Synthesis and non-aqueous medium titrations of some new 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives

Bahceci S., YUKSEK H., OCAK Z., KOKSAL C., OZDEMIR M.

ACTA CHIMICA SLOVENICA, vol.49, no.4, pp.783-795, 2002 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 4
  • Publication Date: 2002
  • Journal Name: ACTA CHIMICA SLOVENICA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.783-795
  • Karadeniz Technical University Affiliated: Yes

Abstract

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) reacted with 3,4-dihydroxybenzaldehyde to afford the corresponding 3-alkyl(aryl)-4-(3,4-dihydroxybenzylidenamino)4,5-dihydro-1H-1,2,4-triazol-5-ones (3). The acetylation and methylation reactions of the latter compounds were investigated, and 4 and 5 type compounds were obtained, respectively. The new compounds were characterized using IR, H-1-NMR, C-13-NMR and UV spectral data. In addition, solutions of the compounds 3a-3e were titrated potentiometrically with tetrabutylammonium hydroxide in three different non-aqueous solvents such as acetonitrile, isopropyl alcohol and N,N-dimethylformamide. The half-neutralization potential values and the corresponding pK(a) values of these compounds were determined in the solvents described above. Thus, the effects of solvents and molecular structure upon acidity were investigated.