A New Synthesis of Pyrazolo[3,4-<i>d</i>]pyrimidine-4,6(5<i>H</i>,7<i>H</i>)-diones by Oxidative N-N Bond Formation of 6-Amino-5-(<i>N</i>-aryliminomethyl)uracils Using Iodobenzene Diacetate
作者:Hironao Sajiki、Kazuyuki Hattori、Magoichi Sako、Kosaku Hirota
DOI:10.1055/s-1997-1073
日期:——
The intramolecular cyclizations of 6-amino-5-(N-aryliminomethyl)-1,3-dimethyluracils (2) involving the N-N bond formation were effected via a hypervalent iodine oxidation using iodobenzene diacetate. This method enabled a facile synthesis of 2-aryl-5,7-dimethylpyrazolo[3,4-d]pyrirnidine-4,6(5H,7H)-diones (3) in moderate to excellent yields. The primary advantage of this N-N bond formation method is that various 2-aryl-substituted pyrazolo[3,4d]pyrimidines can be provided under mild oxidative conditions.
6-amino-5-(N-aryliminomethyl)-1,3-dimethyluracils (2) 的分子内环化涉及 N-N 键的形成,是通过使用二乙酸碘苯的高价碘氧化作用实现的。通过这种方法,可以轻松合成 2-芳基-5,7-二甲基吡唑并[3,4-d]吡咯烷-4,6(5H,7H)-二酮 (3),产率为中等到极佳。这种 N-N 键形成方法的主要优点是可以在温和的氧化条件下提供各种 2-芳基取代的吡唑并[3,4d]嘧啶。