| CAS No. | 1035-69-4 |
| Molecular Formula | C19H24O2 |
| Molecular Weight | 284.39 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
This reference standard supports related-substances testing and method development in line with ICH Q3A/Q3B guidance on impurity control, and is suitable for system suitability testing and forced-degradation studies.
Exemestane Impurity 2 (CAS 1035-69-4) is a certified pharmaceutical impurity reference standard with the molecular formula C19H24O2 and a molecular weight of 284.39 g/mol.
Owing to a steroid core, a hydroxyl group, an ether linkage, Exemestane Impurity 2 is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 284.39 g/mol — guide the selection of appropriate sample preparation and analytical techniques. The high carbon-to-hydrogen ratio imparts good lipophilicity, allowing liquid-liquid extraction with non-polar solvents such as n-hexane or ethyl acetate.
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 | C19H24O2 |
| Molecular Weight | 284.39 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >90% |
| Storage | Store at 2-8°C, protect from light |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 8.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1957 |