In this protocol, 3-(2-carboxybenzoyl)-1-methyl-1H-imidazol-3-ium chloride [Cbmim]Cl and sulfonic acid functionalized pyridinium chloride [pyridine-SO3H]Cl as a new, reusable, and green Brønsted acidic ionic liquid (BAIL) catalyst were synthesized and successfully used for the one-pot ring opening of epoxide with sodium azide (NaN3) in water at room temperature. Epoxides under ring-opening easi...