Pyrazole-3/5-carboxylic acids from 3/5-trifluoromethyl NH-pyrazoles

Mikhail S. Ermolenko (1) , Sandrine Guillou (2) , Yves Louis Janin (2)

1 ICSN - Institut de Chimie des Substances Naturelles
2 CNRS - UMR3523 - Chimie organique

We report here the transformation of 3/5-trifluoromethylpyrazoles derivative into the corresponding NH-pyrazole-3/5-carboxylic acids. Moreover, from 4- or 5-iodinated-3/5-trifluoromethylpyrazoles building blocks and the use of SuzukieMiyaura or Negishi reactions followed by the trifluoromethyl hydrolysis, we illustrate short and original accesses to many series of NH-pyrazole-3/5-carboxylic acids otherwise difficult to prepare.

Keywords: Building blocks 3/5-Trifluoromethylpyrazoles Pyrazole-3/5-carboxylic acids Cross-coupling Palladium catalysis

Domains: Chemical Sciences; Organic chemistry

Mikhail S. Ermolenko, Sandrine Guillou, Yves Louis Janin. Pyrazole-3/5-carboxylic acids from 3/5-trifluoromethyl NH-pyrazoles. Tetrahedron, 2013, 69 (1), pp.257-263. ⟨10.1016/j.tet.2012.10.034⟩. ⟨pasteur-00755935⟩