Synthesis of the Hydrazones of 2‐((3,5‐Di‐tert‐butyl‐4‐hydroxybenzyl)thio) acetohydrazide and the Study of their Radical Scavenging Activity by the DPPH Assay and the Computational Method

Abstract

The synthesis of antioxidant compounds bearing pharmacologically active groups has become a research interest in the last decade. A series of hydrazones containing a butylated hydroxyl group were synthesized from 2‐((3,5‐di‐tert‐butyl‐4‐hydroxybenzyl)thio)acetohydrazide and various benzaldehyde derivatives, and their radical scavenging activity was explored by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) assay and computational calculations. Based on the results, the effects of different substituents on the DPPH IC50 values were discussed. The bond dissociation enthalpies (BDE) of OH and NH bonds and the spin density (SD) values of the compounds were calculated using the density functional theory (DFT) to determine the theoretical capability of the hydrazones as radical scavengers. Based on the results, the effects of the thioether group and the substituent groups next to the NH bond on the BDE values were also discussed.