Cyclization of Methyl-Coumalate-Derived Methyl 1-Benzamido-6-oxo-1,6-dihydropyridine-3-carboxylates: Assembly of the [1,2,4]Triazolo[1,5-<i>a</i>]pyridine Ring System
作者:Harold Moloney、Nicholas A. Magnus、Jonas Y. Buser、Matthew C. Embry
DOI:10.1021/acs.joc.7b00873
日期:2017.6.16
three-step synthesis of a series of fused bicyclic s-[1,2,4]triazolo[1,5-a]pyridines 1 was accomplished utilizing novel intermediates derived from inexpensive, commercially available hydrazides A and methyl coumalate B. A significant feature of this approach was the formation of a dihydrazide intermediate 2, bypassing the need for oxidative N–N bond formation in the 1,2,4-triazole synthesis. Further
利用衍生自廉价的,可商购的酰肼A和香豆酸甲酯B的新型中间体,完成了一系列稠合双环s- [1,2,4]三唑并[1,5- a ]吡啶1的有效三步合成。这种方法的一个显着特点是形成了二酰肼中间体2,而无需在1,2,4-三唑合成中形成氧化N–N键。由于结晶恶二唑鎓盐3所提供的杂质排斥,证明除了简单分离外,无需进一步纯化二酰肼2。。另外,所制得的高氯酸恶二唑鎓盐显示出优异的水分稳定性,这是该类型化合物中的异常特征。