Oxacillin Impurity 33 CAS 5053-35-0（free base）
| CAS No. | 5053-35-0（free base） |
| Molecular Formula | C19H18N3O4S2 |
| Molecular Weight | N/A |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Oxacillin Impurity 33.
Oxacillin Impurity 33 (CAS 5053-35-0（free base）) is a certified pharmaceutical impurity reference standard with the molecular formula C19H18N3O4S2K and a molecular weight of 455.59 g/mol.
Based on its molecular formula C19H18N3O4S2K, Oxacillin Impurity 33 contains a flavonoid core, an amide group, a sulfone group, a hydroxyl group, an ether linkage; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 455.59 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).
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.
Physical & Chemical Properties
| Molecular Formula | C19H18N3O4S2 K |
| Molecular Weight | 455.59 g/mol |
| 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 |
| Degree of Unsaturation (DBE) | 12.5 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Nitrogen Atoms | 3 |
| Sulfur Atoms | 2 |
Related Oxacillin Standards
- Oxacillin Monohydrate EP Impurity C (CAS 1136-45-4)
- Oxacillin Sodium Salt (CAS 1173-88-2)
- Oxacillin D5 Sodium (CAS 1173-88-2 (unlabelled))
- Oxacillin EP Impurity D (CAS 1642559-63-4)
- Oxacillin Impurity N1 (CAS 37699-31-3)
- Oxacillin Monohydrate EP Impurity F (CAS 5053-35-0)
- Oxacillin Sodium Monohydrate (CAS 7240-38-2)
- Oxacillin EP Impurity G (CAS 724695-30-1)
Recommended Standards
- Oxytetracycline EP Impurity B (CAS 60-54-8)
- Baricitinib Impurity 5 (CAS 2271228-52-3)
- Gabapentin Impurity 22 (CAS CATO-C4X-165422)
- (9H-Fluoren-9-yl)MethOxy]Carbonyl L-2-Nitrophe (CAS 210282-30-7)
- (S)-5-Aminocyclohexa-1,3-dienecarboxylic acid (CAS 59556-29-5)
- (3-Chloro-2-fluorobenzyl)(3,4-difluorophenyl)sulfane (CAS 1443304-25-3)
- 7-Bromo-2-methyl-3H-imidazo[4,5-b]pyridine (CAS 1392102-13-4)
- 5-Cyclopropyl-1-(4-methylphenyl)-1h-1,2,3-triazole-4-carboxylic acid (CAS 1017399-13-1)
- Rimegepant Impurity 5 (CAS CATO-C4X-24875)
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