Synthesis of Schiff bases Derivatives of 1,3-oxazepine and Evaluation of Antioxidant Action In vitro

The objective of this work was to synthesize new 1,3-oxazepine derivatives and evaluate the antioxidant activity of the synthesized compounds. The synthesis of Schiff’s base of oxazepine was achieved in four steps involving condensation of aniline and benzaldehyde followed by (2+5) cycloaddition occurs between the imine and anhydride leading to the formation of 1,3-oxazepine-4,7-dione. Later the oxazepine dione undergoes condensation with thiosemicarbazide and finally nucleophilic addition of active carbonyl group to form Schiff’s bases. The synthesized compounds 8a-e were obtained in yield ranging from 69-77%. The antioxidant activity of the compounds was evaluated at various concentrations (100-500µg/mL) using DPPH radical scavenging assay and hydroxy radical scavenging assay. The compounds had IC50 in the range of 34.297 µg to 131.04 µg in the DPPH scavenging assay whereas the IC50 ranged of 49.943 µg to 153.13 µg in the hydroxy radical scavenging assay.