The present work deals with the synthesis of 2-(1-acetyl-1H-benzimidazol -2-yl) methyl) isoindoline-1,3-dione (3), used as a key synthons to synthesize a series of some new heterocyclic compounds incorporating benzimidazole moiety. The newly synthesized compounds are characterized by their elemental analysis, IR, 1H, 13C-NMR and mass spectral data and assessed for their antimicrobial activity.