- Photochemical Synthesis of Benzimidazoles from Diamines and Aldehydes
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An efficient, green, cheap, and metal-free photochemical protocol for the synthesis of benzimidazoles has been developed. 2,2-Dimethoxy-2-phenylacetophenone was employed as the photoinitiator and CFL lamps were used as the light source, leading to the cyc
- Skolia, Elpida,Apostolopoulou, Mary K.,Nikitas, Nikolaos F.,Kokotos, Christoforos G.
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supporting information
p. 422 - 428
(2020/12/13)
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- Cd-MOF@PVDF Mixed-Matrix Membrane with Good Catalytic Activity and Recyclability for the Production of Benzimidazole and Amino Acid Derivatives
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Mixed-matrix membranes (MMMs) incorporating metal-organic framework crystalline fillers as heterogeneous catalysts for organic transformation reactions have attracted more attention in catalysis science. Herein, a new 3D cadmium metal-organic framework (H3O)·[Cd(dppa)] (1) was first synthesized using the rigid 4-(3,5-dicarboxylphenyl)picolinic acid (H3dppa) as an organic ligand under solvothermal conditions, exhibiting a novel 6,6-connected network and good tolerance to various solvents. After activation, 1 showed good catalytic reactivity and selectivity for the synthesis of benzimidazole derivatives, affording solvent-dependent catalytic activity. Then, using the microcrystals of 1 and poly(vinylidene fluoride) (PVDF) as raw materials, 1@PVDF MMMs were successfully prepared by polymer solution casting. Notably, the integration of MOF and PVDF endows the mixed-matrix membrane 1@PVDF with great advantages in terms of more dispersive Lewis acid catalytic sites and recyclability. As expected, 1@PVDF not only displays good catalytic activity comparable to that of activated 1 but also exhibits remarkable recyclability and continuous usability for the production of benzimidazole and α-or β-amino acid derivatives. To the best of our knowledge, this is the first time that a Cd-based MOF and MMMs have been applied as a catalyst for the production of a β-amino acid. The combination of catalytic MOF and PVDF provides a way to simplify the design of a flow reactor and reduce the costs of manufacturing.
- Jiang, Yansong,Sun, Jing,Yang, Xiaona,Shen, Jieyu,Fu, Yu,Fan, Yong,Xu, Jianing,Wang, Li
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p. 2087 - 2096
(2021/02/06)
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- Metal-organic framework mediated expeditious synthesis of benzimidazole and benzothiazole derivatives through an oxidative cyclization pathway
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Herein, we report the facile synthesis of various benzimidazoles and benzothiazoles by using the NH2-MIL-125(Ti) MOF as an efficient oxidant-free heterogeneous catalyst with good yield. Adsorption of the substrate on the NH2-MIL-125(Ti) MOF surface through electron deficient Ti4+ sites initiates the reaction. The broad substrate scope and high reusability of this catalyst are attractive for synthesis of a wide range of medicinally active benzimidazole and benzothiazole derivatives.
