| CAS No. | 220927-27-5 |
| Molecular Formula | C35H36ClNO3S |
| Molecular Weight | 586.18 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Compared with other compounds in its class, the molecular weight of 586.18 g/mol gives Montelukast EP Impurity A distinctive chromatographic separation conditions and mass-spectrometry parameter settings.
Montelukast EP Impurity A (CAS 220927-27-5) is a certified pharmaceutical impurity reference standard with the molecular formula C35H36ClNO3S and a molecular weight of 586.18 g/mol.
Owing to a nitrogen-containing heterocyclic scaffold, an amide group, a sulfone group, a hydroxyl group, an ether linkage, chlorine substitution, Montelukast EP Impurity A is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 586.18 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.
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.
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 | C35H36ClNO3S |
| Molecular Weight | 586.18 g/mol |
| Purity | >95% |
| Storage | Store at room temperature, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| 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) | 18.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2020 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
| Sulfur Atoms | 1 |