Steiger N-acylation of a-alanine with 4-(4-bromophenylsulfonyl)benzoyl chloride led to 2-[4-(4-bromophenylsulfonyl)benzamido]propanoic acid. This compound underwent intramolecular cyclization in the presence of N-methylmorpholine and ethyl chloroformate or acetic anhydride to the corresponding saturated azlactone. Then acylaminoacylation of dry aromatic hydrocarbons with 2-[4-(4-bromophenylsulfonyl)phenyl]-4-methyloxazol-5(4H)-one or 2-[4-(4-bromophenylsulfonyl) benzamido ]propanoyl chloride in the presence of anhydrous aluminum chloride led to corresponding a-acylamino ketones. These new intermediates were heterocyclized under the action of phosphorus oxychloride or concentrated sulfuric acid in the presence of acetic anhydride to the corresponding oxazoles. The newly synthesized compounds were characterized by spectral studies (FT-IR, UV-Vis, MS, 1H- and 13C-NMR) and elemental analysis. The purity of the new compounds was evaluated by RP-HPLC. The experimental research regarding to the in vitro cytotoxic activity of the new compounds were performed using Daphnia magna bioassay.