- Ruthenium(II) carbonyl complexes containing pyridoxal thiosemicarbazone and trans-bis(triphenylphosphine/arsine): Synthesis, structure and their recyclable catalysis of nitriles to amides and synthesis of imidazolines
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Pyridoxal N(4)-substituted thisemicarbazone hydrochloride ligands (L1-3) were synthesized and reacted with the ruthenium(II) starting complexes [RuHCl(CO)(EPh3)3] (EP or As). The resulting complexes [Ru(CO)(L1-3)(EPh3)2] (1-6) were characterized by elemental analyses and spectroscopic techniques. The molecular structure of complex 5 was identified by means of single crystal X-ray diffraction analysis. The catalytic activity of the new complexes was evaluated for the selective hydration of nitriles to primary amides and also the condensation of nitriles with ethylenediamine under solvent free conditions. The processes were operative with aromatic, heteroaromatic and aliphatic nitriles, and tolerated several substitutional groups. The studies on the effect of substitution over thiosemicarbazone, reaction time, temperature, solvent and catalyst loading were carried out in order to find the best catalyst in this series of complexes and favourable reaction conditions. A probable mechanism for both the catalytic reactions of nitrile has also been proposed. The catalyst was recovered and recycled in the hydration of nitriles for five times without any significant loss of its activity.
- Manikandan, Rajendran,Anitha, Panneerselvam,Prakash, Govindan,Vijayan, Paranthaman,Viswanathamurthi, Periasamy,Butcher, Ray Jay,Malecki, Jan Grzegorz
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- Palladium-catalyzed multicomponent synthesis of 2-aryl-2-imidazolines from aryl halides and diamines
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An efficient palladium-catalyzed three-component reaction that combines aryl halides, isocyanides, and diamines provides access to 2-aryl-2-imidazolines in yields up to 96%. Through variation of the diamine component, the reaction can be extended to the s
- Geden, Joanna V.,Pancholi, Alpa K.,Shipman, Michael
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- New one-step synthesis of 2-aryl-1H-imidazoles: Dehydrogenation of 2-aryl-δ2-imidazolines with dimethylsulfoxide
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A new one-step method for the preparation of 2-aryl-1Himidazoles 3, based on the DMSO dehydrogenation of 2-aryl-Δ2-imidazolines, is described. A comparative study between DMSO and 10% Pd/C, the best known catalyst employed in this transformation, has also been developed. Both protocols were carried out at 120 °C for 48 hours.
- Anastassiadou,Baziard-Mouysset,Payard
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- Ultrasound promoted synthesis of 2-imidazolines in water: A greener approach toward monoamine oxidase inhibitors
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A series of sixteen 2-substituted-2-imidazolines (where the substituent R = Ph, Me-4-Ph; MeO-4-Ph; (MeO)2-3,4-Ph; (MeO)3-3,4,5-Ph; Ph-4-O-C(O)-Ph; Cl-4-Ph; Cl-2-Ph; Cl2-2,4-Ph; NO2-4-Ph; NO2-3-Ph; Naphth-2-yl; Fur-2-yl; Benzofur-2-yl; Pyridin-2-yl; Quinolin-2-yl) has been synthesized from the reaction of the substituted-aldehydes and ethylenediamine by ultrasound irradiation with NBS in an aqueous medium in high yields (80-99%). The 2-imidazoline ability to inhibit the activity of the A and B isoforms of monoamine oxidase (MAO) was investigated and some of them showed potent and selective MAO inhibitory activity especially for the MAO-B isoform and could become promising candidates for future development.
- Sant' Anna, Gabriela da S.,Machado, Pablo,Sauzem, Patricia D.,Rosa, Fernanda A.,Rubin, Maribel A.,Ferreira, Juliano,Bonacorso, Helio G.,Zanatta, Nilo,Martins, Marcos A.P.
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p. 546 - 549
(2011/03/19)
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- Radiosynthesis of a 2-substituted 4,5-dihydro-1H-[2-11C] imidazole: The I2 imidazoline receptor ligand [11C] benazoline
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Benazoline (2-naphthalen-2-yl-4,5-dihydro-1H-imidazole) is a selective high-affinity ligand for the imidazoline 12 receptor. This compound was labelled with carbon-11 (T1/2 = 20.4 min) at the number two carbon atom of its 2-imidazoline ring. Cyclotron-produced [11C]carbon dioxide reacted with 2-naphthylmagnesium bromide to give 2-[carboxyl- 11C] naphthoic acid in 60% radiochemical yield. The latter was heated with a mixture of ethylenediamine and its dihydrochloride at 300°C to give [11C]benazoline in 16% overall yield, relative to [ 11C]carbon dioxide and with a specific radioactivity of 54GBq/ μmol, decay corrected for end of irradiation. The procedure requires about 45 min from end of cyclotron irradiation. This method should be extendable to other imidazolines. Copyright
- Roeda,Hinnen,Dolle
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p. 1141 - 1149
(2007/10/03)
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- Benzo- and cyclohexanomazindol analogues as potential inhibitors of the cocaine binding site at the dopamine transporter
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A series of mazindol (1), homomazindol (2), and bishomomazindol (3) derivatives with a benzo or cyclohexano ring fused at various sites were prepared as part of an SAR study to determine the effect of increased aliphatic and aromatic lipophilicity on sele
- Houlihan, William J.,Ahmad, Umer F.,Koletar, Judith,Kelly, Lawrence,Brand, Leonard,Kopajtic, Theresa A.
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p. 4110 - 4118
(2007/10/03)
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- Synthesis and pharmacological evaluation of imidazoline sites I1 and I2 selective ligands
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Several series of 2-aryl or heterocyclic-imidazoline compounds have been prepared and evaluated in vitro as imidazoline sites (I1 and I2) and α-adrenergic (α1 and α2) receptor ligands. Their pKi values indicate that linkage of the imidazoline moiety at the 2-position with an aromatic substituent dramatically decreases α-adrenergic affinity. I1 sites are more accessible by phenyl imidazolines substituted by a methyl or a methoxy group at the ortho or meta position. Indeed, 2-(2′-methoxyphenyl)-imidazoline (17) is one of the best I1 ligands ever reported (pKi=8.53 and I1/I2>3388). On the other hand, I2 selectivity increases in the presence of a methyl group in the para position. The original compound, 2-(3′-fluoro-4′-tolyl)-imidazoline (31) is a new potent ligand for the I2 sites with high selectivity (pKi=8.53 and I2/I1>3388). Copyright
- Anastassiadou, Maria,Danoun, Sada,Crane, Louis,Baziard-Mouysset, Genevieve,Payard, Marc,Caignard, Daniel-Henri,Rettori, Marie-Claire,Renard, Pierre
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p. 585 - 592
(2007/10/03)
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- Imidazoline receptors: Qualitative structure-activity relationships and discovery of tracizoline and benazoline. Two ligands with high affinity and unprecedented selectivity
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The observation that all the attempts to characterize imidazoline (I) receptors have been carried out with non-selective or poorly selective ligands prompted us to undertake research aimed at developing selective ligand(s). In previous work using, as a st
- Pigini, Maria,Bousquet, Pascal,Carotti, Angelo,Dontenwill, Monique,Giannella, Mario,Moriconi, Roberta,Piergentili, Alessandro,Quaglia, Wilma,Tayebati, Seyed K.,Brasili, Livio
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p. 833 - 841
(2007/10/03)
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