Synthesis of Some New Bis- 2, 3-Dihydroquinazolin-4(1H)-one Derivatives from Dapsone Drug and Investigating their Liquid Crystalline Properties and Antibacterial Activities

Abstract

     During this paper, new Schiff's base derivatives [F₁-F₅] were prepared through the reaction of dapsone drug with different substituted benzaldehyde compounds. Schiff's bases were then converted into 2,3-dihyroquinazolin-4(1H)-one derivatives [F₆-F₁₀] through the reaction with 2-amino benzoic acid in ethanol. The synthesized compounds were identified by their physical properties using UV-Vis, FT-IR and ¹H-NMR analyses. The liquid crystalline properties of some prepared compounds revealed smectic and nematic phases. Using two separate bacterial species, Pseudomonas aeruginosa (Gram -ve) and Staphylococcus  aureus (Gram +ve), the antimicrobial activities of certain synthesized compounds [F₁,F₂,F₇,F₈] were investigated using the agar diffusion process. The findings revealed that some of the assayed compounds had antimicrobial activities against the bacteria tested.