A series of 4-(5-bromo-1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-butyryl N-(substituted phenyl) amides (3a-I) were synthesized and evaluated for their anticonvulsant activity in MES test according to the protocols of Antiepileptic Drug Development (ADD) programme of National Institutes of Health (NIH, Bethesda, USA).The most active compounds of the series were 3a, 3c, 3d, 3f, 3g, 3i and 3k at the dose of 30 mg/kg (i.p.) 0.5 h and 4 h after administration. In neurotoxic screen (NT), 3d, 3i and 3k were less toxic when compared with the other compounds.