(E)-N'-(Ethoxymethylene)hydrazinecarboxylic acid methyl ester was synthesized in one step in good yield. This reagent was successfully applied to the one-pot synthesis of 4-substituted 2,4-dihydro-3H-1,2,4-triazolin-3-ones from readily available primary alkyl and aryl amines. This reaction process is relatively mild and easy to carry out. It is especially useful for the formation of sterically hindered triazolinones, which are otherwise difficult to obtain via existing literature procedures. A possible mechanistic pathway for the transformation is outlined. (c) 2006 Elsevier Ltd. All rights reserved.
(E)-N'-(乙氧甲ethylene)hydrazinecarboxylic acid甲酯通过一步反应合成,产率较高。该试剂成功应用于合成4-取代2,4-半氢-3H-
1,2,4-三嗪-3-ones,这些产物可以从现有的容易得到的烷基和苯基一元胺中一步获得。该反应过程相对温和,易于操作。尤其是对于由现有文献方法难以获得的受体 hindered steric effect的三嗪-ones,该反应尤为有用。文中提出了可能发生这一转化的可能机理。