- H2O2/Fe(NO3)3-promoted synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles
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A new, convenient synthesis of 2-substituted benzimidazoles and benzothiazoles is described. Short reaction time, easy and quick isolation of the products, environmentally friendly procedure, excellent chemoselectivity and excellent yields are main advantages of this procedure. Georg Thieme Verlag Stuttgart.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Naali, Fardin
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- An efficient synthesis of 2-arylbenzimidazoles from o-phenylenediamines and arylaldehydes catalyzed by Fe/CeO2-ZrO2 nano fine particles
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75% Fe/CeO2-ZrO2 nano fine particles (0.005 mol%) are reported as a new catalyst for the efficient synthesis of 2-arylbenzimidazoles. A simple and convenient procedure, easy purification and shorter reaction times are the advantageous features of this method. Springer-Verlag 2011.
- Behbahani, Farahnaz K.,Ziaei, Parisa,Fakhroueian, Zahra,Doragi, Neda
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- FeCl3-doped polyaniline nanoparticles as reusable heterogeneous catalyst for the synthesis of 2-substituted benzimidazoles
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FeCl3-doped polyaniline nanoparticles efficiently catalyze the synthesis of 2-substituted benzimidazoles by the reaction of aldehydes with o-phenylenediamine. Synthesis and characterization of the catalyst are described, and the obtained results confirms good dispersion of the FeCl3 on the polyaniline. Simple workup, mild reaction conditions, low cost, easy separation, and reusability of the catalyst are some advantages of this method.
- Abdollahi-Alibeik, Mohammad,Moosavifard, Marzieh
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- Imidazole-Linked Crystalline Two-Dimensional Polymer with Ultrahigh Proton-Conductivity
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Proton-exchange membrane fuel cells are promising energy devices for a sustainable future due to green features, high power density, and mild operating conditions. A facile proton-conducting membrane plays a pivotal role to boost the efficiency of fuel cells, and hence focused research in this area is highly desirable. Major issues associated with the successful example of Nafion resulted in the search for alternate proton conducting materials. Even though proton carrier loaded crystalline porous organic frameworks have been used for proton-conduction, the weak host-guest interactions limited their practical use. Herein, we developed a crystalline 2D-polymer composed of benzimidazole units as the integral part, prepared by the condensation of aryl acid and diamine in polyphosphoric acid medium. The imidazole linked-2D-polymer exhibits ultrahigh proton conductivity (3.2 × 10-2 S cm-1) (at 95% relative humidity and 95 °C) in the pristine state, which is highest among the undoped porous organic frameworks so far reported. The present strategy of a crystalline proton-conducting 2D-polymer will lead to the development of new high performing crystalline solid proton conductor.
- Ranjeesh, Kayaramkodath Chandran,Illathvalappil, Rajith,Veer, Sairam Dnyaneshwar,Peter, Joseph,Wakchaure, Vivek Chandrakant,Goudappagouda,Raj, K. Vipin,Kurungot, Sreekumar,Babu, Sukumaran Santhosh
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- Highly efficient anion transport mediated by 1,3-bis(benzimidazol-2-yl)benzene derivatives bearing electron-withdrawing substituents
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1,3-Bis(benzimidazol-2-yl)benzene exhibits potent anionophoric activity through a process of anion exchange with a minor level of proton/anion symport. Modification of 1,3-bis(benzimidazol-2-yl)benzene with strong electron-withdrawing substituents, such as trifluoromethyl and nitro groups, leads to up to 789-fold increase in the activity. The benzimidazolyl-NH fragments, the relative position and the number of the benzimidazolyl groups on the central phenyl scaffold play an essential role in the transport.
- Peng, Chen-Chen,Zhang, Meng-Jia,Sun, Xiao-Xiao,Cai, Xiong-Jie,Chen, Yun,Chen, Wen-Hua
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- A simple and convenient one-pot synthesis of benzimidazole derivatives using cobalt(II) chloride hexahydrate as catalyst
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A simple and efficient method for the convenient synthesis of 2-arylbenzimidazole has been described on reaction with o-phenylenediamine and various aromatic aldehydes using cobalt(II) chloride hexahydrate as a catalyst. The method is cost-effective, high
- Khan, Abu T.,Parvin, Tasneem,Choudhury, Lokman H.
