4-Hydroxybenzo[d]isoxazole-3-carboxylic acid CAS 57764-43-9
| CAS No. | 57764-43-9 |
| Molecular Formula | C8H5NO4 |
| Molecular Weight | 179.13 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
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.
4-Hydroxybenzo[d]isoxazole-3-carboxylic acid (CAS 57764-43-9) is a high-purity analytical reference standard with the molecular formula C8H5NO4 and a molecular weight of 179.13 g/mol.
Structurally, 4-Hydroxybenzo[d]isoxazole-3-carboxylic acid (C8H5NO4) contains an amino-acid-derived structure, an amide group, a hydroxyl group, an ether linkage. The molecule exhibits a degree of unsaturation (DBE) of 7.0, corresponding to approximately 7 ring(s) or double-bond equivalent(s). With a molecular weight of 179.13 g/mol, it falls into the medium-molecular-weight range. 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).
Recommended for analytical method development and validation; each product is supplied with a full Certificate of Analysis (COA) ensuring ISO 17034 metrological traceability.
Physical & Chemical Properties
| Molecular Formula | C8H5NO4 |
| Molecular Weight | 179.13 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 |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening |
| Degree of Unsaturation (DBE) | 7.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1973 |
| Nitrogen Atoms | 1 |
Related Hydroxybenzo Standards
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- 3-Hydroxybenzo[b]thiophene-2-carbaldehyde (CAS 27751-82-2)
- 4-Hydroxybenzo[b]thiophene-7-carbaldehyde (CAS 199339-71-4)
- 1-(4-Hydroxybenzo[d][1,3]dioxol-5-yl)ethan-1-one (CAS 23780-60-1)
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- N-Hydroxybenzo[d][1,3]dioxole-5-carboximidamide (CAS 4720-72-3)
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Recommended Standards
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- 2-(1H-Pyrrol-1-yl)pyridine (CAS 50966-74-0)
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