Synthesis and characterization of some novel 1,2,4-triazoles, 1,3,4-thiadiazoles and Schiff bases incorporating imidazole moiety as potential antimicrobial agents

Acta Pharm. 2015 Jun;65(2):117-32. doi: 10.1515/acph-2015-0011.

Abstract

(1,4,5-Triphenylimidazol-2-yl-thio)butyric acid hydrazide (3) was obtained via alkylation of 1,4,5-triphenylimidazol-2- thiol (1) with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfide in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol- -2-yl)thiopropyl]-2H-1,2,4-triazole-3-thione (4) in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate afforded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthio)butanoyl]-4-alkyl/arylthiosemicarbazides (5-7), which upon refluxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole - -3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with different aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.

MeSH terms

  • Anti-Infective Agents / chemical synthesis
  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Imidazoles / chemical synthesis
  • Imidazoles / chemistry
  • Imidazoles / pharmacology*
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Schiff Bases / chemical synthesis
  • Schiff Bases / chemistry
  • Schiff Bases / pharmacology
  • Structure-Activity Relationship
  • Thiadiazoles / chemical synthesis
  • Thiadiazoles / chemistry
  • Thiadiazoles / pharmacology*
  • Triazoles / chemical synthesis
  • Triazoles / chemistry
  • Triazoles / pharmacology*

Substances

  • Anti-Infective Agents
  • Imidazoles
  • Schiff Bases
  • Thiadiazoles
  • Triazoles