Synthesis of novel 1,4,5-trisubstituted 3-trifluoromethylpyrazoles via microwave-assisted Stille coupling reactions
作者:Sung Lan Jeon、Ji Hoon Choi、Bum Tae Kim、In Howa Jeong
DOI:10.1016/j.jfluchem.2007.04.029
日期:2007.10
were reacted with N-bromosuccinimide in DMF at room temperature or 70–80 °C for 1–2 h to afford the corresponding 4-bromo-substituted pyrazoles 2 in 95–99% yields. The microwave-assisted Stille coupling reactions of 2 with arylstannanes having a substituent on the benzene ring and allylstannane in refluxing CH3CN in the presence of Pd(PPh3)4 provided the corresponding 1,4,5-trisubstituted 3-trifluoromethylpyrazoles
1,5-二取代的3- trifluoromethylpyrazoles,用与化合物Ñ在室温或70-80℃溴代琥珀酰亚胺的DMF溶液1-2小时,得到相应的4-溴取代的吡唑2在95-99%的产率。的微波辅助的Stille偶联反应2与具有在回流CH苯环和allylstannane上的取代基arylstannanes 3中的Pd(PPh存在CN 3)4提供的相应的1,4,5-三取代的3- trifluoromethylpyrazoles 3在75–98%的产量。