Synthesis of Some New Benzothiazolyl Azo Dyes Based on 6-Amino-1, 3-Dimethyl Pyrimidine-2,4(1H,3H)-Dione and Examination of Their Spectroscopic and Antimicrobial Properties

Four 2-aminobenzothiazole derivatives (1-4) were synthesized via one pot reaction of appropriate aniline with sodium thiocyanate and bromine at room temperature. These heterocyclic amines and 2-aminobenzothiazole were diazotized by nitorsyl sulphuric acid in acetic acid and coupled with 6-amino-1, 3-dimethyl pyrimidine-2, 4(1H, 3H)-dione to afford azo dyes (5-9) in satisfactory yields. The structures of the compounds were confirmed by spectral methods FT-IR, 1H NMR, 13C NMR and UV-vis.  The effects of six organic solvents (acetic acid, ethanol, chloroform, acetonitrile, dimethyl formamide and dimethyl sulfoxide), acid, base, pH changes and substituents of the diazotizing components on the maximum absorption wavelength of the colorants were discussed and evaluated. In addition, the antibacterial activity of the synthesized dyes has been evaluated against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli bacterial strains.