Study of stability of potential betaadrenolytics, derivatives of the [(arylcarbonyl)oxy]aminopropanol by kinetics of alkaline hydrolysis

This work deals with the study of the stability of six derivatives of the [(arylcarbonyl)oxy]amino propanol with carbamate substitution on the benzene ring. The studied compounds are different in the substitution on the amine group in the side chain as well as in the substitution on the carbamate functional group. The hydrolysis of compounds was measured in the aqueous-ethanol sodium hydroxide solution (0.1 mol.l^-1) at 25, 37, 45 and 60°C spectrophotometrically in the ultraviolet and visual regions. The studied compounds possess two functional groups, which undergo hydrolysis. The pseudo-first order rate constants of hydrolysis for individual reaction steps were determined. The ester functional group of compounds hydrolyses very quickly in this medium. The compounds possessing the tertiary substitution on the amino group are less stable toward alkaline hydrolysis. The course of hydrolysis of compounds was also investigated by thin layer chromatography (TLC).