| CAS No. | 221177-56-6 |
| Molecular Formula | C21H19ClF3NO2 |
| Molecular Weight | 409.83 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 Efavirenz Impurity 12.
As a process- or degradation-related impurity, Efavirenz Impurity 12 (CAS 221177-56-6, C21H19ClF3NO2) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
Efavirenz Impurity 12 (C21H19ClF3NO2) contains a steroid core, an amide group, a hydroxyl group, an ether linkage, fluorine/chlorine substitution. Halogen substitution raises its density and boiling point, its high carbon-to-hydrogen ratio confers good lipid solubility, the carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
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 | C21H19ClF3NO2 |
| Molecular Weight | 409.83 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | >95% |
| Storage | Store at room temperature, 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; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 11.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2020 |
| Halogen Content | F/Cl-containing |
| Nitrogen Atoms | 1 |