Investigation of acidic properties of 2-ethoxy-6-(3-substitue-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl-azomethine)-phenyl benzoates

Abstract

In this study, to determine the pKa values of 2-ethoxy-6-(3-substitue-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl-azomethine)-phenyl benzoates (1-9) were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetone and N,N-dimethylformamide (DMF), and graphs were drawn for all cases. In addition, the effects of solvents and molecular structure upon acidity compounds 1-9 were also determined and discussed. The half-neutralization potential values and the corresponding pKa values were determined by the half neutralization method.

Synthesis and determination of pKa values of some new di-{2-ethoxy-6-[(3-substitue-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)azomethine]phenyl} terephthalates

“…It is known that 4,5-dihydro-1H-1,2,4-triazol-5-one ring has weak acidic properties so some 1,2,4-triazole and 4,5dihydro-1H-1,2,4-triazol-5-one derivatives were titrated potentiometrically with TBAH in non-aqueous solvents [1][2][3][4][5][6]. Determination of pKa values of the active constituent of definite pharmaceutical preparations is significant because of the distribution, transport behavior, bonding to receptors, and contributions to the metabolic behavior of the active constituent molecules depend on the ionization constant [7][8][9].…”