Azithromycin EP Impurity B CAS 307974-61-4
| CAS No. | 307974-61-4 |
| Molecular Formula | C38H72N2O11 |
| Molecular Weight | 732.99 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Based on its molecular formula C38H72N2O11, Azithromycin EP Impurity B contains a nitrogen-containing heterocyclic scaffold, an amide group, a hydroxyl group, an ether linkage; these features give the compound characteristic absorption bands in UV spectroscopy. The molecular weight of 732.99 g/mol is directly relevant to the identification of the molecular ion in mass spectrometry. The aromatic system may exhibit native fluorescence, enabling detection with a fluorescence detector (FLD).
CATO supplies Azithromycin EP Impurity B (CAS 307974-61-4), a pharmacopoeial impurity reference standard (molecular formula C38H72N2O11, MW 732.99 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.
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 | C38H72N2O11 |
| Molecular Weight | 732.99 g/mol |
| Purity | >95% |
| Storage | Store in a cool place (≤25°C), protect from light, keep sealed and dry |
| 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 |
| Degree of Unsaturation (DBE) | 4.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 2025 |
| Nitrogen Atoms | 2 |
Related Azithromycin Standards
- Azithromycin EP Impurity A (CAS 76801-85-9)
- Azithromycin EP Impurity C (CAS 620169-47-3)
- Azithromycin EP Impurity I (CAS 172617-84-4)
- Azithromycin impurity 53 (CAS 152727-04-3)
- Azithromycin CP Impurity Q (CAS 99290-97-8)
- Azithromycin CP Impurity R (CAS 161193-44-8)
- Azithromycin Impurity 23 (CAS CATO-C4X-100323)
- Azithromycin Impurity 50 (CAS CATO-C4X-100350)
Recommended Standards
- 25767-20-8 2,7,12,17-Porphinetetrapropionic acid, 3,8,13,18-tetramethyl-, tetramethyl ester (8CI) Tetramethyl 3,8,13,18-tetramethyl-21H,23H-porphine-2,7,12,17-tetrapropionate 21H,23H-Porphine-2,7,12,17-tetrapropanoic acid, 3,8,13,18-tetramethyl-, 2,7,12,17-tetramethyl ester 21H,23H-Porphine-2,7,12,17-tetrapropanoic acid, 3,8,13,18-tetramethyl-, tetramethyl ester Coproporphyrin I tetramethyl ester EINECS 247-253-5 NSC 89196 (CAS 25767-20-8)
- VYL51769RX 3806-34-6 Distearyl pentaerythritol diphosphite O,O'-Dioctadecylpentaerythritol bis(phosphite) 2,4,8,10-Tetraoxa-3,9-diphosphaspiro(5.5)undecane, 3,9-bis(octadecyloxy)- EINECS 223-276-6 HSDB 7257 UNII-VYL51769RX EC 223-276-6 (CAS 3806-34-6)
- N,N'-(Methylenebis(4,1-phenylene))bis(4-(N,N-dipropylsulfamoyl)benzamide) (CAS 325978-76-5)
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- 3-Chloro-5-nitrophenol (CAS 618-63-3)
- 6-(Benzo[d][1,3]dioxol-5-yl)-2-oxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid (CAS 860610-20-4)
- 5-Chloro-2-fluoro-N-(4-methylpyridin-2-yl)benzamide (CAS 1089554-81-3)
- 4,6-Dimethoxy-1-methyl-1H-indole-3-carbaldehyde (CAS 696649-93-1)
- 3,5-Bis-(4-bromo-benzylidenE)-1-propyl-piperidin-4-one (CAS 412957-50-7)
- (3-Cyclobutyloxetan-3-yl)methanol (CAS 131505-95-8)
- Des-Gly34-Tirzepatide (CAS CATO-CPTD788940)
Why CATO?
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