Synthesis of 3-substituted 1-phenyl-1H-pyrazole-4-carbaldehydes and the corresponding ethanones by Pd-catalysed cross-coupling reactions

Abstract

An efficient synthetic route to construct ortho-substituted 1-phenyl-1H-pyrazole-4-carboxaldehydes and the corresponding ethanones starting from 1-phenyl-1H-pyrazol-3-ol is described. Carbon-carbon bond-forming Pd-catalysed cross-coupling reactions were applied for the functionalisation of the intermediate pyrazole triflates. Detailed NMR spectroscopic investigations were undertaken with all obtained products.