Reactivity of antipyrine and haloantipyrines in Pd-catalyzed C–H bond arylations

A. Sasmal (1) , J.K. Bera (2) , H. Doucet (1) , Jean-François Soulé (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 IIT Kanpur - Indian Institute of Technology Kanpur

We reported herein the Pd-catalyzed direct arylation of antipyrine using Pd(OAc)2 as catalyst associated with KOAc as inexpensive base. In most cases, diethyl carbonate was used a sustainable solvent. The reaction tolerated a wide range of functional groups on the aryl bromide partners (e.g., nitrile, nitro, chloro, fluoro, formyl, acetyl, propionyl, benzoyl, ester, methyl, methoxy). In addition, some nitrogen-containing heteroaryl bromides were also efficiently coupled with antipyrine. We also demonstrated that in contrast to 4-bromoantipyrine, 4-iodoantipyrine could be employed as an efficient heteroaryl source in Pd-catalyzed C–H bond arylation of 5-membered ring heteroarenes.

Mots clés: Arylation; Catalysis; C–H Bond; Palladium; Pyrazolone

Domaines: Chimie organique; Catalyse

A. Sasmal, J.K. Bera, H. Doucet, Jean-François Soulé. Reactivity of antipyrine and haloantipyrines in Pd-catalyzed C–H bond arylations. Tetrahedron Letters, 2020, 61 (17), pp.151798. ⟨10.1016/j.tetlet.2020.151798⟩. ⟨hal-02569945⟩