Some new sulfathiazole derivatives were synthesized. The sulfathiazole starting material was reacted with ethyl bromoacetate and gave unpredictably an ester product 2. The substitution occurred selectively at the tautomeric proton of the NH thiazolyl nitrogen rather than the aromatic NH2 protons. The ester was further hydrazinolysed followed by condensation with several aldehydes to establish hydrazones (4a-h). Hantzesch thiazole synthesis was also applied to build antimicrobial agents containing multi-thiazole moieties. The structures of the synthesized compounds were confirmed by 1H, 13C, 2D 1H NMR, MS, and microanalyses. The synthesized compounds were tested for their antimicrobial activity towards Gram-positive and Gram-negative bacteria, and fungi strains. Some of the investigated compounds showed prominent high potency. The docking study revealed the mode of action between the modified sulfathiazole ligands and the binding site of DHPS.