JOURNAL of the Tunisian Chemical Society

serving the Research, the Education and the Industry

Etude de la synthèse diénique en solution aqueuse

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Some aspects of a new method of activation (chemistry in water) are considered. The Diels-Alder reaction is differently affected according to its electronic character (normal, neutral and inverse). The results are compared with the corresponding yields obtained in traditional organic solvents and those derived from catalytic activation by solutions of lithium perchlorate solution in diethyl ether.

N. Habaieb, R. Ben Salem

Hydrophobic effects, Diels-Alder Reactions, Density of cohesion energy

Pages 1-8

Synthèse de nouveaux polyamides entièrement furaniques

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All - furanic polyamides based on a difuranic diacid chloride and various difuranic diamines were prepared by solution and interfacial polycondensation. Regular linear macromolecular structures were thus obtained with reasonably high inherent viscosities. The properties of these materials (glass transition, thermal stability, surface energy) were also examined. Model compounds were prepared in order to facilitate the synthesis and the characterization of the polymers.

A.S. Gharbi, A. Gandini

polyamides, furanic polymers, polycondensation, difunctional furan monomers

Pages 17-25

Synthèse des 1,2,4-triazoles et des 1,2,4-triazin-6-ones à partir des N1-tosylamidrazones

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The condensation of tétraéthyl orthocarbonate with N1-tosylamidrazones in the presence of acetic acid gives 1,2,4-triazoles with good yields. In basic medium, the reaction of a variety of N1-tosylamidrazones with α-bromoesters gives 1,2,4-triazin-6-ones.

H. Chouaieb, M. Ben Mosbah, M. Kossentini, M. Salem

N1-tosylamidrazones, 1,2,4-triazoles, 1,2,4-triazin-6-ones

Pages 27-32

Phenolic compounds with antioxidant activity from olive mill wastewaters

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In this investigation, different methods for the extraction and the purification of phenolic compounds from the olive mill wastewaters (OMW) were used. Consequently, seven phenolic monomers were isolated at pure grade. By means of spectroscopic methods (IR, UV, MS, 1H NMR, HPLC-UV and HPLC-MS), their structures were established as tyrosol, hydroxytyrosol, caffeic acid, protocatechuic acid, para-coumaric acid, apigenin and luteolin. The antiradical activity of the purified phenolic compounds was evaluated by measuring the radical scavenging effect on 1.1-diphenyl 2-picrylhydrazyl (DPPH). Result showed that hydroxytyrosol presented the highest DPPH radical scavenging effect. The antioxidative activity of the isolated compounds was evaluated using a coupled oxidation of β-carotene-linoleic acid method. The antioxidant potency of the various tested polyphenols was in the following decreasing order: hydroxytyrosol > caffeic acid> protocatechuic acid > para-coumane acid > tyrosol.

N. Allouche, S. Sayadi, M. Damak

olive mill wastewaters, polyphenols, isolation, antioxidants, β-carotene, 1.1-diphenyl 2-picrylhydrazyl

Pages 33-43

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