Dear Bongumenzi Ngidi please find attached a potentially useful review article entitled "Synthetic approaches to benzimidazoles from o-phenylenediamine: A literature review"

Thank you!

Try to perform the catalytic reaction using ultrasonic bath ( sonication ) or microwave irradiation.

Synthesis of amino acid derived benzimidazoles from O-phenylenediamine, you can try sulfamic acid catalyst in DMSO at 90 deg.cent. temperature.

I agree with Madhukar baburao answer.