In this study, new oxazolidinone and thiazolidinone derivatives were synthesized through a three-step process. In the first step, o-aminothiophenol was reacted with p-aminobenzoic acid in hydrochloric acid to produce an amine containing a thiazole ring, achieving a product yield of 80%. The second step involves synthesizing Schiff bases (E1-E4) by reacting 4-(benzo[d]thiazol-2-yl)aniline with various aromatic aldehydes in the presence of glacial acetic acid. This reaction yields products of 76% to 90%. In the third step, the Schiff derivatives (E1-E4) are reacted with glycolic acid and thioglycolic acid to obtain the desired products. Oxazolidinone derivatives (N1-T1) were produced with rates ranging from 66% to 74%, while thiazolidinone derivatives (N2-T2) exhibited production rates between 63% and 80%. The synthesized compounds were characterized using FT-IR, 13C-NMR, and 1H-NMR spectroscopy. Additionally, all the prepared compounds were evaluated for their antioxidant potential through the DPPH free radical scavenging method. Among the tested compounds (N2-S2-T1-T2-Q2), all demonstrated antioxidant activity. When compared to L-ascorbic acid as a reference, compound Q2 was found to be the most effective inhibitor of the oxidation process. Some of these compounds were examined for their antimicrobial properties against two types of Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis), two types of Gram-negative bacteria (Escherichia coli, Klebsiella sp.), and one type of fungus (Candida albicans). The study found that most of the compounds exhibited moderate effectiveness, with compounds Q2 and Q1 showing the best results as anti-microbial agents
