A new preparative route to 5,6-diamino-1, 10-phenanthroline is described which triples the isolated yields found in existing syntheses (67% vs. 22% from 1,10-phenanthroline) and utilizes mild reaction conditions. The method is general and can even be used on chiral metal complexes containing the appropriate starting material/ligand, 1,10-phenanthroline-5,6-dione, with retention of stereochemistry. (C) 1997 Elsevier Science Ltd.