- Convenient method for the preparation of 2-aryl-1H-benzimidazole-4- carboxylic acids
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The oxidative cyclization of 2,3-diaminobenzoic acid and aromatic aldehydes to give 2-aryl-1H-benzimidazole-4-carboxylic acids is reported. Moreover, three methods were compared in different perspectives from experimental manipulation to yield. Copyright
- Cheng, Jun,Xiu, Naiyun,Li, Xiangbin,Luo, Xianjin
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- Synthesis and antiviral activity against Coxsackie virus B3 of some novel benzimidazole derivatives
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Some benzimidazole derivatives were synthesized and the antiviral evaluation against Coxsackie virus B3 is reported. These compounds are proved to be excellent inhibitors of CVB3. Some benzimidazole derivatives were synthesized and evaluated for their antiviral properties. Compounds 20 and 21 showed potent selective activity against Coxsackie virus B3 in VERO cells. Some structure-activity relationships were discussed.
- Cheng, Jun,Xie, Jiangtao,Luo, Xianjin
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- Dangling Carboxylic Group That Participates in O-O Bond Formation Reaction to Promote Water Oxidation Catalyzed by a Ruthenium Complex: Experimental Evidence of an Oxide Relay Pathway
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Two mononuclear ruthenium(II) complexes of the types [Ru(trpy)(HL1)(OH2)]2+ (1Aq) and [Ru(trpy)(L2-κ-N2O)] (2) [where trpy = 2,2′:6′,2″-terpyridine, HL1 = 2-(2-pyridyl)benzimidazole, H2L2 = 2-(pyridin-2-yl)-1H-benzo[d]imidazole-4-carboxylic acid] have been synthesized and thoroughly characterized by analytical and spectroscopic [UV-vis, NMR, high-resolution mass spectrometry, and IR] techniques. Complex 1Aq has been further characterized by X-ray crystallography. In an acidic aqueous medium (pH 1), complex 2 undergoes carboxylate/water exchange readily to form an aqua-ligated complex, [Ru(trpy)(H2L2-κ-N2)(OH2)]2+ (2Aq), having a dangling carboxylic group. This exchange phenomenon has been followed by IR, 1H NMR, and UV-vis spectroscopic techniques. Electrochemical analyses of 1Aq and 2Aq (Pourbaix diagram) suggest the generation of a formal RuV=O species that can potentially promote the oxidation of water. A comparative study of the water oxidation activity catalyzed by 1Aq and 2Aq is reported here to see the effect of a dangling carboxylic group in the catalytic performance. Complex 2Aq shows an enormously higher rate of reaction than 1Aq. The pendant carboxylic group in 2Aq participates in an intramolecular O-O bond formation reaction with the reactive formal RuV=O unit to form a percarboxylate intermediate and provides an electron-deficient carbon center where water nucleophilic attack takes place. The isotope labeling experiment using 18O-labeled water verifies the attack of water at the carbon center of the carboxylic group rather than a direct attack at the oxo of the formal RuV=O unit. The present work provides experimental evidence of the uncommon functionality of the carboxylic group, the oxide relay, in molecular water oxidation chemistry.
- Kundu, Animesh,Barman, Suman K.,Mandal, Sukanta
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supporting information
p. 1426 - 1437
(2022/01/19)
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- Ru-based complexes as heterogeneous potential catalysts for the amidation of aldehydes and nitriles in neat water
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Five novel heterogeneous mononuclear complex-anchored Ru(III) have been efficiently sono-synthesized and characterized by utilizing several analytical techniques. The assembled complexes could be utilized as effective, robust and recyclable (up to eight consecutive runs) catalysts for one-pot transformation of a vast array of nitriles and aldehydes to primary amides in H2O under aerobic conditions. Moreover, some unreported di- and tetra-amide derivatives were obtained also under the optimal conditions. The results of ICP/OES analysis demonstrated that there is no detected leaching of the recycled catalyst, which suggests the real heterogeneity of the present protocol. The present Ru-complexes exhibited superiority compared to other reported catalysts for amide preparation in terms of low catalyst load, short reaction time, low operating temperature, no hazardous additives required, and high values of TON (990) and TOF (1980 h11).
- Arafa, Wael Abdelgayed Ahmed
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supporting information
p. 1056 - 1064
(2020/11/09)
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- Synthesis and biological evaluation of novel benzimidazole derivatives bearing a heterocyclic ring at 4/5 position
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A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 (IC50 = 1.08 μg/mL, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.
- Wubulikasimu, Reyila,Yang, Yanbing,Xue, Fei,Luo, Xianjin,Shao, Dongping,Li, Yuhuan,Gao, Rongmei,Ye, Weidong
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p. 2297 - 2304
(2013/09/24)
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- Inhibitory properties of 2-substituent-1H-benzimidazole-4-carboxamide derivatives against enteroviruses
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A series of novel benzimidazole derivatives were designed, synthesized, and evaluated for their activities against four kinds of enteroviruses, that is, Coxsackie virus A16, B3, B6 and Enterovirus 71 in VERO cells. Strong activities against enterovirus replication and low cytotoxicities were observed in these benzimidazoles generally. The most promising compound was (l)-2-(pyridin-2-yl)- N-(2-(4-nitrophenyl)pentan-3-yl)-1H-benzimidazole-4-carboxamide (16), with a high antiviral potency (IC50 = 1.76 μg/mL) and a remarkable selectivity index (328). These compounds were selected for further evaluation as novel enterovirus inhibitors.
- Xue, Fei,Luo, Xianjin,Ye, Chenghao,Ye, Weidong,Wang, Yue
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p. 2641 - 2649
(2011/06/11)
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- Benzamide derivatives having a vasopressin antagonistic activity
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This invention relates to new benzamide derivatives having a vasopressin antagonistic activity, etc. and represented by general formula (I): wherein R1is aryl optionally substituted with lower alkoxy, etc., R2is lower alkyl, etc., R3is hydrogen, etc., A is NH, etc., E is etc., X is —CH═CH—, —CH═N—, or S, and Y is a condensed heterocyclic group, etc., and pharmaceutically acceptable salts thereof, to processes for preparation thereof and to a pharmaceutical composition comprising the same.
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- Potential Antitumor Agents. 59. Structure-Activity Relationships for 2-Phenylbenzimidazole-4-carboxamides, a New Class of "Minimal" DNA-Intercalating Agents Which May Not Act via Topoisomerase II
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A series of substituted 2-phenylbenzimidazole-4-carboxamides has been synthesized and evaluated for in vitro and in vivo antitumor activity.These compounds represent the logical conclusion to our search for "minimal" DNA-intercalating agents with the lowest possible DNA-binding constants.Such "2-1" tricyclic chromophores, of lower aromaticity than the structurally similar 2-phenylquinolines, have the lowest DNA binding affinity yet seen in the broad series of tricyclic carboxamide intercalating agents.Despite very low in vitro cytotoxicities, several of the compoundshad moderate levels of in vivo antileukemic effects.However, the most interesting aspect of their biological activity was the lack of cross-resistance shown to an amsacrine-resistant P388 cell line, suggesting that these compounds may not express their cytotoxicity via interaction with topoisomerase II.
- Denny, William A.,Rewcastle, Gordon W.,Baguley, Bruce C.
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p. 814 - 819
(2007/10/02)
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