5-(Methylthio)isoxazole-3-carboxylic acid CAS 1239775-12-2
| CAS No. | 1239775-12-2 |
| Molecular Formula | C5H5NO3S |
| Molecular Weight | 159.16 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
Chemical Structure
Description
The occurrence of 5-(Methylthio)isoxazole-3-carboxylic acid is closely related to an amide group, a sulfone group, a carboxylic acid group, a hydroxyl group, an ether linkage in its molecular formula, which determines its behaviour during synthesis, purification, or degradation.
CATO supplies 5-(Methylthio)isoxazole-3-carboxylic acid (CAS 1239775-12-2), a certified reference material (molecular formula C5H5NO3S, MW 159.16 g/mol) for analytical method development and quality control.
5-(Methylthio)isoxazole-3-carboxylic acid (C5H5NO3S) contains an amide group, a sulfone group, a carboxylic acid group, a hydroxyl group, an ether linkage. It is notably hygroscopic, 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.
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.
CATO manufactures 5-(Methylthio)isoxazole-3-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 | C5H5NO3S |
| Molecular Weight | 159.16 g/mol |
| 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.) | 1990 |
| Nitrogen Atoms | 1 |
| Sulfur Atoms | 1 |
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Recommended Standards
- 2-(4-Fluorotetrahydro-2H-pyran-4-yl)-2-hydroxyacetonitrile (CAS 1226507-95-4)
- 5-(Hydroxymethyl)thiazole-2-carboxylic acid (CAS 1244948-87-5)
- 2-Methoxythiazole-4-carboxylic acid (CAS 1098202-37-9)
- 5-fluorofuro[2,3-b]pyridin-3-one (CAS 1256794-01-0)
- 7-Chloro-3-hydroxy-2-[3-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-one (CAS 338412-72-9)
- 4-Bromo-5-methoxy-2-(p-tolyl)pyridazin-3(2H)-one (CAS 478080-57-8)
- 3-Chloro-8-thia-4,6-diazatricyclo[7.4.0.0,2,7]trideca-1(9),2(7),3,5,10,12-hexaene (CAS 40142-92-5)
- 2-(Pyrrolidin-3-yloxy)nicotinic acid (CAS 1086392-86-0)
- 4-Chloro-3-(2-(2-chloro-4-nitrophenoxy)acetamido)benzene-1-sulfonyl fluoride (CAS 25299-94-9)
- 2-Ethyl-2,3,5,6,7,8-hexahydroquinazolin-4(1H)-one (CAS 62582-92-7)
- Cefpodoxime Proxetil Impurity 10 (CAS CATO-C4X-157910)
- Methyl 2-{4-[2-(furan-2-yl)-5-methyl-1H-pyrrol-1-yl]phenoxy}benzoate (CAS 866038-44-0)
- 2-[[2-Chloro-5-(Trifluoromethyl)Phenyl]Amino]Benzoic Acid (CAS 102583-95-9)
- Semaglutide impurity 69 (CAS CATO-C4X-222669)
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