Synthesis of 1,2,4-triazoles and 1,2,4,6-tetraazabicyclo[3.3.0]octanes from diphenyl cyanocarbonimidate. Competition between addition of hydrazines to esters or nitriles
作者:Peter J Garratt、Simon N Thorn、Roger Wrigglesworth
DOI:10.1016/s0040-4020(01)80516-0
日期:1993.1
The reaction of hydrazine with suitably substituted isoureas gives tetraazabicyclo[3.3.0]octanes. The products obtained in this reaction are extremely susceptible to the nature of the substrate and the reaction conditions, but a suitable combination of these can usually be found in order to form the bicyclooctane. In cases where the bicyclic system is not formed 1,2,4-triazoles are usually obtained
肼与适当取代的异脲的反应得到四氮杂双环[3.3.0]辛烷。在该反应中获得的产物极易受底物的性质和反应条件的影响,但是通常可以找到它们的合适组合以形成双环辛烷。在未形成双环体系的情况下,通常会得到1,2,4-三唑,但有时咪唑酮是反应产物。基于在这些后面的反应中形成的产物的变化和相互转化,提出了一种机械序列。通过引入空间因子,显着降低了在取代的氮上添加甲基肼的偏好。