| CAS No. | 64404-51-9 |
| Molecular Formula | C9H9NO5S |
| Molecular Weight | 243.24 g/mol |
| Category | Pharmaceutical Standards / API Standards |
| Availability | In Stock |
As a certified reference material (CRM), 5,7-Dimethoxybenzo[d]isothiazol-3(2H)-one 1,1-dioxide meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
5,7-Dimethoxybenzo[d]isothiazol-3(2H)-one 1,1-dioxide (CAS 64404-51-9), molecular formula C9H9NO5S and molecular weight 243.24 g/mol, is a CATO reference standard with documented purity and traceability.
The molecular framework of 5,7-Dimethoxybenzo[d]isothiazol-3(2H)-one 1,1-dioxide (C9H9NO5S) is characterized by a nitrogen-containing heterocyclic scaffold, an amide group, a sulfone group, a hydroxyl group, an ether linkage. In reversed-phase chromatography, its retention is governed primarily by the protonation state of its nitrogen-containing groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. 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).
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.
| Molecular Formula | C9H9NO5S |
| Molecular Weight | 243.24 g/mol |
| 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) | 6.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1975 |
| Nitrogen Atoms | 1 |
| Sulfur Atoms | 1 |