| CAS No. | 951661-84-0 |
| Molecular Formula | C22H20ClN3O4 |
| Molecular Weight | 425.86 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
The occurrence of Tadalafil Impurity N23 is closely related to a flavonoid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
CATO supplies Tadalafil Impurity N23 (CAS 951661-84-0), a pharmacopoeial impurity reference standard (molecular formula C22H20ClN3O4, MW 425.86 g/mol) used for the identification and quantification of trace impurities in APIs.
Based on its molecular formula C22H20ClN3O4, Tadalafil Impurity N23 contains a flavonoid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 425.86 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.
As a certified reference material (CRM), Tadalafil Impurity N23 meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
| Molecular Formula | C22H20ClN3O4 |
| Molecular Weight | 425.86 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| Purity | 97%+ |
| Storage | Store in a cool place (≤25°C), protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 14.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1987 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 3 |