<![CDATA[General Background: The development of heterocyclic compounds, particularly dihydropyrimidine derivatives, has garnered considerable interest due to their broad pharmacological potential. Specific Background: Among these, thioxo-dihydropyrimidines have demonstrated significant bioactivity, including anticancer and antimicrobial properties. Knowledge Gap: However, efficient synthesis methods and biocompatibility assessments for novel thioxo-dihydropyrimidines remain limited. Aims: This study aims to synthesize and characterize a new compound, [(6S)-6-(2-hydroxyphenyl)-5-methoxy-2-thioxo-1,2,3,6-tetrahydropyrimidine-4-carbonitrile], and evaluate its cytotoxic potential on human red blood cells. Results: The compound was synthesized via a one-pot multi-component reaction using 2-hydroxybenzaldehyde, methyl cyanoacetate, and thiourea with ferric (III) chloride and HCl in ethanol, yielding 80% of a light golden solid (m.p. 222–224°C). Characterization was confirmed through FT-IR, ¹H-NMR, and MS analysis. Cytotoxicity tests showed the compound to be non-toxic at tested concentrations (0.1–0.5 mg/mL), as evidenced by minimal hemolytic activity. Novelty: This study presents a novel synthetic route for a thioxo-dihydropyrimidine derivative with confirmed structural integrity and biocompatibility. Implications: These findings highlight the potential of this compound as a safe scaffold for future drug development, especially in therapeutic applications requiring low cytotoxic profiles. Highlights: Thioxo-dihydropyrimidines show promise in biomedical applications. Synthesized novel compound; confirmed structure; non-toxic to red blood cells. Potential safe scaffold for future drug development. Keywards: Dihydropyrimidine , Thiourea, Spectra, Cyanoacetate, 1H-NMR]]>
