4-((5-(1-(4-Fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-1,3,4-thiadiazol-2-yl)amino)benzenesulfonic acid: unexpected synthesis, structure elucidation and antimicrobial activity

Unexpected ring closure of 2-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl)-N-phenylhydrazine-1-carbothioamide (3) on exposure to sulfuric acid at room temperature for an extended duration (12 h) gave 4-((5-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-1,3,4-thiadiazol-2-yl)amino)benzenesulfonic acid (4) in 75% yield. The use of sulfuric acid led to sulfonation at the para-position of the benzene ring in phenyl isothiocyanate. The crystal structure comprises two independent types of molecules of 4 and two disordered ether solvent molecules. The synthesized benzenesulfonic acid inhibits the growth of both Listeria monocytogenes and Escherichia coli and its activity was comparable to those obtained for ampicillin and vancomycin.

Automated summary

Unexpected ring closure of compound 3 under the action of sulfuric acid at room temperature resulted in the formation of compound 4 with a yield of 75%. The synthesized benzenesulfonic acid showed inhibitory activity against both Listeria monocytogenes and Escherichia coli, which was comparable to ampicillin and vancomycin.