Aiming at preparation of biologically active compounds a bromination of N,N'-substituted malonodiamides in a glacial acetic acid was carried out. The use of one equiv of bromine provided mono-bromo derivatives, with two equiv of bromine dibromo-substituted products were obtained. Among the N,N'-dibenzylantides of alkylmalonic acids only the methyl homolog underwent bromination. The structure of compounds was proved by IR and H-1 NMR spectroscopy. The effect of the compounds synthesized on the central nervous system was investigated.