In order to develop new antifective agents, our work focuses on the synthesis of new heterocyclic molecules endowed with an antiparasitic activity mainly against neglected tropical diseases : malaria, leishmaniasis, African and American Human trypanosomiasis. These works aim at identifying the molecular action mechanisms to find new pathways and therefore circumvent resistance phenomena. The physicochemical, properties, structure-activity relationships, and pharmacokinetic parameters of these compounds are determined according to a Hit-to-Lead approach to realize in vivo tests on infected animal models.