This document provides information about sulphonic acid and phenol. It discusses the preparation, chemical properties, reactions, and pharmaceutical importance of both compounds. Sulphonic acids are derivatives of sulfuric acid where an OH group is replaced by an aryl group, making them more acidic than carboxylic acids. They react with bases to form salts and with PCl5. Phenol contains an OH group attached to an aromatic ring. It is prepared from diazonium salts and is more acidic than aliphatic alcohols due to resonance stabilization of its conjugate base. Phenol reacts through halogenation, nitration, and sulfonation. Both compounds have various pharmaceutical uses as antiseptics, analgesics

1. Bangabandhu Sheikh Mujibur Rahman Science and
Technology University
A presentation on Sulphonic acid
Presented by
Md. Shimul Bhuia
St. ID: 16PHR003
Department of Pharmacy

3. Sulphonic acid
They may be regarded derivatives of sulfuric acid in which on –OH
group has been replaced by an aryl group, Ar
H2SO4 ArHSO3
Sulfuric acid Arenosulfonic Acid
Example:

4. Preparation
• Direct Sulfonation :

5. Chemical Properties
1. The order of acidity for sulphonic acid , Sulphonic acids are more
acidic than carboxylic acids

6. Reaction
• Reaction with bases to form salts :
• Reaction with PCl5 :

7. Pharmaceutical importance
• In pharmaceutical materials science
• To develop the dosage forms
• In natral products and anti-cancer drugs
• Implications of the discovery of human genome for drug therapeutic
strategies and advances in tissue engineering
Physical properties
• Aromatic sulfonic acid are white crystalline solids
• They do not have sharp melting points
• They are soluble in water

8. Phenol
Phenol are compounds containing an –OH group attached directly to an
aromatic ring
Preparation:
1. From diazonium salts

9. Chemical properties
The reactions of phenols are the reactions of the –OH group and the
benzene ring
• Formation of salts:
• Phenol is more acidic than aliphatic alcohols because conjugate base
is stabilized by resonance.
O

–
O

–
O

–
 O

–

10. Reaction of Phenol
• Halogenation.
• Nitration.
• Sulfonation.

11. Pharmaceutical uses
• As a antiseptic
• In aspirin
• As an topical anaesthetic and ear drops, sclerosing agent
• In the treatment of ingrown nails in the “nail matrix phenolization
method”
• As a neurolytic agent applied in order to relicve spams and chronic
pain
• It is used in dermatology for chemical face peeling.