| CAS No. | 174819-21-7 |
| Molecular Formula | C22H17ClF3NO3 |
| Molecular Weight | 435.82 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 4.
As a process- or degradation-related impurity, Efavirenz Impurity 4 (CAS 174819-21-7, C22H17ClF3NO3) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
Owing to a steroid core, an amide group, a hydroxyl group, an ether linkage, fluorine/chlorine substitution, Efavirenz Impurity 4 is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 435.82 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.
Recommended for quantitative analysis by HPLC, GC, LC-MS/MS, or GC-MS as an external calibration standard; it can also be used for spiked-recovery experiments, LOD/LOQ determination, and LC-MS/MS multiple-reaction-monitoring (MRM) calibration.
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 | C22H17ClF3NO3 |
| Molecular Weight | 435.82 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | 97%+ |
| 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) | 13.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2006 |
| Halogen Content | F/Cl-containing |
| Nitrogen Atoms | 1 |