Síntese one-pot de 5-amino-1,3-diaril-(4-arilselanil)-1H-pirazóis catalisada por CuI

Abstract

In this work, it was developed a methodology for the synthesis of 5-amine pyrazoles functionalized with selenium 5, from benzoylacetonitriles 1, hydrazines 2 and diaryl diselenides 4, using copper iodide catalytic (20 mol%) and bipyridine (20 mol%) as an agent ligand, dimethyl sulfoxide (DMSO) as solvent. The corresponding 5-amino-4-arylselenyl-pyrazoles 5 were obtained by reactions that the temperature at 100 °C under conventional heating, the desired products were obtained in yields considered of moderate to good, varying between 49-90%. In order to evaluate the antioxidant potential of the compounds obtained from this synthesis, six (3a, 5a, 5c, 5e, 5n e 5m) of them were selected and submitted to neutralization tests of 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobisic acid -3-ethylbenzothiazoline-6-sulfonic acid (ABTS), as well as evaluation of the ferric ion reducing potential (FRAP) Among the samples evaluated, only molecule 3a showed good results in the DPPH radical neutralization assay. While in the ABTS radical neutralization test samples 3a and 5c presented promising results. In the assay evaluating the ferric to ferrous ions reducing ability (FRAP), compounds 3a, 5a and 5c demonstrated excellent results.