The paper deals with analytical evaluation of newly prepared substances, derivatives of N-(4-alkoxy-phenyl)-2-(2-oxo-azepan-1-yl)-acetamide. The substances are a homological series (methyl- to hexyl-). The purity of the substances was verified by thin-layer adsorption chromatography, and the principal physical characteristics--melting point and solubility--were determined. Experimental determination of the partition coefficient, extraction of the substances between two liquids miscible to a limited degree (n-octanol--water), determination of RM values by means of TLC partition chromatography (glass plates DC-Fertigplatten RP-8 F254S), determination of the capacity factor by means of HPLC (column C18 Plaris), and calculation by means of computer programmes were employed to determine the lipophilicity of this series of substances. The antiradical activity of the substances was evaluated by the method of extinguishing the stable radical 2,2-diphenyl-1-picryl-hydrazyl. Ascorbic acid, in which an antiradical effect had been demonstrated, was used for the sake of comparison. The substances show a certain activity, but they do not reach the antioxidative effect of ascorbic acid.