- Sankar, Velayudham,Karthik, Peramaiah,Neppolian, Bernaurdshaw,Sivakumar, Bitragunta
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p. 1021 - 1027
(2020/01/31)
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- Nickel catalysed construction of benzazoles: Via hydrogen atom transfer reactions
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Herein we report a homogeneous, phosphine free, inexpensive nickel catalyst that forms a wide variety of benzazoles from alcohol and diamines by a reaction sequence of alcohol oxidation, imine formation, ring cyclization and dehydrogenative aromatization. A reversible azo/hydrazo couple, that is part of the ligand architecture steers both the alcohol oxidation and dehydrogenation of the annulated amine under fairly mild reaction conditions. Interestingly, both the alcohol oxidation and amine dehydrogenation steps are directly mediated by hydrogen atom transfer (HAT), which is greatly facilitated by the reduced ligand backbone. The kH/kD for the amine dehydrogenation step, measured at 60 °C is 5.9, fully consistent with HAT as the rate determining factor during this step. This is a unique scenario where two consecutive oxidation steps towards benzazole formation undergo HAT, which has been substantiated via kinetic studies, KIE determination and intermediate isolation. This journal is
- Adhikari, Debashis,Bains, Amreen K.,Dey, Dhananjay,Kundu, Abhishek,Yadav, Sudha
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p. 6495 - 6500
(2020/11/13)
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- Direct synthesis of 2-substituted benzimidazoles: Via dehydrogenative coupling of aromatic-diamine and primary alcohol catalyzed by a Co complex
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A Co(ii) complex with a stable structure was designed and synthesized with quinalic acid and Co (OAc)2·4H2O. The single crystal structure of the complex was characterized by X-ray diffraction. A dehydrogenative coupling of aromatic diamines and primary alcohols was developed by using the Co(ii) complex as the catalyst to synthesize 2-substituted benzimidazole. A series of 2-substituted benzimidazoles were obtained with good to excellent yields under mild reaction conditions. In addition, a compound with inhibitory Parkinson's activity was synthesized on a gram-scale by using this method. Finally, the reaction mechanism was proposed and the energy changes in the reaction process were simulated by density functional theory (DFT).
- Zuo, Minghui,Guo, Weihao,Pang, Yucheng,Guo, Rui,Hou, Chuanfu,Sun, Shouneng,Wu, Hongfeng,Sun, Zhizhong,Chu, Wenyi
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p. 14490 - 14495
(2020/10/03)
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- A novel ternary GO@SiO2-HPW nanocomposite as an efficient heterogeneous catalyst for the synthesis of benzazoles in aqueous media
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A new solid acid catalyst, consisting of 12-phosphotungstic heteropoly acid (HPW) supported on graphene oxide/silica nanocomposite (GO@SiO2), has been developed via immobilizing HPW onto an amine-functionalized GO/SiO2 surface through coordination interaction (GO@SiO2-HPW). The GO@SiO2-HPW nanocomposite was characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The prepared nanocomposite could be dispersed homogeneously in water and further used as a heterogeneous, reusable, and efficient catalyst for the synthesis of benzimidazoles and benzothiazoles by the reaction of 1,2-phenelynediamine or 2-aminothiophenol with different aldehydes.
- Habibzadeh, Setareh,Firouzzadeh Pasha, Ghasem,Tajbakhsh, Mahmood,Amiri Andi, Nasim,Alaee, Ehsan
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p. 934 - 944
(2019/06/13)
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- Microwave use of amidine compounds in the aqueous phase benzoate synthesis of benzimidazole compounds method
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The invention discloses a microwave the use of amidine compounds in the aqueous phase benzoate synthesis of benzimidazole compounds, in the aqueous phase under microwave conditions adding benzoic amidine compound under alkaline condition [...] into benzimidazole reaction, invention an environment-friendly, the operation is simple, cheap and safe, efficient process for preparing benzimidazole method. Compared with the prior art, this method not only can be applied to a large number of functional groups, the productive rate is high, few by-products, and the operation is simple, safe, low cost, environmental protection; .
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Paragraph 0018
(2019/03/28)
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- Air-stable Ruthenium(II)-NNN Pincer Complexes for the Efficient Coupling of Aromatic Diamines and Alcohols to 1H-benzo[d]imidazoles with the Liberation of H2
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Two new phosphine-free RuII-NNN pincer complexes ([RuCl(L1)(CH3CN)2]Cl (1) and [RuCl(L2)(CH3CN)2]Cl (2) [L1=2,6-bis(1H-imidazole-2-yl)pyridine, L2=2,6-bis(1-hexyl-1H-imidazole-2-yl)pyridine] were synthesized to catalyze the condensation of benzyl alcohol and benzene-1,2-diamine homogeneously to 2-pheny-1H-benzo[d]imidazole and H2. The reactivity in the order of 1>2 is lower than that of the phosphine-containing RuII-NNN pincer complex [RuCl2(L1)(PPh3)3] (3), and thus a homogeneous system that contained 1, 1 equivalent of 1,2-bis(diphenylphosphanyl)ethane, and 10 equivalents of NaBPh4 was developed to improve the catalytic efficiency for the condensation of primary alcohols and benzene-1,2-diamine (or its derivatives) to 2-substituted 1H-benzo[d]imidazoles in excellent yields (up to 97 %) and turnover numbers (388). This system can be used to realize the facile one-step synthesis of 1H-benzo[d]imidazole derivatives from alcohols without the use of an oxidant and/or a stoichiometric amount of inorganic base that is usually necessary in homogeneous systems reported previously.
