Synthesis of some new 1,2,4-triazoles, their Mannich and Schiff bases and evaluation of their antimicrobial activities


BAYRAK H., DEMİRBAŞ A., Karaoglu S. A. , DEMİRBAŞ N.

EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY, vol.44, no.3, pp.1057-1066, 2009 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 44 Issue: 3
  • Publication Date: 2009
  • Doi Number: 10.1016/j.ejmech.2008.06.019
  • Title of Journal : EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
  • Page Numbers: pp.1057-1066

Abstract

4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (3) was obtained in basic media via the formation of 2-isonicotinoyl-N-phenylhydrazine-carbothioamide (2), and converted to some alkylated derivatives (4a,b) and Mannich base derivatives (5a-c). 2-[(4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]acetohydrazide (7) that was obtained by using compound 3 as precursor in two steps was converted to thiosemicarbazide derivative (8), Schiff base derivatives (9) and 5-([(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl)-1,3,4-oxadiazole-2-thiol (10). Moreover, 5-([(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl)-3-{[(2-morpholin-4-ylethyl)amino]methyl}-1,3,4-oxadiazole-2(3H)-thione (11) was synthesized via reaction of compound 10 with 2-(4-morpholino)ethylamine. The treatment of compound 8 with NaOH gave 4-(4-methylphenyl)-5-{[(4-phenyl-5-pyridine-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-4H-1,2,4-triayole-3-thiol (12), while the acidic treatment of compound 8 afforded 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-2(4-methylphenyl)-amino-1,3,4-thiadiazole (14). N-Methyl derivative of compound 14 and a Mannich base derivative of compound 12 were synthesized from the reactions of these precursors with methyl iodide and methyl piperazine, respectively.