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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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- Synthesis of 2,2′-(p-phenylene)bisbenzazoles compounds from terephthalohydroxamoyl chloride
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In this study, synthesis of symmetric compounds of 2,2′-(p-phenylene) bisbenzothiazole, 2,2′-(p-phenylene)bisbenzimidazole and 5,5′-dimethyl-2,2′-(N-phenylene)bisbenzoxazole were benefited from the reaction of terephthalohydroxamoyl chloride with 2-amino-4-methyl phenol, o-aminothio phenol and o-phenylenediamin compounds. The structures of these compounds were confirmed by elemental analysis, mass, 1H-NMR and FT-IR techniques.
- Oezaytekin, Ilkay,Karatas, Ibrahim
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- 1,4-Bis(2-benzimidazolyl)benzene
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The title compound, C20H14N4, lies about an inversion centre and the benzimidazole moiety and the phenyl ring are twisted by 30.9(1)°. The benzimidazole moiety is completely planar, with a maximum deviation of 0.009 (2) angstroms. Intermolecular N-H···N hydrogen bonds give rise to a layered structure, with the layers stacked by van der Waals interactions.
- Bei, Fengli,Jian, Fangfang,Yang, Xujie,Lu, Lude,Wang, Xin,Sundara Raj, S. Shanmuga,Fun, Hoong-Kun
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- Fe3O4@SiO2/collagen: An efficient magnetic nanocatalyst for the synthesis of benzimidazole and benzothiazole derivatives
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In this project, Fe3O4@SiO2 was synthesized and combined with collagen for the preparation of Fe3O4@SiO2/collagen. It was characterized by FT-IR, 1H NMR, VSM, XRD, EDX, SEM and T
- Ghafuri, Hossein,Esmaili, Elahe,Talebi, Majid
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- Nanosized sulfated zirconia as solid acid catalyst for the synthesis of 2-substituted benzimidazoles
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The condensation reaction of o-phenylenediamine and arylaldehydes was investigated in the presence of nanosized sulfated zirconia (SO 4 2- -ZrO2) as the solid acid catalyst. Nanosized SO 4 2- -ZrOsub
- Abdollahi-Alibeik, Mohammad,Hajihakimi, Mohammad
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- Regulation of conjugate rigid plane structures for achieving transformation of fluorescence recognition properties
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Bisbenzimidazole is an important class of fluorescence molecular probe materials with applications in environmental, clinical, and biological systems. Moreover, different bisbenzimidazole derivatives, due to excellent coordination properties and fluorescence characteristics, were widely studied for cation recognition. In this study, the relationship between three bisbenzimidazole derivatives (B1, B2 and B3) with respect to the increase of the phenyl group conjugate systems and fluorescence sensing properties for the detection of toxic heavy metal ions such as Hg2+ is explored and analyzed. B1 contains a bisbenzimidazole unit without an appendage, while B2 and B3 have different phenyl appendages between two benzimidazole rings; with the extension of the conjugated system, the selectivity of cation recognition increases but the stability decreases significantly. Simultaneously, their limits of detections (LODs) and recognition mechanism for Hg2+ were investigated via various methods such as fluorescence spectroscopy, 1H NMR spectroscopy, ICP analysis, and DFT calculations. Inspiringly, B2 shows high adsorption and separation efficiency, which provides a reference for the development of mercury ion absorption/removal materials. This journal is
- Hu, Yin-Ping,Kan, Xiao-Tong,Lin, Qi,Niu, Yan-Bing,Wei, Tai-Bao,Yao, Hong,Zhang, You-Ming
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p. 2858 - 2862
(2022/02/22)
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- Ruthenium(II)-catalyzed synthesis of 2-arylbenzimidazole and 2-arylbenzothiazole in water
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Benzimidazoles/benzothiazoles are heterocyclic compounds which contain a five membered heteroatom and a benzene ring. They constitute a crucial structural unit of numerous bioactive compounds and natural products. Since the compounds containing benzimidaz
- Singh, Keisham S.,Joy, Francis,Devi, Prabha
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p. 181 - 190
(2020/11/26)
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- Solid Phase Synthesis of Biologically active Benzimidazole Derivatives Catalysed by CH3S03H-Si02 under Solvent free Condition
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A simple an expeditious method was established for the synthesis of 2-Substituted-1H-Benzimidazole derivatives at 90°C using o-phenylenediamine and different aldehydes. It has been found that a mixture of Methanesulphonic acid-Si02to be an effective catal
- Datta, Arup,Roy, Sanjay
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p. 537 - 543
(2020/07/23)
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- Cyanide Boosting Copper Catalysis: A Mild Approach to Fluorescent Benzazole Derivatives from Nonemissive Schiff Bases in Biological Media
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An application of nucleophilic cyclization and oxidation of nonemissive Schiff bases via cyanide boosting copper catalysis to synthesize fluorescent benzazole derivatives in high conversion yield is disclosed. This approach is highlighted by broad substra
- Li, Hongjuan,Sun, Shiguo,Wang, Dejia,Xu, Yongqian
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p. 3361 - 3366
(2020/04/20)
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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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- 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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- 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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- 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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- A fluorescent identification fluorinion sensor and its preparation and use
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The invention provides a high-selectivity fluorescence identifying fluorinion sensor and belongs to the field of anion detection. The sensor takes terephthalic acid and o-phenylenediamine as substrates, polyphosphoric acid as a catalyst and phosphoric acid as a dehydrant, the materials are stirred and reacted at the temperature of 160-200 DEG C for 5-6 hours, the product is poured into distilled water and regulated with an alkaline liquor to enable the pH value to be 8-9, then the mixture is subjected to suction filtration, water washing, drying and recrystallizing to obtain a yellow target product. Experiment shows that only the addition of F- makes the solution emit remarkable blue fluorescence under an ultraviolet lamp after F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, ClO4- and SCN- are respectively added into a DMSO (dimethyl sulfoxide) solution of sensor molecules. Therefore, the sensor can be used for the rapid fluorescence detection of F-, and in addition, the identifying process is not affected by other anions. To facilitate practical application, the invention further manufactures a piece of fluorinion test paper based on the sensor.
