120588-02-5Relevant articles and documents
Facile access to polymer supported zinc–salen complex: highly efficient heterogeneous catalyst for synthesizing hydantoins, thiohydantoins and Schiff bases in aqueous medium
Balinge, Kamlesh Rudreshwar,Khiratkar, Avinash Ganesh,Muskawar, Prashant Narayan,Thenmozhi,Bhagat, Pundlik Rambhau
, p. 2075 - 2097 (2017/12/26)
The synthesis of polymer supported zinc–salen complex (PS-Zn–salen) is described. The mononuclear zinc(II)–salen complex was characterized by Fourier-transform NMR spectroscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrophotometry (FT-IR), thermogravimetric analysis, scanning electron microscopy, surface area and pore size distribution by Brunauer–Emmett–Teller. The synthesized PS-Zn–salen complex used as a recyclable heterogeneous catalyst for the efficient synthesis of hydantoins, thiohydantoins and Schiff bases in an aqueous medium. The isolated yields of hydantoins, thiohydantoins and Schiff bases achieved up to 89, 95 and 94%, respectively. In spite of conventional heterogeneous catalysts, current PS-Zn–salen complex shows thermal stability up to 280?°C. Moreover, the catalyst could be recovered easily by simple filtration and reused for next run with slightly declining its activity up to six successive runs. The FT-IR spectrum of recycle catalyst after 6th run confirmed that the catalyst was stable during the course of a reaction. The leaching of metal from the PS-Zn–salen is negligible, which was confirmed by AAS and hot filtration test.
Tetrahydroimidazoles - A promising group of expected NSAIDS - Their synthesis and anti-inflammatory activity
Khan,Chawla, Gita
, p. 653 - 663 (2007/10/03)
Several new 1, 2, 3-trisubstituted tetrahydroimidazoles (11-28) have been synthesised and their structures elucidated on the basis of spectral data. These compounds show promising anti-inflammatory activity by carrageenin induced paw edema test in rats and few of them showed an activity better than indomethacin.
O2 activation and aromatic hydroxylation performed by diiron complexes
Ménage, Stéphane,Galey, Jean-Baptiste,Dumats, Jacqueline,Hussler, Georges,Seité, Michel,Luneau, Isabelle Gautier,Chottard, Geneviève,Fontecave, Marc
, p. 13370 - 13382 (2007/10/03)
Chemical models of active sites of diiron oxo proteins have been synthesized. The polydendate ligands are EDTA derivatives which provide a balanced supply of nitrogen atoms and carboxylate groups together with an oxidizable phenyl moiety, thus mimicking both the iron coordination in methane monooxygenase and a nearby substrate site. All the diferric complexes have been characterized in solution by ESI-MS, optical absorption, and in some cases by 1H NMR. In the case of the ligand L1 [L1 = (N,N'-bis(3,4,5- trimethoxybenzyl)ethylenediamine N,N'-diacetic acid)], the X-ray structure of the corresponding iron complex has been determined, revealing an original tetranuclear unit, Fe4O2(L1)4·10H2O, issued from the dimerization of two [Fe2O(L1)2] units linked by carboxylate bridges. In a solution containing water or acetate, the tetranuclear complex decomposed into dinuclear complexes, which proved to be able to react with hydrogen peroxide or dioxygen in the presence of ascorbate. The final product was a mononuclear complex identified as [Fe(III)L'1(H2O)] with L'1 resulting from the quantitative hydroxylation of L1. The complex and the oxidized ligand were characterized by EPR, NMR, and UV-vis spectroscopies and by mass spectrometry. Labeling experiments showed that with both H2O2 or O2 and ascorbate, the incorporated oxygen came from the oxidant exclusively. This reaction mimicks the transformation of a tyrosine residue, brought into proximity of the active center of Ribonucleotide reductase of Escherichia coli by site-directed mutagenesis, into 3,4-dihydroxyphenylalanine.
