and tetrasubstitution. Aromatic cycles are bearing one or two different functions. This was leading to the derivatives: Dibromo, tetrabromo, tetranitro, dicyano, tetracyano, dibromodinitro, bromodinitro, and cyanodinitro, dibenzo-14crown-4. The substituted crowns were characterized by 1H-NMR, IR, UV and MS.
A. Ould Hadou, G. Jaouen, F. Meganem
dibenzo-14crown-4, synthesis, functionalization
N-(3-carbethoxy-2-thienyl) iminoethers 2, obtained from 2-amino-3-carbethoxythiophenes 1, react with primary amines and hydrazines derivatives to give thieno [2,3-d] pyrimidin-4(3H)-ones 3 and 4. From a mechanistic view point, the reaction proceeds by the intermediary amidines 3' which were isolated.
K. Dridi, M.L. El Efrit, H. Zantour
The condensation of enamines 1 with the ylidenes 2a-b, 2c-e and 2f leads to the formation of dienamines A1, A2 and A3 respectively. Cycloallcanepyridines 3 , 4 and cycloalkanepyridinones 5 were obtained in good yields from the reaction of the intermediates A1, A2 and A3 with ammonia . Their structure is confirmed by IR and NMR spectroscopy.
S. Naceur, H. Zantour
enamines, ethoxylidenes, cycloalkanepyridines, cycloalkanepyridinones
The essential oil obtained by hydrodistillation of marjoram commonly cultivated in Sfax (Tunisia) was analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The terpinen-4-ol (32,84%) and the γ-terpinene (9,85%) are the main components of the oil.
N. Ben Hamida-Ben Ezzeddine, M.M. Abdelkefi, M.M. Chaabouni
marjoram, essential oil, GC-MS, terpinen-4-ol, Origanum Majorana L.
Cold vapor in atomic absorption spectrometry technic allows the determination of mercury at low levels. In sediments, mercury occurs generally in sulfur or in the organic forms, this latter is linked to the micro-organism activities. Thus an appropriate procedure for sample digestion is required. Among the nombrous method of digestion included in the literature we retain the acid mixture procedure [HNO3/HCl (3/1)]. After optimisation of the procedure of analysis, sediment samples collected from different ports in the Gulf of Tunis revealed that concentrations of mercury are in the range of 300-900 ng/g.
N. Mzoughi, A. El Abed, M.S. Medimagh
mercury, marines sediment, Cold vapor, digestion
With regard to very high concentrations of alkaline and alcalino-terreux elements in the naturals brines, it is very difficult to determine Lithium witch is very diluted in the system. Interference phenomena between lithium and Na, K, Ca and Mg are studied and proved by the authors. The limits of the standard additions method when we dose lithium in a natural brine are determined. The aim of this study is to determine the effect of the major elements considered individually and then per couple. The objective is the definition of an area, with regard to Li and interferon concentrations, were the direct determination of lithium is viable. This work is a part of a more detailed study made in order to elaborate a specific method for analysing lithium as a trace in a natural brine.
H. Hamzaoui, A. M’nif, R. Rokbani
naturals brines, lithium, interference phenomena, flame emission spectrometry
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