Chromatographic parameters, pKa, and surface activity of a series of hydrochlorides of perhydroazepinylethyl esters of alkoxyphenylcarbamic acids and their relation to anaesthetic activity

Hydrochlorides of perhydroazepinylethyl esters of alkoxyphenylcarbamic acids were separated by adsorption and partition TLC. The surface tensions, γ, of aqueous solutions of the compounds were measured and the values of p K a were determined. The relation between structure and physico-chemical properties has been confirmed by the dependences of R M and γ on the number of carbon atoms in the alkoxyl chain. Employing the method of regression analysis, the physico-chemical parameters of lipophilicity and the surface activity were correlated, and their effect on biological activity (relative local anaesthetic efficacy) has been assessed.