Bromine-Lithium Exchange on Bromo-8-hydroxyquinolines via Formation of their Sodium Salts.

Article abstract of DOI:10.1016/0040-4039(95)01776-E

A short and versatile method is reported for the preparation of 8-hydroxyquinoline derivatives by reaction of n-butyllithium with 5,7-dibromo-8-hydroxyquinoline 2 and 7-bromo-8-hydroxyquinoline 1 as their sodium salts.Thus, bromine-lithium exchange reaction on compound 2, highly regioselective, gave after addition of various electrophiles, 5-substituted 7-bromo-8-hydroxyquinolines 4a-j in moderate to good yields.The same procedure was also applicable to 7-bromo-8-hydroxyquinoline 1 which led to 7-substituted 8-hydroxyquinolines 3a-b.