Pirfenidone Impurity 44 CAS 21901-18-8
| CAS No. | 21901-18-8 |
| Molecular Formula | C6H6N2O3 |
| Molecular Weight | 154.12 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
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.
As a process- or degradation-related impurity, Pirfenidone Impurity 44 (CAS 21901-18-8, C6H6N2O3) is essential for impurity profiling, related-substances testing, and forced-degradation studies in pharmaceutical development.
Pirfenidone Impurity 44 (C6H6N2O3) contains an amino-acid-derived structure, an amide group, a hydroxyl group, an ether linkage. It is notably hygroscopic, the carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. 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).
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 | C6H6N2O3 |
| Molecular Weight | 154.12 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (faint amine-like odor) |
| Purity | >95% |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO, water |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening |
| Degree of Unsaturation (DBE) | 5.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1963 |
| Nitrogen Atoms | 2 |
Related Pirfenidone Standards
- Pirfenidone Impurity 43 (CAS 7464-14-4)
- Pirfenidone Impurity 33 (CAS 108-86-1)
- Pirfenidone Impurity 32 (CAS 92-53-5)
- Pirfenidone Impurity 35 (CAS 2412-49-9)
- Pirfenidone Impurity 26 (CAS 4588-15-2)
- Pirfenidone Impurity 25 (CAS 2512237-43-1)
- Pirfenidone Impurity 40 (CAS CATO-C4X-222940)
- Pirfenidone Impurity 16 (CAS CATO-C4X-222916)
Recommended Standards
- Finerenone Impurity 225 (CAS CATO-C4X-2880225)
- Salicylic Acid Impurity 25 (CAS 303-07-1)
- 5-Methyl-4-nitropyridin-2(1H)-one (CAS 1416354-34-1)
- Acipimox Impurity 2 (CAS 98502-96-6)
- Luliconazole impurity 18 (CAS CATO-C4X-285318)
- Tetracaine Impurity 5 (CAS 94-32-6)
- Suzetrigine Impurity 36 (CAS CATO-C4X-336936)
- 6-Amino-1-(2-methoxyphenyl)pyrimidine-2,4(1H,3H)-dione (CAS 180028-89-1)
- rel-(1R,2S)-2-phenylcyclohexanol (CAS 2362-61-0)
- 3-(4-Methoxyphenyl)-1-methyl-1H-indol-2-amine (CAS 62693-66-7)
- Methyl 4-(cyclopropylmethyl)-3-oxo-2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine-7-carboxylate (CAS 1707603-12-0)
- 1-(Tert-butyl)-3-cyclobutylurea (CAS 932807-80-2)
- 2-Methyl-N-((1-((tetrahydrofuran-3-yl)methyl)-1h-1,2,3-triazol-4-yl)methyl)propan-2-amine (CAS 1466937-58-5)
- Semaglutide Impurity 131 (CAS 2618647-80-4)
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