Synthesis of antitrypanosomal thiosemicarbazones using anthranilic acid as an innovative Green nucleophilic catalyst

Abstract

Trypanosomiasis constitutes a severe health problem for sub-saharian African and latin American population and there is an urgent need for better drugs to cure this life-threatening disease. In this context, aromatic thiosemicarbazones appears attractive drug candidates. The condensation reaction of thiosemicarbazides with aldehydes and ketone to form thiosemicarbazones is very efficiently catalyzed by nucleophilic catalysis in the general context of generalized acid-base catalysis. In this paper, we developed anthranilic acid as a general purpose green catalyst. Methanol appears to be a performants solvent for this reaction. In general, good to excellent yields in the range of 70-99% were obtained. In the condensation of various ketones with 4-phenylthiosemicarbazide the choice of anthranilic acid as catalyst was rationalized on the basis of mechanistic considerations