Síntese verde e assinalamento completo de novos oxadiazóis 2,3-enopiranosídeos

Abstract

In carbohydrate chemistry, the 2,3-unsaturated O-glycoside is a vital organic molecule with varied biological applications that can be enhanced by utilizing other functional groups that are linked through the glycosidic bond. In this work, the use of the 1,2,4-Oxadiazole functional group as an aglycone connected to the saccharide group was developed, considering that it has multiple applications, whether in medicinal chemistry, in the chemistry of new materials or also in agricultural chemistry. The synthesis and characterization of different arylamidoximes, precursors of the oxadiazole ring, are also described; of 1,2,4-oxadiazole and of the 2,3-enopyranoside ring, as sequenced reactions. Deriving from the synthesis of arylamidoximes, the results were obtained in good yields (80-90%) when compared with results already described in the literature. The six specimens of 3,5-Disubstituted-1,2,4-oxadiazole were synthesized through the methodology of heating without solvent and without base, which constitutes an innovative method to obtain 1,2,4-oxadiazoles, with yield ranging from 40-70%. After synthesizing the 1,2,4-oxadiazoles, they were reacted with tri-o-Acetyl-D-Glical in the presence of Montimorillonite K-10, as a catalyst, using a focused microwave under different reaction conditions, with yield of 25-50%. The structures of the compounds obtained were clarified using conventional spectroscopic techniques: Infrared and 1H and 13C Nuclear Magnetic Resonance. Despite the divergence between the yields obtained, this project demonstrates the importance of adopting green and eco-conscious synthesis, aiming at the preservation of the environment and the safety of employees for the construction of an inclusive and plural chemistry.