2,6-Diamino-3'-iodo-4'-hydroxy-3,5'-azopyridine 2,6-Diamino-3-((3'-iodo-4'-hydroxy-5-pyridyl)azo)pyridine 4-Pyridinol, 3-(2,6-diamino-3-pyridylazo)-5-iodo- Pyridine, 2,6-diamino-3-((3'-iodo-4'-hydroxy-5-pyridyl)azo)- US7659000