作者:R. A. Novikov、V. A. Korolev、Yu. V. Tomilov
DOI:10.1007/s11172-011-0252-2
日期:2011.8
4-triazoline-3,5-dione (PTAD) acts as an efficient Michael acceptor in reactions with 1-unsubstituted 2-pyrazolines, giving substituted (3,5-dioxo-4-phenyl-1,2,4-triazol-idin-1-yl)-1-pyrazolines in quantitative yields. Through elimination of molecular nitrogen, the latter are easily transformed into the corresponding cyclopropanes. A reaction of methyl 5-methyl-2-pyrazoline-5-carboxylate with a twofold excess
摘要 4-苯基-1,2,4-三唑啉-3,5-二酮 (PTAD) 在与 1-未取代的 2-吡唑啉反应中作为有效的迈克尔受体,得到取代的 (3,5-dioxo-4-phenyl-1 ,2,4-三唑-idin-1-yl)-1-吡唑啉的定量产率。通过消除分子氮,后者很容易转化为相应的环丙烷。5-甲基-2-吡唑啉-5-羧酸甲酯与两倍过量的 PTAD 反应生成中间体双加合物,其经过去重氮化形成 1,3,5-三氮杂双环 [3.3.0] 辛烷-2,4 -二酮衍生物。1-取代的 2-吡唑啉也添加到 PTAD 中,但由于 C(3)H 质子迁移到 PTAD,2-吡唑啉结构保留在产品中。