| CAS No. | 3561-24-8 |
| Molecular Formula | C21H8Br4O7 |
| Molecular Weight | 691.90 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
The occurrence of 2',4',5',7'-Tetrabromo-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-6-carboxylic acid is closely related to a flavonoid core, a hydroxyl group, an ether linkage, bromine substitution in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
2',4',5',7'-Tetrabromo-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-6-carboxylic acid (CAS 3561-24-8), molecular formula C21H8Br4O7 and molecular weight 691.90 g/mol, is a CATO reference standard with documented purity and traceability.
The molecular framework of 2',4',5',7'-Tetrabromo-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-6-carboxylic acid (C21H8Br4O7) is characterized by a flavonoid core, a hydroxyl group, an ether linkage, bromine substitution. In reversed-phase chromatography, its retention is governed primarily by the polarity and ionization state of its functional groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
Recommended for analytical method development and validation; each product is supplied with a full Certificate of Analysis (COA) ensuring ISO 17034 metrological traceability.
The assigned purity is verified by mass-balance and quantitative NMR (qNMR) approaches, with the expanded uncertainty reported at a 95% confidence level (k=2). Batch homogeneity and stability are independently assessed for every lot.
| Molecular Formula | C21H8Br4O7 |
| Molecular Weight | 691.90 g/mol |
| Purity | 97%+ |
| Storage | Store at room temperature, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, acetonitrile, DMSO, water (slightly soluble) |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 16.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1958 |
| Halogen Content | Br-containing |