TBHP/Cu(OAc)₂ mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles

Electrochemically enabled oxidative aromatization of pyrazolines

“…20 There are synthetic strategies which feature a two-step approach via initial formation of a pyrazoline from readily available starting materials and subsequent oxidation. For the latter step, oxidizing agents such as oxygen, 21 peroxides, 22 or halogens 23,24 in over-stoichiometric quantities are necessary, which typically necessitates a transition metal catalyst. 25 To name one example, the synthesis of pyraclostrobin ( 2 ) involves the oxidative aromatization of a pyrazolidinone as a key step.…”