Abstract The three N-phenylphthalimide derivatives, 2-(3, 4-dichlorophenyl) isoindoline-1, 3- dione (I), 2-(2, 4-dichlorophenyl) isoindoline-1, 3-dione (II) and 2-(2, 4, 5-trichlorophenyl) isoindoline-1, 3-dione (III), were synthesized by the condensation of equimolar amounts of phthalic anhydride and 3, 4-dichloroaniline, 2, 4-dichloroaniline, 2, 4, 5-trichloroaniline, respectively, under acetic acid reflux and their structures determined by a combination of ...