118469-15-1Relevant articles and documents
A combined-redox synthesis of 2-alkylbenzimidazoles from 2-nitroanilines by semiconductor photocatalysis
Annadhasan,Selvam,Swaminathan
, p. 1500 - 1508 (2012)
One-pot photocatalytic synthesis of 2-substituted benzimidazoles from 2-nitroanilines with different alcohols by combined redox cyclization reaction using TiO2-P25 is reported. The reaction, when performed with ethanol, gives 2-methylbenzimidazole as a single product. However, in a mixture of ethanol and water (1:1), it gives both 2-methylbenzimidazole and 1-ethyl-2-methylbenzimidazole. The products have been characterized by Fourier transorm-infrared, 1H NMR, 13CNMR, and gas chromatography-mass spectrometry analysis. TiO2-P25 behaves as a combined redox photocatalyst by reducing 2-nitroaniline and oxidizing alcohols simultaneously under ultraviolet light. Easy product isolation under mild conditions and good yield make this one-pot synthesis ecofriendly. Copyright Taylor & Francis Group, LLC.
Benzimidazoles and benzothiazoles from styrenes and N-vinylimidazole via palladium catalysed oxidative C[dbnd]C and C[sbnd]N bond cleavage
Shaikh, Altab,Ravi, Owk,Pushpa Ragini,Sadhana, Nimma,Reddy Bathula, Surendar
, (2020)
Herein we report a first, palladium catalyzed, one-pot methodology for the synthesis of pharmacologically important benzimidazoles and benzothiazoles from readily available terminal aromatic olefins. The process involves sequential C[dbnd]C/C[sbnd]N bond cleavage followed by C[sbnd]N/C[sbnd]S bond formation.
Cu-Pd/γ-Al2O3 catalyzed the coupling of multi-step reactions: Direct synthesis of benzimidazole derivatives
Feng, Feng,Ye, Jia,Cheng, Zheng,Xu, Xiaoliang,Zhang, Qunfeng,Ma, Lei,Lu, Chunshan,Li, Xiaonian
, p. 72750 - 72755 (2016)
The coupling of multi-step reactions catalyzed by a heterogeneous catalyst is an important path to accomplish some unconventional chemical transformations. Since the starting materials generated from previous steps were adsorbed on the catalyst, the activation energy of following steps was largely decreased, and thus the reaction conditions were more mild and environmental friendly. Catalyzed by a multifunctional Cu-Pd/γ-Al2O3 catalyst, the transfer hydrogenation and successive cyclization coupling reaction from o-nitroaniline and alcohol to afford benzimidazole derivatives in high yield was realized. The catalyst could be reused several times without loss of activity. The synergies of reforming hydrogenation of Cu-Pd bimetal and support acidity of γ-Al2O3 were responsible for this catalytic transformation.
A facile one-pot synthesis of benzimidazoles from 2-nitroanilines by reductive cyclization
Liu, Zheng,Li, Haihong,Zhao, Qingjie,Shen, Jingshan
, p. 1907 - 1911 (2008)
A facile one-pot process to prepare benzimidazole derivatives is described. Reductive cyclization of a serial of 2-nitroanilines with orthoesters in the presence of Pd/C in methanol at room temperature, which is promoted by a catalytic amount of acetic acid, affords the corresponding benzimidazole derivatives in high yields.
Rhodium catalyzed 2-alkyl-benzimidazoles synthesis from benzene-1,2-diamines and tertiary alkylamines as alkylating agents
Yamini,Sharma, Saurabh,Das, Pralay
, (2021/05/17)
Substituted 2-alkyl-benzimidazoles were synthesized from benzene-1,2-diamine and tertiary amines as alkylating agent under polystyrene supported rhodium (Rh@PS) nanoparticles (NPs) catalyzed conditions. The heterogeneous rhodium catalyst was applied first time for the synthesis of 2-alkyl-benzimidazoles. The reaction followed through oxidation of alkylamines, transamination, and oxidative cyclisation with benzene-1,2-diamines for the corresponding products synthesis with good yields. The process is applicable for vast substrate scope, several functional groups are tolerable, and the Rh@PS catalyst is recyclable up to four cycles without significant loss in catalytic activity.
Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C2H3/CH Source
Sharma, Saurabh,Sharma, Ajay,Yamini,Das, Pralay
supporting information, p. 67 - 72 (2018/12/05)
An effective and stable polystyrene supported rhodium (Rh@PS) nano-catalyst has been synthesized by following reduction-deposition approach and applied for the selective benzimidazoles synthesis from 1,2-phenylenediamines and ethanol/methanol as C2H3/CH source. The ethanol/methanol in the presence of trace amounts of aerobic oxygen under Rh@PS catalysed condition, first participated in oxidation of alcohol followed by consecutive condensation, cyclization and hydrogen elimination reactions with 1,2-phenylenediamine gave the desired products in good yields. The Rh@PS catalyst in a single system performed both oxidation and reduction reactions in a selective/specific manner and applied for large substrate scope. Easy recovery, handling, stability, recyclability of the catalyst and less chance of metal contamination with the products are the added advantages of the process. (Figure presented.).
Oxalic/malonic acids as carbon building blocks for benzazole, quinazoline and quinazolinone synthesis
Sharma, Saurabh,Bhattacherjee, Dhananjay,Das, Pralay
supporting information, p. 1337 - 1342 (2018/03/06)
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.
3-ARYL AND HETEROARYL SUBSTITUTED 5-TRIFLUOROMETHYL OXADIAZOLES AS HISTONE DEACETYLASE 6 (HDAC6) INHIBITORS
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Page/Page column 84, (2018/04/11)
The present invention is directed to substituted 5-trifluoromethyl oxadiazole compounds of generic formula (I) or a pharmaceutically acceptable salt thereof. In particular, the invention is directed to a class of aryl and heteroaryl substituted 5-trifluoromethyl oxadiazole compounds of formula I which may be useful as HDAC6 inhibitors for treating cellular proliferative diseases, including cancer, neurodegenerative diseases, such as schizophrenia and stroke, as well as other diseases.
Derisking the Cu-Mediated 18F-Fluorination of Heterocyclic Positron Emission Tomography Radioligands
Taylor, Nicholas J.,Emer, Enrico,Preshlock, Sean,Schedler, Michael,Tredwell, Matthew,Verhoog, Stefan,Mercier, Joel,Genicot, Christophe,Gouverneur, Véronique
supporting information, p. 8267 - 8276 (2017/06/27)
Molecules labeled with fluorine-18 (18F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a derisking approach toward the radiosynthesis of heterocyclic positron emission tomography (PET) radioligands using the copper-mediated 18F-fluorination of aryl boron reagents with 18F-fluoride as a model reaction. This approach is based on a study examining how the presence of heterocycles commonly used in drug development affects the efficiency of 18F-fluorination for a representative aryl boron reagent, and on the labeling of more than 50 (hetero)aryl boronic esters. This set of data allows for the application of this derisking strategy to the successful radiosynthesis of seven structurally complex pharmaceutically relevant heterocycle-containing molecules.
Gadolinium (III) chloride catalyzed facile synthesis of 2-substituted benzimidazoles under solvent-free conditions
Sathaiah,Venkat Lingaiah,Chandra Shekhar,Ravi Kumar,Raju,Shanthan Rao
, p. 953 - 957 (2015/08/19)
A series of 2-substituted benzimidazoles have been prepared from o-diamines and 1,3-dicarbonyl compounds using Gadolinium chloride as a catalyst under solvent free condition in good yields. Gadolinium chloride has been demonstrated as a mild and efficient catalyst.