- Li, Lin,Luo, Qi,Cui, Huahua,Li, Renjie,Zhang, Jing,Peng, Tianyou
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p. 1607 - 1613
(2018/02/28)
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- Synthesis, anti-proliferative activity, SAR study, and preliminary in vivo toxicity study of substituted N,N′-bis(arylmethyl)benzimidazolium salts against a panel of non-small cell lung cancer cell lines
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A series of N,N′-bis(arylmethyl)benzimidazolium salts have been synthesized and evaluated for their in vitro anti-cancer activity against select non-small cell lung cancer cell lines to create a structure activity relationship profile. The results indicate that hydrophobic substituents on the salts increase the overall anti-proliferative activity. Our data confirms that naphthylmethyl substituents at the nitrogen atoms (N1(N3)) and highly lipophilic substituents at the carbon atoms (C2and C5(C6)) can generate benzimidazolium salts with anti-proliferative activity that is comparable to that of cisplatin. The National Cancer Institute's Developmental Therapeutics Program tested 1, 3–5, 10, 11, 13–18, 20–25, and 28–30 in their 60 human tumor cell line screen. Results were supportive of data observed in our lab. Compounds with hydrophobic substituents have higher anti-cancer activity than compounds with hydrophilic substituents.
- Shelton, Kerri L.,DeBord, Michael A.,Wagers, Patrick O.,Southerland, Marie R.,Williams, Travis M.,Robishaw, Nikki K.,Shriver, Leah P.,Tessier, Claire A.,Panzner, Matthew J.,Youngs, Wiley J.
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p. 421 - 439
(2016/12/18)
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- Facile and efficient aerobic one-pot synthesis of benzimidazoles using Ce(NO3)3·6H2O as promoter
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A series of 2-substituted benzimidazoles was synthesized under aerobic conditions, by simply heating 1,2-diaminobenzene and aldehydes in DMF at 80 °C, employing Ce(NO3)3·6H2O as promoter and atmospheric air as an efficient oxidant. The procedure afforded the products from good to excellent yields. Furthermore, this new economic and eco-friendly protocol avoids the use of toxic metal catalysts, as well as additional bases and oxidants.
- Martins, Guilherme M.,Puccinelli, Thiago,Gariani, Rogério A.,Xavier, Fernando R.,Silveira, Claudio C.,Mendes, Samuel R.
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supporting information
p. 1969 - 1972
(2017/04/27)
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- Copper-Catalyzed Double C-N Bond Formation for the Synthesis of Diverse Benzimidazoles from N -Alkyl-2-iodoaniline and Sodium Azide
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An efficient approach to the synthesis of benzimidazole derivatives has been achieved by copper-catalyzed double C-N bonds formation of N-alkyl-2-iodoaniline and sodium azide. The reaction was supposed to proceed through copper-catalyzed tandem reaction of SNAr reaction, aerobic oxidation of C(sp3)-H bond and intramolecular C-N bond formation sequence. Structurally diverse 2-aryl, alkenyl and alkyl benzoimidazole derivatives were assembled by this methodology.
- Chen, Zhengkai,Li, Hongli,Cao, Gangjian,Xu, Jianfeng,Miao, Maozhong,Ren, Hongjun
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supporting information
p. 504 - 508
(2017/02/24)
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- Direct Synthesis of Benzimidazoles by Dehydrogenative Coupling of Aromatic Diamines and Alcohols Catalyzed by Cobalt
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Herein, we present the base-metal-catalyzed dehydrogenative coupling of primary alcohols and aromatic diamines to selectively form functionalized 2-substituted benzimidazoles, liberating water and hydrogen gas as the sole byproducts. The reaction is catalyzed by pincer complexes of Earth-abundant cobalt under base-free conditions.
