ch21 - Chapter 21 Phenols and Aryl Halides: Nucleophilic...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 21 Phenols and Aryl Halides: Nucleophilic Aromatic Substitution
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 21 2 Structure and Nomenclature of Phenols Phenols have hydroxyl groups bonded directly to a benzene ring Naphthols and phenanthrols have a hydroxyl group bonded to a polycyclic benzenoid ring
Background image of page 2
Chapter 21 3 Nomenclature of Phenols Phenol is the parent name for the family of hydroxybenzenes Methylphenols are called cresols
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 21 4 Synthesis of Phenols Laboratory Synthesis Phenols can be made by hydrolysis of arenediazonium salts
Background image of page 4
Chapter 21 5 Industrial Syntheses 1. Hydrolysis of Chlorobenzene (Dow Process) Chlorobenzene is heated with sodium hydroxide under high pressure The reaction probably proceeds through a benzyne intermediate (Section 21.11B) 2. Alkali Fusion of Sodium Benzenesulfonate Sodium benzenesulfonate is melted with sodium hydroxide
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 21 6 3. From Cumene Hydroperoxide Benzene and propene are the starting materials for a three-step sequence that produces phenol and acetone Most industrially synthesized phenol is made by this method The first reaction is a Friedel-Crafts alkylation
Background image of page 6
Chapter 21 7 The second reaction is a radical chain reaction with a 3 o benzylic radical as the chain carrier
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 21 8 The third reaction is a hydrolytic rearrangement (similar to a carbocation rearrangement) that produces acetone and phenol A phenyl group migrates to a cationic oxygen group
Background image of page 8
Chapter 21 9 Reactions of Phenols as Acids Strength of Phenols as Acids Phenols are much stronger acids than alcohols
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Chapter 21 10 Phenol is much more acidic than cyclohexanol Experimental results show that the oxygen of a phenol is more positive and this makes the attached hydrogen more acidic The oxygen of phenol is more positive because it is attached to an electronegative sp 2 carbon of the benzene ring Resonance contributors to the phenol molecule also make the oxygen more positive
Background image of page 10
Chapter 21 11 Distinguishing and Separating Phenols from Alcohols and Carboxylic Acids
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/14/2011 for the course CHEM 20A3 taught by Professor Brooke during the Spring '10 term at McMaster University.

Page1 / 30

ch21 - Chapter 21 Phenols and Aryl Halides: Nucleophilic...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online