2620-79-3Relevant academic research and scientific papers
Catalyst-free synthesis of benzodiazepines and benzimidazoles using glycerol as recyclable solvent
Radatz, Catia S.,Silva, Rodrigo B.,Perin, Gelson,Lenardao, Eder J.,Jacob, Raquel G.,Alves, Diego
, p. 4132 - 4136 (2011)
We described herein the use of glycerol as solvent in the catalyst-free synthesis of benzodiazepines and benzimidazoles. This simple and efficient method furnishes the corresponding 1-H-1,5-benzodiazepines and 1,2-disubstituted benzimidazoles in good yiel
A pentanuclear Er (III) coordination cluster as a catalyst for selective synthesis of 1,2-disubstituted benzimidazoles
Sarkar, Arijit,Jana, Sourav,Nayek, Hari Pada
, (2021)
A new tridentate ligand (H3L) was prepared from the reaction of 6-formyl-2-(hydroxymethyl)-4-tert-butylphenol and 2-amino-4-nitrophenol. The ligand H3L and acetylacetone were treated with Er (NO3)3·5H2/sub
Design, synthesis, characterization, and in vitro cytotoxic activity evaluation of 1,2-disubstituted benzimidazole compounds
Akko?, Senem
, (2020/08/19)
A series of 2-p-tolyl-1H-benzo[d]imidazole derivatives were synthesized and characterized. For finding an effective anticancer drug, which could be used in future generations, the developed heterocyclic compounds were screened in the human epithelial breast adenocarcinoma cell line (MCF-7) and human liver epithelial hepatocellular carcinoma cell line (HepG2) using the MTT assay method. Two positive control drugs were used for comparison with the compounds. The substituents on the 1- and 2-positions of the benzimidazole core had an important effect on the antiproliferation of cancerous cells. According to the results obtained, a compound, namely, 1-(4-methylbenzyl)-2-p-tolyl-1H-benzo[d]imidazole, which has electron donating groups (CH3) in the para position of a phenyl ring, showed higher cytotoxic activities compared to other compounds towards liver and breast cell lines. The compounds were found to have more cytotoxicity in HepG2 rather than MCF-7.
Electrochemical Synthesis of Benzo[ d]imidazole via Intramolecular C(sp3)-H Amination
Li, An,Li, Caohui,Li, Lijun,Liu, Yu,Tang, Kewen,Yang, Tao,Yang, Zan,Zhou, Congshan
, (2022/01/03)
An electrochemical dehydrogenative amination for the synthesis of benzimidazoles was developed. This electrosynthesis method could address the limitations of the C(sp3)-H intramolecular amination synthesis reaction and provide novel access to obtain 1,2-disubstituted benzimidazoles without transition metals and oxidants. Under undivided electrolytic conditions, various benzimidazole derivatives could be synthesized, exhibiting functional group tolerance.
Nickel catalyzed sustainable synthesis of benzazoles and purines: Via acceptorless dehydrogenative coupling and borrowing hydrogen approach
Chakraborty, Gargi,Guin, Amit Kumar,Mondal, Rakesh,Paul, Nanda
, p. 7217 - 7233 (2021/08/30)
Herein we report nickel-catalyzed sustainable synthesis of a few chosen five-membered fused nitrogen heterocycles such as benzimidazole, purine, benzothiazole, and benzoxazole via acceptorless dehydrogenative functionalization of alcohols. Using a bench stable, easy to prepare, and inexpensive Ni(ii)-catalyst, [Ni(MeTAA)] (1a), featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)), a wide variety of polysubstituted benzimidazole, purine, benzothiazole, and benzoxazole derivatives were prepared via dehydrogenative coupling of alcohols with 1,2-diaminobenzene, 4,5-diaminopyrimidine, 2-aminothiphenol, and 2-aminophenol, respectively. A wide array of benzimidazoles were also prepared via a borrowing hydrogen approach involving alcohols as hydrogen donors and 2-nitroanilines as hydrogen acceptors. A few control experiments were performed to understand the reaction mechanism.
