Eclectic 1-Aryl-1,2-diazabuta-1,3-dienes: Valuable Tools for the Preparation of Pyrrol-2-ones, 1-Arylpyrazoles, 2-(3-Oxopyrazol-4-yl)malonates and 4-(2-Oxopyrrol-3-yl)pyrazol-3-ones
prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal
1 H -Pyrazole-4,5-dicarboxylates 和 chromenopyrazole carboxylates 是通过在没有催化剂的纯净条件下使吡唑啉与活化的炔烃反应制备的。产物是通过吡唑啉的意外开环和苯乙烯/乙烯的消除而形成的。这些类型的转化是未知的,并且使用它们的光谱/分析数据确认了所形成的产物。此外,化合物5e和5n的结构通过单晶X射线分析证实。进行了对照实验以支持所提出的反应机理。