- Daw, Prosenjit,Ben-David, Yehoshoa,Milstein, David
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p. 7456 - 7460
(2017/11/10)
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- Oxidant-free synthesis of benzimidazoles from alcohols and aromatic diamines catalysed by new Ru(II)-PNS(O) pincer complexes
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Benzimidazoles are chemically and pharmaceutically important, and an environmentally benign synthetic method based on acceptorless dehydrogenative condensation of primary alcohols and benzene-1,2-diamine is developed in this work. Three Ru(ii) hydride complexes [RuHCl(CO)(PNS(O))] (containing two isomers 1a and 1b) and [RuHCl(CO)(PPh3)(SNCNHC)]PF6 (2) based on two new quinoline-based ligands 2-(diphenylphosphanylmethyl)-8-phenylsulfinylquinoline (PNS(O)) and 1-mesityl-3-(8-phenylthioquinolyl-2-methyl)-2-imidazole carbene (SNCNHC) are prepared and fully characterized. These complexes catalyse the condensation of benzyl alcohol and benzene-1,2-diamine to 2-phenylbenzimidazole with the liberation of H2, and the catalytic activity follows the order: 1a ≈ 1b > 2. When 0.2 mol% of 1a and 2 mol% of NaBPh4 were used, various 2-functionalized benzimidazoles were obtained in good yields (70-85%) and high turnover numbers (TONs ~ 425). This homogeneous system does not need oxidants or stoichiometric strong bases (KOH or KOtBu, etc.) that are normally used in the reported homogeneous systems, and thus is a greener process.
- Luo, Qi,Dai, Zengjin,Cong, Hengjiang,Li, Renjie,Peng, Tianyou,Zhang, Jing
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p. 15012 - 15022
(2017/11/14)
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- Supercritical methanol as solvent and carbon source in the catalytic conversion of 1,2-diaminobenzenes and 2-nitroanilines to benzimidazoles
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Benzimidazoles and N-methylbenzimidazoles were synthesized by simply heating 1,2-diaminobenzenes in supercritical methanol over copper-doped porous metal oxides. These catalysts were derived from synthetic hydrotalcites that only contain earth-abundant starting materials. The carbon equivalents needed for the construction of the benzimidazole core originated from the solvent itself, which is known to undergo reforming to hydrogen and carbon monoxide through the formation of a formaldehyde intermediate. A variety of 1,2-diaminobenzenes were converted to the corresponding mixtures of benzimidazoles and N-methylated analogues in good yields. Interestingly, the more challenging, but readily available 2-nitroanilines, which require an additional reduction step prior to cyclization, could also be successfully converted to benzimidazoles in high selectivity. Furthermore, various other alcohols were applied besides methanol, to obtain 2-alkyl- and 1,2-dialkylbenzimidazoles. Preliminary mechanistic insights into the origins of N-alkylation as well as the reactivity of the nitro derivatives are discussed.
- Sun, Zhuohua,Bottari, Giovanni,Barta, Katalin
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p. 5172 - 5181
(2015/12/08)
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- Polystyrene-supported pyridinium chloroaluminate ionic liquid as a new heterogeneous Lewis acid catalyst for selective synthesis of benzimidazoles
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Polystyrene-supported pyridinium chloroaluminate ionic liquid was prepared from the reaction of a Merrifield resin with pyridine followed by reaction with aluminium chloride. This catalyst was used as a new chemoselective Lewis acid catalyst for the exclusive synthesis of 2-substituted benzimidazoles from the reaction of aldehydes with o-phenylenediamines. The catalyst was stable (as a benchtop catalyst) and could easily be recovered and reused without appreciable change in its efficiency.
