4-Bromo-5-methyl-1,2-dihydro-3H-pyrazol-3-one CAS 89363-91-7
| CAS No. | 89363-91-7 |
| Molecular Formula | C4H5BrN2O |
| Molecular Weight | 177.00 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
This reference standard is suitable for quantitative analysis on major chromatographic platforms including HPLC, GC, LC-MS/MS, and GC-MS, serving as an external calibration standard or a system suitability test reference material.
4-Bromo-5-methyl-1,2-dihydro-3H-pyrazol-3-one (CAS 89363-91-7), molecular formula C4H5BrN2O and molecular weight 177.00 g/mol, is a CATO reference standard with documented purity and traceability.
Owing to an amide group, a hydroxyl group, an ether linkage, bromine substitution, 4-Bromo-5-methyl-1,2-dihydro-3H-pyrazol-3-one is typically white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 177.00 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).
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 | C4H5BrN2O |
| Molecular Weight | 177.00 g/mol |
| Appearance | White to pale yellow crystalline powder. (slight halide-like odor, faint amine-like odor) |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, 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 |
| Degree of Unsaturation (DBE) | 3.0 |
| UV Absorption | UV-absorbing |
| CAS Registry Year (est.) | 1982 |
| Halogen Content | Br-containing |
| Nitrogen Atoms | 2 |
Related Bromo Standards
- 5-Bromo-3-methoxypyrazole (CAS 1015779-81-3)
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- 3-Bromo-5,6-dihydropyran-2-one (CAS 104184-64-7)
- 4-Bromo-3-methoxy-1H-pyrazole (CAS 1147011-26-4)
- (2-Bromo-1h-imidazol-4-yl)methanol (CAS 1162674-62-5)
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- 4-Bromo-3-methyl-2,5-dihydro-1,2-oxazol-5-imine (CAS 1356635-81-8)
Recommended Standards
- 4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (CAS 51395-52-9)
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- 4-(Bromomethyl)furan-2(5H)-one (CAS 61934-55-2)
- 5-(2-Bromoethyl)-1H-tetrazole (CAS 82049-79-4)
- 4-Chloro-6-iodopyrrolo[2,1-f][1,2,4]triazine (CAS 916420-31-0)
- 2-((2-Oxo-2H-chromen-7-yl)oxy)-n-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)acetamide (CAS 2484920-10-5)
- 1-(2-Ethynylpyrrolidin-1-yl)ethan-1-one (CAS 118800-19-4)
- 2-Bromo-1-(5-chloro-2-fluorophenyl)ethanone (CAS 725743-40-8)
- (S)-tert-Butyl 2-(methoxy(methyl)carbamoyl)piperidine-1-carboxylate (CAS 203056-27-3)
- 2-(4-Fluorophenyl)-N-(2-methoxybenzyl)ethan-1-amine hydrobromide (CAS 1609407-56-8)
- tert-Butyl (2S,4S)-2-(5-chloro-3-(3-fluorophenyl)-4-oxo-3,4-dihydropyrrolo[2,1-f][1,2,4]triazin-2-yl)-4-fluoropyrrolidine-1-carboxylate (CAS 1551158-99-6)
- 1-(Methylsulfonyl)-3-oxocyclobutane-1-carboxylic acid (CAS 1340337-99-6)
- 2-(2-(Pyridin-3-yl)thiazol-4-yl)aniline (CAS 1204297-94-8)
- Insulin Degludec Impurity 10 (CAS CATO-C4X-215710)
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