- Homology modelling, molecular dynamics simulation and docking evaluation of β-tubulin of Schistosoma mansoni
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Schistosomiasis is one of the neglected diseases causing considerable morbidity and mortality throughout the world. Microtubules with its main component, tubulin play a vital role in helminthes including schistosomes. Benzimidazoles represent potential drug candidates by binding β-tubulin. The study aimed to generate a homology model for the β-tubulin of S. mansoni using the crystal structure of O vis aries (Sheep) β-tubulin (PDB ID: 3N2G D) as a template, then different β-tubulin models were generated and two previously reported benzimidazole derivatives (NBTP-F and NBTP-OH) were docked to the generated models, the binding results indicated that both S. mansoni, S. haematobium were susceptible to the two NBTP derivatives. Additionally, three mutated versions of S. mansoni β-tubulin wild-type were generated and the mutation (F185Y) seems to slightly enhance the ligand binding. Dynamics simulation experiments showed S. haematobium β-tubulin is highly susceptible to the tested compounds; similar to S. mansoni, moreover, mutated models of S. mansoni β-tubulin altered its NBTPs susceptibility. Moreover, additional seven new benzimidazole derivatives were synthesized and tested by molecular docking on the generated model binding site of S. mansoni β-tubulin and were found to have good interaction inside the pocket.
- El-Shehabi, Fouad,Mansour, Basem,Bayoumi, Waleed A.,El Bialy, Serry A.,Elmorsy, Mohammad A.,Eisa, Hassan M.,Taman, Amira
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- Sustainable Synthesis of 2-Hydroxymethylbenzimidazoles using D-Fructose as a C2 Synthon
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D-fructose, a biomass-derived carbohydrate has been identified as an environmentally benign C2 synthon in the preparation of synthetically useful 2-hydroxymethylbenzimidazole derivatives by coupling with 1,2-phenylenediamines. Proof of concept was established by synthesizing 23 examples using BF3.OEt2 (20 mol%), TBHP (5.5 M, decane) (1.0 equiv.) in CH3CN at 90 °C for 1 h. The pivotal features of this method include metal-free conditions, short time, good functional group tolerance, gram scale feasibility and the synthesis of benzimidazole fused 1,4-oxazine. Control studies with conventional C2 synthons did not produce the desired product, thus suggesting a new reaction pathway from D-fructose.
- Raja, Dineshkumar,Philips, Abigail,Sundaramurthy, Devikala,Chandru Senadi, Gopal
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supporting information
p. 3754 - 3759
(2021/10/14)
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- A substituent- And temperature-controllable NHC-derived zwitterionic catalyst enables CO2upgrading for high-efficiency construction of formamides and benzimidazoles
-
Chemocatalytic upgrading of the greenhouse gas CO2 to valuable chemicals and biofuels has attracted broad attention in recent years. Among the reported approaches, N-formylation of CO2 with an amine is of great significance due to its versatility in the construction of N-containing linear and cyclic skeletons. Herein, a stable N-heterocyclic carbene-carboxyl adduct (NHC-CO2) was facilely prepared and could be used as a recyclable zwitterionic catalyst for efficient CO2 reductive upgrading via either N-formylation or further coupling with cyclization under mild conditions (25 °C, 1 atm CO2) using hydrosilane as a hydrogen source. More than 30 different alkyl and aromatic amines could be transformed into the corresponding formamides or benzimidazoles with remarkable yields (74%-98%). The electronic effect of the introduced substituent on NHC-CO2 was found to evidently affect the thermostability and nucleophilicity of the zwitterionic catalyst, which is directly correlated with its catalytic activity. Moreover, NHC-CO2 could supply CO2 by in situ decarboxylation at a specific temperature that is dependent on the introduced substituent type. Experimental and computational studies showed that the carboxyl species on NHC-CO2 was not only a nucleophilic center, but also a C1 source which rapidly captures or substitutes ambient CO2 during hydrosilylation. In addition, a simple and green conceptual process was designed for the product purification and catalyst recycling, with a good feasibility for small-scale production.
- Li, Hu,Li, Zhengyi,Wu, Hongguo,Yang, Song,Yu, Zhaozhuo,Zhang, Lilong,Zhu, Kaixun
-
supporting information
p. 5759 - 5765
(2021/08/23)
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- Method for synthesizing benzimidazole from carbon dioxide and o-phenylenediamine compound
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The invention discloses a method for synthesizing benzimidazole from carbon dioxide and an o-phenylenediamine compound, the method is characterized in that an amino-containing functionalized ordered mesoporous polymer is used as a catalyst, o-phenylenediamine and carbon dioxide are used as raw materials, dimethylaminoborane is used as a hydrogen reduction reagent, carbon dioxide and the o-phenylenediamine compound are catalyzed to react in an NMP solvent to generate a benzimidazole compound, wherein the dosage of a catalyst is 0.01-1mol% based on the nitrogen content of the o-phenylenediamine compound; the filling pressure of the carbon dioxide is 0.1-2MPa; the reaction temperature is 60-180DEG C; the molar ratio of the catalyst to the NMP is 1:50-100. Compared with the prior art, the catalyst has the advantages of simple preparation, high catalytic activity, capability of catalyzing the reaction of carbon dioxide and the o-phenylenediamine compound under mild conditions to generate benzimidazole and derivatives thereof, and the like.
