Exemestane EP Impurity E CAS 19457-55-7
| CAS No. | 19457-55-7 |
| Molecular Formula | C20H26O2 |
| Molecular Weight | 298.42 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Owing to a steroid core, a hydroxyl group, an ether linkage, Exemestane EP Impurity E is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 298.42 g/mol — guide the selection of appropriate sample preparation and analytical techniques. 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).
Exemestane EP Impurity E (CAS 19457-55-7) is a certified pharmaceutical impurity reference standard with the molecular formula C20H26O2 and a molecular weight of 298.42 g/mol.
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.
Physical & Chemical Properties
| Molecular Formula | C20H26O2 |
| Molecular Weight | 298.42 g/mol |
| Appearance | Pale yellow to yellow crystalline powder |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light |
| Solubility (reference) | Soluble in chloroform, dichloromethane, ethyl acetate, DMSO |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light |
| Degree of Unsaturation (DBE) | 8.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1962 |
Related Exemestane Standards
- Exemestane EP Impurity H (CAS 122370-91-6)
- Exemestane EP Impurity F (CAS 72648-46-5)
- Exemestane-d3 (CAS 107868-30-4 (unlabelled))
- Exemestane Impurity 17 (CAS 10104-53-7)
- Exemestane-13C,D3 (CAS CATO-C4X-164116)
- Exemestane Impurity 36 (CAS CATO-C4X-164136)
- Exemestane (CAS 107868-30-4)
- Exemestane Impurity 25 (CAS 2467590-81-2)
Recommended Standards
- Betamethasone Impurity 126 (CAS 90039-84-2)
- Diphenhydramine impurity 18 (CAS 150556-79-9)
- Norethisterone EP Impurity G (CAS 38673-36-8)
- Spironolactone EP Impurity H (CAS 53866-24-3)
- Bexarotene Impurity 4 (CAS 29641-87-0)
- Finerenone Impurity 40 (CAS CATO-C4X-288040)
- Lanreotide Impurity 10 (CAS 1353092-24-6(free base))
- N-Isopropylquinoline-2-carboxamide (CAS 586982-18-5)
- 1,3-Bis(1,1-dimethylethyl) 2-(3-bromo-5-nitrophenyl)imidodicarbonate (CAS 2446931-63-9)
- Tadalafil Impurity 19 (CAS 22839-21-0)
- (S)-tert-Butyl 3-(thiazol-5-ylmethoxy)pyrrolidine-1-carboxylate (CAS 1289585-54-1)
- (2Z)-2-Cyano-3-(3,4-dimethoxyphenyl)prop-2-enethioamide (CAS 156632-50-7)
- 7,7-Diphenyl-1,4-oxazepane cyclohexylsulfamate (CAS 60163-57-7)
- [Glu]17-Liraglutide (CAS CATO-C4X-199236)
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