- Boroujeni, Kaveh Parvanak,Zhianinasab, Ashkan,Jafarinasab, Mina
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p. 155 - 164
(2013/08/25)
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- DBSA mediated chemoselective synthesis of 2-substituted benzimidazoles in aqueous media
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An efficient synthetic method has been developed for the facile synthesis of 2-substituted benzimidazoles in organized aqueous media in the presence of a surfactant (viz. DBSA) as catalyst and I2 as co-catalyst. The method described has the advantages of operational simplicity, excellent yields, high chemoselectivity, and clean and green reaction profile.
- Kumar, Vikash,Khandare, Dipratn G.,Chatterjee, Amrita,Banerjee, Mainak
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p. 5505 - 5509
(2013/09/23)
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- An efficient and environmental benign synthesis of 2-benzimidazoles and 2-benzothiazoles using CeCl3-NaI as catalyst
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A one-pot condensation of an aldehyde with 1,2-phenylenediamine or 2-aminothiophenol in dimethyl carbonate at 100°C under O2 in the presence of catalytic amounts of CeCl3-NaI gave an imine intermediate, which cyclised and dehydrogenated to give 2-arylbenzimidazoles or 2-arylbenzothiazoles in good yields.
- Zhu, Xun,Wei, Yunyang
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p. 119 - 121
(2013/04/23)
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- Microwave-assisted synthesis of 2-substituted 1h-benzo[d]imidazoles and their antifungal activities in vitro
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An efficient and novel microwave-assisted synthesis of 1H-benzo[d]imidazole derivatives via nitriles and o-phenyldiamines in the presence of polyphosphoric acid (PPA) and phosphoric acid is described. This method provides several advantages such as commercially high availabilities of starting materials, short reaction times, high yields and a simple workup procedure. Systematically antifungal biological tests showed 3f was most promising candidate against six phytopathogenic fungi.
- Zhang, Tao,Huang, Liang-Zhu,Wu, Jia,Lu, Dong,Ma, Bo-Lin,Du, Zhen-Ting
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p. 1545 - 1552
(2013/07/26)
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- γ-Maghemite-silica nanocomposite: A green catalyst for diverse aromatic N-heterocycles
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γ-Maghemite-silica nanocomposite has been applied as a green catalyst to synthesize variety of aromatic N-heterocycles under solvent free conditions. Characterization was done by modern analytical tools (UV, IR, AAS, DSC, EDXRF, powdered XRD, EPR, Mo?ssbauer and TEM). Mild reaction conditions and recyclability have made the present protocol both environmentally and economically viable.
- Ghosh, Pranab,Mandal, Amitava,Subba, Raju
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p. 146 - 152
(2013/09/02)
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- Catalyst free approach to benzimidazoles using air as the oxidant at room temperature
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A green and practical method to construct benzimidazoles, which are ubiquitous structural units in a number of biologically active compounds, has been developed. The catalyst and additive free conditions, using air as oxidant and the mild conditions make
- Zhang, Chun,Zhang, Liangren,Jiao, Ning
-
supporting information
p. 3273 - 3276
(2013/01/16)
-
- Synthesis and biological evaluation of 4′-[(benzimidazole-1-yl) methyl]biphenyl-2-sulfonamide derivatives as dual angiotensin II/endothelin A receptor antagonists
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A series of 4′-[(benzimidazole-1-yl)methyl]biphenyl-2-sulfonamide derivatives (Ia-Il) were synthesized and biologically evaluated. It was found that Ig, the most active compound, antagonized both Ang II AT1 and endothelin ETA receptors (AT1 IC50 = 8.5, ETA IC50 = 8.9 nM), and was more potent than losartan in RHRs with no significant effect on heart rate. The preliminary structure-activity relationships were also discussed in the present paper.
