The aim of the present study was to synthesis of isoindole-1,3(2H)-dione (Phthalimides) derivatives and to investigation the inhibition of xanthine oxidase (XO). In study, xanthine oxidase inhibitory activities of complexes were observed in the range from 7.15 to 22.56 mu M for isoindole-1,3-dione (2a-c and 3a-c). N-phenyl isoindole-1,3-dione derivatives (2c, 3c) showed better activity (almost two times) than the other two derivatives (N-methyl (2a, 3a), N-ethyl (2b, 3b). It means that phenyl ring (R) remarkably enhances the xanthine oxidase inhibitory effect of complexes. In the meantime, molecular docking studies of these compounds against XO were also investigated by providing the inhibitory efficiency and estimating the interaction mechanisms of isoindol-1,3-dion derivatives with XO. (C) 2019 Elsevier B.V. All rights reserved.