Tryptophan Impurity 21 CAS 55325-48-9
| CAS No. | 55325-48-9 |
| Molecular Formula | C11H11ClN2O2 |
| Molecular Weight | 238.67 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Tryptophan Impurity 21 (C11H11ClN2O2) contains a nitrogen-containing heterocyclic scaffold, an amide group, a hydroxyl group, an ether linkage, chlorine substitution. It is notably hygroscopic, halogen substitution raises its density and boiling point, its high carbon-to-hydrogen ratio confers good lipid solubility, the carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
CATO supplies Tryptophan Impurity 21 (CAS 55325-48-9), a pharmacopoeial impurity reference standard (molecular formula C11H11ClN2O2, MW 238.67 g/mol) used for the identification and quantification of trace impurities in APIs.
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.
As a certified reference material (CRM), Tryptophan Impurity 21 meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
Physical & Chemical Properties
| Molecular Formula | C11H11ClN2O2 |
| Molecular Weight | 238.67 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (slight halide-like odor) |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry, 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; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 7.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1972 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 2 |
Related Tryptophan Standards
- Tryptophan Impurity 14 (CAS 33468-35-8)
- Tryptophan Impurity 46 (CAS 56632-86-1)
- Tryptophan Impurity 7 (CAS 13081-15-7)
- Tryptophan Impurity 16 (CAS CATO-C4X-137316)
- Tryptophan EP Impurity B (Mixture of Diastereomers) (CAS 184955-21-3)
- Tryptophan impurity 38 (Mixture of Diastereomers) (CAS CATO-C4X-137338)
- Tryptophan Impurity 44 (CAS 101948-12-3)
- Tryptophan EP Impurity E (CAS 3978-11-8)
Recommended Standards
- n-(4-Chlorophenyl)-5-oxopyrrolidine-2-carboxamide (CAS 4108-12-7)
- Paliperidone Impurity 50 (CAS 260273-82-3)
- N-(4-Chloro-2-methoxy-5-methylphenyl)-2-cyanoacetamide (CAS 380190-51-2)
- 7-Chloro-L-Tryptophan (CAS 73945-46-7)
- Aprepitant Impurity 36 (CAS 638990-20-2)
- Flecainide Acetate EP Impurity E (CAS 57415-36-8)
- Olodaterol Impurity 8 (CAS CATO-C4X-19438)
- (2-((3-Chloro-5-(trifluoromethyl)pyridin-2-yl)thio)-1-(3,4-dimethoxyphenethyl)-1H-imidazol-5-yl)methanol (CAS 338422-54-1)
- Ethyl 2-chloro-5-formylnicotinate (CAS 176433-48-0)
- Metolachlor-2-ethoxy (CAS 68544-97-8)
- 2-Cyano-4-(4-hydroxyphenyl)phenol (CAS 1261973-27-6)
- 4-(4-Bromobutyl)morpholine Hydrobromide (CAS 1803587-12-3)
- 2-Propynyl [3-(Triethoxysilyl)propyl]carbamate (CAS 870987-68-1)
- Fibrinopeptide B (human) (CAS 36204-23-6)
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