Synthesis of phthalimide derivatives and evaluation of their anxiolytic activity

Based on the molecular modeling studies on two major families of anxiolytics and sedative hypnotics (benzodiazepines and barbiturates) a series of phthalimide derivatives were prepared from corresponding di-methyl phthalate derivatives in two steps, namely trans-amidification and ring closer of di-methyl phthalate with urea and base catalysed condensation of 4-bromobenzyl chloride and benzoyl chloride with resulting imide. The designed compounds were synthesized with satisfactory yields and chemical structures were confirmed using IR, NMR and Mass spectrophotometery. Among the compounds that were tested for anxiolytic activity using elevated plus-maze technique, N-benzoyl-phthalimide increased the time spent and the number of entries into the open arms at doses of 0.5 mg/kg (P < 0.05).