It was shown that dichloramine-T (1) reacted with cyclohexene in acetonitrile to give N'-(2-chlorocyclohexyl) amidine 2a and N-(2-chlorocyclohexyl)acetamide (3) via the competitive addition of acetonitrile and N-chloro-N-tosylamino anion to cyclohexenechloronium ion. This reaction can be catalyzed by Cu(OAc)(2), primarily affording 2a. Furthermore, the resulting 2a can be cyclized to benzimidazol 14a in good yield by treating with KOH in dioxane.