Design, Synthesis, and Antimicrobial and Antioxidant Activities of Some New Dihydrotetrazole, Dihydroquinazolin-4-one, and 1,3-Benzothiazin-4-one Derivatives Based on 6-Amino-1,3-dimethyluracil

The condensation of 6-amino-1,3-dimethyluracil with substituted benzaldehydes gave six Schiff base derivatives which were brought into cyclizations with sodium azide, anthranilic acid, and 2-sulfanylbenzoic acid to afford new dihydrotetrazoles, dihydroquinazolin-4-ones, and 1,3-benzothiazine-4-ones containing a 1,3-di­methyluracil fragment. The structure of the newly synthesized compounds was confirmed by FTIR and NMR spectroscopy, and their in vitro antioxidant and antimicrobial activities against some bacterial and fungal strains were evaluated.