Lipophilicity study of some antipyrine derivatives and their interaction with aminoacids

Lipophilicities of five antipyrine derivatives (antipyrine (1), 4-aminoanti pyrine (2), 4-N-(2,4-dinitrophenyl)-aminoantipyrine (3), 4-N-(2,4,6-trinitr ophenyl)-aminoantipyrine (4), and 4-N-(3,4-methylenedioxybenzalidine)aminoa ntipyrine (5) were studied by reverse phase: thin layer chromatography (RPT LC). The compounds 3-5 were synthesised and characterised by H-1- and C-13- NMR spectra. A linear correlation was found between the experimental values of lipophilicity determined by RPTLC and the computed values of the partit ion coefficient. The interaction of antipyrine derivatives with amino acids (Gly, His, Asp, Fen, Met, Ser, Leu) was performed by RPTLC. The interactio n strength of amino acids was higher for compound 4, and the amino acid wit h higher interaction with compounds 1-5 was Asp.