5-Chloro-3-methylisoxazole-4-carboxylic acid CAS 3356-99-8
| CAS No. | 3356-99-8 |
| Molecular Formula | C5H4ClNO3 |
| Molecular Weight | 161.54 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
5-Chloro-3-methylisoxazole-4-carboxylic acid (CAS 3356-99-8) is a high-purity analytical reference standard with the molecular formula C5H4ClNO3 and a molecular weight of 161.54 g/mol.
Owing to an amide group, a carboxylic acid group, a hydroxyl group, an ether linkage, chlorine substitution, 5-Chloro-3-methylisoxazole-4-carboxylic acid is typically off-white to pale yellow crystalline powder. Its solid-state physicochemical attributes — including a molecular weight of 161.54 g/mol — guide the selection of appropriate sample preparation and analytical techniques. 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.
CATO manufactures 5-Chloro-3-methylisoxazole-4-carboxylic acid under ISO 17034:2016 accreditation with dual CNAS and ANAB accreditation. Each batch is characterized by orthogonal methods and supplied with a full Certificate of Analysis (COA), ensuring metrological traceability.
Physical & Chemical Properties
| Molecular Formula | C5H4ClNO3 |
| Molecular Weight | 161.54 g/mol |
| Appearance | Off-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 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; Light-sensitive; avoid direct strong light; Hygroscopic; reseal immediately after opening; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 4.0 |
| UV Absorption | UV-absorbing |
| CAS Registry Year (est.) | 1957 |
| Halogen Content | Cl-containing |
| Nitrogen Atoms | 1 |
Related Chloro Standards
- 4-Chloro-3-methylisoxazole-5-carboxylic acid (CAS 103912-63-6)
- 2-Chloro-5-methyloxazole-4-carboxylic acid (CAS 1240600-64-9)
- 2-Chloro-4-methyloxazole-5-carboxylic acid (CAS 1558276-80-4)
- 3-Chloro-5-methylisoxazole-4-carboxylic acid (CAS 16880-29-8)
- 3-chloro-N-hydroxyfuran-2-carboxamide (CAS 1849273-07-9)
- 4-Chloro-1,3-dihydroxypyridin-2(1H)-one (CAS 19352-46-6)
- 3-Chloro-4-methylisoxazole-5-carboxylic acid (CAS 272773-09-8)
- 4-Chloro-5-methylisoxazole-3-carboxylic acid (CAS 524729-12-2)
Recommended Standards
- 5-(Chloromethyl)isoxazole-4-carboxylic acid (CAS 870704-27-1)
- 5-Chloro-4-methylisoxazole-3-carboxylic acid (CAS 3357-01-5)
- 5-(Chloromethyl)isoxazole-3-carboxylic acid (CAS 3209-41-4)
- 5-Methoxyisoxazole-3-carbonyl chloride (CAS 53064-59-8)
- 2-(3,5-Dichlorophenoxy)-2-methylpropanoic acid (CAS 33995-37-8)
- URANYL ACETATE DIHYDRATE (CAS 6159-44-0)
- 3-Amino-2,6-dimethoxypyridine monohydrochloride (CAS 80789-72-6)
- 4-(Piperazin-1-ylmethyl)phenol hydrochloride (CAS 1881320-76-8)
- 3'-Formyl-4'-hydroxy-[1,1'-biphenyl]-4-carbonitrile (CAS 769971-95-1)
- 1-ethoxy-3-ethynylbenzene (CAS 922735-06-6)
- Flurbiprofen Impurity 78 (CAS CATO-C4X-144478)
- N-Me-Lys-OH (CAS 7431-89-2)
- Budesonide Impurity 14 (CAS 5541-37-7)
- Semaglutide impurity 208 (CAS CATO-C4X-2226208)
Why CATO?
- ISO 17034 accredited reference material producer (CNAS + ANAB dual accreditation)
- 130,000+ catalog items in stock, COA supplied with every batch
- Worldwide shipping with full export documentation (HS code guidance available)
- Technical support: +86 18665070610 / Nicole.chen@cato-chem.com