Synthesis and determination of pK(a) values of some new 3,4-disubstituted-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives in non-aqueous solvents


YUKSEK H., OCAK Z., ALKAN M. Z. , Bahceci S. , OZDEMIR M.

MOLECULES, vol.9, no.4, pp.232-240, 2004 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 4
  • Publication Date: 2004
  • Doi Number: 10.3390/90400232
  • Title of Journal : MOLECULES
  • Page Numbers: pp.232-240

Abstract

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with 2-furoyl chloride and thiophene-2-carbonyl chloride to afford the corresponding 3-alkyl(aryl)-4-(2 -furoylamino)-4,5 -dihydro-1H-1,2,4-triazol-5-ones (3) and 3-alkyl(aryl)4-(2-thienylcarbonylamino)-4,5-dihydro- 1H-1,2,4-triazol-5-ones (4), respectively. The new compounds synthesized were characterized by using IR, H-1-NMR, C-13-NMR and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 3 and 4 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide and acetonitrile). The half-neutralization potential values and the corresponding pK(a) values were determined for all cases.