79877-53-5Relevant articles and documents
A one-step synthesis of substituted benzo- and pyridine-fused 1H-imidazoles
Bhatt, Ashish,Kant, Ravi,Kumar, Sonu,Reddy, Yella,Sarmah, Manash P.
, (2021/11/23)
Substituted benzimidazoles and pyrimidazoles are an important group of heterocyclic aromatic organic compounds in the field of medicinal chemistry. A one-step microwave accelerated synthesis of substituted benzo- and pyridine-fused 1H-imidazoles has been described. Mechanistically, the reaction proceeds by reacting substituted 2-fluoronitrobenzene and substituted arylamine through the formation of N-hydroxy intermediate, which at higher temperature cleaves to afford the desired product. This approach achieved reductions in reaction times, higher yields, cleaner reactions than the previously described synthetic processes.
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.
New synthesis method of thiabendazole
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Paragraph 0026; 0035; 0036; 0037; 0038; 0190; 0191, (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.
