One-pot three-component synthesis of pyrazoles through a tandem coupling-cyclocondensation sequence

HL Liu, HF Jiang, M Zhang, WJ Yao, QH Zhu, Z Tang

Index: Liu, Hai-Ling; Jiang, Huan-Feng; Zhang, Min; Yao, Wen-Juan; Zhu, Qiu-Hua; Tang, Zhou Tetrahedron Letters, 2008 , vol. 49, # 23 p. 3805 - 3809

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Citation Number: 93

Abstract

An efficient and general one-pot procedure for the synthesis of pyrazoles from acid chlorides, terminal alkynes and hydrazines was described via a coupling and cyclocondensation sequence. Acid chlorides coupled with terminal alkynes to give α, β- unsaturated ynones, and in situ converted into pyrazoles by the cycloaddition of hydrazines. The desired pyrazoles were obtained with 15–85% isolated yields.