- Bai, Renren,Wei, Zhen,Liu, Jie,Xie, Weijia,Yao, Hequan,Wu, Xiaoming,Jiang, Jieyun,Wang, Qiujuan,Xu, Jinyi
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experimental part
p. 4661 - 4667
(2012/09/07)
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- KF/Al2O3: An efficient solid heterogeneous base catalyst in one-pot synthesis of benzimidazoles and bis-benzimidazoles at room temperature
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KF/Al2O3 is an efficient solid heterogeneous base catalyst in the one-pot synthesis of 2-substituted benzimidazoles and 2,2′-disubstituted bis-benzimidazoles from 1,2-phenylenediamines or 3,3′-diaminobenzidines and acid chlorides, anhydrides, and esters at room temperature. Springer-Verlag 2011.
- Khalili, Saeed Bahadori,Sardarian, Ali Reza
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experimental part
p. 841 - 846
(2012/08/07)
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- Expeditious and efficient synthesis of benzoxazoles, benzothiazoles, benzimidazoles catalyzed by Ga(OTf)3 under solvent-free conditions
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A new and efficient method for the synthesis of benzoxazoles, benzothiazoles, benzimidazoles from reactions of o-substituted aminoaromatics with orthoesters in the presence of catalytic amounts of Ga(OTf)3 under solvent-free conditions is presented. The remarkable features of this new protocol are high conversion, very short reaction times, cleaner reaction profiles under solvent-free conditions, straight forward procedure, and use of relatively non-toxic catalysts.
- Liu, Juyan,Liu, Qian,Xu, Wei,Wang, Weilu
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experimental part
p. 1739 - 1744
(2012/02/14)
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- Benzazoles. 3*. Synthesis and arylsulfonylation of 2-substituted benzimidazoles
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2-Alkylbenzimidazoles have been obtained from o-nitroaniline and aliphatic carboxylic acids by reductive cyclization. Interaction of the former with arenesulfonyl chlorides led to the synthesis of 2-alkyl-1- arylsulfonylbenzimidazoles, the yield of which depended on the structure of the substituent in position 2.
- Abdireimov,Mukhamedov,Aiymbetov,Shakhidoyatov
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experimental part
p. 941 - 946
(2011/09/20)
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- A mild, efficient and one-pot synthesis of 2-substituted benzimidazoles by ZrOCl2. 8H2O catalyzed ring closure reaction
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A mild, efficient and one-pot synthesis of an array of 2-substituted benzimidazoles from an appropriate o-phenylenediamine and orthoesters such as orthoformate, orthoacetate and orthovalerate using ZrOCl2-8H 2O, at room temperature and under microwave irradiation is described. Ecofriendly, solvent-free methodology has been employed under microwave condition. Compared with the conventional method, microwave irradiation method has the advantages of excellent yields (81-93%) and shorter reaction time (5-10 min).
- Sanjeeva Reddy,Nagaraj
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experimental part
p. 1154 - 1159
(2009/04/11)
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- A highly effective sulfamic acid/methanol catalytic system for the synthesis of benzimidazole derivatives at room temperature
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Sulfamic acid/methanol was found to be an efficient catalytic system for the synthesis of benzimidazole compounds through the condensation of o-phenylenediamine with orthoester in high yields at room temperature.
- Zhang, Zhan-Hui,Li, Tong-Shuang,Li, Jian-Jiong
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- Synthesis of 2-substituted benzimidazoles by iodine-mediated condensation of orthoesters with 1,2-phenylenediamines
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(Chemical Equation Presented) Iodine was found to be an efficient catalyst for the synthesis of 2-substituted benzimidazoles by the condensation of orthoesters and 1,2-phenylenediamines in good to excellent yields under mild reaction conditions.
- Zhang, Zhan-Hui,Li, Jian-Jiong,Gao, Yuan-Zhe,Liu, Yu-Heng
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p. 1509 - 1512
(2008/09/18)
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- Simple and convenient one-pot synthesis of benzimidazoles and benzoxazoles using N,N-dimethylchlorosulfitemethaniminium chloride as condensing agent
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N,N-Dimethylchlorosulfitemethaniminium chloride (SOCl2-DMF) has been found to be an efficient reagent for the one-pot synthesis of benzimidazoles and benzoxazoles in excellent yield by condensation of carboxylic acids with o-phenylenediamine/2-amino-phenol. Copyright Taylor & Francis Group, LLC.
