Special Reaction of Phenol
Phenol undergoes various chemical reactions to a number of compounds. Some of these reactions are mentioned below:
Electrophilic Aromatic Substitution Reactions
Phenol undergoes various electrophilic aromatic substitution reactions due to the presence of the hydroxyl group, which is strongly activating and ortho/para directing. These reactions include halogenation, sulfonation, nitration, and Friedel–Crafts.
- Halogenation: Phenol undergoes halogenation in the presence of a halogen carrier such as iron(III) halide. The general reaction is:
Phenol + X2 –––FeX3––› C6H4OHX+ HX
- Sulfonation: Phenol undergoes sulfonation with fuming sulfuric acid to produce a mixture of ortho- and para-sulfonated products. The general reaction is:
Phenol + SO3 ––H2SO4––› C6H4OHSO3H+ H2O
- Nitration: Phenol undergoes nitration with dilute nitric acid at low temperature to give ortho and para nitrophenols. The general reaction is:
Phenol + HNO3 –––298K––› C6H4OHNO2 + H2O
- Friedel-Crafts Alkylation: Phenol can undergo Friedel-Crafts alkylation to introduce an alkyl group onto the benzene ring. The general reaction is:
Phenol + R-Cl ––– AlCl3––› C6H4OHR+ HCl
Oxidation to Quinones: Phenol can be oxidized to form quinones, such as benzoquinone, through reactions with oxidizing agents like potassium dichromate.
Quinone + Oxidizing agent –––––› Oxidized quinone
Kolbe’s Reaction: When Phenol is treated with sodium hydroxide, it forms the phenoxide ion, which undergoes electrophilic substitution to form ortho-hydroxybenzoic acid. This reaction is called Kolbe’s reaction.
C6H5OH + CO2 + NaOH –––––› Aromatic hydroxy acid
Reimer-Tiemann Reaction: Treatment of Phenol with chloroform in the presence of sodium hydroxide leads to the forming an aldehyde group at the ortho position of the benzene ring, called the Reimer-Tiemann reaction.
Phenol + CHCl3 + NaOH ––––› C6H4OHCHO + NaCl + H2O
Esterification: Phenol can react with acetyl chloride and acetic anhydride to form esters, where an alkoxy group replaces the hydroxyl group.
Phenol + Carboxylic acid derivative → C6H5COOR’ + By product
Phenol (C6H5OH)
Phenol is an aromatic organic compound. Its molecular formula is C6H6O. Phenol is characterized by a hydroxyl group attached to a carbon atom that is part of an aromatic ring. It is also known as carbolic acid and consists of hydroxyl and phenyl groups attached to each other. In this article, we look into what phenol is, its structure, its classification, general properties, preparation and reactions, etc.
Table of Content
- What is Phenol?
- Classification of phenol
- Properties of phenol
- Preparation of Phenol
- Reaction of Phenol
- Derivatives of Phenol
- Uses of Phenol