Synthesis of Urazoles<i>via</i>Cycloaddition Employing 4-Phenyl-4<i>H</i>-1,2,4-Triazole-3,5-dione (PTAD) Transfer
作者:Waldemar Adam、Markus Dörr
DOI:10.1055/s-1986-31804
日期:——
A new method was developed involving transfer of 4-phenyl-4H-1,2,4-triazole-3,5-dione (PTAD) from thermally labile urazoles 9 and 10 to bicyclic olefin derivatives 1-8, which irreversibly undergo cycloaddition accompanied by Wagner-Meerwein rearrangement. In most cases purer products and significantly improved yields of the corresponding urazoles 11-18 are obtained than by direct PTAD cycloaddition.
研究人员开发了一种新方法,将 4-苯基-4H-1,2,4-三唑-3,5-二酮(PTAD)从热易变的脲唑 9 和 10 转移到双环烯烃衍生物 1-8,后者在发生瓦格纳-梅尔韦恩重排的同时不可逆地发生环化反应。在大多数情况下,与直接 PTAD 环加成相比,得到的相应乌拉唑 11-18 的产物更纯,收率也显著提高。