Mikhailov, Kirill I. et al. published their research in Journal of Organic Chemistry in 2018 | CAS: 73387-46-9

3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9) belongs to pyrazole derivatives. Pyrazoles, a five-membered heterocycle containing two adjacent nitrogen atoms, are the core structures found in a number of molecules that possess a wide range of pharmaceutical and agricultural activities. 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.Product Details of 73387-46-9

Fe(II)-Catalyzed Isomerization of 5-Chloroisoxazoles to 2H-Azirine-2-carbonyl Chlorides as a Key Stage in the Synthesis of Pyrazole-Nitrogen Heterocycle Dyads was written by Mikhailov, Kirill I.;Galenko, Ekaterina E.;Galenko, Alexey V.;Novikov, Mikhail S.;Ivanov, Alexander Yu.;Starova, Galina L.;Khlebnikov, Alexander F.. And the article was included in Journal of Organic Chemistry in 2018.Product Details of 73387-46-9 This article mentions the following:

2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines were synthesized by in situ trapping of 2H-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed isomerization of 5-chloroisoxazoles, with pyrazoles. According to DFT calculations, the selectivity of nucleophilic substitution at the carbonyl group of 2H-azirine-2-carbonyl chloride by a pyrazole nucleophile, which is a mixture of two tautomers, is controlled by thermodn. factors. 2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines, e.g., I (X-rays single crystal structure shown), are excellent precursors for the preparation of two other pyrazole-nitrogen heterocycle dyads: 5-(1H-pyrazol-1-yl)oxazoles by photolysis and 1-(1H-pyrrol-2-ylcarbonyl)-1H-pyrazoles by a Ni(II)-catalyzed reaction with 1,3-dicarbonyl compounds 5-(1H-Pyrazol-1-yl)oxazoles show strong emission in acetonitrile at 360-410 nm with high quantum yields. In the experiment, the researchers used many compounds, for example, 3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9Product Details of 73387-46-9).

3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9) belongs to pyrazole derivatives. Pyrazoles, a five-membered heterocycle containing two adjacent nitrogen atoms, are the core structures found in a number of molecules that possess a wide range of pharmaceutical and agricultural activities. 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.Product Details of 73387-46-9

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics