3-(Bromomethyl) furan-2,5-dione 5, a highly functionalized and reactive compound was prepared in three steps with an excellent yield starting from the dimethyl itaconate 1.
A. Arfaoui, T. Ben Ayed, H. Amri
Allyl bromide, 3-(bromomethyl) furan-2,5-dione , dimethyl itaconate
In this paper, we describe a new and general method of preparation of chiral and achiral 2-substituted N-alkylaziridines is described. Good to high yields were obtained.
J. Khiari, B. Ben Hassine
Novel spiroheterocyclic succinimide-derivatives containig γ-butyrolactone moities were prepared via spirocyclization using N-bromosuccinimide (NBS), N-iodosuccinimide (NIS) or silver carbonate (Ag2CO3). Importantly, in all cases, the reaction seems to be highly regioselective because during the cyclization process only the exo-dig products were obtained in high yields. The resulting heterocycle derivatives could serve as intermediates for the access to new natural alkaloids with a biological interest.
M.M. Rammah, M. Othman, M. B. Rammah
spirolactones, halocyclization, succinimide, butyrolactone
The 1,3-dipolar cycloaddition of arylnitriloxides on the enamines has made it possible to synthesize polycyclic heterocycles. The structure of the obtained cycloadducts was determined from 1D-NMR and 2D-NMR. The structural resolution by X-ray diffraction confirms the proposed regiochemistry.
H. Jelizi, M. Askri, A. Guesmi, M.B. Rammah
enamines, 1,3-dipolar cycloaddition, arylnitriloxides, structural resolution
The Diels-Alder reaction between the acrylic products 1 and the cyclopentadiene offers an easy access road to substituted bicyclo[2.2.1]hept-5-ene 2 and 3. The stereochemistry of the obtained products was established.
M. Ould Mhamed, H. Mrabet, M.L. Efrit
Diels-Alder, cyclopentadiene, bicyclo[2.2.1]hept-5-ene
This paper deals with the kinetic hydrolysis mecanism of Zectran or 3,5-diméthyl-4-dimethylaminophényl-N-methylcarbamate in aqueous media. This work is carried out by reversed phase Liquid Chromatography and UV Spectrophotometry. The determination of 3,5-diméthyl-4-diméthylamino-phénol, as the main product of Zectran hydrolysis gives evidence for the significant reactivity of this insecticide in aqueous media. The obtained positive activation entropy ΔS = +7,05 J mol-1 K-1 and the absence of basic general catalysis indicate an E1cB mechanism involving unimolecular collapse of the Zectran via a methylisocyanate intermediate. This elimination process is confirmed by the position of the point corresponding to the Zectran on the Brönsted and Hammett lines, determined for a serie of substituted N-methylcarbamate which the decomposition mechanism in aqueous media procede via E1cB.
F. Boujelbane, N. Ben Hamida
Zectran, kinetic, mechanism, HPLC, spectrophotometric UV
Polythiazide is a thiazidic present in the list of forbidden substances since 1988 by the CIO. This substance was used by athletes in order to reduce their weight and the concentration of other dopant agents. The identification of polythiazide based on GC/MS methods show the deterioration of the thiazidic. Tandem mass spectrometry with negative electrospray ionization LC-ESI-MS/MS shows a high sensitivity of detection of this substance in urine. Mass spectra of the polythiazide have been established “in source” and in the collision cell of “CID”. The identification of the most specific fragments of the polythiazide permits the search of this doping substance.
F. Oueslati, N. Ben Hamida, A. Toumi
Polythiazide, diuretics, doping, LC-MS/MS, ESI-, CID, IOC
The volatile constituents of cactus pear seeds (Opuntia ficus indica) from Tunisia were concentrated by steam distillation, followed by liquid-liquid extraction with hexane, dichloromethane and diethyl ether. The composition of extracts was analysed by GC and GC-MS. The three extracts showed different chemical compositions varying according to extraction solvent. Fourty three constituents were identified in hexanic extract, representing 84,31 % of the concentrate. The major components were 2-methoxy-4-vinyl phenol (37,61%), 2,3-Dihydrobenzofuran (26.57%) and phenyl ethanal (10,88%). Fourty seven constituents were identified in the extract with dichloromethane that represented 88,68 % of the concentrate. Oleamide (27,07%) is the major component in the concentrate followed by 4'-Hydroxy-2'-methylacetophenone (16,44%), phenyl ethanal (14,28%) and 1-propylbenzene (10,03%). Fourty five constituents were identified in diethyl ether extract, representing 93,75% of the concentrate. Linoleic acid (41,30%) and 4,6-di-tert-butyl-2-methylphenol (21,62%) were the major components.
I. El Mannoubi, S. Barrek, T. Skanji, H. Zarrouk
Opuntia ficus indica, seed, volatile compounds, steam distillation, GC-MS
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