Abstract:

Since its discovery, Ferrocene and its derivatives, have been attracting much attention for its use in catalysis, organic synthesis, new materials such as liquid crystals or polymers and supramolecular chemistry. Incorporation of a ferrocene fragment into a molecule of an organic compound often results in unexpected biological activity which is rationalized as being due to its different membranepermeation properties and anomalous metabolism. It is well known that certain substituted dihydropyrazole derivatives are highly biologically active and can be used as medications in human and/or veterinary therapy and as insecticides and herbicides in agriculture and horticulture. Hydrazones are organic compounds characterized by the presence of the NH-N = CHR group in its molecules. Such molecules have anticonvulsant, antidepressant, analgesic, antibiotic, antitumor, antiviral and anti-platelet properties and it is therefore of great value to develop synthetic methods to access this class of compounds. In this context, this study aims to differentiate the reactivity of 6-hydrazinonicotinic acid hydrazide against ferrocene carboxaldehyde and acetyferrocene in order to obtain, selectively, ferrocenyl hydrazones and subsequently allow the cyclization of the hydrazide moeity with β-alkoxyvinyl trifluoromethyl ketones to obtain a series of pyrazolyl-pyridine ferrocenyl hydrazones.