MERCURATION OF 8-HYDROXYQUINOLINE AND SOME OF ITS METAL CHELATES

The mercuration of 8-hydroxyquinoline (oxine) and some of its metal chelates has been studied. The mercurated chelates were decomposed in hydrochloric acid-d to furnish the deuterated ligand which was analyzed by nuclear magnetic resonance spectroscopy to determine the sites of substitution. Chemical shifts for the phenol-ring protons in oxine were assigned by analogy to the 5-acetyl derivative. Treated with an excess of mercurating reagent, the oxine chelates gave 5,7-dimercurated derivatives. No evidence for serious steric hindrance to substitution in the 7 position was obtained, even in tris chelates. A mixture of 5- and 7-monosubstituted derivatives was obtained when the ligand concentration greatly exceeded that of the mercurating agent. Substitution in the pyridine ring of the oxine ligand did not occur. © 1969, American Chemical Society. All rights reserved.