Chin. J. Org. Chem. ›› 2017, Vol. 37 ›› Issue (6): 1487-1493.DOI: 10.6023/cjoc201612029 Previous Articles     Next Articles



崔涛, 李丛香, 李明, 文丽荣   

  1. 青岛科技大学化学与分子工程学院 生态化工国家重点实验室培育基地 青岛 266042
  • 收稿日期:2016-12-07 修回日期:2017-01-20 发布日期:2017-02-08
  • 通讯作者: 文丽荣
  • 基金资助:


Efficient Copper-Catalyzed Coupling Reaction for the Synthesis of Benzo[4,5]imidazo[1,2-b]pyrazoles

Cui Tao, Li Congxiang, Li Ming, Wen Lirong   

  1. State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology, Qingdao 266042
  • Received:2016-12-07 Revised:2017-01-20 Published:2017-02-08
  • Contact: 10.6023/cjoc201612029
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21572110, 21372137) and the Natural Science Foundation of Shandong Province (No. ZR2014BM006).

A fast and efficient CuI-catalyzed intramolecular C—N coupling reaction of N-(2-bromoaryl)-1H-pyrazol-5-amines to synthesize benzo[4,5]imidazo[1,2-b]pyrazoles has been developed from N-(2-bromoaryl)-thioacetanilides. A series of benzo[4,5]imidazo[1,2-b]pyrazoles were obtained in excellent yields with CuI/heterocyclic ketene aminals catalytic system in the presence of Cs2CO3 in dimethyl sulfoxide (DMSO) at 120 ℃ within 10 min. The reaction provides an fast and efficient protocol to access a series of benzo[4,5]imidazo[1,2-b]pyrazoles in good to high yields.

Key words: copper catalysis, C—N coupling reaction, heterocyclic ketene aminals, benzo[4,5]imidazo[1,2-b]pyrazoles