- Metallosupramolecular architectures based upon new 2-(1-pyrazolyl)-benzimidazole chelating ligands
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In this article, we report the synthesis and characterisation of five ligands L1-L5 containing the 2-(pyrazol-1-yl)-benzimidazole chelating group, and investigate their structural chemistry when reacted with either Cu(II) or Zn(II) ions. The mononuclear c
- Hawes, Chris S.,Kruger, Paul E.
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- Cytotoxic Ruthenium(II) Complexes of Pyrazolylbenzimidazole Ligands That Inhibit VEGFR2 Phosphorylation
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Eight new ruthenium(II) complexes of N,N-chelating pyrazolylbenzimidazole ligands of the general formula [RuII(p-cym)(L)X]+ [where the ligand L is 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole (L1) substituted at the 4 position of the pyrazole ring by Cl (L2), Br (L3), or I (L4) and X = Cl- and I-] were synthesized and characterized using various analytical techniques. Complexes 1 and 3 were also characterized by single-crystal X-ray crystallography, and they crystallized as a monoclinic crystal system in space groups P21/n and P21/c, respectively. The complexes display good solution stability at physiological pH 7.4. The iodido-coordinated pyrazolylbenzimidazole ruthenium(II) p-cymene complexes (2, 4, 6, and 8) are more resistant toward hydrolysis and have less tendency to form monoaquated complexes in comparison to their chlorido analogues (1, 3, 5, and 7). The halido-substituted 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole ligands, designed as organic-directing molecules, inhibit vascular endothelial growth factor receptor 2 (VEGFR2) phosphorylation. In addition, the ruthenium(II) complexes display a potential to bind to DNA bases. The cytotoxicity profile of the complexes (IC50 ca. 9-12 μM for 4-8) against the triple-negative breast cancer cells (MDA-MB-231) show that most of the complexes are efficient. The lipophilicity and cellular accumulation data of the complexes show a good correlation with the cytotoxicity profile of 1-8. The representative complexes 3 and 7 demonstrate the capability of arresting the cell cycle in the G2/M phase and induce apoptosis. The inhibition of VEGFR2 phosphorylation with the representative ligands L2 and L4 and the corresponding metal complexes 3 and 7 in vitro shows that the organic-directing ligands and their complexes inhibit VEGFR2 phosphorylation. Besides, L2, L4, 3, and 7 inhibit the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and proto-oncogene tyrosine-protein kinase (Src), capable of acting downstream of VEGFR2 as well as independently. Compounds L2, L4, 3, and 7 have a lesser effect on ERK1/2 and more prominently affect Src phosphorylation. We extended the study for L2 and 3 in the Tg(fli1:gfp) zebrafish model and found that L2 is more effective in vivo compared to 3 in inhibiting angiogenesis.
- Acharya, Moulinath,Chakraborty, Ayan,Chakraborty, Manas Pratim,Das, Rahul,Koley, Tuhin Subhra,Mukherjee, Arindam,Purkait, Kallol,Roy, Shantanu Saha,Roy, Souryadip
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p. 18379 - 18394
(2021/12/01)
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- Direct, metal-free amination of heterocyclic amides/ureas with NH-heterocycles and N-substituted anilines in POCl3
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A POCl3-mediated, direct amination reaction of heterocyclic amides/ureas with NH-heterocycles or N-substituted anilines is described. Compared to the existing methods, this operationally simple protocol provides unique reactivity and functional
- Deng, Xiaohu,Roessler, Armin,Brdar, Ivana,Faessler, Roger,Wu, Jiejun,Sales, Zachary S.,Mani, Neelakandha S.
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experimental part
p. 8262 - 8269
(2011/12/04)
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- Emission material and organic electroluminescent device using the same
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An organic electroluminescent device (OELD) is provided. The OELD includes a substrate, an anode, a cathode, a hole transport layer, an electron transport layer and an emission layer. The anode and the cathode are disposed on the substrate. The hole transport layer is disposed between the anode and the cathode. The electron transport layer is disposed between the hole transport layer and the cathode. The emission layer is disposed between the hole transport layer and the electron transport layer. The emission layer includes a host and a dopant. The chemical structure of the dopant is shown as the formula [I]: “M” is a metal atom whose atomic weight is greater than 40. “S” is selected from a group consisting of alkyl, alkoxy, haloalkyl, halogen, hydrogen and any other substituents.
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Page/Page column 3; 4
(2009/09/07)
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- Reaction of 2-hydrazinobenzimidazole with β-diketones: A structural reinvestigation
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The reaction of 2-hydrazinobenzimidazole (1) with pentane-2,4-dione yields a pyrazole derivative (2) instead of the reported triazepine (3).Several 2-pyrazolylbenzimidazoles (4) have similarly been synthesized using unsymmetrical β-diketones and their precursors.It has been shown that 1H NMR spectroscopy can easily distinguish the isomeric pairs.
- Singh, S. P.,Kumar, Savita,Kumar, Devinder
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p. 262 - 265
(2007/10/02)
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- Heterocyclic Betaines. Aza Analogues of Sesquifulvalene. 2. Azolium Azolate Inner Salts: Synthesis, Reactivity, and Structure of a 1:1 Adduct with Dimethyl Acetylenedicarboxylate
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Reaction of an activated 2-chloroazole with several N-alkylazoles afforded the N-azolylazolium salts, deprotonation of which results in a series of the title mesomeric betaines 7 and 8.Their reactivity towards electrophiles and dipolarophiles under mild conditions reflects the highly dipolar structures of 7 and 8.The thermal stability and dequaternization reactions of some of their corresponding N-azolylimidazolium and -pyrazolium salts have also been studied.
- Alcalde, Ermitas,Dinares, Immaculada
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p. 4233 - 4238
(2007/10/02)
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