5-Bromo-3-methyl-1H-pyrazole CAS 5744-68-3
| CAS No. | 5744-68-3 |
| Molecular Formula | C4H5BrN2 |
| Molecular Weight | 161.00 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
The occurrence of 5-Bromo-3-methyl-1H-pyrazole is closely related to a nitrile group, bromine substitution in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
5-Bromo-3-methyl-1H-pyrazole (CAS 5744-68-3), molecular formula C4H5BrN2 and molecular weight 161.00 g/mol, is a CATO reference standard with documented purity and traceability.
Owing to a nitrile group, bromine substitution, 5-Bromo-3-methyl-1H-pyrazole is typically white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 161.00 g/mol — guide the selection of appropriate sample preparation and analytical techniques. Halogen substitution (F/Cl/Br/I) produces a distinctive isotope pattern in mass spectrometry, a valuable aid for qualitative confirmation.
Recommended for analytical method development and validation; each product is supplied with a full Certificate of Analysis (COA) ensuring ISO 17034 metrological traceability.
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 | C4H5BrN2 |
| Molecular Weight | 161.00 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.) | 1958 |
| Halogen Content | Br-containing |
| Nitrogen Atoms | 2 |
Related Bromo Standards
- 2-Bromo-2-cyclopentenone (CAS 10481-34-2)
- 4-Bromo-5-methyl-1H-pyrazole (CAS 1076223-98-7)
- 2-Bromo-5-methylfuran (CAS 123837-09-2)
- 4-Bromo-3-methylpyrazole (CAS 13808-64-5)
- 3-Bromo-1-methyl-1<I>H</I>-pyrazole (CAS 151049-87-5)
- 4-Bromo-1-methyl-1H-pyrazole (CAS 15803-02-8)
- 4-Bromo-5-methylimidazole (CAS 15813-08-8)
- 4-Bromo-2-methyl-1H-imidazole (CAS 16265-11-5)
Recommended Standards
- 5-bromo-1-methyl-1H-Pyrazole (CAS 361476-01-9)
- Iodoethane-d5 (stabilized with copper) (CAS 6485-58-1)
- 4-Bromocyclopent-2-en-1-one (CAS 765-56-0)
- 1,4-Dichloro-2-methylbenzene (CAS 19389-61-9)
- (2,2-dimethylcyclopropyl)boronic acid (CAS 1089708-34-8)
- potassium 4-ethyl-5-(2-phenylethyl)-4H-1,2,4-triazole-3-sulfonate (CAS 1864054-14-7)
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- 2-((3-(4-Fluorophenyl)benzo[c]isoxazol-5-yl)methylene)-1H-indene-1,3(2H)-dione (CAS 685107-61-3)
- CB-25 (CAS 869376-63-6)
- URB754 (CAS 86672-58-4)
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