LIMA, J. A. C.; A. C. LIMA, JOSEFA; AQUELINE DA CUNHA LIMA, JOSEFA; http://lattes.cnpq.br/3214694428691890; LIMA, Josefa Aqueline da Cunha.
Resumo:
Oxadiazoles are five-membered heterocyclics that have a
range of applications in the field of medicinal chemistry and materials. As,
a (R)-Gonitalamine, some compounds containing the oxadiazole nucleus
have good antiproliferative activity against a variety of strains
of tumor cells. In this context, the central idea of the work was the synthesis of
3,5-disubstituted 1,2,4-oxadiazoles that have molecular architecture
similar to (R)-Gonitalamine in order to obtain new structures with a high
antiproliferative activity. For this, the synthetic strategy initially consisted
in the esterification of (E)-cinnamic acid through catalysis, followed by synthesis
of the aryl-amidoximes obtained from the reaction between the hydrochloride of
hydroxylamine and the corresponding aryl nitriles. Once synthesized and
characterized these intermediaries, the next step was the construction of the 1,2,4-
3,5-disubstituted oxadiazoles via the 0-acylamidoxime reaction followed
of cyclodehydration using microwave oven as heating
domestic. Additionally, the new 3,5-disubstituted 1,2,4-oxadiazoles
were characterized by the usual spectrometric methods (IR and 1 H NMR and
13C). Ethyl (E)-cinnamate was obtained in 89% yield in the form
of a viscous yellow liquid, while the aryl-amidoximes were obtained
with yields ranging from 35 to 98% in reaction times from 2.3 to 78
hours. The 3,5-disubstituted 1,2,4-oxadiazoles obtained through
microwave oven heating with short reaction times from 15 to 26
minutes and yields in the range of 12 to 66%.