The reactivity of N-[(2-oxoindolin-3-ylidene)-2-oxiacetyl] amino acids

S. V. Kolisnyk, O. M. Svechnikova, R. I. Kratenko, O. V. Kolisnyk
2015 Vìsnik farmacìï  
The reactivity of N-[(2-oxoindolin-3-ylidene)-2-oxiacetyl] amino acids has been investigated in the reversible conditions by studying their acid-base properties in the binary solvent of dioxane -water (60 volume % of dioxane) at 25°С. The experimental compounds have been proven to be weak dibasic acids. Their рКа values have been determined by Noyes method. The correlation of these values to both of the reactive sites (СООН-and ОН-groups) has been performed. It has been shown that each CH 2
more » ... longation step of the polymethylene chain reduces acidity of compounds at both reactive sites of ionization. Hammett correlation equations (рКа 1,2 -f(σ)) have been calculated for N-[(2-oxoindolin-3-ylidene)-2-oxiacetyl] amino acids, and it allows to predict the acid-base properties of compounds of the given homological series. The low sensitivity of the reactive sites towards polymethylene chain prolongation has been found. The results obtained are used for mathematical modeling of QSAR-analysis of the compounds of the isostructural series.
doi:10.24959/nphj.15.2050 fatcat:uzcpesq5ljh4bpdikkszcnqhge