- -
-
Paragraph 0041-0044
(2021/06/06)
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- Reductive cyclization of o-phenylenediamine with CO2 and BH3NH3 to synthesize 1H-benzoimidazole derivatives
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A simple and green protocol was developed for the reductive cyclization of o-phenylenediamine with CO2 and BH3NH3 to yield 1H-benzimidazole. The desired 1H-benzimidazole derivatives were produced under mild conditions. Mechanism investigation indicated that the coordination of o-phenylenediamine with the boron atom of BH3NH3 promoted the transfer of the formyl group to form a stable intermediate, which facilitated the intramolecular nucleophilic addition-elimination for the formation of target product. In this process, BH3NH3 served multifunctional roles, acting as a reducing agent and a formylation catalyst.
- Han, Limin,Hong, Hailong,Li, Xiao,Yang, Yue,Zhang, Junhua,Zhu, Ning
-
supporting information
(2021/09/28)
-
- ARYL-PHOSPHORUS-OXYGEN COMPOUND AS EGFR KINASE INHIBITOR
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Disclosed is a class of new aryl-phosphorus-oxygen compounds as shown in formula (I) as EGFR kinase inhibitors, and pharmaceutically acceptable salts thereof.
- -
-
Paragraph 0590; 0591
(2020/06/16)
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- ACTIVATORS OF THE RETINOIC ACID INDUCIBLE GENE "RIG-I' PATHWAY AND METHODS OF USE THEREOF
-
The present invention is directed to compounds of Formula (I), which are activators of the RIG-I pathway.
- -
-
Page/Page column 55-56
(2020/03/05)
-
- ACTIVATORS OF THE RETINOIC ACID INDUCIBLE GENE "RIG-I" PATHWAY AND METHODS OF USE THEREOF
-
The present invention is directed to compounds of Formula (I), which are activators of the RIG-I pathway.
- -
-
Paragraph 0439
(2020/03/01)
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- A NaH-promoted N-detosylation reaction of diverse p-toluenesulfonamides
-
A NaH-mediated detosylation reaction of various Ts-protected indoles, azaheterocycles, anilines and dibenzylamine was reported. The method features cheap reagent, convenient operations, mild reaction conditions and broad substrate scope. Moreover, this study revealed that the loading of NaH in tosylation reactions of nitrogen-containing compounds with NaH as a base in DMA or DMF should be controlled due to the possibility of adverse detosylation.
- Sun, Wanwan,Chen, Xiaobei,Hu, Ying,Geng, Huihui,Jiang, Yuanrui,Zhou, Yuxin,Zhu, Wenjing,Hu, Min,Hu, Haohua,Wang, Xingyi,Wang, Xinli,Zhang, Shilei,Hu, Yanwei
-
supporting information
(2020/10/05)
-
- Transition-metal and oxidant-free approach for the synthesis of diverse N-heterocycles by TMSCl activation of isocyanides
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A highly efficient TMSCl-mediated addition of N-nucleophiles to isocyanides has been achieved. This transition-metal and oxidant-free strategy has been applied to the construction of various N-heterocyles such as quinazolinone, benzimidazole and benzothiazole derivatives by the use of distinct amino-based binucleophiles. The notable feature of this protocol includes its mild reaction condition, broad functional group tolerance and excellent yield. This journal is
- Chen, Fen-Er,Dong, Lin,Li, Hongyan,Liu, Jinxin,Luo, Liangliang,Xiao, You-Cai,Zhou, Yuan
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p. 29257 - 29262
(2020/10/02)
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- Facile access to: N-formyl imide as an N-formylating agent for the direct synthesis of N-formamides, benzimidazoles and quinazolinones
-
N-Formamide synthesis using N-formyl imide with primary and secondary amines with catalytic amounts of p-toluenesulfonic acid monohydrate (TsOH·H2O) is described. This reaction is performed in water without the use of surfactants. Moreover, N-formyl imide is efficiently synthesized using acylamidines with TsOH·H2O in water. In addition, N-formyl imide was successfully used as a carbonyl source in the synthesis of benzimidazole and quinazolinone derivatives. Notable features of N-formylation of amines by using N-formyl imide include operational simplicity, oxidant- A nd metal-free conditions, structurally diverse products, and easy applicability to gram-scale operation.
- Huang, Hsin-Yi,Liang, Chien-Fu,Lin, Xiu-Yi,Yen, Shih-Yao
-
supporting information
p. 5726 - 5733
(2020/08/21)
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- K2S as Sulfur Source and DMSO as Carbon Source for the Synthesis of 2-Unsubstituted Benzothiazoles
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We describe a three-component reaction of o-iodoanilines with K2S and DMSO that provides 2-unsubstituted benzothiazoles in moderate to good isolated yields with good functional group tolerance. Electron-rich aromatic amines and o-phenylenediamines instead of o-iodoanilines provided 2-unsubstituted benzothiazoles and 2-unsubstituted benzimidazoles with and without K2S under similar conditions. Notably, DMSO plays three vital roles: carbon source, solvent, and oxidant.
