Iron is indispensable to biology, but repeated transfusions can supply more of it than the body can readily remove. Deferiprone offers a particularly direct example of coordination chemistry applied to that problem. The substance registered as CAS 30652-11-0 is 1,2-dimethyl-3-hydroxy-4-pyridone, the drug molecule itself rather than merely a related chemical. Its small heterocyclic ring carries two adjacent oxygen donor sites that can bind ferric iron.
The chelating unit consists of a hydroxyl group next to a carbonyl group. On binding, the ligand can coordinate through both oxygen atoms, creating a chelate ring around the metal. Each deferiprone molecule supplies two donor atoms, and three molecules can surround one iron(III) ion to form a neutral complex. This three-to-one arrangement is an important connection between a structural formula and biological function. The molecule does not destroy iron; it changes its coordination environment and facilitates removal from the body.
The clinical motivation was practical as well as chemical. Desferrioxamine had provided an effective route to iron chelation but commonly required prolonged administration by infusion. An orally active compound could reduce that burden. In 1987, George Kontoghiorghes and colleagues reported an early study of the compound, then called L1, in three multiply transfused patients with myelodysplasia. Oral administration increased urinary iron excretion. The small study established an important proof of principle, while being far too limited to define long-term efficacy or the full safety profile.
That distinction between an early signal and an established treatment is important in the history of drug development. A molecule that binds iron in a laboratory must also be absorbed, reach relevant iron pools and produce a complex that can be eliminated. Unwanted interactions and toxicity must be assessed separately. Molecular size and donor geometry provide a design rationale, but they do not replace clinical evidence. Deferiprone's development connected all of these questions over years of investigation.
Ferriprox, a deferiprone product, received initial United States approval in 2011. The prescribing information identifies it as an iron chelator for specified patients with transfusional iron overload. Its mechanism is described in terms of stable neutral iron complexes at physiological pH. The pharmaceutical product includes a defined formulation and prescribing conditions; a laboratory bottle of the same chemical is not a substitute for a medicine manufactured and controlled for clinical use.
Its useful metal-binding behavior also illustrates why selectivity is more than a statement that a compound has two oxygen atoms. Protonation equilibria affect how donor sites are available. Competing ligands and the concentrations of different metals affect the system in which binding occurs. The amount of excess iron, exposure to the drug and the route by which complexes leave the body are further variables. A favorable coordination motif is therefore one part of a therapeutic system, not an automatic guarantee of clinical benefit.
The historical name L1 is consequently useful when tracing early publications, while the systematic name and CAS number connect those reports with modern substance records. These different naming systems identify the same active molecular framework.
The drug's history also includes a serious safety limitation: agranulocytosis can occur, and clinical use requires monitoring of neutrophil counts. Prescribing information also addresses liver enzymes and zinc status. These requirements belong alongside the explanation of iron binding, rather than being obscured by the elegance of the chemical design. Deferiprone remains a clear example of how a simple oxygen-donor arrangement can become an oral medicine, provided that coordination chemistry, clinical evidence and ongoing safety management are considered together.
References:
1. FDA Global Substance Registration System. DEFERIPRONE; UNII 2BTY8KH53L; CAS 30652-11-0. https://precision.fda.gov/uniisearch/srs/unii/2BTY8KH53L
2. Kontoghiorghes GJ, Aldouri MA, Sheppard L, Hoffbrand AV. 1,2-Dimethyl-3-hydroxypyrid-4-one, an orally active chelator for treatment of iron overload. Lancet. 1987;1:1294-1295. DOI: 10.1016/S0140-6736(87)90545-9. https://doi.org/10.1016/S0140-6736(87)90545-9
3. DailyMed. FERRIPROX (deferiprone) tablets. Prescribing information; sections 5, 11 and 12; accessed 2026-10-19. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=946718ff-df43-1baa-74d1-e5bcfbe8ad86
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