bifunctional nucleophile methylhydrazine reacts in an alkaline medium in a regioselective mode with chalcones to yield 2-pyrazolines, which can be oxidized by DDQ to the corresponding 1H-pyrazoles. From oligo(chalcone)s this reaction yields cross-conjugated compounds with an alternating sequence of 1,4-disubstituted benzene rings and 3,5-disubstituted 1H-pyrazole rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451
双功能亲核试剂甲基
肼在碱性介质中以区域选择性模式与
查耳酮反应生成 2-
吡唑啉,可通过
DDQ 将其氧化为相应的 1H-
吡唑。从低聚(
查耳酮)中,该反应产生具有 1,4-二取代苯环和 3,5-二取代 1H-
吡唑环交替序列的交叉共轭化合物。(© Wiley-
VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)