- Deng, Guobo,Kuang, Daizhi,Liang, Yun,Yang, Yuan,Yu, Jiangxi,Zhang, Fuxing,Zhu, Xiaoming
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supporting information
p. 3789 - 3793
(2020/06/04)
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- Synthesis method of ammonium acetate mediated benzimidazole compound
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The invention discloses a synthesis method of a benzimidazole compound mediated by ammonium acetate. The synthesis method comprises the following steps: adding an o-phenylenediamine compound, dimethylsulfoxide, an additive 1 and an additive 2 into a reaction tube, carrying out a stirring reaction at 130-150 DEG C, cooling the reaction product to room temperature after the reaction is finished, and carrying out separation and purification on the product to obtain the benzimidazole compound. The invention develops a method for synthesizing a benzimidazole compound under the mediation of ammonium acetate by taking DMSO as a carbon source and an oxidant and an o-phenylenediamine compound as a substrate under the condition of no metal catalyst. The synthesis method does not need a metal catalyst, and the required carbon source and oxidant have the characteristics of low toxicity, low price, easiness in obtaining, stable performance and the like. The method has the advantages of easiness inoperation, few steps, mild reaction conditions, better functional group tolerance and the like, and provides a new valuable way for synthesizing benzimidazole compounds.
- -
-
Paragraph 0051-0053
(2020/11/23)
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- Endogenous X-C=O species enable catalyst-free formylation prerequisite for CO2reductive upgrading
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CO2, the main component of greenhouse gas, is currently developed as a promising surrogate of carbon feedstock. Among various conversion routes, CO2undergoing catalytic reduction can furnish hydrogen/energy carriers and value-added chemicals, while specific metal-containing catalysts or organocatalysts are often prerequisite for smooth proceeding of the involved reaction processes. In this work, both formic acid and N-containing benzoheterocyclic compounds (including various benzimidazoles, benzothiazole, and benzoxazole) along with silanols could be synthesized with high yields (>90%) from catalyst-free reductive upgrading of CO2under mild conditions (50 °C). The endogenous X-CO species, derived from the N-methyl-substituted amide-based solvent [Me2N-C(O)-R], especially PolarClean, and O-formyl group [O-C(O)-H] of in situ formed silyl formate, were found to play a prominent promotional role in the activation of the used hydrosilane for reductive CO2insertion, as demonstrated by density functional theory (DFT) calculations and isotopic labeling experiments. Moreover, reaction mechanisms and condition-based sensitivity assessment were also delineated.
- Dai, Wenshuai,Li, Hu,Saravanamurugan, Shunmugavel,Wu, Hongguo,Yang, Song
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p. 5822 - 5832
(2020/10/21)
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- Metal-Free Synthesis of Benzimidazoles via Oxidative Cyclization of d -Glucose with o-Phenylenediamines in Water
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d-Glucose has been identified as an efficient C1 synthon in the synthesis of benzimidazoles from o-phenylenediamines via an oxidative cyclization strategy. Isotopic studies with 13C6-d-glucose and D2O unambiguously confirmed the source of methine. The notable features of this method include the following: broad functional group tolerance, a biorenewable methine source, excellent reaction yields, a short reaction time, water as an environmentally benign solvent, and the synthesis of vitamin B12 component on the gram scale.
- Raja, Dineshkumar,Philips, Abigail,Palani, Pushbaraj,Lin, Wei-Yu,Devikala, Sundaramurthy,Senadi, Gopal Chandru
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p. 11531 - 11540
(2020/10/12)
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- Sustainable methine sources for the synthesis of heterocycles under metal- and peroxide-free conditions
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Alcohols and ethers were identified as sustainable methine sources for synthesizing quinazolinone and benzimidazole derivatives using a combination of TsOH·H2O/O2 and appropriate bis-nucleophiles for the first time. Deuterium labeling studies clearly proved that the C2 hydrogen of the synthesized heterocycles came from the methine source. These unique reaction conditions were successfully applied to the synthesis of echinozolinone (2e′), 2f′ (a common precursor of rutaecarpine and (±) evodiamine), and dimedazole (6d). Notable features of this method include its low toxicity, use of commercial feedstocks as substrates, low cost, broad functional group tolerance and suitability for a wide range of bis-nucleophilic starting materials.
- Senadi, Gopal Chandru,Kudale, Vishal Suresh,Wang, Jeh-Jeng
-
supporting information
p. 979 - 985
(2019/03/12)
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- Microwave use of amidine compounds in the aqueous phase benzoate synthesis of benzimidazole compounds method
-
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; .
- -
-
Paragraph 0097
(2019/03/28)
-
- In Situ Formation of Frustrated Lewis Pairs in a Water-Tolerant Metal-Organic Framework for the Transformation of CO2
-
Frustrated Lewis pairs (FLPs) consist of sterically hindered Lewis acids and Lewis bases, which provide high catalytic activity towards non-metal-mediated activation of “inert” small molecules, including CO2 among others. One critical issue of homogeneous FLPs, however, is their instability upon recycling, leading to catalytic deactivation. Herein, we provide a solution to this issue by incorporating a bulky Lewis acid-functionalized ligand into a water-tolerant metal-organic framework (MOF), named SION-105, and employing Lewis basic diamine substrates for the in situ formation of FLPs within the MOF. Using CO2 as a C1-feedstock, this combination allows for the efficient transformation of a variety of diamine substrates into benzimidazoles. SION-105 can be easily recycled by washing with MeOH and reused multiple times without losing its identity and catalytic activity, highlighting the advantage of the MOF approach in FLP chemistry.
- Shyshkanov, Serhii,Nguyen, Tu N.,Ebrahim, Fatmah Mish,Stylianou, Kyriakos C.,Dyson, Paul J.
