p-Toluenesulfonic acid monohydrate Property

Melting point:

96-99 °C(lit.)

Boiling point:

140°C 20mm

Density 

1,24 g/cm³

vapor density 

5.9 (vs air)

refractive index 

1,382-1,384

Flash point:

180 °C

storage temp. 

Store at +5°C to +30°C.

solubility 

H₂O: 0.1 g/mL, clear

form 

Solid

Colour Index 

42655

color 

White to pink

PH

1 (650g/l, H2O, 20℃)(anhydrous substance)

Water Solubility 

soluble

Sensitive 

Hygroscopic

Merck 

14,9533

BRN 

3568023

Stability:

Stable. Incompatible with strong oxidizing agents, strong bases, most common metals. Protect from moisture.

InChIKey

KJIFKLIQANRMOU-UHFFFAOYSA-N

CAS DataBase Reference

6192-52-5(CAS DataBase Reference)

EPA Substance Registry System

Benzenesulfonic acid, 4-methyl-, monohydrate (6192-52-5)

Safety

Hazard Codes 

Xi,C

Risk Statements 

36/37/38-34-37

Safety Statements 

26-37-45-36/37/39

RIDADR 

UN 2585 8/PG 3

WGK Germany 

-

RTECS 

XT6300000

F 

3

Autoignition Temperature

600 °C

TSCA 

Yes

HazardClass 

8

PackingGroup 

III

HS Code 

29041000

Toxicity

LD50 orally in Rabbit: 2570 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H290May be corrosive to metals

H314Causes severe skin burns and eye damage

H335May cause respiratory irritation

H412Harmful to aquatic life with long lasting effects

Precautionary statements

P234Keep only in original container.

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

p-Toluenesulfonic acid monohydrate Chemical Properties,Usage,Production

Chemical Properties

White crystals

Uses

Derivitizing agent.

Uses

p-Toluenesulfonic acid monohydrate is used as a catalyst in the synthesis of resveratrol, in oxane derivatives as an antimalarial agent, as substituted piperidine and unsymmetrical benzyl. It acts as a catalyst in the preparation of 1,3,5-trisubstituted pyrazoles derivatives, selenated ketene dithioacetals, triazoloquinazolinone and benzimidazoquinazolinone derivatives. It also serves as an intermediate in the esterification and in reductive amination reactions.

Uses

p-Toluenesulfonic acid monohydrate (p-TsOH·H₂O) may be used as a catalyst in the synthesis of the following:

• Unsymmetrical benzils.
• Highly substituted piperidines.
• 1,3,5-Trisubstituted benzenes by trimerization of alkynes.
• Triazoloquinazolinone and benzimidazoquinazolinone derivatives.
• 1,3,5-Trisubstituted pyrazoles derivatives.
• Selenated ketene dithioacetals.

General Description

p-Toluenesulfonic acid monohydrate, an oxonium salt, is an inexpensive and easy to handle organic catalyst used in organic synthesis. The study of its crystalline structure shows that it is monoclinic with P2₁/c space group. Its solubility in aqueous sulfuric acid solutions has been studied.

Purification Methods

Purify the acid by precipitation from a saturated solution at 0o by introducing HCl gas. It can also be crystallised from conc HCl, then crystallised from dilute HCl (charcoal) to remove benzenesulfonic acid. It has been crystallised from EtOH/water. Dry it in a vacuum desiccator over solid KOH and CaCl2. p-Toluenesulfonic acid can be dehydrated by azeotropic distillation with *benzene or by heating at 100o for 4hours under water-pump vacuum. The anhydrous acid can be crystallised from *benzene, CHCl3, ethyl acetate, anhydrous MeOH, or from acetone by adding a large excess of *benzene. It can also be dried under vacuum at 50o. The S-benzylisothiuronium salt has m 182o (from aqueous EtOH). [Beilstein 11 IV 241.]