Various 2-substituted benzimidazoles were prepared in one pot by condensation of o-phenylenediamine with an appropriate aldehyde in good to excellent yields using a mixture of Ti(IV) isopropoxide and cumene hydroperoxide. ... Various 2-substituted benzimidazoles were prepared in one pot by condensation of o-phenylenediamine with an appropriate aldehyde in good to excellent yields using a mixture of Ti(IV) isopropoxide and cumene hydroperoxide.