-
supporting information
p. 5371 - 5375
(2019/03/17)
-
- Synthesis, characterization, antitumor, antibacterial and urease inhibitory activity of a small series of N-tosyl benzimidazoles
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Benzimidazole derivatives exhibited a broad range of biological activities, e.g., antimicrobial, antiviral, anthelmintic, anti-inflammatory, anticancer and as an anti-ulcer/proton pump inhibitor. Keeping in view the large number of reported drugs containing benzimidazole moiety on one hand and sulfonamide on the other hand, a small series of N-tosyl benzimidazoles (4a-e) have been synthesized. The present work describes the synthesis, characterization and bio-evaluation of five new N-tosyl benzimidazoles with the objective to develop new compounds with improved anticancer, antibacterial and urease inhibitory activities. The substituted 1,2-phenylenediamines in the first step were condensed with aliphatic carboxylic acids to synthesize the substituted benzimidazoles. In the second step the tosyl chloride was reacted with substituted benzimidazoles in basic conditions to afford the title N-tosyl benzimidazoles (4a-e). The screening for their antitumor activities was performed against Agrobacterium tumefaciens by following the potato disc tumor assay. The compound (4e) exhibited excellent antitumor activity with IC50 values 474.45μgml-1 compared to other synthesized compounds. Antibacterial activity results revealed that compounds 4d and 4e having methyl and ethyl substitution respectively at the imidazole ring showed excellent zone inhibition against both gram positive and gram negative strains. The urease inhibitory activity results showed that derivative 4e exhibited highest potential to inhibit the urease enzyme compared to all other derivatives. Based upon our investigation it is proposed that compound (4e) may serve as lead structure to design more potent biological active compounds having multitargets inhibition activities.
- Rashid, Naghmana,Kiran, Almas,Ashraf, Zaman,Bhatti, Moazzam Hussain,Mirza, Bushra,Ismail, Hammad,Rafiq, Muhammad,Jasinski, Jerry P.
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p. 366 - 374
(2018/06/06)
-
- Nanoporous TiO2 containing an ionic liquid bridge as an efficient and reusable catalyst for the synthesis of: N, N ′-diarylformamidines, benzoxazoles, benzothiazoles and benzimidazoles
-
In this work, a green and efficient procedure is reported for the preparation of N,N'-diarylformamidines, benzoxazoles, benzothiazoles, and benzimidazoles using nanoporous TiO2 containing an ionic liquid bridge. This reagent is prepared via the modification of nanoporous TiO2 with bis-3-(trimethoxysilylpropyl)-ammonium hydrogen sulfate (TiO2-[bip]-NH2+ HSO4-). The procedure gave the products in excellent yields in very short reaction times under solvent-free conditions. The reusability of the catalyst is the other important feature of the reported method.
- Mazloumi,Shirini,Goli-Jolodar,Seddighi
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p. 5742 - 5752
(2018/04/23)
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- Novel pyrrolo-imidazole derivatives and preparation method and application thereof
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The invention discloses novel pyrrolo-imidazole derivatives and a preparation method and application thereof, and relates to the field of organic synthesis and medical chemistry. The derivatives referto benzimidazo-pyrrole compounds and medicinal salts, enantiomers, diastereoisomers or racemes; a synthetic method of the novel pyrrolo-imidazole derivatives is simple and high in yield; the derivatives are of good antibacterial activity against various fungi and have a promising application prospect in antibacterial anti-cancer activity application.
- -
-
Paragraph 0041; 0042; 0044-0051
(2018/09/12)
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- Synthesis of 1H-1,3-benzimidazoles, benzothiazoles and 3H-imidazo[4,5-c]pyridine using DMF in the presence of HMDS as a reagent under the transition-metal-free condition
-
An operationally simple method for synthesis of benzimidazole and 3H-imidazo[4,5-c]pyridine from o-phenylenediamine or pyridine-3, 4-diamine and N,N-dimethylformamide (DMF) in the presence of hexamethyldisilazane (HMDS) as a reagent is described. To evaluate the scope of application of this reagent, it was also used to prepare benzothiazole, 1H-perimidine, and benzoxazole, which was successful for benzothiazole and 1H-perimidine but benzoxazole was not formed. This reaction complies with the principles of green chemistry as it does not use toxic solvents, transition metals, or strong acids. The products are obtained in moderate to excellent yields.
- Mostafavi, Hamid,Islami, Mohammad Reza,Ghonchepour, Ehsan,Tikdari, Ahmad Momeni
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p. 2973 - 2978
(2018/10/02)
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- Oxalic/malonic acids as carbon building blocks for benzazole, quinazoline and quinazolinone synthesis
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An oxidant, base and metal free methodology has been developed for the synthesis of various 2-substituted and non-substituted benzazoles, quinazolines and quinazolinones using oxalic/malonic acids as an in situ carbon source. This methodology is applicable for a wide range of substituted o-phenylenediamine, o-aminothiophenol, o-aminophenol and o-aminobenzamide containing various functional groups and provides good to excellent yields of the corresponding product. Furthermore an easy workup procedure, high yield and easy isolation of products are key features of this methodology. The developed protocol is also applicable for the gram scale synthesis of benzimidazoles.
- Sharma, Saurabh,Bhattacherjee, Dhananjay,Das, Pralay
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supporting information
p. 1337 - 1342
(2018/03/06)
-
- Design, synthesis and biological activity evaluation of novel 2,6-difluorobenzamide derivatives through FtsZ inhibition
-
Novel series of 3-substituted 2,6-difluorobenzamide derivatives as FtsZ inhibitors were designed, synthesized and evaluated for their in vitro antibacterial activity against various phenotype of Gram-positive and Gram-negative bacteria, and their cell division inhibitory activity against three representative strains. As a result, 3-chloroalkoxy derivative 7, 3-bromoalkoxy derivative 12 and 3-alkyloxy derivative 17 were found to exhibit the best antibacterial activity against Bacillus subtilis with MICs of 0.25–1 μg/mL, and good activity (MIC 10 μg/mL) against both susceptible and resistant Staphylococcus aureus. Additionally, all the three compounds displayed potent cell division inhibitory activity with MIC values of below 1 μg/mL against Bacillus subtilis and Staphylococcus aureus.
