Copper-Promoted Coupling of Propiophenones and Arylhydrazines for the Synthesis of 1,3-Diarylpyrazoles

Abstract

Synthesis of 1,3-diarylpyrazoles from commercial substrates and/or simple transformations is still underrated. In this report, we have developed a method for copper-promoted coupling of propiophenones and arylhydrazines. The reactions afforded substituted pyrazoles in the presence of TEMPO oxidant, acetic acid additive, and DMF solvent. A number of functionalities were compatible with reaction conditions, including halogens, methoxy, trifluoromethyl, and nitro groups. An indazole could be obtained if an electron-poor propiophenone was used.

Key words

copper - 1,3-diarylpyrazoles - TEMPO - oxidative - dehydrogenation

• References and Notes

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