Pyridinium p-toluenesulfonate
Appearance
Names | |
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IUPAC name
4-methylbenzenesulfonate; pyridin-1-ium
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Other names
pyridinium p-toluenesulfonate
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Identifiers | |
3D model (JSmol)
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Abbreviations | PPTS |
ChemSpider | |
ECHA InfoCard | 100.041.806 |
PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
C12H13NO3S | |
Molar mass | 251.30 g·mol−1 |
Appearance | Colourless solid |
Melting point | 120 °C (248 °F; 393 K) source[2] |
Acidity (pKa) | 5.21[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pyridinium p-toluenesulfonate (PPTS) is a colourless solid salt of pyridine and p-toluenesulfonic acid.
Uses
In organic synthesis, PPTS is used as a weakly acidic catalyst, providing an organic soluble source of pyridinium (C5H5NH+) ions. For example, PPTS is used to deprotect silyl ethers or tetrahydropyranyl ethers when a substrate is unstable to stronger acid catalysts. It is also a commonly used catalyst for the preparation of acetals and ketals from aldehydes and ketones.
References
- ^ David A. Evans (2005-11-04). "Evans pKa Table" (PDF). Retrieved 2016-03-02.
- ^ TOKYO CHEMICAL INDUSTRY CO., LTD. "Pyridinium p-Toluenesulfonate". Retrieved 2011-09-16.