Butanoic moiety of 4-aryl-2,4-dioxobutanoic acids is involved in interactions with metal ions within HIV-1 integrase active site. Sixteen congeneric 4-phenyl-2,4-dioxobutanoic acid derivatives with different substitution on the phenyl ring were prepared. Effects of substitution were studied by spectrometric methods (NMR, MS, UV/VIS) and linear free energy relationships. Better metal complexation ability of meta-alkyl substituted compounds, was observed. This observation might have pharmacological implications.