| CAS No. | 444728-13-6 |
| Molecular Formula | C15H15ClN2OS |
| Molecular Weight | 306.81 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
The occurrence of Clopidogrel Impurity 18 is closely related to a nitrogen-containing heterocyclic scaffold, an amide group, sulfur-containing functionality, a hydroxyl group, an ether linkage, chlorine substitution in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
Clopidogrel Impurity 18 (CAS 444728-13-6) is a certified pharmaceutical impurity reference standard with the molecular formula C15H15ClN2OS and a molecular weight of 306.81 g/mol.
Structurally, Clopidogrel Impurity 18 (C15H15ClN2OS) contains a nitrogen-containing heterocyclic scaffold, an amide group, sulfur-containing functionality, a hydroxyl group, an ether linkage, chlorine substitution. The molecule exhibits a degree of unsaturation (DBE) of 9.0, corresponding to approximately 9 ring(s) or double-bond equivalent(s). With a molecular weight of 306.81 g/mol, it falls into the moderately-high-molecular-weight range. 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 | C15H15ClN2OS |
| Molecular Weight | 306.81 g/mol |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 9.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2025 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 2 |
| Sulfur Atoms | 1 |