- Bi, Fangchao,Guo, Liwei,Wang, Yinhu,Venter, Henrietta,Semple, Susan J.,Liu, Fang,Ma, Shutao
-
supporting information
p. 958 - 962
(2017/02/10)
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- Preparative-scale synthesis of amino coumarins through new sequential nitration and reduction protocol
-
In contrast to the conventional deleterious approach for nitration (for example HNO3/H2SO4) and for reduction (for example Zn/HCl), we hypothesized that sensitive heterocycles such as coumarins could not withstand with those hard conditions. Hence, while studying this reaction sequence to prepare amino coumarins (which is our ongoing project to synthesize antitubercular coumarin agents), we came across mild and greener reagent for nitration using calcium nitrate (Ca(NO3)2·4H2O; lime nitrate), and reduction using D-glucose. These two mild, chemoselective, high yielding methods are discussed herein.
- Chaudhari, Hemchandra K.,Pahelkar, Akshata,Takale, Balaram S.
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p. 4107 - 4110
(2017/09/28)
-
- Fusion of 2-(furan-2-yl)thiazole to 1-methyl-1H-benzimidazole
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Methylation of 5(6)-nitro-1H-benzimidazole with methyl iodide in the presence of potassium hydroxide and N-methylpyrrolidin-2-one gave a mixture of isomeric 1-methyl-5-nitro- and 1-methyl-6-nitro-1H-benzimidazoles which were reduced with tin in concentrated aqueous HCl on heating. The resulting amines reacted with furan-2-carbonyl chloride in N-methylpyrrolidin-2-one to give furan-2-carboxamides which were treated with excess P2S5 in pyridine. Oxidation of isomeric furan-2-carbothioamides with K3[Fe(CN)6] in alkaline medium afforded a mixture of intramolecular cyclization products, 2-(furan-2-yl)-6-methyl-6H-imidazo[4,5-g][1,3]benzothiazole and 2-(furan-2-yl)-8-methyl-8H-imidazo[4,5-g][1,3]benzothiazole which were separated by column chromatography and identified.
- El’chaninov,Aleksandrov
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p. 547 - 549
(2017/06/06)
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- Synthesis of benzimidazoles from o-phenylenediamines and DMF derivatives in the presence of PhSiH3
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A simple approach to preparation of benzimidazoles from o-phenylenediamines and DMF derivatives, only employing PhSiH3 as promoter without any other additives, was reported. This route provided moderate to high yields with a broad substrate scope. A plausible mechanism for the reaction is proposed based on the spectroscopic characterization (e.g., HRMS and 1H NMR) of the reaction mixture.
- Zhu, Jianhua,Zhang, Zhenbei,Miao, Chengxia,Liu, Wei,Sun, Wei
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p. 3458 - 3462
(2017/05/31)
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- The Forgotten Nitroaromatic Phosphines as Weakly Donating P-ligands: An N-Aryl-benzimidazolyl Series in RhCl(CO) Complexes
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The coordination chemistry of a priori weakly σ-donating nitroaromatic phosphines is addressed through a series of nitro-substituted (N-phenyl-benzimidazol-1-yl)diphenylphosphines in RhI complexes. From a set of seven such phosphines L=Lxyz (′) (x, y, z=0 or 1=number of NO2 substituents at the 5, 6 and N-Ph para positions, respectively), including the non-nitrated parent L000 and its dicationic N-methyl counterpart L000′, three LRhCl(COD) and seven L2RhCl(CO) complexes have been obtained in 72–95 % yield. Despite of a cis orientation of the L and CO ligands, the C=O IR stretching frequency νCO varies in the expected sense, from 1967±1 cm?1 for Lxy0 to 1978±1 cm?1 for Lxy1, and 2005 cm?1 for L000′. The 103Rh NMR chemical shift δRh varies from ?288 ppm for L000 to ?316±1 ppm for L10z or L01z, and ?436 ppm for L000′. The νCO and δRh probes thus reveal moderate but systematic variations, and act as “orthogonal” spectroscopic indicators of the presence of nitro groups on the N-Ph group and the benzimidazole core, respectively. For the dicationic ligand L000′, a tight electrostatic sandwiching of the Rh-Cl bond by the benzimidazole moities is evidenced by X-ray crystallography (RhClδ????CN2 + ≈3.01 ?). Along with the LRhCl(CO) complexes, dinuclear side-products (μ-CO)(RhClL)2 were also obtained in low spectroscopic yield: for the dinitro ligand L=L011, a unique 1:6.7 clathrate structure, with dichloromethane as solvate, is also revealed by X-ray crystallography.
- Zhu, Chongwei,Gras, Emmanuel,Duhayon, Carine,Lacassin, Francis,Cui, Xiuling,Chauvin, Remi
-
supporting information
p. 2845 - 2856
(2017/10/20)
-
- Acidic ionic liquid immobilized on nanoporous Na+-montmorillonite as an efficient and reusable catalyst for the formylation of amines and alcohols
-
In this work, nanoporous sodium montmorillonite clay (Na+-MMT) was used as a support for the immobilization of 1-methyl-3-(trimethoxysilylpropyl)-imidazolium hydrogen sulfate. The Na+-MMT chemical modification ([Na+-MMT-[pmim]HSO4) was confirmed by a variety of techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy and potentiometric titration. The catalytic performance of this immobilized acidic ionic liquid was probed for the N-formylation of a variety of amines using formic acid under solvent-free conditions. This reagent is also useful for the formylation of benzylic alcohols. The procedure gave the products in excellent yields in very short reaction times. Also, this catalyst can be reused ten times without loss of its catalytic activity.
