Síntese e caracterização do 3-fenil-5-heptadecil-1,2,4-oxadiazol utilizando a irradiação de micro-ondas

Abstract

Among the various categories of heterocyclic compounds, 1,2,4-oxadiazoles are noteworthy, since they present innumerable biological activities and are present in the structure of drugs available in the market. In this work the 1,2,4-oxadiazolic unit was incorporated into the structure of stearic acid, which is a fatty acid that has several industrial applications. The work was started with the preparation of benzamidoxime, which was synthesized using three different energy sources. The first involved the reaction of benzonitrile with hydroxylamine hydrochloride in hydroethanolic medium and stirring, which amidoxime was obtained in 79.02% yield in a reaction time of 24 hours. In the second strategy, ultrasonic energy was used, and the amidoxime was obtained in 96.04% yield in 1 hour. Finally, heating under reflux was used and amidoxime was obtained in 95.03% yield in 3 hours. In parallel, the stearic acid esterification reaction was carried out in acidic ethanolic medium, which was obtained in 94.57% yield in a reaction time of 3 hours. Then the 1,2,4- oxadiazol was prepared by the reaction between the stearic ester and the benzamidoxime. The desired oxadiazole was obtained in 80.94% yield in 1 hour of reaction. Additionally, the compounds were characterized by 1H and 13C IR spectroscopic techniques. The synthetic challenge for incorporation of the 1,2,4- oxadiazolic unit into the structure of stearic acid has been achieved and it is hoped that this new product may present a promising biological potential, whether against fungi, bacteria or even against tumor cells.