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。