| CAS No. | 110753-14-5 |
| Molecular Formula | C13H10ClNO2S |
| Molecular Weight | 279.74 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Etizolam Impurity 4.
Etizolam Impurity 4 (CAS 110753-14-5) is a certified pharmaceutical impurity reference standard with the molecular formula C13H10ClNO2S and a molecular weight of 279.74 g/mol.
Owing to a nitrogen-containing heterocyclic scaffold, an amide group, a sulfone group, a hydroxyl group, an ether linkage, chlorine substitution, Etizolam Impurity 4 is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 279.74 g/mol — guide the selection of appropriate sample preparation and analytical techniques. 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 | C13H10ClNO2S |
| Molecular Weight | 279.74 g/mol |
| Purity | ≥95% |
| Storage | Store at 2-8°C, protect from light, keep tightly closed to prevent evaporation |
| 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) | 9.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1988 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
| Sulfur Atoms | 1 |