Síntese e estudo de enantiômeros puros derivados do praziquantel e de composto quiral para aplicação em organocatálise

Abstract

Praziquantel is a very important medication, as it has been used to combat schistosomiasis for over 40 years. However, PZQ is a racemic mixture in which only one of its enantiomers is active against the disease, while its distomer only appears to contribute to some negative factors, such as increased dosage, side effects, bitter taste, etc. Due to the intensive use of the drug over the decades, studies in the literature have focused on the possibility of resistance to the drug by schistosomiasis parasites. This has led to the need to better evaluate its pure enantiomers, in addition to proposing alternatives related to structural modifications in order to improve its clinical applicability. Thus, this doctoral thesis emphasized the use of two methods to obtain the drug Praziquantel with enantiomeric excess. Initially, racemic resolution was applied to obtain the pure enantiomers separated from the drug praziquantel, with the aim of carrying out a more detailed study in relation to improving the efficiency obtained in the synthesis of some derivatives. While the other method consisted of asymmetric organocatalysis through the synthesis and application of a new stereoselective organocatalyst based on L-Cysteine in order to obtain better results in relation to obtaining optically pure products with greater economy. For the structural elucidation of the synthesized compounds, 1H and 13C NMR, infrared, mass and alpha D techniques were used.