Banca de QUALIFICAÇÃO: RICARTE TAVARES
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.STUDENT : RICARTE TAVARES
DATE: 23/05/2023
TIME: 14:00
LOCAL: Departamento de Química
TITLE:
SYNTHESIS AND CHARACTERIZATION OF 1,2,4-OXADIAZOLES AND 2,3-UNSATURATED O-GLYCOSIDE TARGETING COMPOUNDS WITH BIOLOGICAL ACTIVITIES
KEY WORDS:
2,3-unsaturated O-Glycosides, 1,2,4-oxadiazole, amidoximes, Drugs.
PAGES: 103
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:
The development of new drugs has been exponential among researchers, and one of the classes of compounds is heterocyclics, mainly 1,2,4-oxadiazoles and 2,3-unsaturated O-glycosides. Furthermore, the synthesis of a compound containing these two types of molecules has been widely studied in order to verify their biological activities. With that in mind, this work aims to synthesize new molecules of 1,2,4-oxadiazole and O-glycosides containing 1,2,4-oxadiazole as an aglycone, as potential biological agents. In view of this, initially, the syntheses of the starting reagents were necessary. For 1,2,4-oxadizoles, amidoximes and ethyl oleate were synthesized. The syntheses of the amidoximes 47a-e were carried out using the classical method, in basic medium. Products 47a-e were obtained in moderate to good yields (40% - 95%). Ethyl oleate (46) was obtained through the Fischer esterification reaction of oleic acid, obtaining 79% yield. Thus, the 1,2,4-oxadiazoles (49a-e) were synthesized using microwave irradiation, which provided compounds with moderate yields (50 to 68% yield). The O-glycosides were synthesized from the Ferrier rearrangement reaction using tri-O-acetyl-D-glycal with oleyl alcohol, providing O-glycoside (50a) with 72% yield which, in turn, underwent a basic hydrolysis generating the deacetylated product (50b), with 80% yield. Furthermore, the other O-glycoside (55) was synthesized with 40% yield. This glycoside has ethyl 4-hydroxybenzoate as an aglycone, which will still be made into the oxadiazoles of these compounds for subsequent glycosylation. The synthesized compounds were characterized by Infrared and Nuclear Magnetic Resonance (1H and 13C NMR) techniques. For the 1,2,4-oxadiazoles, the signs of the aromatic ring of the side chain were verified in the 1H NMR (0.98-5.37 ppm), and in the 13C NMR, the characteristic signs of the carbons of the aromatic ring were observed (121.31-134.61 ppm) and the 1,2,4-oxadiazole ring (166.73-180.89 ppm). Regarding the O-glycosides, the hydrogens of the pyranoside ring (3.50-5.97 ppm) and the aglycone (0.88-2.11 ppm) were found in the 1H NMR, and in the 13C NMR signals shifted between 63, 08 to 129.97 ppm for the glycone and between 14.8 to 31.90 ppm for the aglycone.
COMMITTEE MEMBERS:
Interno - JOAO RUFINO DE FREITAS FILHO
Interno - MARCILIO MARTINS DE MORAES
Externo ao Programa - 3022573 - JUCLEITON JOSE RUFINO DE FREITAS - UFRPEExterno à Instituição - JONH ANDERSON MACÊDO SANTOS