Model: | MOS 104-15-4 |
Brand Name: | MOSINTER |
CAS No.: | 104-15-4 |
Melting point: | 106~107℃ |
Boiling Point: | 116 °C |
Density: | 1.07 |
Flashing point: | 41 °C |
Refractive index: | 1.3825-1.3845 |
Soluble: | 1 g/L (20 ºC) |
Storage condiion: | Flammables area |
P-Toluenesulfonic acid (CAS: 104-15-4)
Item | Index |
Appearance | White crystalline powder |
Total acidity (C7H8O3S) ≥% | 95.00 |
Dissociative acid (H2SO4) ≤% | 2.50 |
Moisture (Include crystal water) ≤% | 4.00 |
p-Toluenesulfonic acid (PTSA or pTsOH) or tosylic acid (TsOH) is an organic compound with the formula CH3C6H4SO3H. It is a white solid that is soluble in water, alcohols, and other polar organic solvents. The 4-CH3C6H4SO2– group is known as tosyl group and is often abbreviated as Ts or Tos. 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 strong mineral acids (especially nitric acid,
sulfuric acid, and perchloric acid), TsOH is non-oxidizing.
Preparation and handling
TsOH is prepared on an industrial scale by the sulfonation of toluene. It hydrates readily. Common impurities
includebenzenesulfonic acid and sulfuric acid. Impurities can be removed by recrystallization from its concentrated
aqueous solution followed by azeotropic drying with toluene.
Toluenesulfonic acid finds use in organic synthesis as an “organic-soluble” acid catalyst. Examples of uses:
· Acetalization of an aldehyde.
· Esterification of carboxylic acids.
· Transesterification of an ester.
Tosylate esters
Ball-and-stick model of the tosylate anion
Tosylate esters are used as alkylating agents because the tosyl group is electron-withdrawing, which makes the tosylate
anion a good leaving group. The tosyl group is also a protecting group for
alcohols and amines, prepared by combining the alcohol with 4-toluenesulfonyl chloride, usually in an aprotic solvent,
often pyridine, the basicity of which activates the reaction.
Toluenesulfonate esters undergo nucleophilic attack orelimination. Reduction of tosylate esters gives the hydrocarbon.
Thus, tosylation followed by reduction allows for the deoxygenation of alcohols.
Reactions
· p-Toluenesulfonic acid may be converted to p-toluenesulfonic anhydride by heating with phosphorus pentoxide.[
· When TsOH is heated with acid and water, a hydrolysis reaction takes place and toluene is formed:
CH3C6H4SO3H + H2O → C6H5CH3 + H2SO4
This reaction is general for aryl sulfonic acids, but the rate at which it occurs depends upon the structure of the acid, the
temperature and the nature of the catalyzing acid. For example p-TsOH is unaffected by cold concentratedhydrochloric
acid, but hydrolyzes when heated to 186°C in concentrated
phosphoric acid.
You must be logged in to post a review.
Reviews
There are no reviews yet.