Abstract
Reaction of pyrazoles with N‐halosuccinimides (NXS, X=Br, Cl) in either CCl4 or water gave 4‐halopyrazoles in excellent yields. The reaction was carried out under mild conditions and did not require any catalysts or special precautions. The reaction provides an efficient method for 4‐C halogenation of pyrazoles.
Acknowledgment
We thank the Natural Science Fund of Anhui Province, China, for financial support.