We report the synthesis of novel benzimidazole derivatives by performing following reaction and all the synthesized compounds characterized using spectroscopic techniques. The reaction of O-phenylenediamine (1) with 2- cyanoquanidine (2) produced 2-quanidinobenzimidazole (3). The compound 3 was reacted with various chalcones (4a-f) obtained from reaction between acetophenone and substituted benzaldehyde produced benzimidazole derivatives 6a-f in very good yields.