Applications on Acrylic Fabrics and Antimicrobial Assessment of Synthesized Azo Derivatives of 4-hydroxy-6-methyl-2-mercaptopyrimidine

Abstract

The study presents the synthesis of novel pyrimidine azo dyes achieved through systematic diazotization and coupling reactions, using 4-hydroxy-6-methyl-2-mercaptopyrimidine as the core substrate. The molecular structures of the synthesized dyes were characterized using advanced spectroscopic techniques. These included Fourier transform infrared (FTIR) spectroscopy for functional group analysis, ultraviolet-visible (UV-Vis) spectroscopy for electronic transitions and both proton nuclear magnetic resonance (¹H-NMR) spectroscopy, and carbon-13 nuclear magnetic resonance (¹³C-NMR) spectroscopy for structural elucidation. The azo compounds were tested for their effectiveness in dyeing acrylic fabrics. Four derivatives yielded vibrant pink colouration (except for compound 8), demonstrating uniform dye uptake and excellent colour fastness properties, with ratings ranging between 4 and 4/5, indicative of high durability and stability under standard washing, light, and rubbing conditions. Furthermore, the biological activity of the synthesized dyes was evaluated against a range of bacterial and fungal strains. Compounds 5 (5-[1H,3-methyl-2,6-dioxo(pyrimidyl)diazenyl]-4-hydroxy-6-methyl-2-mercaptopyrimidine) and 6 (5-[3H,4-hydroxy-2-oxo(pyrimidyl)diazenyl]-4-hydroxy-6-methyl-2-mercaptopyrimidine) exhibited remarkable antimicrobial efficacy, displaying potent inhibitory effects against both gram-positive and gram-negative bacteria as well as fungal pathogens