Synthetic Utility of Catalytic Fe(III)/Fe(II) Redox Cycling Towards Fused Heterocycles: A Facile Access to Substituted Benzimidazole, Bisbenzimidazole and Imidazopyridine Derivatives
作者:Malvinder P. Singh、Sanjita Sasmal、Wei Lu、Manashi N. Chatterjee
DOI:10.1055/s-2000-7111
日期:——
A catalytic Fe(III)/Fe(II) redox cycling approach has been examined and applied towards synthesis of a wide range of benzimidazole, bis-benzimidazole and imidazopyridine derivatives from oxidative coupling of aromatic ortho-diamines with aromatic as well as heterocyclic aldehydes bearing different types of substituents. This versatile and convenient method has further proven to be particularly useful
Structure-activity relationships of arylimidazopyridine cardiotonics: discovery and inotropic activity of 2-[2-methoxy-4-(methylsulfinyl)phenyl]-1H-imidazo[4,5-c]pyridine
作者:David W. Robertson、E. E. Beedle、Joseph H. Krushinski、G. Don Pollock、Harve Wilson、Virginia L. Wyss、J. Scott Hayes
DOI:10.1021/jm00383a006
日期:1985.6
2-phenylimidazo[4,5-b]pyridines (e.g., sulmazole) or 8-phenylpurines. Furthermore, all imidazo[4,5-c]pyridine analogues we tested were orally active; in contrast, only one of the imidazo[4,5-b]pyridinederivatives, sulmazole, was significantly active. One of several highly active compounds in the [4,5-c] series was 50 (LY175326, 2-[2-methoxy-4-(methylsulfinyl)phenyl]-1H-imidazo[4,5-c]pyridine hydrochloride)
versatile method for the synthesis of benzimidazoles was achieved in one step via the Na 2 S 2 O 4 reduction of o-nitroanilines in the presence of aldehydes. Heating a solution of o-nitroaniline (1c) and an aldehyde in EtOH or another appropriate solvent, in the presence of aqueous or solid Na 2 S 2 O 4 , provided facile access to a series of 2-substituted N-H benzimidazoles 5a-m containing a wide range of
通过在醛的存在下通过Na 2 S 2 O 4 还原邻硝基苯胺,一步实现了一种高效且通用的苯并咪唑合成方法。在存在水性或固体 Na 2 S 2 O 4 的情况下,加热邻硝基苯胺 (1c) 和醛在 EtOH 或其他合适溶剂中的溶液,可轻松获得一系列 2-取代的 NH 苯并咪唑 5a-m,其中含有广泛的官能团并不总是与现有的合成方法兼容。该方法也已分别通过相应的 N-取代的硝基苯胺 13a-e 的环化应用于 N-烷基和 N-芳基苯并咪唑 6a-f 的区域选择性合成。此外,该方法成功地应用于合成其他含咪唑杂环体系如1H-咪唑[4,
Eco-friendly and facile synthesis of 2-substituted-1H-imidazo[4,5-b]pyridine in aqueous medium by air oxidation
作者:Rajesh P. Kale、Mohammad U. Shaikh、Ganesh R. Jadhav、Charansingh H. Gill
DOI:10.1016/j.tetlet.2008.12.104
日期:2009.4
a new environmentally-benign, convenient, and facile methodology for the synthesis of 2-substituted-1H-imidazo[4,5-b]pyridine. The reaction of 2,3-diaminopyridine with substituted arylaldehydes in water under thermal conditions without the use of any oxidative reagent has been studied. The reaction has yielded 1H-imidazo[4,5-b]pyridine derivatives by an air oxidative cyclocondensation reaction in
我们报告了一种新的环境友好,方便,简便的方法合成2-取代-1 H-咪唑并[4,5- b ]吡啶。研究了2,3-二氨基吡啶与取代的芳基醛在水中在热条件下不使用任何氧化剂的反应。反应产生1 H-咪唑并[4,5- b吡啶衍生物通过空气氧化环缩合反应一步一步即可获得极佳的收率。此外,合成了一系列化合物,并通过熔点,EI-MS,NMR和IR工具对其进行了表征。为了比较,参考样品通过报道的方法制备。从经济和环境的角度来看,利用水性介质,容易的反应条件,分离和纯化使这种操作非常有趣。
Dubey; Vinod Kumar, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2000, vol. 39, # 10, p. 746 - 751