Side_Chain_Reaction_of_Alkylbenzene_BSc_5th_Semester.pptx

this ppt is informed you about side chain of alkybenzene for b.sc 5th semester

1. Side Chain Reaction of Alkylbenzene Presented by: Mahak Sharma B.Sc. 5th Semester Department of Chemistry Topic Overview: Side chain oxidation, halogenation, nitration, sulphonation , etc.

2. Introduction Alkylbenzenes are aromatic hydrocarbons containing an alkyl group attached to a benzene ring. They undergo several reactions at the side chain rather than the ring due to stability and activation of benzylic position.

3. Side Chain Oxidation Oxidation occurs mainly at the benzylic carbon. Common oxidizing agents: KMnO₄, K₂Cr₂O₇. Example: Toluene → Benzoic acid (with KMnO₄) Condition: Alkaline or neutral medium, heat.

4. Mechanism of Oxidation 1. Abstraction of benzylic hydrogen. 2. Formation of benzylic radical. 3. Conversion to benzoic acid after oxidation. This shows high reactivity of benzylic position due to resonance stabilization.

5. Side Chain Halogenation Occurs at benzylic carbon in presence of UV light or heat. Example: C₆H₅CH₃ + Cl₂ → C₆H₅CH₂Cl + HCl Catalyst: Light or heat. Product: Benzyl chloride, which may further chlorinate to benzal chloride and benzotrichloride .

6. Side Chain Nitration and Sulphonation Nitration: Replacement of benzylic hydrogen by –NO₂ group using dilute nitric acid. Sulphonation : Replacement by –SO₃H group using fuming sulphuric acid. Both reactions occur at the side chain.

7. Industrial Importance Side chain reactions are important for the synthesis of: - Benzoic acid (preservatives) - Benzyl chloride (perfume industry) - Nitro compounds (dyes and drugs) These reactions form the basis of many organic industrial processes.

8. Conclusion Side chain reactions of alkylbenzenes mainly involve oxidation, halogenation, and substitution at benzylic carbon. They are crucial for preparation of aromatic derivatives used in chemical and pharmaceutical industries. Thank You!