Synthesis, Characterization, and Antimicrobial Activity of New Azo Dyes Derived from Pyrazolones

Four different dyes were synthesized, based on 4-nitroaniline and 4-aminobenzene sulfonamide as diazo components and two different pyrazolone derivatives as coupling components. The antimicrobial properties of these dyes were evaluated. The results revealed that the nitro group moiety in dyes ((5-oxo-1-phenyl-3-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-4-yl)diazenyl)benzenesulfonamide (Zb) and 4-((4-nitrophenyl)-diazenyl)-1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one (Zd) rendered these dyes highly active against both Gram-positive and Gram-negative bacteria and the most potent dye against bacteria and fungi was Zd. [GRAPHICS]