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P-Toluenesulfonic acid
Chemical name
Other names	''p''-toluenesulfonic acid tosic acid
Chemical formula
Molecular mass	g/mol
CAS number	[] [] (monohydrate)
Melting point	°C °C (monohydrate)
Boiling point	°C at 20 mmHg
SMILES
Appearance	colorless (white) solid
Properties
Density and phase	? g/cm³, ?
Solubility in water	67g/100 ml
Acidity (p''K''a)	-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)

'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

Preparation and handling

See also

Reference

External links

Preparation and handling

pTsOH 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]

See also

★ Tosyl

★ Collidine p-toluenesulfonate
It is also used as a catalyst with 3,4 dihydro-2H pyran in alcohol protection.

Reference

1. Perrin, D. D. and Armarego, W. L. F., Purification of Laboratory Chemicals, Pergamon Press: Oxford, 1988.
2. 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.
3. 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.
4. 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'.

External links

★ MSDS for toluenesulfonic acid