A series of pyrazole-4-carboxylates have been synthesised using indium bromide catalyst and the cyclisation of respective 3-substituted-isoquinolinylhydrazines 1 into their corresponding ethyl-2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoates 3 in ethanol solvent under ultrasonic irradiation at 90 °C for 30 min. The regio-selective cyclisation products were efficiently provided by indium bromide catalyst and are confirmed by nuclear Overhauser effect spectroscopy–nuclear magnetic resonance (NOESY–NMR) studies.
使用
溴化
铟催化剂合成了一系列
吡唑-4-羧酸盐,并在 90 ℃ 超声波辐照 30 分钟的条件下,在
乙醇溶剂中将各自的 3-取代-
异喹啉基
肼 1 环化为相应的 2-(乙氧基亚甲基)-
4,4,4-三氟-3-氧代丁酸乙酯 3。
溴化
铟催化剂有效地提供了具有区域选择性的环化产物,核奥弗霍塞尔效应光谱-核磁共振(NOESY-NMR)研究证实了这一点。