Synthesis of pyrazolo[1,5-<i>a</i>]pyridines and pyrazolo[1,5-<i>c</i>]pyrimidines by reaction of heterocyclic amidrazones with 1,3-dicarbonyl compounds
作者:Peter Köckritz、Beate Riemer、Anke Michler、Ahmed Hassoun、Jürgen Liebscher
DOI:10.1002/jhet.5570310510
日期:1994.9
1-amino-2(1H)-pyridin-2-imines or 1-amino-2(1H)-pyrimidin-2-imines 1 giving new pyrazolo[1,5-a]pyridines or pyrazolo[1,5-c]pyrimidines 5 respectively by addition, oxidation and condensation. Isolation of an intermediate 3 shows that surprisingly the addition of the CH acidic 1,3-dicarbonyl compound to position 6 of the pyrimidine 1 is the initial step.
1,3-二羰基化合物2与1-氨基-2(1 H)-吡啶-2-亚胺或1-氨基-2(1 H)-嘧啶-2-亚胺1反应生成新的吡唑并[1,5- a吡啶或吡唑并[1,5- c ]嘧啶5分别通过加成,氧化和缩合反应获得。中间体3的分离显示出令人惊奇的是,将CH酸性的1,3-二羰基化合物添加到嘧啶1的位置6是起始步骤。