An efficient synthesis of 2H-indazoles via reductive cyclization of 2-nitrobenzylamines induced by low-valent titanium reagent
作者:Fang Sun、Xian Feng、Xuan Zhao、Zhi-Bin Huang、Da-Qing Shi
DOI:10.1016/j.tet.2012.03.043
日期:2012.5
An efficient and improved synthesis of 2H-indazoles via reductive cyclization of 2-nitrobenzylamines induced by low-valent titanium reagent (TiCl4/Zn) is described. In this reaction triethylamine (TEA) was used to control the pH value. This method has the advantages of easily accessible starting materials, convenient manipulation, higher yield, shorter reaction time, and wider substrate scope.
描述了通过低价钛试剂(TiCl 4 / Zn)诱导的2-硝基苄胺的还原环化,有效和改进的2 H-吲唑合成。在该反应中,使用三乙胺(TEA)来控制pH值。该方法的优点是容易获得起始原料,方便的操作,较高的产率,较短的反应时间和较宽的底物范围。