Fluorine-19 (19F)-MR is of high relevance for the study of fluorinated drugs in vivo. Due to low drug concentrations and low numbers of fluorine atoms per molecule, the signal to be detected is very low. To address this drawback this work enhances 19F MRI of the antiinflammatory drug teriflunomide. For this purpose, derivatives of the trifluorinated drug were synthesized including modifications of the number and position of fluorine atoms in the 19F side-chains. We studied the 19F NMR characteristics and compared the SNR efficiencies of these compounds. The inhibitory activity was studied and correlated with the detectability of the compounds. By this, we can select drugs which provide a better signal than the original teriflunomide and which show an equal or even better biological activity.