Sildenafil EP Impurity C CAS 139755-91-2
| CAS No. | 139755-91-2 |
| Molecular Formula | C20H26N6O4S |
| Molecular Weight | 446.52 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
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.
CATO supplies Sildenafil EP Impurity C (CAS 139755-91-2), a pharmacopoeial impurity reference standard (molecular formula C20H26N6O4S, MW 446.52 g/mol) used for the identification and quantification of trace impurities in APIs.
Owing to a flavonoid core, an amide group, a sulfone group, a hydroxyl group, an ether linkage, Sildenafil EP Impurity C is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 446.52 g/mol — guide the selection of appropriate sample preparation and analytical techniques. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
CATO manufactures Sildenafil EP Impurity C under ISO 17034:2016 accreditation with dual CNAS and ANAB accreditation. Each batch is characterized by orthogonal methods and supplied with a full Certificate of Analysis (COA), ensuring metrological traceability.
Physical & Chemical Properties
| Molecular Formula | C20H26N6O4S |
| Molecular Weight | 446.52 g/mol |
| Purity | >80% |
| 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) | 11.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1996 |
| Nitrogen Atoms | 6 |
| Sulfur Atoms | 1 |
Related Sildenafil Standards
- Sildenafil Impurity 284 (CAS CATO-C4X-1128284)
- Sildenafil Impurity 270 (CAS 1229017-26-8)
- Sildenafil Impurity 271 (CAS 1229017-15-5)
- Sildenafil Impurity 285 (CAS CATO-C4X-1128285)
- Sildenafil Impurity 295 (CAS CATO-C4X-1128295)
- Sildenafil Impurity 280 (CAS CATO-C4X-1128280)
- Sildenafil Impurity 95 (CAS CATO-C4X-112895)
- Sildenafil Impurity 245 (CAS CATO-C4X-1128245)
Recommended Standards
- Vardenafil Impurity 48 (CAS 224785-72-2)
- Mizolastine Impurity 9 (CAS CATO-C4X-20069)
- tert-Butyl 4-{[(4E)-4-[(2H-1,3-benzodioxol-5-yl)methylidene]-5-oxo-2-sulfanylideneimidazolidin-1-yl]methyl}piperazine-1-carboxylate (CAS 865659-64-9)
- Baricitinib Impurity 106 (CAS CATO-C4X-2260106)
- Nicergoline Impurity 15 (CAS CATO-C4X-208515)
- Esmolol Impurity 29 (CAS CATO-C4X-189129)
- Ornidazole Impurity 94 Oxalate (CAS 16773-42-5（free base）)
- 2-(3,5-Dimethyl-1H-pyrazole-1-carbonyl)-N-(4-ethylphenyl)-N-methyl-4-phenylthiophene-3-sulfonamide (CAS 1173745-62-4)
- 3-(3-Methoxyphenyl)pentan-3-ol (CAS 74385-17-4)
- N-(2,4-difluorobenzyl)thietan-3-amine (CAS 1872979-58-2)
- (3a'S,7a'R)-1'-Benzyloctahydrospiro[[1,3]dioxolane-2,5'-indole] (CAS 1260608-58-9)
- 1-(2,3-Dichlorobenzoyl)piperazine (CAS 926236-13-7)
- p-Aminobenzoylmorpholine (CAS 51207-86-4)
- Liraglutide Impurity 26 (CAS CATO-C4X-199226)
Why CATO?
- ISO 17034 accredited reference material producer (CNAS + ANAB dual accreditation)
- 130,000+ catalog items in stock, COA supplied with every batch
- Worldwide shipping with full export documentation (HS code guidance available)
- Technical support: +86 18665070610 / Nicole.chen@cato-chem.com