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Paragraph 0031
(2017/05/16)
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- One-pot synthesis of benzimidazoles in water in the presence of SiO 2-OPO3H
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Silica-bound phosphoric acid (SiO2-OPO3H), as an eco-friendly, reusable, and heterogeneous catalyst, was applied for synthesis of 2-substituted benzimidazoles in water at 70°C. Very short reaction times, clean work-up, and high yields are among the advantages of this protocol.
- Mirjalili,Bamoniri,Rahimi Kazerouni
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- Synthesis and characterization of Cu(II) containing nanosilica triazine dendrimer: A recyclable nanocomposite material for the synthesis of benzimidazoles, benzothiazoles, bis-benzimidazoles and bis-benzothiazoles
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The present study describes the synthesis, characterization, and catalytic activity of Cu(II) containing nanosilica triazine dendrimer (Cu(II)-TD@nSiO 2). The prepared catalyst was characterized by FT-IR, TGA, elemental analysis, UV-vis, FE-SEM
- Nasr-Esfahani, Mahboobeh,Mohammadpoor-Baltork, Iraj,Khosropour, Ahmad Reza,Moghadam, Majid,Mirkhani, Valiollah,Tangestaninejad, Shahram
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p. 243 - 254
(2013/10/08)
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- Photocatalysis by 3,6-disubstituted-s-tetrazine: Visible-light driven metal-free green synthesis of 2-substituted benzimidazole and benzothiazole
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s-Tetrazine based molecules were prepared for visible-light-driven organic transformations. The 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) derivative shows visible light absorption and reversible one-electron reduction behavior. In the presence of pytz and aerial oxygen, aldehyde reacts with o-phenylenediamine or o-aminothiophenol under visible light irradiation at ambient temperature to produce corresponding 2-substituted benzimidazoles and benzothiazoles, respectively. Pytz catalyst demonstrates excellent catalytic activity for alkyl, aryl, organo-metallic substituted aldehydes and reducing sugar. The reaction yield is high for both the electron-donating and electron withdrawing substituents in aromatic aldehydes. The use of a metal-free catalyst and visible light energy, along with the mild reaction conditions, makes this reaction an environmentally benign and energy-saving chemical process.
- Samanta, Suvendu,Das, Sudipto,Biswas, Papu
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p. 11184 - 11193
(2013/12/04)
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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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- An Efficient and inexpensive synthesis of 2-substituted benzimidazoles in water using boric acid at room temperature
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2-Substituted benzimidazoles have been synthesized in a one-pot reaction from o-phenylenediamine and aldehydes in the presence of boric acid in water at room temperature. The method was proved to be eco-friendly, convenient and the products were isolated with good yields.
- Karimi-Jaberi, Zahed,Amiri, Mohammad
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experimental part
p. 167 - 170
(2012/06/01)
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- One-pot synthesis of 2-substituted benzimidazoles catalyzed by anhydrous FePO4
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Anhydrous FePO4 has been employed as a catalyst for efficient synthesis of 2-substituted benzimidazoles. Simple and convenient procedure, easy purification and shorter reaction time are the advantages of this method, resulting in several known and three new compounds.
