Stannous chloride catalyzed synthesis of Schiff bases from hydroxybenzaldehydes and determination of their antioxidant activity by ABTS and DPPH assay

Abstract

Abstract: Phenolic compounds play a very important role in human life because of their antioxidant activity which can prevent harmful diseases caused by free radicals. In the present work, we have synthesized some Schiff bases by the reaction of different hydroxybenzaldehydes and primary aromatic diamines using Stannous Chloride (SnCl 2· 2 H 2O ) as the catalyst. The products were characterized by FT-IR spectroscopy, GCMS and NMR spectroscopy. Furthermore, the antioxidant activity of the Schiff bases were determined by using DPPH assay and ABTS assay and the results were compared with a standard compound, trolox as well as with the parent aldehydes. The synthesized compounds were found to have better antioxidant activity than their corresponding parent aldehydes. Graphic abstract: Phenolic Schiff bases were synthesized by the reaction of different hydroxybenzaldehydes and primary aromatic diamines using SnCl 2· 2 H 2O as the catalyst and dichloromethane as the solvent. Antioxidant activity of the synthesized compounds were determined by DPPH assay and ABTS assay and results were compared to the parent aldehydes as well as Trolox.[Figure not available: see fulltext.]