Paratoluen Sülfonik Asit, Para Toluene Sulfonic Acid, Paratoluenesulfonic Acid, Metilbenzenesülfonik Asit, Tosylic acid, Tosic acid, TsOH, PTSA, 104-15-4, 6192-52-5

Paratoluen Sülfonik Asit, Para Toluene Sulfonic Acid, Paratoluenesulfonic Acid, Metilbenzenesülfonik Asit, Tosylic acid, Tosic acid, TsOH, PTSA, 104-15-4, 6192-52-5

PARA TOLUENE SULFONIC ACID (PTSA)

p-Toluenesulfonic Acid / Tosic Acid / Tosyl Acid / TsOH
CAS Numbers: 104-15-4 (Anhydrous), 6192-52-5 (Monohydrate)
EC Numbers: 203-180-0 (Anhydrous), 228-149-4 (Monohydrate)

1. IDENTIFICATION INFORMATION

2. PHYSICAL PROPERTIES

3. CHEMICAL PROPERTIES

Acid Dissociation Reaction:

CH3-C6H4-SO3H  ⇌  CH3-C6H4-SO3- + H+

Esterification Reaction (Tosylate Production):

CH3-C6H4-SO3H + R-OH  →  CH3-C6H4-SO3R + H2O

Salt Formation (with Base):

CH3-C6H4-SO3H + NaOH  →  CH3-C6H4-SO3Na + H2O

Sulfonamide Formation (with Amine):

CH3-C6H4-SO3H + R-NH2  →  CH3-C6H4-SO2-NH-R + H2O

4. ANHYDROUS VS MONOHYDRATE COMPARISON

Conversion:

Anhydrous + H2O  →  Monohydrate

5. AVAILABLE FORMS AND SPECIFICATIONS

Typical Specifications (Anhydrous Technical Grade):

Typical Specifications (Monohydrate Technical Grade):

6. APPLICATIONS

6.1. Pharmaceutical Industry – Largest Use

6.2. Agrochemicals

6.3. Polymer and Coating Industry

6.4. Textile and Dye Industry

6.5. Detergents and Surfactants

6.6. Cosmetic Industry

6.7. Paper Industry

6.8. Analytical Chemistry

7. CAS NUMBER USAGE PREFERENCES

Summary:

• CAS 104-15-4 (Anhydrous): Most preferred form on industrial scale. Widely used in pharmaceutical, agrochemical, polymer and textile sectors.

• CAS 6192-52-5 (Monohydrate): More stable, laboratory-friendly form. Preferred in analytical chemistry, cosmetics, and paper sectors.

8. USAGE INTENSITY SUMMARY TABLE

9. STORAGE AND HANDLING

Handling Notes:

• Anhydrous form is highly hygroscopic; use quickly or reseal tightly after opening

• Monohydrate form is more stable in air, preferred for long-term storage

• When preparing solutions, add slowly to water (dissolution is slightly exothermic)

• Use stainless steel or glass equipment; avoid aluminum or carbon steel

• Avoid inhalation of dust and skin/eye contact

• Keep away from heat and ignition sources

10. SAFETY AND HEALTH INFORMATION (GHS CLASSIFICATION)

11. HAZARD STATEMENTS (H-CODES)

12. SAFETY STATEMENTS (P-CODES)

13. TOXICOLOGICAL INFORMATION

Health Effects:

14. FIRST AID MEASURES

15. FIRE FIGHTING MEASURES

16. ENVIRONMENTAL INFORMATION

17. TRANSPORT INFORMATION

18. REGULATORY INFORMATION

19. OTHER NAMES AND SYNONYMS

Database Identifiers (Anhydrous - CAS 104-15-4):

Database Identifiers (Monohydrate - CAS 6192-52-5):

20. SUMMARY AND IMPORTANT WARNINGS

SUMMARY:

p-Toluenesulfonic acid (PTSA, TsOH, C7H8O3S) is a very strong organic acid with a pKa value of -0.4 to -0.6 (close to sulfuric acid). It is a white crystalline solid commercially available in two CAS-numbered forms: anhydrous (104-15-4) and monohydrate (6192-52-5). It shows high solubility in water, methanol, ethanol, acetone, and DMSO. Its most common industrial use is as a strong acid catalyst in esterification and acetylation reactions for pharmaceutical synthesis, as well as in polymer production (epoxy, phenolic, polyester resins), agrochemical synthesis, and textile dye production.

Key Properties:

Main Application Areas:

Key Safety Points:

• CORROSIVE: Causes skin irritation and serious eye damage (H315, H318)

• SENSITIZER: May cause allergic skin reaction (H317)

• RESPIRATORY IRRITANT: May cause respiratory irritation (H335)

• HYGROSCOPIC: Anhydrous form is highly hygroscopic; protect from moisture

• USE PPE: Protective gloves, safety goggles, face shield, dust mask

• STORAGE: Keep in a dry, cool place away from moisture

IMPORTANT WARNINGS:

Strong Organic Acid: PTSA has a pKa of -0.4 to -0.6, making it one of the strongest organic acids available, with acidity close to sulfuric acid. This property makes it an ideal catalyst for esterification, acetylation, and other acid-catalyzed reactions.

Anhydrous vs Monohydrate Selection: For industrial-scale production, the anhydrous form (104-15-4) is preferred due to cost effectiveness. For laboratory applications and where storage stability is important, the monohydrate form (6192-52-5) is preferred. The monohydrate is more stable in air and does not cake.

Tosylate Formation: PTSA reacts with alcohols to form tosylate esters. Tosylates are excellent leaving groups in nucleophilic substitution reactions.

Hygroscopicity Warning: Anhydrous PTSA is highly hygroscopic. It cakes upon exposure to moisture and converts to the monohydrate. Tightly closed containers must be used during storage.

Sulfonamide Formation: PTSA reacts with amines to form sulfonamide compounds. This reaction is used in pharmaceutical and agrochemical synthesis.

Phthalate Alternative: PTSA is being evaluated as an alternative to phthalates in some plasticizer applications.

Role in Pharmaceutical Industry: PTSA is an important catalyst and intermediate in the synthesis of certain antibiotics and other pharmaceutical compounds. Tosylate salts are used in drug formulations.

Role in Polymer Industry: PTSA serves as a catalyst in epoxy resin curing, phenolic resin polymerization, and polyester resin esterification.

Analytical Chemistry: PTSA is used as a strong acid reference in titrations and pH calibration. The monohydrate form is preferred for these applications.

Solution Preparation: When dissolving PTSA in water, slight heat is released. Always add slowly to water, never add water to PTSA. The anhydrous form may release more heat upon dissolution.

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS) provided by the manufacturer/supplier. Pay special attention to protecting the anhydrous form from moisture. Use appropriate personal protective equipment when working with PTSA.