N-Heterociclos funcionalizados com Selênio: Síntese de 4-arilselanil-7- cloroquinolinas, 6-arilselanil-purinas e arilselanil-piridin-3-il-1,2,3-triazóis

Abstract

The present work is divided in three parts, where the results of the synthesis of N-heterocycles functionalized with arylselenium in their structures will be reported. First, the results of the synthesis of 4-arylselanyl-7-chloroquinolines 3 in which the hypophosphorous acid / water solution (50%) was used as the solvent and starting materials diaryl diselenide 1 and 4,7-dichloroquinoline 2 (Scheme A) as successfully completed. With this methodology it was possible to obtain the desired products 3a-h with good yields (67-97%). The synthesized products were submitted to biological tests, where they demonstrated important activities as antioxidant and anti-inflammatory. Scheme A In a second step, the results obtained in the synthesis of 6-arylselanyl-purines 5 using as substrate, 6-chloropurine 4, diaryl diselenide 1, PEG-400 as solvent and sodium borohydride (NaBH4) (Scheme B). Through this reaction condition it was possible to obtain the desired products in good yields (35-69%).X The synthesized products presented in in-vitro tests an inhibitory activity of the enzyme acetylcholine esterase, an enzyme that is related to diseases such as Alzheimer. Scheme B In a third step the results of the synthesis of 1,2,3-triazoles 1,4,5-trisubstituted 8 through an enamine-azide cycloaddition reaction between 2-arylselanyl-3- azidopyridines 6 and alpha-activated carbonyl compounds 7, using diethylamine (DEA) as an organocatalyst in dimethylsulfoxide (DMSO) (Scheme C). The 1,4,5- trisubstituted 1,2,3-triazoles 8 could be obtained in excellent yields (94-97%). Scheme C