Difenidol Impurity 4 HCl CAS 55701-20-7
| CAS No. | 55701-20-7 |
| Molecular Formula | C21H27NO |
| Molecular Weight | N/A |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Under current pharmacopoeial and regulatory frameworks, quality-control requirements for this class of reference material explicitly involve the control of targets including Difenidol Impurity 4 HCl.
As a process- or degradation-related impurity, Difenidol Impurity 4 HCl (CAS 55701-20-7, C21H27NOHCl) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
Difenidol Impurity 4 HCl (C21H27NOHCl) contains a steroid core, an amide group, a hydroxyl group, an ether linkage, chlorine substitution. Halogen substitution raises its density and boiling point, its high carbon-to-hydrogen ratio confers good lipid solubility; these physicochemical properties determine the optimal preparation and storage of its standard solutions. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
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 | C21H27NO HCl |
| Molecular Weight | 345.91 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor) |
| Purity | 97%+ |
| 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.) | 1972 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
Related Difenidol Standards
- Difenidol Impurity 8 HCl (CAS 17874-62-3)
- Difenidol Impurity 1 (CAS 40220-79-9)
- Difenidol Impurity 10 (CAS 5180-33-6)
- Difenidol Impurity 7 DiHCl (CAS 63114-16-9)
- Difenidol Impurity 3 (CAS 63645-18-1)
- Difenidol Impurity 11 (CAS 778-66-5)
- Difenidol Impurity 9 DiHCl (CAS 88826-31-7)
- Difenidol - API Standards (CAS 972-02-1)
Recommended Standards
- Gefitinib Impurity 99 3/2HCl (CAS 847949-51-3（free base）)
- Esomeprazole Impurity 103 (CAS CATO-C4X-1112103)
- Bevantolol Impurity 36 (CAS 762182-55-8)
- 4-((5-Chloropentyl)oxy)benzoic acid (CAS 464900-37-6)
- 1-(7-Methoxy-1-naphthyl)cyclobutanecarbonitrile (CAS 1204103-37-6)
- Caspofungin Acetate C0 Analog Acetate (CAS CATO-C4X-15753)
- Lenvatinib Impurity 29 (CAS 417717-21-6)
- 1,2,3-oxathiazolidine,3-ethyl-,2,2-dioxide (CAS 153631-34-6)
- Tofacitinib Impurity 202 (CAS CATO-C4X-1079202)
- Semaglutide Impurity 177 (CAS CATO-C4X-2226177)
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