A simple and efficient method for the synthesis of highly substituted imidazoles using 3-aroylquinoxalin-2(1H)-ones
作者:Vakhid A. Mamedov、Nataliya A. Zhukova、Tat′yana N. Beschastnova、Aidar T. Gubaidullin、Dimitry V. Rakov、Il’dar Kh. Rizvanov
DOI:10.1016/j.tetlet.2011.06.014
日期:2011.8
analogues of α-diketones for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted imidazoles and imidazo[1,5-a]quinoxalin-4(5H)-ones in boiling methanol. The key advantages of this process are high yields, ready availability and low cost of 3-aroylquinoxalin-2(1H)-ones and easy work-up and separation of the products by non-chromatographic methods. Furthermore, the presence of an
发现3-Aroylquinoxalin-2(1 H)-ones是α-二酮的杂类似物,可高效,一锅,三组分合成2,4,5-三取代的咪唑和咪唑[1,5- a ]喹喔啉-4(5 H)-在沸腾的甲醇中的混合物。该方法的主要优点是高产率,3-芳基喹喔啉-2(1 H)-1的易得性和低成本以及通过非色谱法易于处理和分离产物的能力。此外,在获得的咪唑的4位上存在邻-亚氨基苯胺片段使得以几乎定量的产率生产2-(咪唑-4-基)苯并咪唑成为可能。
An efficient method for the synthesis of imidazo[1,5-a]quinoxalines from 3-acylquinoxalinones and benzylamines via a novel imidazoannulation
作者:Vakhid A. Mamedov、Aleksey A. Kalinin、Alsu A. Balandina、Il'dar Kh. Rizvanov、Shamil K. Latypov
DOI:10.1016/j.tet.2009.08.081
日期:2009.11
The reaction of 3-aroylquinoxalin-2(1H)-ones and their N-alkyl analogues with benzylamines in DMSO proceeds through an intermediate formation of N-(alpha-quinoxalinylbenzylydene)benzylamine, which when subjected to oxidative cyclocondensation gives imidazo[1,5-a]quinoxalines. Applying this new approach of imidazoannullation to the bis-3-aroylquinoxalines makes it possible to develop fundamentally new methods of the synthesis of bis-imidazo[1,5-a]quinoxalines with the use of different benzylamines and heteromacrocycles with the 1,3-bis(3-arylimidazo[1,5-a]quinoxalin-1-yl)benzene structural fragment when m-xylylenediamine is used. (c) 2009 Elsevier Ltd. All rights reserved.