Collect. Czech. Chem. Commun. 2002, 67, 1215-1222

Synthesis and Potentiometric Titrations of Some New 4-(Benzylideneamino)-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives in Non-Aqueous Media

Şule Bahçecia, Haydar Yüksekb,*, Zafer Ocakc, Ibrahim Azaklia, Muzaffer Alkanb and Mustafa Özdemirc

a Fatih Education Faculty, Karadeniz Technical University, 61335 Trabzon, Turkey
b Department of Chemistry, Kafkas University, 36100 Kars, Turkey
c Department of Chemistry, Karadeniz Technical University, 61080 Trabzon, Turkey


The synthesis of 3-alkyl(aryl)-4-[4-(dimethylamino)benzylideneamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) with 4-(dimethylamino)benzaldehyde is described. The newly synthesized 3 type compounds were titrated potentiometrically with tetrabutylammonium hydroxide in three non-aqueous solvents, including acetonitrile, isopropyl alcohol and N,N-dimethylformamide. The half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, N-acetyl derivatives of 3 type compounds were also obtained. The new synthesized compounds in the study were fully characterized.

Keywords: 4,5-Dihydro-1H-1,2,4-triazol-5-ones; Schiff bases; Acetylation; Acidity; Acidity constants; Potentiometric titration.

References: 31 live references.