| CAS No. | 1355357-49-1 |
| Molecular Formula | C33H31N5O4 |
| Molecular Weight | 561.63 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Compared with other compounds in its class, the molecular weight of 561.63 g/mol gives Remdesivir Impurity 3 distinctive chromatographic separation conditions and mass-spectrometry parameter settings.
CATO supplies Remdesivir Impurity 3 (CAS 1355357-49-1), a pharmacopoeial impurity reference standard (molecular formula C33H31N5O4, MW 561.63 g/mol) used for the identification and quantification of trace impurities in APIs.
The molecular framework of Remdesivir Impurity 3 (C33H31N5O4) is characterized by a nitrogen-containing heterocyclic scaffold, an amide group, a hydroxyl group, an ether linkage. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
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 | C33H31N5O4 |
| Molecular Weight | 561.63 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >95% |
| 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 |
| Degree of Unsaturation (DBE) | 21.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1991 |
| Nitrogen Atoms | 5 |