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Preferred IUPAC name Benzenecarbothioic S-acid | |
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ECHA InfoCard | 100.002.466 |
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Gmelin Reference | 1071790 |
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Properties | |
Chemical formula | C7H6OS |
Molar mass | 138.18 g·mol |
Appearance | yellow liquid |
Density | 1.1775 g/cm3 |
Melting point | 24 °C (75 °F; 297 K) |
Boiling point | 222 °C (432 °F; 495 K) |
Solubility in water | soluble |
Vapor pressure | 0.1 |
Acidity (pKa) | 3.61 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references |
Thiobenzoic acid is an organosulfur compound with molecular formula C6H5COSH. It is the parent of aryl thiocarboxylic acids. It is a pale yellow liquid that freezes just below room temperature.
Thiobenzoic acid is prepared by treatment of benzoyl chloride with potassium hydrosulfide:
- C6H5C(O)Cl + KSH → C6H5C(O)SH + KCl
Acidity
With a pKa near 2.5, this acid is almost 100x more acidic than benzoic acid. The conjugate base is thiobenzoate, C6H5COS.
See also
References
- Noble, Paul Jr.; Tarbell, D. S. (1952). "Thiobenzoic Acid". Organic Syntheses. 32: 101. doi:10.15227/orgsyn.032.0101.
- Matthys J. Janssen "Carboxylic Acids and Esters" in PATAI's Chemistry of Functional Groups: Carboxylic Acids and Esters, Saul Patai, Ed. John Wiley, 1969, New York: pp. 705–764. doi:10.1002/9780470771099.ch15