Catalyst-free synthesis of (7<i>E</i>)-7-benzylidene-3,3a,4,5,6,7-hexahydro-2,3-diphenyl-2<i>H</i>-indazole derivatives in PEG-400 as a green and reusable solvent
The reaction of 2,6-bisbenzylidenecyclohexanones and phenylhydrazine in polyethylene glycol (PEG)-400 as a green and reusable solvent under catalyst-free conditions gave hexahydroindazoles as the major product and, in some cases, tetrahydroindazoles were also produced as a minor product. The products were easily separated by simple recrystallisation. The structures of the indazoles were confirmed using
2,6-双亚苄基环己酮和苯肼在聚乙二醇 (PEG)-400 中作为绿色可重复使用的溶剂在无催化剂条件下反应得到六氢吲唑作为主要产物,在某些情况下,四氢吲唑也作为次要产物产生。产品很容易通过简单的重结晶分离。使用 FTIR 和 NMR 光谱证实了吲唑的结构。报告了两种 X 射线结构。