1,2,4-triazole derivative with Schiff base; thiol-thione tautomerism, DFT study and antileishmanial activity

摘要: Abstract Thiol-thione tautomerism of 1,2,4-triazole derivative with Schiff base was investigated by spectroscopic methods and quantum mechanical calculations. Theoretical study thiol-thione tautomeric forms of 1,2,4-triazole base; 1,2,4-triazole-thiol form, 1-((5-mercapto-4-(thiophene-2-ylmethyleneamino)-4H-1,2,4-triazole-3-yl)methyl)-3-(thiophene-2-ylmethyl)-4-(thiophene-2-ylmethyleneamino)-1H-1,2,4-triazole-5(4H)-one ( I) 1,2,4-triazole-thione 3-(thiophene-2-ylmethyl)-4-(thiophene-2-ylmethyleneamino)-1-((4-(thiophene-2-ylmethyleneamino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazole-3-yl)methyl)-1H-1,2,4-triazole-5(4H)-one II ) performed the density functional theory (DFT) method 6–311++G(d,p) basis set. Structural parameters were obtained spectral NMR, FTIR UV–vis compared experimental ones to determine structural details. In vitro antileishmanial activity studied against Leishmania infantum promastigots microdilution broth assay Alamar Blue Dye. The results indicate that exists in both thiol thione form and, can be evaluated as antiparasitic term activity.