P-Toluenesulfonic acid
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- The correct title of this article is p-Toluenesulfonic acid. The initial letter is shown capitalized due to technical restrictions.
| p-Toluenesulfonic acid | |
|---|---|
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| Chemical name | 4-methylbenzenesulfonic acid |
| Other names | p-toluenesulfonic acid tosic acid |
| Chemical formula | C7H8O3S |
| Molecular mass | 172.20 g/mol |
| CAS number | [104-15-4] [6192-52-5] (monohydrate) |
| Melting point | 106-107 °C 103-106 °C (monohydrate) |
| Boiling point | 140 °C at 20 mmHg |
| SMILES | Cc1ccc(S(=O)(O)=O)cc1 |
| Appearance | colorless (white) solid |
| Properties | |
| Density and phase | ? g/cm3, ? |
| Solubility in water | 67g/100 ml |
| Acidity (pKa) | -2.8 |
| Structure | |
| Molecular shape | tetrahedral at S |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | skin irritant |
| NFPA 704 | |
| R/S statement | R: 36/37/38 S: 26 |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | ? |
| Other cations | ? |
| Related ? | ? |
| Related compounds | ? |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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p-Toluenesulfonic acid is an organic compound with the formula CH3C6H4SO3H. TsOH, as it is abbreviated, is a white solid that is soluble in water, alcohols, and other polar organic solvents. Most often, TsOH refers to the monohydrate, TsOH.H2O.
TsOH is a strong organic acid, about a million times stronger than benzoic acid. It is one of the few strong acids that is solid and, hence, conveniently weighed. Also, unlike some other strong acids, TsOH is non-oxidizing.
Contents |
[edit] Preparation and handling
TsOH is prepared on an industrial scale by the sulfonation of toluene. It hydrates readily. Common impurities include benzenesulfonic acid and sulfuric acid. Impurities can be removed by recrystallization from concentrated hydrochloric acid followed by azeotropic drying.[1]
Toluenesulfonic acid finds use in organic synthesis as an "organic-soluble" acid catalyst. Examples of uses:
- acetalization an aldehyde.[2]
- Esterification of carboxylic acids.[3]
- Transesterification of an ester.[4]
[edit] See also
[edit] Reference
- ^ Perrin, D. D. and Armarego, W. L. F., Purification of Laboratory Chemicals, Pergamon Press: Oxford, 1988.
- ^ H. Griesser, H.; Öhrlein, R.; Schwab, W.; Ehrler, R.; Jäger, V. "3-Nitropropanal, 3-Nitropropanol, AND 3-Nitropropanal Dimethyl Acetal" Organic Syntheses, 2004 Collected Volume 10, p.577.
- ^ Furuta, K. Gao, Q.-z.; Yamamoto, H. "Chiral (Acyloxy)borane Complex-catalyzed Asymmetric Diels-Alder Reaction: (1R)-1,3,4-Trimethyl-3-cyclohexene-1-carboxaldehyde" Organic Syntheses,1998 Collected Volume 9, p.722.
- ^ Imwinkelried, R.; Schiess, M.; Seebach, D. "Diisopropyl (2S,3S)-2,3-O-isopropylidenetartrate" Organic Syntheses,1993 Collected Volume 8, p.201
- Merck Index, 11th Edition, 9459.
