Synthesis, characterization of 3,5-disubstitutedaryl-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives and evaluation of their antioxidant activity

Abstract

The pyrazolines are nitrogen-containing heterocyclic structures with five members that are used in the production of pharmaceuticals and organic materials. The goal of this work was to preparation and characterization a novel series of derivatives of 3,5-disubstitutedaryl-4,5-dihydro-1H-pyrazole-1-carbothioamide. Two steps were taken in the synthesis of the novel derivatives from chalcones: the first step chalcones was prepared from reaction of {3,4-(methylenedioxy) acetophenone or para methoxy acetophenone} with various aldehydes (previously prepared) in Claisen-Schmidt condensation at room temperature. seven novel 3,5-disubstitutedaryl-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives were made in the second step by cyclization reaction of a variety substituted chalcone derivatives with thiosemicarbazide in ethanol. The structures of the newly derivatives are characterized via: 1H-NMR, FT-IR and Mass spectra, then screened for their antioxidant activity.