8-hydroxyquinoline was first obtained by
Hugo Weidel and his student Albert Cobenzl in 1880. They
decarboxylated so-called oxycinchoninic acid (from
cinchonine) and characterized the resulting compound as melting at about 70°C. They identified that the
hydroxy group is on the benzene ring (but not its particular place) and called the compound
oxyquinoline and
α-quinophenol. In the following year more chemists found other ways to make the compound.
Zdenko Hans Skraup discovered a way to synthesize substituted quinolines from substituted phenols and described three isomers of oxyquinoline, identifying the structure of 8-hydroxyquinoline. and his student Karl Bedall made the compound from a sulphonic acid independently at about the same time, but misidentified its structure. By 1888
azo dyes were made from the compound. In the 1920s insoluble chelates of 8-hydroxyquinoline were discovered. ==Bioactivity==