Acetazolamide EP Impurity A CAS 60320-32-3
| CAS No. | 60320-32-3 |
| Molecular Formula | C4H4ClN3OS |
| Molecular Weight | 177.61 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
The molecular framework of Acetazolamide EP Impurity A (C4H4ClN3OS) is characterized by an amide group, sulfur-containing functionality, a hydroxyl group, an ether linkage, chlorine substitution. 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. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
As a process- or degradation-related impurity, Acetazolamide EP Impurity A (CAS 60320-32-3, C4H4ClN3OS) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
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 | C4H4ClN3OS |
| Molecular Weight | 177.61 g/mol |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in DMSO, DMF, methanol |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 4.0 |
| UV Absorption | UV-absorbing |
| CAS Registry Year (est.) | 1974 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 3 |
| Sulfur Atoms | 1 |
Related Acetazolamide Standards
- Acetazolamide Impurity 8 (CAS 4454-63-1)
- Acetazolamide EP Impurity C (CAS 32873-56-6)
- Acetazolamide EP Impurity D (CAS 14949-00-9)
- Acetazolamide Impurity 7 (CAS 50608-12-3)
- Acetazolamide EP Impurity B (CAS 5393-55-5)
- Acetazolamide EP Impurity G (CAS 2349-67-9)
- Acetazolamide (CAS 59-66-5)
- Acetazolamide EP Impurity E (CAS 827026-60-8)
Recommended Standards
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- 1,3-Dihydroisobenzofuran-4-sulfonamide (CAS 98475-12-8)
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- 2-(Aminomethyl)-6-azaindole (CAS 867140-61-2)
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