2,5-Dimethyl-4-nitro-1H-pyrazol-3(2H)-one CAS 81649-68-5
| CAS No. | 81649-68-5 |
| Molecular Formula | C5H7N3O3 |
| Molecular Weight | 157.13 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.
2,5-Dimethyl-4-nitro-1H-pyrazol-3(2H)-one (CAS 81649-68-5), molecular formula C5H7N3O3 and molecular weight 157.13 g/mol, is a CATO reference standard with documented purity and traceability.
Structurally, 2,5-Dimethyl-4-nitro-1H-pyrazol-3(2H)-one (C5H7N3O3) contains an amino-acid-derived structure, an amide group, a hydroxyl group, an ether linkage. The molecule exhibits a degree of unsaturation (DBE) of 4.0, corresponding to approximately 4 ring(s) or double-bond equivalent(s). With a molecular weight of 157.13 g/mol, it falls into the medium-molecular-weight range. Nitrogen-containing functional groups confer excellent ionization efficiency in positive-ion electrospray (ESI) mode, making the compound well suited to LC-MS/MS analysis.
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 | C5H7N3O3 |
| Molecular Weight | 157.13 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (faint amine-like odor) |
| Purity | 97%+ |
| Storage | Store at 2-8°C, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO, water |
| 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 |
| CAS Registry Year (est.) | 1980 |
| Nitrogen Atoms | 3 |
Related Dimethyl Standards
- 1,2-Dimethyl-4-nitro-1H-imidazol-5-ol (CAS 770647-41-1)
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- 1,3-Dimethyl-1,3,5-triazinane-2,4,6-trione (CAS 6726-48-3)
- 1,5-Dimethyl-4-nitro-1,2-dihydro-3H-pyrazol-3-one (CAS 61885-22-1)
- 5,5-Dimethyl-1-nitrosoimidazolidine-2,4-dione (CAS 37137-26-1)
- (S)-4,4-dimethyl-5-oxopyrrolidine-2-carboxylic acid (CAS 1217832-12-6)
- 3,3-dimethyl-5-oxopyrrolidine-2-carboxylic acid (CAS 141978-97-4)
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Recommended Standards
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- 5，7，4’-Trihydroxy-3，6-dimethoxy-3’-prenylflavone (CAS 959421-20-6)
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