- Kaul, Savita,Kumar, Ajay,Sain, Bir,Bhatnagar
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p. 2457 - 2460
(2008/02/10)
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- Towards organo-click reactions: Development of pharmaceutical ingredients by using direct organocatalytic bio-mimetic reductions
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Economic and environmentally friendly bio-mimetic one-pot three and four-component Knoevenagel-hydrogenation (K-H), five-component Knoevenagel-hydrogenation-alkylation (K-H-A) and six-component Knoevenagel-hydrogenation-alkylation-Huisgen cycloaddition (K-H-A-HC) reactions of aldehydes, CH-acids, o-phenylenediamine, alkyl halides and azides using proline, proline-metal carbonate and proline-metal carbonate-Cu I-catalysis, respectively have been developed. Many of K-H and K-H-A compounds have direct application in pharmaceutical chemistry. The Royal Society of Chemistry.
- Ramachary, Dhevalapally B.,Reddy, G. Babul
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p. 4463 - 4468
(2008/09/19)
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- Manganese(IV) dioxide-catalyzed synthesis of quinoxalines under microwave irradiation
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We synthesize quinoxalines, catalyzed by manganese(IV) dioxide, from a variety of α-hydroxyketones followed by trapping with aromatic or aliphatic 1,2-diamines without using a solvent, within one minute under microwave irradiation. The Royal Society of Chemistry 2005.
- Kim, So Yeon,Park, Kang Hyun,Chung, Young Keun
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p. 1321 - 1323
(2008/09/17)
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- Design, synthesis, and evaluation of novelly substituted benzimidazole compounds as angiotensin II receptor antagonists
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5-Nitrobenzimidazole derivatives with varying substituents at 2-position have been designed, synthesized, and evaluated for angiotensin II antagonistic activity. A drug-receptor interaction model has been proposed.
- Bali, Alka,Bansal, Yogita,Sugumaran,Saggu, Jatinder Singh,Balakumar,Kaur, Gurpreet,Bansal, Gulshan,Sharma, Ajay,Singh, Manjeet
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p. 3962 - 3965
(2007/10/03)
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- Novel synthesis of benzoxazoles from o-nitrophenols and amines
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o-Nitrophenols and o-nitroaniline were reacted with amines at 210-215°C to produce the corresponding benzoxazoles and benzimidazoles, respectively, in moderate yields. The reactions between o-nitrophenols containing a CO2Me or OMe group on their benzene rings and N,N-diethylaniline were examined to investigate the effects of the position and electronic character of these substituents on the formation of the oxazole ring.
- Nishioka, Hiromi,Ohmori, Yukiko,Iba, Yumiko,Tsuda, Eri,Harayama, Takashi
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p. 193 - 198
(2007/10/03)
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- Synthesis and insecticidal activity of some benzimidazolic and benzothiazolic derivatives
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The benzimidazolic and benzothiazolic derivatives with a (CH2)n radical in 2 position of the heterocycle had been synthesized and then tested for their insecticidal activity on Culex pipiens larvae. The benzothiazolic derivatives were found to be the most active. The study has also showed that this activity was related to the nature of the substitute in 2 position of the heterocycle. This activity increased when (CH2)n chain increased until n = 6; above this value, the activity decreased.
- Lahlou, M.,Weliou, M.,Salem, M.,Hajji, M. S.
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- Microwave irradiation synthesis of 2-substituted benzimidazoles using PPA as a catalyst under solvent-free conditions
-
An efficient microwave irradiation synthesis of 2-substituted benzimidazoles using polyphosphoric acid (PPA) as a catalyst from organic acid and o-phenylenediamine under solvent-free conditions is described. This method is a good option to obtain the title compounds in a simple and an inexpensive way.