- Behbahani, Farahnaz K.,Ziaei, Parisa
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p. 1011 - 1017
(2013/03/13)
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- An inorganic iodine-catalyzed oxidative system for the synthesis of benzimidazoles using hydrogen peroxide under ambient conditions
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A simple and efficient catalytic oxidative system for the synthesis of benzimidazole derivatives with H2O2 in the presence of catalytic amounts of Bu4NI is developed. The formation of highly reactive iodine (III) intermediate [Bu4N]+[IO 2]- is detected by ESI-MS for the first time, and a possible mechanism for the oxidation is proposed.
- Zhu, Chenjie,Wei, Yunyang
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experimental part
p. 1082 - 1086
(2012/04/17)
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- Application of N,N′-diiodo-N,N′-1,2-ethandiylbis(p-toluene sulfonamide) as a new reagent for synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles under solvent-free conditions
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N,N′-Diiodo-N,N′-1,2-ethandiylbis(p-toluene sulfonamide) (NIBTS) is a good and new reagent for synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles at room temperature under solvent-free condition with good to high yield. Absence of solvent, short reaction times, non-corrosive, operational simplicity and environmentally friendliness are the main advantages of this procedure. Copyright
- Veisi, Hojat,Ghorbani-Vaghei, Ramin,Faraji, Alireza,Ozturk, Turan
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experimental part
p. 2249 - 2254
(2011/10/08)
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- Rapid and cheap synthesis of benzimidazoles via intermittent microwave promotion: A simple and potential industrial application of air as oxidant
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Using inexpensive KI as the catalyst in the presence of ambient air, benzimidazoles were synthesized from aromatic aldehydes and o-phenylenediamine with excellent yields via intermittent microwave irradiation without reflux equipment. The synthesis process was mild and only needed only a short reaction time (7-10min). As a simple example of the utilization of molecular oxygen under mild conditions, this method provides a novel way to synthesize benzimidazoles. The industrial synthesis of benzimidazoles may be realized by a cycle of microwave irradiation. Copyright
- Mao, Zhengzhou,Wang, Zhaoyang,Li, Jingning,Song, Xiumei,Luo, Yufen
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experimental part
p. 1963 - 1977
(2010/09/07)
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- PEG-mediated catalyst-free expeditious synthesis of 2-substituted benzimidazoles and bis-benzimidazoles under solvent-less conditions
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A wide variety of 2-substituted benzimidazoles and bis-benzimidazoles were synthesized in high yields by PEG-mediated catalyst-free synthesis under solvent-less conditions. The products were directly recrystallized from hot methanol. The reaction occurred giving excellent yields with low as well as high molecular weight PEGs.
- Mukhopadhyay, Chhanda,Tapaswi, Pradip Kumar
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experimental part
p. 6237 - 6240
(2009/04/04)
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- A simple and efficient one-pot synthesis of 2-substituted benzimidazoles
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A simple and efficient procedure for the synthesis of substituted benzimidazoles through a one-pot condensation of o-phenylenediamines with aryl aldehydes in the presence of H2O2/HCl system in acetonitrile at room temperature is described. Short reaction time, large-scale synthesis, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure. Georg Thieme Verlag Stuttgart.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Kavianinia, Iman
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p. 547 - 550
(2008/01/03)
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- Unprecedented reaction between ethyl α-cyanocinnamate and o-phenylenediamine: Development of an efficient method for the transfer hydrogenation of electronically depleted olefins
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A reaction between ethyl α-cyanocinnamate and o-phenylenediamine under thermal conditions yielded 2-cyano-3-phenyl-propionic acid ethyl ester, 2-phenyl benzimidazole, and ethyl cyanoacetate. The mechanistic revelations led to the development of a simple and efficient transfer-hydrogenation process from the in situ generated benzimidazolines to activated olefins under solventless and catalyst-free conditions. Georg Thieme Verlag Stuttgart.
- Kumar, Satish,Kapoor, Kamal K.
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p. 2809 - 2814
(2008/02/13)
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- Synthesis of 2,5(6)-Disubstituted-benzimidazoles, 2-Substituted-5-(4-substituted-phenyl)-1,3,4-thiadiazoles and Imidazothioxanthene and Their Antifilarial Activity
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2-Carbomethoxyaminothioxanthenoimidazol-12-one-13,13-dioxide (5), 2,5(6)-disubstituted-benzimidazoles (10-13) and 2-substituted-5-(3-nitro-4-substituted-phenyl)-1,3,4-thiadiazoles (18-24) have been synthesized and evaluated for their antifilarial a
- Chauhan, P. M. S.,Bhakuni, D. S.
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p. 1146 - 1149
(2007/10/02)
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