| CAS No. | 135206-76-7 |
| Molecular Formula | C4H6ClN3 |
| Molecular Weight | N/A |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Ensitrelvir Impurity 4 HCl (CAS 135206-76-7) is a certified pharmaceutical impurity reference standard with the molecular formula C4H6ClN3HCl and a molecular weight of 168.02 g/mol.
Based on its molecular formula C4H6ClN3HCl, Ensitrelvir Impurity 4 HCl contains a nitrile group, chlorine substitution; these features give the compound characteristic molecular-ion distribution patterns in mass spectrometry. The molecular weight of 168.02 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
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 | C4H6ClN3 HCl |
| Molecular Weight | 168.02 g/mol |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 2.0 |
| CAS Registry Year (est.) | 1995 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 3 |