铜催化邻卤代乙酰苯胺衍生物与盐酸脒通过串联反应合成苯并咪唑类化合物。

Copper-catalyzed synthesis of benzimidazoles via cascade reactions of o-haloacetanilide derivatives with amidine hydrochlorides.

作者信息

Yang Daoshan, Fu Hua, Hu Liming, Jiang Yuyang, Zhao Yufen

机构信息

Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China.

出版信息

J Org Chem. 2008 Oct 3;73(19):7841-4. doi: 10.1021/jo8014984. Epub 2008 Aug 28.

DOI:10.1021/jo8014984

PMID:18754576

Abstract

We have developed an efficient method for the synthesis of benzimidazoles via cascade reactions of o-haloacetoanilide derivatives with amidine hydrochlorides. The protocol uses 10 mol % CuBr as the catalyst, Cs2CO3 as the base, and DMSO as the solvent, and no ligand is required. The procedure proceeds via the sequential coupling of o-haloacetoanilide derivatives with amidines, hydrolysis of the intermediates (amides), and intramolecular cyclization with the loss of NH3 to give 2-substituted 1H-benzimidazoles.

摘要

我们已经开发出一种通过邻卤代乙酰苯胺衍生物与盐酸脒的级联反应高效合成苯并咪唑的方法。该方案使用10 mol%的CuBr作为催化剂，碳酸铯作为碱，二甲基亚砜作为溶剂，且无需配体。该过程通过邻卤代乙酰苯胺衍生物与脒的顺序偶联、中间体（酰胺）的水解以及分子内环化并失去氨生成2-取代的1H-苯并咪唑。