Halogenation of pyrazoles using N-halosuccinimides in CCl4 and in water was written by Zhao, Zhi-Gang;Wang, Zhong-Xia. And the article was included in Synthetic Communications in 2007.HPLC of Formula: 15953-73-8 This article mentions the following:
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 C(4) halogenation of pyrazoles. In the experiment, the researchers used many compounds, for example, 4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8HPLC of Formula: 15953-73-8).
4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).Pyrazole used as a ligand to prepare organometallic compounds. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.HPLC of Formula: 15953-73-8
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics