Letrozole Impurity 35 CAS CATO-C4X-182935
| CAS No. | CATO-C4X-182935 |
| Molecular Formula | C16H11ClN4 |
| Molecular Weight | 294.74 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Compared with other compounds in its class, the molecular weight of 294.74 g/mol gives Letrozole Impurity 35 distinctive chromatographic separation conditions and mass-spectrometry parameter settings.
Letrozole Impurity 35 (CAS CATO-C4X-182935) is a certified pharmaceutical impurity reference standard with the molecular formula C16H11ClN4 and a molecular weight of 294.74 g/mol.
Owing to a nitrogen-containing heterocyclic scaffold, a nitrile group, chlorine substitution, Letrozole Impurity 35 is typically pale yellow to yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 294.74 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).
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 | C16H11ClN4 |
| Molecular Weight | 294.74 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| 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) | 13.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 4 |
Related Letrozole Standards
- Letrozole-d4 (CAS 1133712-96-5)
- Letrozole Impurity 11 (CAS CATO-C4X-182911)
- Letrozole Impurity 36 (CAS CATO-C4X-182936)
- Letrozole impurity 40 (CAS CATO-C4X-182940)
- Letrozole Impurity 3 (CAS CATO-C4X-18293)
- Letrozole Impurity 34 (CAS 2500927-63-7)
- Letrozole EP Impurity A (CAS 112809-52-6)
- Letrozole Impurity 18 (CAS CATO-C4X-182918)
Recommended Standards
- Suvorexant Impurity 46 (CAS CATO-C4X-181246)
- Estazolam Impurity 7 (CAS 163167-55-3)
- N-(4-Butoxy-6-chloropyrido[3,2-d]pyrimidin-2-yl)acetamide (CAS 897362-17-3)
- 6-Chloro-9a-(2-fluoroethyl)-7-methoxy-9,9a-dihydro-1H-fluoren-3(2H)-one (CAS 1039456-85-3)
- Levonorgestrel Impurity 41 (CAS CATO-C4X-167741)
- Empagliflozin impurity 262 (CAS CATO-C4X-1065262)
- Cefaclor Impurity 40 HCI (CAS 53483-70-8)
- 1-(4-(Azetidin-3-yloxy)phenyl)ethanone hydrochloride (CAS 1956379-17-1)
- 5-Methylthiophene-3-carboxylic Acid (CAS 19156-50-4)
- 5-((Azetidin-3-yloxy)methyl)-4-chloro-3-ethyl-1-methyl-1h-pyrazole (CAS 1487635-26-6)
- tert-Butyl (6-bromo-4-chloropyridin-2-yl)carbamate (CAS 1206247-91-7)
- 2-(3,5-Difluorophenyl)pyrrolidine hydrochloride (CAS 1197236-08-0)
- Cloxacillin Impurity 5 (CAS CATO-C4X-15975)
- Semaglutide impurity 227 (CAS CATO-C4X-2226227)
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