Facile synthesis of pyrazolo[1,5-a]pyridopyrazin-one via Smiles rearrangement or direct cyclization
作者:Youxin Xiao、Zhicheng Zhang、Yinbo Chen、Xusheng Shao、Zhong Li、Xiaoyong Xu
DOI:10.1016/j.tet.2015.01.059
日期:2015.3
A facile access to pyrazolo[1,5-a]pyridopyrazin-one is presented via Smiles rearrangement or direct cyclization. The method allows the convenient construction of a novel biaryl lactam in moderate to excellent yields starting from easily available precursors (18 examples, 75–97% yield). When R is an aryl group, two regioisomeric products were obtained, Smiles rearrangement product and direct cyclization
通过Smiles重排或直接环化,可轻松获得吡唑并[1,5- a ]吡啶并吡嗪一。该方法可以方便地从容易获得的前体开始,以中等至极好的收率构建新型联芳基内酰胺(18例,收率75-97%)。当R为芳基时,获得两个区域异构产物,Smiles重排产物和直接环化产物,但是当R为烷基或苄基时,选择性地提供Smiles重排产物。为了证明所提出的机制,捕获了中间6k。