- Lu, Jun,Yang, Bingqin,Bai, Yinjuan
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p. 3703 - 3709
(2007/10/03)
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- Nonpeptide angiotensin II receptor antagonists. Synthesis and biological activity of benzimidazoles
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A series of substituted 2-butylbenzimidazoles bearing a biphenylylmethyl moiety at the 1-position was prepared via three synthetic routes and evaluated for angiotensin II (AII) receptor antagonistic activity (in vitro and in vivo). Binding affinity was determined using bovine adrenal cortical membrane. Substitution at the 4-, 5-, or 6-position reduced the affinity relative to that of the unsubstituted compound (13a). However, most of the compounds with a substituent at the 7-position showed binding affinity comparable to that of DuP 753 (losartan). In functional studies, a carboxyl group was found to be very important for antagonistic activity against AII. Comparison of 2-butyl-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H- benzimidazole-4-,-5-,-6-, and -7-carboxylic acids (15a-d) in an AII-induced rabbit aortic ring contraction assay clearly demonstrated the importance of the substitutional position of the carboxyl group. In an in vivo assay, oral administration of benzimidazole-7-carboxylic acids caused long-lasting inhibition of the AII-induced pressor response in rats. The optimum substituent at the 7-position of the benzimidazole ring was found to be a carboxyl or an ester group. The representative compound, 2-butyl-1-[[2'-(1H- tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimidazole-7-carboxylic acid (15d, CV-11194), inhibited the specific binding of [125I]AII to bovine adrenal cortical membrane with an IC50 value of 5.5 x 10-7 M. The AII-induced contraction of rabbit aortic strips was antagonized by CV-11194 (IC50 value, 5.5 x 10-11 M), while the compound had no effect on the contraction induced by norepinephrine or KCl. Orally administered CV-11194 at doses of 0.3-10 mg/kg dose-dependently inhibited the AII-induced pressor response in rats and dogs. CV-11194 at 1 mg/kg po reduced blood pressure in spontaneously hypertensive rats (SHR). The three-dimensional molecular structure of CV- 11194 was determined by X-ray diffraction.
- Kubo,Inada,Kohara,Sugiura,Ojima,Itoh,Furukawa,Nishikawa,Naka
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p. 1772 - 1784
(2007/10/02)
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- 6-Substituted benzimidazoles as new nonpeptide angiotensin II receptor antagonists: Synthesis, biological activity, and structure-activity relationships
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Starting from the recently reported nonpeptidic angiotensin II (AII) receptor antagonists DuP 753 (1) and Exp 7711 (2), we have designed and investigated novel substituted benzimidazoles. Systematic variation of several substituents at the benzimidazole ring positions 4-7 led to the finding that substitution in position 6 with acylamino groups results in highly active AII antagonists. Compounds with 6-membered lactam or sultam substituents in position 6 of benzimidazole showed receptor activities in the low nanomolar range but were only weakly active when given orally to rats. In contrast, analogous substitution of the benzimidazole moiety with basic heterocycles resulted in potent AII antagonists which were also well absorbed after oral application. The most active compound of this series, 33 (BIBR 277), was selected as a candidate for clinical development. On the basis of molecular modeling studies a binding model of this new class of AII antagonists to the AT1 receptor is proposed.
- Ries,Mihm,Narr,Hasselbach,Wittneben,Entzeroth,Van Meel,Wienen,Hauel
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p. 4040 - 4051
(2007/10/02)
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- Angiotensin II antagonists incorporating a substituted thiophene or furan
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There are disclosed substituted thiophene and furan derivatives of Formula I which are useful as angiotensin II antagonists. STR1
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- ANGIOTENSIN II ANTAGONISTS INCORPORATING AN INDOLE OR DIHYDROINDOLE
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There are disclosed substituted indoles and dihydroindoles of Formula I which are useful as angiotensin II antagonists. STR1
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- Substituted benzimidazoles as angiotensin II antagonists
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There are disclosed new substituted benzimidazole compounds and derivatives thereof which are useful as angiotensin II antagonists. These compounds have the general formula:
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