Crisaborole Impurity 40 CAS 2737-21-5
| CAS No. | 2737-21-5 |
| Molecular Formula | C7H6Br2O2 |
| Molecular Weight | 281.93 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
Owing to a carboxylic acid group, a hydroxyl group, an ether linkage, bromine substitution, an aromatic ring system, Crisaborole Impurity 40 is typically off-white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 281.93 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).
CATO supplies Crisaborole Impurity 40 (CAS 2737-21-5), a pharmacopoeial impurity reference standard (molecular formula C7H6Br2O2, MW 281.93 g/mol) used for the identification and quantification of trace impurities in APIs.
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.
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 | C7H6Br2O2 |
| Molecular Weight | 281.93 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | >95% |
| Storage | Store at room temperature, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in methanol, acetonitrile, DMSO, water (slightly soluble) |
| Stability | May oxidize slowly on prolonged air exposure; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 4.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1957 |
| Halogen Content | Br-containing |
Related Crisaborole Standards
- Crisaborole Impurity 30 (CAS 2988644-41-1)
- Crisaborole Impurity 5 (CAS 3111-51-1)
- Crisaborole lmpurity 89 (CAS 1187187-13-8)
- Crisaborole lmpurity 77 (CAS CATO-C4X-202177)
- Crisaborole impurity 125 (CAS CATO-C4X-2021125)
- Crisaborole lmpurity 94 (CAS 947162-20-1)
- Crisaborole lmpurity 96 (CAS 526218-72-4)
- Crisaborole impurity 152 (CAS CATO-C4X-2021152)
Recommended Standards
- 5,6-Dibromo-2-methyl-2,3-dihydroimidazo[2,1-b]oxazole (CAS 591254-77-2)
- 2,6-Dibromo-3-fluoro-p-xylene (CAS 1160574-44-6)
- 4,5-Dibromo-2-methoxyphenol (CAS 38926-86-2)
- 1-Bromo-4-(2-bromo-1-fluoroethyl)benzene (CAS 1297549-91-7)
- Vitamin K1 Impurity 30 (CAS 15448-59-6)
- Venlafaxine Impurity 76 (CAS CATO-C4X-143476)
- Lidocaine Impurity 32 (CAS 294852-91-8)
- 2,6-dibromo-1H-inden-1-one (CAS 1909313-83-2)
- Minocycline EP Impurity F (CAS 1075240-33-3)
- (S)-Benzyl 2-(((S)-1-((2-((S)-1-(4-methoxynaphthalen-2-yl)pyrrolidine-2-carboxamido)-2-oxoethyl)amino)-1-oxopropan-2-yl)carbamoyl)pyrrolidine-1-carboxylate (CAS 100900-21-8)
- 2-Bromo-1-propoxy-4-(trifluoromethyl)benzene (CAS 1881329-92-5)
- 2-Hydroxy-5-iodo-N-methylbenzamide (CAS 1243391-62-9)
- Ethyl 1-aminospiro[2.5]octane-6-carboxylate (CAS 1824049-56-0)
- Serpent Peptide 2AcOH (CAS 823202-99-9(free base))
Why CATO?
- ISO 17034 accredited reference material producer (CNAS + ANAB dual accreditation)
- 130,000+ catalog items in stock, COA supplied with every batch
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- Technical support: +86 18665070610 / Nicole.chen@cato-chem.com