- Shirini, Farhad,Mazloumi, Masoumeh,Seddighi, Mohadeseh
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p. 1759 - 1776
(2016/03/16)
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- CO2 as a C1 Source: B(C6F5)3-Catalyzed Cyclization of o-Phenylene-diamines To Construct Benzimidazoles in the Presence of Hydrosilane
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The catalytic construction of benzimidazoles using CO2 as a carbon source represents a facile and sustainable approach to obtaining these valuable compounds. Herein, we describe the B(C6F5)3-catalyzed synthesis of benzimidazoles via cyclization of o-phenylenediamines with CO2 and PhSiH3. This metal-free catalytic route achieves the desired products in high yield under convenient reaction conditions and is applicable to a broad substrate scope. A plausible mechanism for the reaction involving a frustrated Lewis pair pathway is proposed based on spectroscopic characterization (e.g., 13C NMR) of the reaction intermediates.
- Zhang, Zhenbei,Sun, Qiangsheng,Xia, Chungu,Sun, Wei
-
supporting information
p. 6316 - 6319
(2016/12/23)
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- Atmospheric CO2 promoted synthesis of N-containing heterocycles over B(C6F5)3 catalyst
-
B(C6F5)3 combined with atmospheric CO2 was found to be highly effective for the cyclization of ortho-substituted aniline derivatives with N,N-dimethylformamide (DMF), and a series of N-containing heterocycles including benzothiazoles, benzimidazoles, quinazolinone and benzoxazole were obtained in good to excellent yields.
- Gao, Xiang,Yu, Bo,Mei, Qingqing,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Hao, Leiduan,Liu, Zhimin
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p. 8282 - 8287
(2016/10/11)
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- Nano-Ni(II)/Y Zeolite Catalyzed Synthesis of 2-Aryl- and 2-Alkyl Benzimidazoles Under Solvent-Free Conditions
-
Synthesis of some benzimidazole derivatives via condensation reaction of o-phenylenediamine derivatives with aromatic aldehydes or orthoesters under solvent-free conditions over nano-Ni(II)/Y zeolite as a heterogeneous catalyst is reported. Some advantages of this green method are easy purification, environmentally friendly conditions, low catalyst loadings, and nontoxic nature.
- Mobinikhaledi,Zendehdel,Goudarzi,Bardajee, G. Rezanejade
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p. 1526 - 1531
(2016/06/09)
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- Synthesis and evaluation of selected benzimidazole derivatives as potential antimicrobial agents
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A library of 53 benzimidazole derivatives, with substituents at positions 1, 2 and 5, were synthesized and screened against a series of reference strains of bacteria and fungi of medical relevance. The SAR analyses of the most promising results showed that the antimicrobial activity of the compounds depended on the substituents attached to the bicyclic heterocycle. In particular, some compounds displayed antibacterial activity against two methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentrations (MICs) comparable to the widely-used drug ciprofloxacin. The compounds have some common features; three possess 5-halo substituents; two are derivatives of (S)-2-ethanaminebenzimidazole; and the others are derivatives of one 2-(chloromethyl)-1Hbenzo[ d]imidazole and (1H-benzo[d]imidazol-2-yl)methanethiol. The results from the antifungal screening were also very interesting: 23 compounds exhibited potent fungicidal activity against the selected fungal strains. They displayed equivalent or greater potency in their MIC values than amphotericin B. The 5-halobenzimidazole derivatives could be considered promising broad-spectrum antimicrobial candidates that deserve further study for potential therapeutic applications.
- Alasmary, Fatmah A.S.,Snelling, Anna M.,Zain, Mohammed E.,Alafeefy, Ahmed M.,Awaad, Amani S.,Karodia, Nazira
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supporting information
p. 15206 - 15223
(2015/09/21)
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- Rhodium(I) N-Heterocyclic Carbene Bioorganometallics as in Vitro Antiproliferative Agents with Distinct Effects on Cellular Signaling
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Organometallics with N-heterocyclic carbene (NHC) ligands have triggered major interest in inorganic medicinal chemistry. Complexes of the type Rh(I)(NHC)(COD)X (where X is Cl or I, COD is cyclooctadiene, and NHC is a dimethylbenzimidazolylidene) represent a promising type of new metallodrugs that have been explored by advanced biomedical methods only recently. In this work, we have synthesized and characterized several complexes of this type. As observed by mass spectrometry, these complexes remained stable over at least 3 h in aqueous solution, after which hydrolysis of the halido ligands occurred and release of the NHC ligand was evident. Effects against mitochondria and general cell tumor metabolism were noted at higher concentrations, whereas phosphorylation of HSP27, p38, ERK1/2, FAK, and p70S6K was induced substantially already at lower exposure levels. Regarding the antiproliferative activity in tumor cells, a clear preference for iodido over chlorido secondary ligands was noted, as well as effects of the substituents of the NHC ligand.
