Broønsted acidic ionic liquid 1-n-butylimidazolium tetrafluoroborate ([hbim]bf4): A green catalyst and recyclable medium for the azidolysis of epoxides

Epoxides undergo rapidly ring opening with sodium azide in [hbim]bf 4/h 2o (2:1) medium,under mild condition to afford the corresponding 2-azidoalchols in high yields. the remarkable features of this procedure are improved yields,enhanced reaction rates,regiospecify and ease of recyclability of ionic liquids (ils). the recovered ionic liquid can be reused for five times but with only a gradual decrease in activity observed.