2-Chloro-5-hydroxybenzoic acid CAS 56961-30-9
| CAS No. | 56961-30-9 |
| Molecular Formula | C7H5ClO3 |
| Molecular Weight | 172.57 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
Recommended for analytical method development and validation; each product is supplied with a full Certificate of Analysis (COA) ensuring ISO 17034 metrological traceability.
2-Chloro-5-hydroxybenzoic acid (CAS 56961-30-9), molecular formula C7H5ClO3 and molecular weight 172.57 g/mol, is a CATO reference standard with documented purity and traceability.
2-Chloro-5-hydroxybenzoic acid (C7H5ClO3) contains a carboxylic acid group, a hydroxyl group, an ether linkage, chlorine substitution, an aromatic ring system. 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. 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 | C7H5ClO3 |
| Molecular Weight | 172.57 g/mol |
| Appearance | Off-white to pale yellow crystalline powder. (slight halide-like odor) |
| Purity | 97%+ |
| Storage | Store at 2-8°C, keep sealed and dry, keep tightly closed to prevent evaporation |
| Solubility (reference) | Soluble in methanol, ethanol, DMSO, water |
| Stability | May oxidize slowly on prolonged air exposure; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 5.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1973 |
| Halogen Content | Cl-containing |
Related Chloro Standards
- 3-Chloro-5-methyl-2-nitropyridine (CAS 1210909-07-1)
- 6-Chloro-3-methyl-2-nitropyridine (CAS 1211516-41-4)
- 6-Chloro-5-methyl-3-pyridazinecarboxylic acid (CAS 1211516-60-7)
- 6-Chloro-N-hydroxypyridine-2-carboxamide (CAS 125309-38-8)
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Recommended Standards
- 2-Chloro-4-methyl-5-nitropyridine (CAS 23056-33-9)
- 2-Chloro-5-methyl-3-nitropyridine (CAS 23056-40-8)
- 2-Chloro-4-methyl-3-nitropyridine (CAS 23056-39-5)
- 2-Chloro-5-nitroaniline (CAS 6283-25-6)
- 3-(2-Methoxyphenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylic acid (CAS 878427-14-6)
- H-Leu-OtBu · HCl (CAS 2748-02-9)
- Sancycline (CAS CATO-C4X-169913)
- (5-amino-1,3-benzoxazol-2-yl)methanol (CAS 948306-37-4)
- (1E)-2-(sec-butylamino)-2-methylpropanal oxime 108302-58-5 (CAS 108302-58-5)
- 4-Cyano-2-(difluoromethyl)-3-nitropyridine-5-acetic acid (CAS 1807123-45-0)
- 1-Cyclopropyl-2-methyl-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine (CAS 1341418-85-6)
- Ethyl 3-((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)-4,4,4-trifluorobutanoate (CAS 886505-47-1)
- 5-Bromo-2-(((tert-butyldimethylsilyl)oxy)methyl)pyridine (CAS 88139-92-8)
- (Des-Bromo)-Neuropeptide B (1-23) (human) (CAS 434897-64-0)
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