Chemical Reactions
Chapter Name : Haloalkanes And Haloarenes |
Sub Topic Code : 102_12_10_06_05 |
Topic Name : Chemical Reactions |
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Sub Topic Name : Reactions Of Haloarenes |
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Introduction
• Similar to Haloalkanes, haloarenes have 3 types of reactions • 1) Nucleophilic substitution reactions • 2) Electrophilic substitutions reactions • 3) Reactions with metals • Aryl halides are extremely less reactive towards nucleophilic substitution reactions due to: • 1) Resonance effects • 2) Difference in hybridisation of carbon atom in C—X bond. • 3) Instability of phenyl cation • 4) Because of the possible repulsion • Haloarenes undergo the usual electrophilic reactions of the benzene ring such as halogenation, nitration, sulphonation and Friedel-Crafts reactions. • Reactions with metals involves two types of reactions: • 1) Wurtz-Fittig reaction • 2) Fittig reaction
Pre-Requisites:
Elements, bond, halides
Activity:
• Synthetic halogen compounds, viz. • chloroquine is used for the treatment of malaria; • Halothane is used as an anaesthetic during surgery.
Real Life Question:
What are haloarenes and haloalkanes?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| - Haloalkanes - Haloarenes | • Haloalkanes contain halogen atom(s) attached to the sp3 hybridised carbon atom of an alkyl group. • Haloarenes contain halogen atom(s) attached to sp2 hybridised carbon atom(s) of an aryl group. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| • Chlorine containing antibiotic, chloramphenicol, produced by soil microorganisms is very effective for the treatment of typhoid fever. |
Real life uses :
• Synthetic halogen compounds, viz. ? chloroquine is used for the treatment of malaria; ? Halothane is used as an anesthetic during surgery..
Places to visit :
Pharmacy.
Practical examples around us
| Examples | Explainations |
|---|---|
| • Synthetic halogen compounds, viz. ? chloroquine is used for the treatment of malaria; ? Halothane is used as an anesthetic during surgery. |
What you learn in Theory:
• Similar to Haloalkanes, haloarenes have 3 types of reactions • 1) Nucleophilic substitution reactions • 2) Electrophilic substitutions reactions • 3) Reactions with metals • Aryl halides are extremely less reactive towards nucleophilic substitution reactions due to: • 1) Resonance effects • 2) Difference in hybridisation of carbon atom in C—X bond. • 3) Instability of phenyl cation • 4) Because of the possible repulsion • Haloarenes undergo the usual electrophilic reactions of the benzene ring such as halogenation, nitration, sulphonation and Friedel-Crafts reactions. • Reactions with metals involves two types of reactions: • 1) Wurtz-Fittig reaction. • 2) Fittig reaction.
What you learn in Practice:
• Haloalkanes and Haloarenes are classified based on the number of halogen compounds contained in them.