Water extract of onion catalyst: An economical green route for the synthesis of 2-substituted and 1,2-disubstituted benzimidazole derivatives with high selectivity
Kaliyan, Prabakaran,Selvaraj, Loganathan,Muthu, Seenivasa Perumal
supporting information, p. 340 - 349 (2020/12/01)
An efficient, environmental friendly and substrate controlled method of synthesis of 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 with high selectivity has been achieved from the reaction of o-phenylenediamine 1 and aldehydes 2 in the presence of water extract of onion and selecting suitable reaction medium. This method is widely applicable for variety of aldehydes such as aromatic/aliphatic/heterocyclic aldehydes and 1,2-diamines to afford 2-substituted benzimidazole derivatives 3 and 1,2-disubstituted benzimidazole derivatives 4 in good to excellent yields (up to 96%). The developed method of water extract of onion catalysis produced 2-substituted benzimidazoles 3 from aromatic aldehydes having electron-withdrawing groups, whereas aromatic aldehydes bearing electron donating groups selectively furnished 1,2-disubstituted benzimidazole 4 derivatives. The process described here has several advantages of cheap, low energy consumption, commercially available starting materials, operational simplicity and nontoxic catalyst. The use of water extract of onion makes this present methodology green and giving a useful contribution to the existing methods available for the preparation of benzimidazole derivatives. In addition, Hammett correlation of substituent constant (σ) vs percentage (%) yield has been established.
1,2-Disubstituted Benzimidazoles by the Iron Catalyzed Cross-Dehydrogenative Coupling of Isomeric o-Phenylenediamine Substrates
Foss, Frank W.,Palacios, Philip M.,Pierce, Brad S.,Thapa, Pawan,Tran, Tam
, p. 1991 - 2009 (2020/03/13)
Benzimidazoles are common in nature, medicines, and materials. Numerous strategies for preparing 2-arylbenzimidazoles exist. In this work, 1,2-disubstituted benzimidazoles were prepared from various mono- and disubstituted ortho-phenylenediamines (OPD) by iron-catalyzed oxidative coupling. Specifically, O2 and FeCl3·6H2O catalyzed the cross-dehydrogenative coupling and aromatization of diarylmethyl and dialkyl benzimidazole precursors. N,N′-Disubstituted-OPD substrates were significantly more reactive than their N,N-disubstituted isomers, which appears to be relative to their propensity for complexation and charge transfer with Fe3+. The reaction also converted N-monosubstituted OPD substrates to 2-substituted benzimidazoles; however, electron-poor substrates produce 1,2-disubstituted benzimidazoles by intermolecular imino-transfer. Kinetic, reagent, and spectroscopic (UV-vis and EPR) studies suggest a mechanism involving metal-substrate complexation, charge transfer, and aerobic turnover, involving high-valent Fe(IV) intermediates. Overall, comparative strategies for the relatively sustainable and efficient synthesis of 1,2-disubstituted benzimidazoles are demonstrated.
Nickel catalysed construction of benzazoles: Via hydrogen atom transfer reactions
Adhikari, Debashis,Bains, Amreen K.,Dey, Dhananjay,Kundu, Abhishek,Yadav, Sudha
, p. 6495 - 6500 (2020/11/13)
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
Facile Synthesis of 1,2-Disubstituted Benzimidazoles Usingp-Toluenesulfonic Acid through Grinding Method
Kathing, C.,Nongkhlaw, R.,Nongrum, R.,Singh, N. G.,World Star Rani, J.
, p. 1628 - 1634 (2020/10/22)
Abstract: An efficient synthetic method for the highly selective synthesis ofpharmacologically active 1,2-disubstituted benzimidazole derivatives fromo-phenylenediamine and various aromaticaldehydes catalyzed by p-toluenesulfonic acidthrough grinding unde
Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation
Godugu, Kumar,Gundala, Trivikram Reddy,Mohinuddin Pinjari, Mohammad Khaja,Reddy Nallagondu, Chinna Gangi,Sanapareddy, Lakshmi Reddy,Sri Yadala, Venkata Divya
supporting information, p. 1881 - 1900 (2020/10/02)
Natural dolomitic limestone (NDL) is employed as a heterogeneous green catalyst for the synthesis of medicinally valuable benzimidazoles, dihydropyrimidinones, and highly functionalized pyridines via C–N, C–C, and C–S bond formations in a mixture of ethan
