79529-98-9Relevant academic research and scientific papers
One-Pot Transformation of Lignin and Lignin Model Compounds into Benzimidazoles
Guo, Tao,He, Jianghua,Liu, Tianwei,Zhang, Yuetao
supporting information, (2022/02/07)
It is a challenging task to simultaneously achieve selective depolymerization and valorization of lignin due to their complex structure and relatively stable bonds. We herein report an efficient depolymerization strategy that employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant/catalyst to selectively convert different oxidized lignin models to a wide variety of 2-phenylbenzimidazole-based compounds in up to 94 % yields, by reacting with o-phenylenediamines with varied substituents. This method could take full advantage of both Cβ and/or Cγ atom in lignin structure to furnish the desirable products instead of forming byproducts, thus exhibiting high atom economy. Furthermore, this strategy can effectively transform both the oxidized hardwood (birch) and softwood (pine) lignin into the corresponding degradation products in up to 45 wt% and 30 wt%, respectively. Through a “one-pot” process, we have successfully realized the oxidation/depolymerization/valorization of natural birch lignin at the same time and produced the benzimidazole derivatives in up to 67 wt% total yields.
H2 Activation with Co Nanoparticles Encapsulated in N-Doped Carbon Nanotubes for Green Synthesis of Benzimidazoles
Lin, Chuncheng,Wan, Weihao,Wei, Xueting,Chen, Jinzhu
, p. 709 - 720 (2020/11/30)
Co nanoparticles (NPs) encapsulated in N-doped carbon nanotubes (Co@NC900) are systematically investigated as a potential alternative to precious Pt-group catalysts for hydrogenative heterocyclization reactions. Co@NC900 can efficiently catalyze hydrogenative coupling of 2-nitroaniline to benzaldehyde for synthesis of 2-phenyl-1H-benzo[d]imidazole with >99 % yield at ambient temperature in one step. The robust Co@NC900 catalyst can be easily recovered by an external magnetic field after the reaction and readily recycled for at least six times without any evident decrease in activity. Kinetic experiments indicate that Co@NC900-promoted hydrogenation is the rate-determining step with a total apparent activation energy of 41±1 kJ mol?1. Theoretical investigations further reveal that Co@NC900 can activate both H2 and the nitro group of 2-nitroaniline. The observed energy barrier for H2 dissociation is only 2.70 eV in the rate-determining step, owing to the presence of confined Co NPs in Co@NC900. Potential industrial application of the earth-abundant and non-noble transition metal catalysts is also explored for green and efficient synthesis of heterocyclic compounds.
Photochemical Synthesis of Benzimidazoles from Diamines and Aldehydes
Skolia, Elpida,Apostolopoulou, Mary K.,Nikitas, Nikolaos F.,Kokotos, Christoforos G.
supporting information, p. 422 - 428 (2020/12/13)
An efficient, green, cheap, and metal-free photochemical protocol for the synthesis of benzimidazoles has been developed. 2,2-Dimethoxy-2-phenylacetophenone was employed as the photoinitiator and CFL lamps were used as the light source, leading to the cyc
Preparation method of 2-substituted benzimidazole compound
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Paragraph 0079-0083, (2021/02/20)
The invention discloses a preparation method of a 2-substituted benzimidazole compound, and belongs to the field of synthesis of benzimidazole compounds. The 2-substituted benzimidazole compound is synthesized in an organic solvent by taking an o-nitroaniline compound, aromatic aldehyde, o-dinitrobenzene and aromatic aldehyde as raw materials and taking Co particles wrapped by a nitrogen-doped carbon material as a catalyst. According to the method, the 2-substituted benzimidazole compound can be prepared at room temperature, the reaction conditions are mild, the yield is as high as 95%, the selectivity is as high as 99%, and the method is economical, environmentally friendly and wide in substrate applicability. The used catalyst is easy to prepare, low in cost and good in reusability, canbe separated by utilizing magnetism, and is convenient to recover, so that the method has a relatively strong industrial application prospect.
A heterogeneous catalytic strategy for facile production of benzimidazoles and quinoxalines from primary amines using the Al-MCM-41 catalyst
Vasu, Amrutham,Naresh, Mameda,Krishna Sai, Gajula,Divya Rohini, Yennamaneni,Murali, Boosa,Ramulamma, Madasu,Ramunaidu, Addipilli,Narender, Nama
, p. 9439 - 9446 (2021/12/09)
This study reports a straightforward heterogeneous catalytic (Al-MCM-41) approach to synthesize nitrogen heterocycle moieties from primary amines under solvent-free conditions. The Al-MCM-41 catalyst was prepared using a hydrothermal method and characterized by various analytical techniques. The probability and limitations of the catalytic methodology were presented with various substrates. The catalytic method grants an attractive route to a wide variety of benzimidazole and quinoxaline moieties with good to excellent yields. The gram scale reaction and reusability (up to five cycles) of the Al-MCM-41 catalyst would greatly benefit industrial applications. This journal is
A one-pot synthesis of benzimidazoles via aerobic oxidative condensation of benzyl alcohols with o-phenylenediamines catalyzed by [MIMPs]+Cl-/NaNO2/TEMPO
Geng, Zhenzhen,Zhang, Hong-Yu,Yin, Guohui,Zhang, Yuecheng,Zhao, Jiquan
, p. 557 - 565 (2020/03/30)
The ionic liquid 1-methyl-3-(3-sulfopropyl)imidazolium chloride ([MIMPs]+Cl-) in combination with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and sodium nitrite (NaNO2) as a catalytic system demonstrates high efficiency in the one-pot two-step aerobic oxidative condensation of benzyl alcohols with 1,2-phenylenediamines to give benzimidazoles. Various benzimidazoles are obtained in good to excellent yields by this strategy.
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
, (2019/12/26)
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.
Oxidative Cyclization Approach to Benzimidazole Libraries
Arnold, Eric P.,Mondal, Prolay K.,Schmitt, Daniel C.
supporting information, p. 1 - 5 (2020/02/20)
An efficient approach to the parallel synthesis of benzimidazoles from anilines is described. Library approaches to vary the N1 and C2 vectors of benzimidazoles are well established; however, C4-C7 variation has traditionally relied on 1,2-dianiline build
New synthesis method of thiabendazole
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Paragraph 0026; 0035; 0036; 0037; 0038; 0194; 0195, (2020/02/20)
The invention relates to a new synthetic route of a drug commonly named as thiabendazole. Thiazole-4-formaldehyde is used as a raw material, and is condensed with hydroxylamine hydrochloride to obtainthiazole-4-formaldoxime, thiazole-4-formaldoxime is subjected to chlorination by using NCS, and then reacts with aniline to obtain N-phenylthiazole-4-methylamine oxime, then N-phenylthiazole-4-methylamine oxime reacts with p-trifluoromethyl benzoyl chloride to obtain an amidoxime ester, and finally a visible-light-catalyzed free radical reaction is adopted for cyclization to obtain thiazole. According to the method, the visible-light-catalyzed free radical reaction is used to the synthesis of thiabendazole for the first time, the reaction conditions of a high temperature and a strong acid inthe traditional synthesis method are avoided, and thereby the reaction is greener and milder. The method has a broad spectrum, and can also be used for synthesis of imidazole compounds Ia-Ial.
