- Some contribution to W(VI)-peroxo-chemistry: Synthesis, spectroscopic characterization, reactivity and DFT studies
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Synthesis of white microcrystalline oxodiperoxotungstate(VI) complexes, K[WO(O2)2(L)(H2O)]·H2O, (L ?= ?salicylate, 5-chlorosalicylate, 4-hydroxybenzoate) have been achieved from reaction of Na2WO4·2H2O with 30% H2O2 and the respective hetero-ligands at pH Ca. 7–7.5 in aqueous medium. The newly synthesized compounds were comprehensively characterized by elemental analyses, spectral studies, room temperature magnetic moment measurements and mass spectrometric studies. Infrared spectra suggest that, peroxo groups are bonded to the WO+4 center in a triangular bidentate (C2v) fashion and the hetero-ligands benzene-core hydroxycarboxylic acids viz. salicylic acid, 5-chlorosalicylic acid, 4-hydroxybenzoic acid in anoinic form are coordinated in monodentate manner. Compounds are fairly stable in aqueous solution for sufficient period of time. The results of mass spectrometric analysis lend support to the molecular composition of the complexes ascertained on the basis of elemental analyses and spectroscopic studies. Compound potassium(aquo)(5-chlorosalicylato)oxodiperoxotungstate(VI)monohydrate, K[WO(O2)2(5-chlorosalicylate)(H2O)]·H2O, act as an oxidant of bromide ion in aqueous phase bromination of chosen organic substrates to their corresponding bromo organics. Density Functional Theory (TD-DFT) calculations were performed on the synthesized complexes substantiated the experimentally obtained results. The TD-DFT optimized structures are in excellent agreement with the results of elemental analyses, spectral as well as mass spectrometric data.
- Bhattacharjee, M.,Boruah, S. R.,Chowdhury, S.,Das, N.,Dutta Purkayastha, R. N.
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- BI-ARYL DIHYDROOROTATE DEHYDROGENASE INHIBITORS
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Disclosed are compounds, compositions and methods for treating diseases, disorders, or medical conditions that are affected by the modulation of DHODH. Such compounds are represented by Formula I as follows: Formula I wherein R1, R2, R3, and Q are defined herein.
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Page/Page column 200; 204-205
(2021/04/17)
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- Peroxo–tungstate(VI) complexes: syntheses, characterization, reactivity, and DFT studies
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Abstract: Three new oxodiperoxo–tungsten(VI) complexes containing benzene core carboxylic acids, viz., benzoic acid, 2-chlorobenzoic acid, and 3-aminobenzoic acid as co-ligands have been synthesized from reaction of Na2WO6H4, 30% H2O2 and the corresponding co-ligands in aqueous medium. The compounds have been comprehensively characterized by elemental analyses, FT-IR, 1H NMR, UV–Vis spectral studies as well as by mass spectrometric and TGA analyses. The infrared spectra suggest occurrence of terminally bonded W=O as well as triangular bidentate peroxo groups (C2v) and monodentate carboxylate group bound to the WO4+ center. The mass spectra of the compounds are in good agreement with proposed molecular formulations. Thermogravimetric analyses indicate the existence of both lattice and coordinated water molecules in the complexes. Density functional theory (DFT) calculations were used to compute the frequencies of relevant vibrational modes, electronic properties and also to investigate structure of the compounds. Compound potassium(aquo)(2-chlorobenzoato)oxodiperoxo–tungstate(VI)dihydrate acts as an oxidant for bromide ion in aqueous phase bromination of chosen organic substrates to their corresponding bromo-organics. Graphical abstract: [Figure not available: see fulltext.]
- Das, Nandita,Chowdhury, Shubhamoy,Purkayastha, Ranendra N. Dutta
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p. 1255 - 1266
(2019/07/04)
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- A new synthetic approach to the imidazo[1,5-: A] imidazole-2-one scaffold and effective functionalization through Suzuki-Miyaura cross coupling reactions
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We report herein a synthetic pathway to new 7-bromo-1-(4-methoxybenzyl)-5-methyl-imidazo[1,5-a]imidazole-2-one. The synthetic potential of this scaffold was demonstrated by displacing bromine by Suzuki-Miyaura cross-coupling reactions. A large panel of bo
- Loubidi,Pillard,El Hakmaoui,Bernard,Akssira,Guillaumet
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p. 7229 - 7238
(2016/07/14)
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- Highly regioselective C-5 alkynylation of imidazoles by one-pot sequential bromination and Sonogashira cross coupling
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A variety of 2-substituted 5-alkynyl-1H-imidazoles were easily prepared by a one-pot sequential procedure involving a highly regioselective electrophilic C-5 bromination of 1,2-dimethyl-1H-imidazole, 2-chloro-1-methyl-1H-imidazole, and 2-aryl-1-methyl-1H-imidazoles, followed by an efficient palladium/copper co-catalyzed Sonogashira-type alkynylation.
- Bellina, Fabio,Lessi, Marco,Marianetti, Giulia,Panattoni, Alessandro
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supporting information
p. 3855 - 3857
(2015/06/08)
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- Synthesis, crystal structure and antibacterial activity of new highly functionalized ionic compounds based on the imidazole nucleus
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Several new highly functionalized imidazolium derivatives were synthesized, via appropriate synthetic routes, using imidazole, 1-methylimidazole and 2-phenyl-1-methylimidazole as key intermediates. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella thipymurium using disk-diffusion and MIC methods. Crystal X-ray structures are reported for six compounds.
- Bahnous, Mebarek,Bouraiou, Abdelmalek,Chelghoum, Meryem,Bouacida, Sofiane,Roisnel, Thierry,Smati, Farida,Bentchouala, Chafia,Gros, Philippe C.,Belfaitah, Ali
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p. 1274 - 1278
(2013/03/14)
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- Halogen bond anion templated assembly of an imidazolium pseudorotaxane
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Halogen bonding has been exploited in the assembly of an interpenetrated molecular system. The strength of chloride-anion-templated pseudorotaxane formation with a 2-bromo-functionalized imidazolium threading component and an isophthalamide macrocycle (see picture) is significantly enhanced compared to hydrogen-bonded pseudorotaxane analogues. (Figure Presented).
- Serpell, Christopher J.,Kilah, Nathan L.,Costa, Paulo J.,Felix, Vitor,Beer, Paul D.
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supporting information; experimental part
p. 5322 - 5326
(2010/10/19)
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- Convenient multi-gram scale synthesis of polybrominated imidazoles building blocks
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The multi-gram scale polybromination of variously substituted imidazoles has been realized using a stoichiometric amount of the Br2-DMF complex. Good yields have been obtained compared to other methods using large amounts of acetic acid-sodium acetate buffer.
- Bahnous, Mebarek,Mouats, Chabane,Fort, Yves,Gros, Philippe C.
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p. 1949 - 1951
(2007/10/03)
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