5-bromo-1-methyl-1H-pyrazole-4-sulfonyl chloride CAS 1781461-27-5
| CAS No. | 1781461-27-5 |
| Molecular Formula | C4H4BrClN2O2S |
| Molecular Weight | 259.51 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
5-bromo-1-methyl-1H-pyrazole-4-sulfonyl chloride (C4H4BrClN2O2S) contains an amide group, a sulfone group, a carboxylic acid group, a hydroxyl group, an ether linkage, chlorine/bromine substitution. It is notably hygroscopic, halogen substitution raises its density and boiling point, the carboxyl group imparts weak acidity; these physicochemical properties determine the optimal preparation and storage of its standard solutions. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
5-bromo-1-methyl-1H-pyrazole-4-sulfonyl chloride (CAS 1781461-27-5), molecular formula C4H4BrClN2O2S and molecular weight 259.51 g/mol, is a CATO reference standard with documented purity and traceability.
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.
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 | C4H4BrClN2O2S |
| Molecular Weight | 259.51 g/mol |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry, 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; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 3.0 |
| UV Absorption | UV-absorbing |
| CAS Registry Year (est.) | 1994 |
| Halogen Content | Cl/Br-containing |
| Nitrogen Atoms | 2 |
| Sulfur Atoms | 1 |
Related bromo Standards
- 3-bromo-1-methyl-1H-pyrazole-4-sulfonyl chloride (CAS 1378866-77-3)
- 4-Bromo-1-methyl-1H-pyrazole-5-sulfonyl chloride (CAS 1603244-22-9)
- 3-Bromo-1-methyl-1H-pyrazole-5-sulfonyl chloride (CAS 1936381-19-9)
- 1-Bromo-4-chloro-2-fluoronaphthalene (CAS 51670-80-5)
- 8-Bromo-1-chloro-2-fluoronaphthalene (CAS 2387365-85-5)
- 4-Bromo-7-chloro-1H-pyrrolo[3,2-c]pyridine-3-carbaldehyde (CAS 1000341-99-0)
- 7-Bromo-4-chloro-1H-pyrrolo[3,2-c]pyridine-3-carbaldehyde (CAS 1000342-10-8)
- 7-Bromo-4-chlorophthalazin-1(2H)-one (CAS 1028338-57-9)
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