5-Aminopyrazoles from enolisable ketones and 1-cyano-1-alkylhydrazines.
作者:Thomas Ryckmans、Heinz-Gunter Viehe、Janine Feneau-Dupont、Bernard Tinant、Jean-Paul Declerco
DOI:10.1016/s0040-4020(96)01074-5
日期:1997.2
of enolisable ketones with 1-alkyl-1-cyanohydrazines leads to the corresponding cyanohydrazones. These compounds cyclise under thermal or mildly basic conditions, furnishing the corresponding 5-aminopyrazoles in good yield. In some cases, the hydrazones cannot be isolated, and the pyrazole derivatives are directly obtained. Hydrazone-enehydrazine tautomerism was observed, but no subsequent [3,3] rearrangement
可缩合的酮与1-烷基-1-氰基肼的反应产生相应的氰基azo。这些化合物在热或弱碱性条件下会环化,从而以良好的产率提供相应的5-氨基吡唑。在某些情况下,不能分离出hydr,而是直接获得吡唑衍生物。dra-互变异构现象被观察到,但是没有随后的[3,3]重排。