Síntese de 2-aril-3-(piridin-2-il)-1,3-tiazolidin-4-tionas usando reagente de Lawesson e bioisosterismo em estudos de ação antioxidante em reagentes e produtos

Abstract

Heterocyclic compounds could be obtained by conventional heating and alternative methodologies such as microwaves and ultrasound, have shown large pharmacological properties. Thus, this work report the synthesis of twelve novel 2-aryl-3-(pyridin-2-yl)-1,3-thiazolidin-4-thiones (aryl: 2-ClPh, 2- FPh, 2-OMePh, 2 NO2Ph, 3-ClPh, 3-FPh, 3-OMePh, 3-NO2Ph, 4-ClPh, 4-FPh, 4-OMePh, 4- NO2Ph) by conventional methodology transfer energy (heating plate) from the reaction of 2-aryl-3- (pyridin-2-yl)-1,3-thiazolidin-4-ones and the Lawesson's reactant refluxing toluene for 12 hours. The products were obtained in good yields (71-96%). All compounds were identified by gas chromatography (GC) and characterized by mass spectroscopy (GC-MS). Next, we study the antioxidant ability of the products (thiazolidin-4-thiones) as well as the precursors (thiazolidin-4- ones) in the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The results show that the proposed bioisosterism exchange, carbonyl C=O to thiocarbonyl C=S group, was satisfactory for some compounds, since the thiazolidin-4-thiones showed lower EC50 values than their respective carbonyl bioisosters. Furthermore, compounds with R = 3-F (IC50 57.5 M), 3-OMe (IC50 57.3 M) 4-Cl (IC50 62.6 M), 4-F (IC50 56.6 M) had IC50 values lower than standard eugenol (IC50 72.0 M).