- Oehninger, Luciano,Spreckelmeyer, Sarah,Holenya, Pavlo,Meier, Samuel M.,Can, Suzan,Alborzinia, Hamed,Schur, Julia,Keppler, Bernhard K.,W?lfl, Stefan,Ott, Ingo
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p. 9591 - 9600
(2016/01/12)
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- Facile synthesis of benzimidazole, benzoxazole, and benzothiazole derivatives catalyzed by sulfonated rice husk ash (RHA-SO3H) as an efficient solid acid catalyst
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A mild, simple, and efficient solvent-free method, with sulfonated rice husk ash as solid acid catalyst, has been developed for preparation of benzimidazole, benzoxazole, and benzothiazole derivatives. The products are obtained in good to high yields after very short reaction times, and the catalyst can be reused five times without loss of its catalytic activity.
- Shirini, Farhad,Mamaghani, Manouchehr,Seddighi, Mohadeseh
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p. 5611 - 5619
(2015/07/08)
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- A novel ionic liquid based on imidazolium cation as an efficient and reusable catalyst for the one-pot synthesis of benzoxazoles, benzthiazoles, benzimidazoles and 2-arylsubstituted benzimidazoles
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A novel dicationic ionic liquid based on imidazolium cation is designed, synthesized and successfully used as catalyst for the one-pot synthesis of benzoxazoles, benzthiazoles, benzimidazoles and 2-arylsubstituted benzimidazoles. The remarkable feature of this new catalyst is its ethyleneoxy bridge which participates in dissolving organic compound in ionic liquid. The application of this ionic liquid is studied in a new one-pot method for synthesis of heterocyclic compounds under solvent-free conditions. Simple and convenient procedure, high conversion, reusability of catalyst, easy purification and shorter reaction time are the advantageous features of this method.
- Hasanpour, Maede,Eshghi, Hossein,Bakavoli, Mehdi,Mirzaeia, Mahdi
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p. 412 - 419
(2015/05/27)
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- N-Substituted Formamides as C1-Sources for the Synthesis of Benzimidazole and Benzothiazole Derivatives by Using Zinc Catalysts
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An efficient and convenient one-pot protocol has been developed for the synthesis of a variety of benzimidazole, benzoxazole, and benzothiazole derivatives. This novel approach uses various o-phenylenediamines and N-substituted formamides (C1 sources) in a zinc-catalyzed cyclization in the presence of poly(methylhydrosiloxane) to afford the corresponding derivatives as sole products in moderate to excellent yields.
- Nale, Deepak B.,Bhanage, Bhalchandra M.
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p. 2835 - 2842
(2015/12/18)
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- Ionic Liquid-Catalyzed C-S Bond Construction using CO2 as a C1 Building Block under Mild Conditions: A Metal-Free Route to Synthesis of Benzothiazoles
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The construction of the C-S bond using CO2 as a C1 feedstock can be considered as a green route for the synthesis of S-containing compounds and is of great significance. Herein, we report the acetate-based ionic liquids (ILs)-catalyzed synthesis of benzothiazoles via cyclization of 2-aminothiophenols with CO2 and hydrosilane under mild conditions (e.g., 60 °C, 0.5 MPa). It was found that the IL (e.g., 1-butyl-3-methylimidazolium acetate, [Bmim][OAc]) served as a multifunctional catalyst with activating CO2 and hydrosilane to form a formoxysilane intermediate, as well as simultaneously activating 2-aminothiophenols through a hydrogen bond, finally resulting in the production of benzothiazoles. [Bmim][OAc] showed the best performance, and a series of benzothiazoles were obtained in high yields. To the best of our knowledge, this is the first protocol for the synthesis of benzothiazoles using CO2 as a C1 building block under metal-free and mild conditions.
- Gao, Xiang,Yu, Bo,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Hao, Leiduan,Han, Buxing,Liu, Zhimin
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p. 6648 - 6652
(2015/11/23)
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- Expedient synthesis of benzimidazoles using amides
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In the present report an efficient, rapid, facile and inexpensive route for the synthesis of benzimidazoles using 1,2-arylenediamines and N,N-dimethylformamide in acidic medium under thermal/microwave condition is developed. This reaction was further explored with the different amides to afford a library of 2-substituted benzimidazoles. The advantage of the present synthetic method includes shorter reaction time, easy work up and excellent yields without using catalysts.
- Kattimani, Pramod P.,Kamble, Ravindra R.,Meti, Gangadhar Y.
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p. 29447 - 29455
(2015/04/14)
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- Combinatorial synthesis of benzimidazole-azo-phenol derivatives as antifungal agents
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A chemically diverse library of benzimidazole-azo-phenol derivatives was efficiently prepared and screened for their antifungal activities against five phytopathogenic fungi. Some compounds exhibited potent antifungal activities. As compared with a commercially available agricultural fungicide, hymexazol, especially compound V-5 showed the most promising broad-spectrum antifungal activities against five phytopathogenic fungi. The EC50 values of V-5 against F. graminearum, A. solani, V. mali, B. cinerea, and C. lunata were 0.09, 0.08, 0.06, 0.07, and 0.11 mol/mL, respectively.
