JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Addition 1,3-dipolaire du 2-diazopropane (DAP) sur des énones aromatiques parasubstituées

Written by sctunisie no comments

The reaction of 1,3-dipolar cycloaddition of 2-diazopropane 1 with enones 2a-d at 0°C, has led to Δ2-pyrazolines 4a-d. Pyrazolenines 5a-d resulted, in a good yield, from oxidation of Δ2-pyrazolines 4a-d by MnO2.

H. Hammami, Y. Ben Dhia, A. Khemiss

2-diazopropane, 1,3-dipolar cycloaddition, Δ2-pyrazolines, pyrazolenines

Pages 1539-1543

Structure of a new neo-clerodane diterpenoid from Ajuga pseudoiva leaves and its insect antifeedant and antibacterial activities

Written by sctunisie no comments

From the leaves of the plant Ajuga pseudoiva a new neo-clerodane diterpenoid, Hativene D, has been isolated. Its structure was established by spectroscopic means. The antifeedant activity of this compound has been studied against Egyptian cotton leafworm Spodoptera littoralis (Boisd.) (Lepidoptera) by application of the leaf disk method. This substance exhibited an interesting activity even at 1 ppm. Structure-activity relationship is discussed. The antibacterial effect of this neo-clerodane has been also tested.

H. Ben Jannet, M.H. Oueslati, A. Chaari, M.T. Martin, A. Loukaci, M.J. Simmonds, Z. Mighri

Ajuga pseudoiva, Lamiacea, clerodane diterpenoid, Hativene D, anti-insect, antibacterial

Pages 1545-1549

Dibenzopyridino-18-couronnes-6 polyfonctionnelles: Synthèse extraction des cations alcalins et étude d’acidité

Written by sctunisie no comments

This research is a contribution to the synthesis of functionalized dibenzo-pyridino-18-crown-6 (DB-P-18-C-6). The functions bromo and nitro were fixed on the aromatic rings. New di and tri substituted derivatives of DB-P-l8-C-6 were synthesized. The substituted crowns were characterized by 1H-NMR, IR, U.V, MS and elemental analysis. Likewise, we have tested these crowns for their complexing properties for alkali cations by the determination of extraction equilibrium constants (Ke) and the complexation constants (Kc). The determination of pKa for these compounds was realized by different methods and in different solvent systems.

A. Ben Hadj Amor, F. Meganem

Dibenzo-pyridino-18-crown-6, Synthesis, Fictionalisation, Extraction, Acidity

Pages 1551-1563

Triterpenoids from the fruit barks of Periploca laevigata growing in Tunisia

Written by sctunisie no comments

Three compounds, previously identified in other natural sources, have been isolated for the first time from the fruit barks of Periploca laevigata (Asclepiadaceae): oleanolic acid 1, maslinic acid 2 and β-sitosterol-3-β-D-glucoside 4. β-amyrine 3 has been also re-isolated. Their structures have been established by spectroscopic procedures.

F. Hichri, O. Hammouda, H. Ben Jannet, Z. Mighri, P.J.M. Abreu

Periploca laevigata, Asclepiadaceae, Triterpenoids, Sterol, NMR

Pages 1565-1569

Utilisation des micro-ondes dans la synthèse de nouveaux hétérocycles azépiniques à partir de l’isophorone

Written by sctunisie no comments

New caprolactams and related compounds were synthesized via Beckmann rearrangements and subsequent Diels-Alder additions starting from ketone oximes of isophorone derivatives. The reactions were activated by microwave irradiation and the results were compared to those obtained under conventional heating. Anyhow, microwave activation was more efficient as compared to conventional heating, every conditions equal elsewhere.

Y. El Barkaoui, A. El Louzil, A. Loupy, M. Soufiaoui, S. Fkih-Tetouani

Microwave, isophorone, caprolactames, azipines, rearrangement de Beckmann, addition de Diels-Alder

Pages 1571-1576

Action d’aminoazoles sur les 2-dialkylaminométhylpropénenitriles

Written by sctunisie no comments

The condensation of guanidine, aminobenzimidazole and 5-amino-1,2,4-triazole with 2- dialkylaminomethylpropenenitriles constitute a highly regiospecific reaction and an original route for synthesis of new dihydropyrimidines, dihydropyrimidobenzimidazoles and dihydrotriazolopyrimidines.

F. Yaccoubi, M.L. El Efrit, H. Zantour

dihydropyrimidines, dihydropyrimidobenzimidazoles, dihydrotriazolopyrimidines

Pages 1577-1584

Relations de dépendance entre les acides gras et les triglycérides au cours de la maturation des olives de la variété Chemlali

Written by sctunisie no comments

This article deals with olive oil and has for objects to study the evolution of acidic and triglyceridic composition during maturity and the interrelation between the palmitic acid (16:0) and oleic acid (C18:1) and linoleic acid (C18:2) on the one hand and between these three acids and the 12 triglycerids (LLL, OLLn, OLL, OOLn, PLL, OOL, POL, PPL, OOO, P00, PPO and SOO) of others part. The results obtained showed a stability of oleic acid, a reduction of the palmitic acid and an increase of linoleic acid during the process of maturity. They also revealed that this process is accompanied by a decrease in percentage of POL, PPL and POO and an increase of the percentage of OLL. As for links of dependence, the statistical calculations done, showed a strong relation of dependence between the palmitic acid and the two other acids combined (oleic and linoleic) (r2 = 0,952) and between the palmitic acid and the linoleic acid (r2 = 0,736 ). The linear relation between the palinitic acid and the oleic acid is rather weak (r2 = 0,36). Otherwise, these calculations revealed the very important relation of dependence existing between every fatty acid and triglycerids corresponding to it. In fact, the factors of determination are superior than. 0,84.

A. Lazez, B. Karray, M. Ayadi, M. Khlif, M. Cossentini

olive oil, maturity, fatty acids, triglycerids, relation of dependence

Pages 1585-1590

Nouvelle méthode de préparation de complexants du ferIII et synthèse ameliorée de l’intermédiaire pyrocatéchol monobenzyléther

Written by sctunisie no comments

A new synthetic route is reported for siderophores APn having pyrocatechol groups located α to each carboxylic acid of a α,ω-linear diacid. The use of a benzyl group for protecting a phenolic hydroxide allows an easy deprotection by hydrogenolysis and gives a better yield for the multistep synthesis. An improved synthetic procedure for preparing the intermediate 2-benzyloxyphenol (pyrocatechol monobenzylether), by solid-liquid phase transfer catalysis, is reported (K2CO3, Aliquat, xylene; yield = 75%).

M. Ismaïl, A. Zinelabidine, F. Mhenni, R. Gallo

siderophores, protecting group, hydrogenolysis, ether cleavage, Phase Transfer Catalysis (PTC)

Pages 1591-1598

Rss feed of the category