Synthesis, Characterization, and Antioxidant Activities of New Heterocyclic Derivatives from Hydralazine Drug

This study reports the synthesis of new hydralazine-based heterocyclic derivatives (S1–S8), including β-lactam, aza-β-lactam, and quinazoline-4-one derivatives. First, Schiff bases (S1 and S2) were prepared by reacting hydralazine with substituted aromatic aldehydes. These Schiff bases were then cyclized with chloroacetyl chloride, phenyl isocyanate, and anthranilic acid to obtain β-lactam derivatives (S3 and S4), aza-β-lactam derivatives (S5 and S6), and quinazoline-4-one derivatives (S7 and S8), respectively. The synthesized compounds were characterized using FT-IR, ¹H NMR, and ¹³C NMR spectroscopy. In addition, their antioxidant activities were evaluated at three concentrations: 25, 50, and 100 ppm. The results indicated that the synthesized compounds exhibited moderate antioxidant activity, with increased activity at 100 ppm; however, their activities remained lower than that of ascorbic acid used as the standard.