Pyrazolylbenzoic acids based on polyfluoroalkylated lithium 1,3-diketonates bearing acetal groups

An alternative synthesis was developed for the preparation of polytopic ligands, which combine both the NH-pyrazole and carboxyl moieties, based on polyfluoroalkylated lithium 1,3-diketonates bearing acetal groups. The proposed approach involves the transformation of diketonates into the corresponding acetylpyrazoles followed by the condensation with p-hydrazinobenzoic acid. The reaction of unsubstituted hydrazine with the condensation product of diketonate and 4-hydrazinobenzoic acid results in the transamination to form bis-pyrazoles bearing a hydrazone moiety, which does not contain an arylcarboxyl substituent.