- Ke, Yazhen,Zhi, Xiaoyan,Yu, Xiang,Ding, Guodong,Yang, Chun,Xu, Hui
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- Synthesis, characterization, screening and docking analysis of 4-anilinoquinazoline derivatives as tyrosine kinase inhibitors
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We report here the design and synthesis of a series of 4-anilinoquinazoline derivatives, of which 7 compounds were crystallographically characterized, as epidermal growth factor receptor (EGFR) inhibitors by modifications on the aniline ring or at the 6-alkoxy site of the 6,7-dimethoxy-4-anilinoquinazoline pharmacophore. The relative inhibition efficiency on EGFR of all as-prepared compounds were measured and ordered, and the IC50 values of nine highly active compounds were determined by ELISA. Docking studies indicated that all 4-anilinoquinazoline derivatives could be inserted into the ATP-binding pocket of the EGFR via indirect docking, and that the modifications at the 3′-position of the anilino group and 6-alkoxy site of the quinazoline ring have little interference with the formation of the two essential H-bonds between the N3 of the quinazoline ring and Thr766 through a water molecule, and the N1 of the quinazoline ring and N-H of Met769. The displacing of the phenyl at 4-position with pyridinyl dramatically reduces the activity of the quinazoline pharmacophore, the resulting derivative (10) being the least active compound. The docking results also showed that the formation of new H-bonds between the N-H of the ethylenediamine group linked to the 6-alkoxy site and Asp776/Cys773 in the binding pocket of EGFR makes compounds 19 (IC50 = 12.1 ± 1.6 nM) and 20 (IC50 = 13.6 ± 0.8 nM) the most potent EGFR inhibitors in this class and worthy of further modification to obtain more potent anticancer compounds.
- Lue, Shuang,Zheng, Wei,Ji, Liyun,Luo, Qun,Hao, Xiang,Li, Xianchan,Wang, Fuyi
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- Cyclization of o-phenylenediamines by CO2 in the presence of H2 for the synthesis of benzimidazoles
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The cyclization of o-phenylenediamines by CO2 in the presence of H2 was presented to directly synthesize benzimidazoles, and a series of benzimidazoles were obtained in excellent yields using RuCl 2(dppe)2 as the catalyst.
- Yu, Bo,Zhang, Hongye,Zhao, Yanfei,Chen, Sha,Xu, Jilei,Huang, Changliang,Liu, Zhimin
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supporting information
p. 95 - 99
(2013/02/25)
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- Trimethylsilyl chloride catalyzed synthesis of substituted benzimidazoles using two phase system under microwave conditions, and their antimicrobial studies
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A convenient method using TMSCl (20 mol%) and microwave-induced technique for the synthesis of various benzimidazole is described. This has reduced the reaction time drastically as well as improved the yield when compared to conventional heating. The synthesized compounds were evaluated for their in vitro antibacterial and antifungal activities against four strains each. Preliminary results indicated that, compounds 3e, 3f, 3g, 3k, 3m, 3n and 3o demonstrated very good antimicrobial activity, comparable to the first line standard drugs. The most effective compounds have exhibited activity at MIC of 6.25 μg/mL.
- Karuvalam, Ranjith P.,Haridas, Karickal R.,Shetty, Suchetha N.
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p. 1122 - 1125,4
(2020/08/24)
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- Novel Approach to Benzimidazoles Using Fe3O4 Nanoparticles as a Magnetically Recoverable Catalyst
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Magnetically recoverable Fe3O4 nanoparticles have been synthesized as a catalyst for the cyclocondensation of 1,2-phenylenediamines with orthoesters under solvent-free conditions. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding benzimidazole derivative at 80 °C. This green method offers significant advantages in terms of its simplicity, low catalyst loadings, high product yields, and non-toxic nature. The Fe3O4 nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy.
- Karami, Bahador,Nikoseresht, Shaghayegh,Khodabakhshi, Saeed
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p. 298 - 301
(2016/04/10)
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- Novel silica tungstic acid (STA): Preparation, characterization and its first catalytic application in synthesis of new benzimidazoles
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A novel silica tungstic acid (STA) as a highly efficient catalyst has been synthesized and employed for the cyclocondensation of 1,2-phenylenediamines with orthoesters under solvent-free conditions. Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding benzimidazoles at 80 °C. To make the catalyst, sodium tungstate reacted with silica chloride under refluxing n-hexane. The STA as a novel solid acid was characterized by X-ray fluorescence, X-ray diffraction, and Fourier transform infrared spectroscopy.
- Karami, Bahador,Ghashghaee, Vahideh,Khodabakhshi, Saeed
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experimental part
p. 71 - 75
(2012/06/16)
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- Novel approach to benzimidazoles using Fe3O4 nanoparticles as a magnetically recoverable catalyst
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Magnetically recoverable Fe3O4 nanoparticles have been synthesized as a catalyst for the cyclocondensation of 1,2- phenylenediamines with orthoesters under solvent-free conditions. Catalyst loadings can be as low as 1 mol to give high yields of the corresponding benzimidazole derivative at 80°C. This green method offers significant advantages in terms of its simplicity, low catalyst loadings, high product yields, and non-toxic nature. The Fe3O4 nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy.
- Karami, Bahador,Nikoseresht, Shaghayegh,Khodabakhshi, Saeed
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experimental part
p. 298 - 301
(2012/06/29)
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- A rapid access to novel and known benzimidazole derivatives using silica chloride as a reusable catalyst
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A new application of silica chloride as an easily available and reusable solid acid catalyst for the synthesis of benzimidazole and its derivatives through the condensation of o-phenylenediamines and orthoesters under thermal and solvent-free conditions is described. This novel and eco-friendly method is very cheap and has many advantages including excellent yields, short reaction time, and simple work-up procedure. Copyright
- Karami, Bahador,Ghashghaee, Vahideh,Khodabakhshi, Saeed
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experimental part
p. 959 - 964
(2012/05/31)
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