Synthesis, characterization and evaluation of antibacterial activity of some thiazolo[3,2-b][1,2,4]triazole incorporating diphenylsulfone moieties

A series of thiazolo[3,2-b][1,2,4]triazole incorporating diphenylsulfone moieties were synthesized starting from 5-[4-(4-X-phenylsulfonyl)phenyl]-4H-1,2,4-triazole-3-thioles 3a–c, X = H, Cl, Br. Thus, alkylation of 1,2,4-triazoles 3 with phenacyl bromide or 4-bromophenacyl bromide afforded S-substituted 1,2,4-triazoles 4, 5. These new intermediates 4 and 5, in the presence of H₂SO₄ (c), were cyclized to 2-[4-(4-X-phenylsulfonyl)phenyl]-6-(4-Y-phenyl)[1,3]thiazolo[3,2-b]-[1,2,4]-triazoles 6, 7 (I) and not to isomeric thiazolo[2,3-c][1,2,4]-triazoles 6, 7 (II). The newly synthesized compounds were characterized by IR, ¹H, ¹³C NMR and elemental analysis. MS spectra confirmed the formation of thiazolo[3,2-b][1,2,4]triazole 6, 7 (forms I) in detriment of [2,3-c] isomeric compounds (forms II). The potential antibacterial effects of the synthesized compounds were investigated using standard bacterial strains: Acinetobacter baumannii ATCC 19606, Citrobacter freundii ATCC 8090, Escherichia coli ATCC 11775, Pseudomonas aeruginosa ATCC 9027, Enterococcus faecalis ATCC 19433, Staphylococcus aureus ATCC 12600, Staphylococcus epidermidis ATCC 14990, Bacillus cereus ATCC 14579.     

Synthesis, characterization and antibacterial activity of some triazole Mannich bases carrying diphenylsulfone moieties

A series of Mannich bases of 4-substituted 5-[4-(4-X-phenylsulfonyl)phenyl]-2,4-dihydro-3H-1,2,4-triazole-3-thiones, X=H, Cl, Br, 3 and 5 were synthesized and characterized on the basis of IR, NMR and elemental analyses. The potential antibacterial effects of the synthesized compounds were investigated using the Acinetobacter baumanii ATCC 19606; Citrobacter freundii ATCC 8090; Pseudomonas aeruginosa ATCC 9027; Enterococcus faecalis ATCC 19433; Staphylococcus aureus ATCC 12600; Staphylococcus epidermidis ATCC 14990; Bacillus subtilis ATCC 6633 strains. Some of them exhibited promising activities against A. baumanii and B. subtilis.     

Synthesis and antimicrobial evaluation of some fused heterocyclic [1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives

A series of fused 1,2,4-triazoles with diphenylsulfone moiety are prepared utilizing 4-amino-5-[4-(4-X-phenylsulfonyl)phenyl]-4H-1,2,4-triazole-3-thiol 1 (X=H, Br). The latter on reaction with aromatic isothiocyanate in DMF, aromatic acid in POCl3 and CDI in dioxane gives five membered fused triazole derivatives 2a-c, 3a-c, 4a-g, 5a-g and 6a,b. The structures of newly synthesized compounds were confirmed on the basis of their elemental analysis and spectral data results (IR, 1H-and 13C NMR). New synthesized compounds were screened for their antimicrobial activities. The preliminary results revealed that some of the compounds exhibited promising antimicrobial activities.