Synthesis of 1H-3-Ferrocenyl-1-phenyl-4-substituted Pyrazoles

Abstract

Synthesis of 1H-3-ferrocenyl-1-phenylpyrazole-4-carboxaldehyde was achieved by condensation of acetylferrocene with phenylhydrazine followed by intramolecular cyclization of the ­hydrazone obtained under Vilsmeier-Haack conditions. Several ­derivatives, such as the corresponding thiosemicarbazone, oxime, imine, alcohol, halide, and primary amine were then prepared by known reactions. Also 1,1′-diacetylferrocene was transformed into the corresponding dipyrazolyl derivative.