Browsing by Author "Hammadi, M."
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Item Easy and green synthesis of 6-(arylvinyl)-4-hydroxy-3-(phenylsulfanyl)-2H-pyran-2-ones in aqueous potassium hydroxide(Springer, 2016) Benferrah, N.; Hammadi, M.; Berthiol, F.Item Environmentally desirable synthesis: one-pot and solvent free formation of arylidenes compounds from gem-diacetates(Université M'Hamed Bougara Boumerdes, 2015) Benferrah, N.; Hammadi, M.; Dokari, H.; Berthiol, F.Heterogeneous acid catalysts are of importance in the fine chemicals area, and several been investigated in reactions such as the Knoevenagel reaction, an important reaction with pronounced solvent dependency. The condensation of active methylene compounds with gem-diacetates in the presence of acid aluminosilicates (montmorillonite KSF, K10/ZnCl2) without solvent and under microwave irradiation, an efficient of synthesis of arylidenes compounds without isolation of aldehydes compounds. Cleavage of arylidene rhodanine derivative in position 5 in basic medium on Potassium Fluoride–Barium Oxide (BaO-KF) under focused microwave irradiation and free solvent is a simple and effective method for synthesis of, β-aryl-α-thiolacrylic acidsItem Formation of Benzylidenes-Diacetates catalyzed by activated zeolite "LZY-562" and clay (K10/ZnCl2) : an unexpected functional selectivity(2015) Dokari, H.; Hammadi, M.; Benferrah, N.; Rachedi, Y.Item Liquid and solid acids as catalysts for the Thiele–Winter reaction of menadione(2000) Villemin, D.; Bar, N.; Hammadi, M.; Hachemi, M.Liquid acid such as perchloric acid, chlorosulfonic or triflic acid can effectively replace sulfuric acid as a catalyst in Thiele–Winter reaction of menadione. Solid acids like zeolites and heteropolyacids are described for the first time as catalysts in Thiele–Winter reaction. The two step sequence (Thiele–Winter), saponification–oxidation) constitutes a new synthesis of the antibiotic phthiocol from menadioneItem Potassium fluoride-barium oxide catalysis in an easy and efficient synthesis of methysticin from piperonal under microwave irradiation(Springer, 2015) Benferrah, N.; Hammadi, M.; Berthiol, F.Item Study of leaching of a 2M-Zirconolite (Ca0,83Ce0,17ZrTi1,66Al0.34O7) in acidic and basic media(2015) Souag, Rafika; Kamel, N.; Hammadi, M.; Kamel, Z.; Moudir, D.; Aouchich, F.; Kamariz, S.Zirconolite is a mineral intended for actinides elements confinement and is known for its good chemical durability. In this work, 2M-zirconolite, with the chemical formula: Ca0,83Ce0,17ZrTi1,66Al0.34O7 have been synthesized at 1400 o C by the metallurgical route at a laboratory scale. This stoechiometry corresponds to a CeO2 loading of 8.61 m.%. Ce is employed as an actinide surrogate. The effect of both pH and temperature on the chemical durability of this mineral has been studied. Phase identification and micrography observations have been done by X-ray diffraction, scanning electronic microscopy, and Fourrier transform infra-red spectroscopy. The end-product has a monophasic structure of 2M-zirconolite. Its density is about 4.013 g/cm3 , and its relative density is of 96 %TD. It has a microhardeness of 370 MPa. The Ce behavior in leaching media of extreme pH values: acidic medium (pH = 2) and basic medium (pH = 12), at 23 o C and 70 o C, shows that the Ce dissolution speeds are faster at 70 o C compared with those obtained at 23 o C. The 2M-zirconolite matrice presently studied appears to have a good chemical durabilityItem Study of the effect of Ca/Mg alkali-oxides ratio on the structure of a glass-ceramic based on an aluminosilicated glass containing 2wt.% of zirconolite crystalline phase(2014) Souag, Rafika; Kamel, N.; Mouheb, Y.; Hammadi, M.; Kamel, Z.; Moudir, D.; Aouchich, F.; Kamariz, S.New nuclear glass-ceramics are extensively studied for the radioactive waste confinement, due to the double confinement conferred by the glass-ceramics. In this study, a glass-ceramic constituted by an aluminosilicate glass in the system: SiO2-Al2O3-CaO-MgOZrO2-TiO2, containing 2wt.% of Ca0.83Ce0.17ZrTi1.66Al0.34O7 zirconolite, has been synthesized by the discontinuous method. Cerium, an actinide surrogate is introduced both in the glass and ceramic phases. The synthesis is performed by a double melting at 1350 °C, followed by a nucleation at 564°C, during 2 h, and a crystal growth at 1010°C during 3 h. Then effect of Ca / Mg ratio on the distribution of the crystalline network in the material was studied for Ca / Mg ratios ranging from 0.4 to 5.5. For the whole of the materials, Archimedes density is about 2.80 g/cm3 . X-ray diffraction (XRD) analysis shows that the increase of Ca/Mg ratio leads to the increase of aluminosilicated crystalline phases with high Ca contents; the materials molar volumes remaining constant. The zirconolite phase is not affected by these additive aluminosilicated phases. The scanning electron microscopy analysis (SEM) coupled with energy dispersive X-ray (EDX) analysis confirmed these results; and shows the uniformity of distribution of the ceramics in the bulk of the materialsItem Synthesis of 1, 3-oxathiolanes without use of organic solvent at room temperature. Remarkable functional selectivity(2016) Dokari, H.; Hammadi, M.; Benferrah, N.; Villemin, D.The aluminosilicates acids are efficient catalysts for the synthesis of oxathiolanes without solvent at room temperature. A functional selectivity was observed between aldehydes and ketones, aldehydes were transformed quantitatively. A functional selectivity has not been described before, it was observed within differents aldehydes or within differents ketones. This selectivity is important for the control of the reactions (activation or protection) of carbonyl compounds in organic synthesisItem Tungstosilicic acid (H4SiW12O40) Have Efficient Catalysts for Synthesis of 2,3-Dihydroxynaphthoquinone from Lawsone(Université M'Hamed Bougara Boumerdes, 2017) Benferrah, N.; Hammadi, M.; Dokari, H.; Berthiol, F.The Thiele–Winter reaction is of interest for synthesis of tetracetoxyaromatic precursors of hydroxynaphtoquinones. Solid acids such as Tungstosilicic acid (H4SiW12O40) have an efficient catalyst in acetoxylation reaction of naphtoquinones without the use of organic solvent at room temperature. 1,2,3,4-Tetrahydroxynaphthalene was easily oxidized at room temperature in 2,3-Dihydroxynaphthoquinone by using (Pc[Co]/K10) and air (1 atm). We have also tested this type of reaction in 2-hydroxynaphthoquinone (Lawsone). Many naphthoquinones are natural products with interesting biological properties