Regioselective Microwave-Assisted Synthesis of Substituted Pyrazoles from Ethynyl Ketones
作者:Mark Bagley、M. Lubinu、Christopher Mason
DOI:10.1055/s-2007-970783
日期:2007.3
Reaction of α,β-ethynyl ketones and hydrazine derivatives gives 1,3- and 1,5-disubstituted pyrazoles in good yield. -Microwave irradiation in concentrated hydrochloric acid-methanol (1.5% v/v), with concurrent cooling at sub-ambient temperatures or at 120 °C, for 30 or 2 minutes, respectively, facilitates rapid heterocyclization and preferentially gives the 1,3-disubstituted regio-isomer.
α,β-乙炔基酮和肼衍生物的反应以良好的收率得到 1,3- 和 1,5- 二取代的吡唑。- 在浓盐酸-甲醇 (1.5% v/v) 中进行微波照射,同时在低于环境温度或 120 °C 下分别冷却 30 或 2 分钟,促进快速杂环化并优先得到 1,3-双取代的区域异构体。