TBAI-促进3-氧-3-芳基丙腈与芳基磺酰肼的三组分反应

TBAI-promoted three-componentreactions of 3-oxo-3-arylpropanenitriles with arylsulfonylhydrazides

吡唑-5-胺是一类重要的五元杂环化合物,具有多种药理和生物活性,对于吡唑-5-胺的合成和衍生化在有机合成领域具有重要意义。本文建立了3-氧代-3-芳基丙腈与芳基磺酰肼的新的三组分反应,在四丁基碘化铵(TBAI)的作用下,依次通过环化、芳硫化反应实现了3-芳基-4-(芳硫基)-1H-吡唑-5-胺骨架的构建,最佳反应条件为:3-氧代-3-芳基丙腈(0.3 mmol),芳基磺酰肼(0.9 mmol),TBAI (0.5 equiv.),EtOH (0.5 mL),反应温度80℃,反应时间6 h。该体系具有反应条件温和,底物适用范围广,原料廉价易得等优点。

Pyrazol-5-amines as an important class of five-membered heterocycles have exhibited a variety of pharmacological and biological activities.Therefore, it is of great significance for the synthesis and derivatization of pyrazol-5-amine in the field of organic synthesis.In this paper, new three-component reactions of 3-oxo-3-arylpropanenitriles with arylsulfonyl hydrazides have been established, and an expanded inventory of 3-aryl-4-(arylthio)-1H-pyrazol-5-amines is synthesized by sequential cyclization and sulfenylation reactions under the action of TBAI.The optimal reaction conditions were as follow: 3-oxo-3-arylpropanenitrile(0.3 mmol),arylsulfonyl hydrazide(0.9 mmol),TBAI(0.5 equiv.),EtOH(0.5 mL),reaction temperature 80℃,reaction time 6 h.The protocol represents broad substrate scope, good functional group tolerance, and mild reaction conditions.