6528-76-3Relevant academic research and scientific papers
RESEARCH ON THE CHEMISTRY OF 2-HETARYLBENZIMIDAZOLES. 4. OXIDATION OF 1-METHYL-2-(5'-METHYL-2'-HETARYL)BENZIMIDAZOLES
El'chaninov, M. M.,Simonov, A. M.,Simkin, B. Ya.
, p. 833 - 835 (1982)
The methyl group in 1-methyl-2-(5'-methyl-2'-hetaryl)benzimidazoles (hetaryl = furyl and thienyl) was oxidized.It was found that a salt of a carboxylic acid, which in an acidic medium loses carbon dioxide to give 1-methyl-2-(2'-furyl)-benzimidazole, is formed when 1-methyl-2-(5'-methyl-2'-furyl)benzimidazole is treated with an aqueous solution of potassium permanganate.The carboxy derivative of thiophene is considerably more stable.Oxidation by means of selenium dioxide leads to the corresponding 5'-formyl derivative.The structures of the compounds obtained were confirmed by data from the IR and PMR spectra.
Preparation method of benzimidazole compounds in sterilizing agent and pesticide
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Paragraph 0050-0052; 0064-0068; 0081-0082, (2021/03/03)
The invention provides a new synthesis method of benzimidazole compounds which can be applied to preparation of disinfectants and pesticides, and the benzimidazole compounds are synthesized by using oxalyl diamine compounds which are simple and easy to prepare as ligands and using CuI to catalyze o-amide substituted chlorinated aryl compounds. The method has the advantages that a reaction system is cheap and easy to prepare, the method can be suitable for industrial production, and reaction conditions are mild. In addition, the reaction also has the advantages of low catalyst and ligand equivalents, simplicity, convenience, economy, wide substrate application range and the like. The benzimidazole compound obtained by the preparation method can be used as a killing agent and a pesticide bactericide.
A dual biomimetic process for the selective aerobic oxidative coupling of primary amines using pyrogallol as a precatalyst. Isolation of the [5 + 2] cycloaddition redox intermediates
Deschamps, Patrick,Fleury, Maurice-Bernard,Hammad, Karim,Largeron, Martine
, p. 1894 - 1905 (2020/04/07)
A bioinspired organocatalytic cascade reaction mimicking both purpurogallin biosynthesis and copper amine oxidases (CuAOs) activity is described, at room temperature under ambient air, for the activation of the α-C-H bond of primary amines. The reaction sequence uses low-cost commercially available pyrogallol as a precatalyst which undergoes an in situ oxidative self-processing step, resulting in its conversion into natural purpurogallin, a [5 + 2] cycloaddition redox intermediate. This is further involved in the CuAOs-like transamination mechanism for producing, under single turnover, the active biomimetic organocatalyst which mediates the selective oxidative coupling of primary amines, including the non-activated substrates of CuAOs. Without any metal cocatalyst or additives, the protocol gives access to cross-coupled imines as well as 1,2-disubstituted benzimidazoles. The isolation of not easily accessible [5 + 2] cycloaddition redox intermediates provides direct and clear evidence for the proposed dual biomimetic process.
Catalytic Oxidative Coupling of Primary Amines under Air: A Flexible Route to Benzimidazole Derivatives
Nguyen, Khac Minh Huy,Largeron, Martine
supporting information, p. 1025 - 1032 (2016/03/01)
Benzimidazoles are of fundamental importance in chemistry and biology, and the development of efficient, environmentally benign methods for their preparation remains a key challenge for organic chemists. In a biomimetic approach inspired by copper amine oxidases, we disclose herein the scope and factors influencing the success of the cooperative action of CuBr2 as electron-transfer mediator and a topaquinone-like substrate-selective catalyst in the oxidative cyclocondensation of primary amines with o-aminoanilines. This one-pot atom-economic multistep process, which works under green conditions with ambient air as the terminal oxidant, low loadings of catalyst, and equimolar amounts of commercially available amine substrates, is particularly suitable for the preparation of 1,2-disubstituted benzimidazoles. Furthermore, it allows the functionalization of nonactivated primary aliphatic amines, which are known to be challenging substrates for non-enzymatic catalytic aerobic systems.
A Keggin heteropoly acid as an efficient catalyst for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles
Chakrabarty, Manas,Mukherji, Ajanta,Mukherjee, Ratna,Arima, Shiho,Harigaya, Yoshihiro
, p. 5239 - 5242 (2008/02/08)
The Keggin heteropoly acid, silicotungstic acid, H4SiW12O40, has been demonstrated to be highly efficient for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles from N-methyl-1,2-phenylenediamine and (hetero)aryl aldehydes in ethyl acetate at room temperature. The catalyst works equally well for N-phenyl-1,2-phenylenediamine.
