Methods Of Preparation Of Phenols, Important Topics For JEE Main 2024

Methods Of Preparation Of Phenols : Any organic compound that belongs to the phenol family can be identified by its aromatic ring-attached hydroxyl (OH) group to a carbon atom. The most basic member of the family is phenol, also known as carbolic acid or monohydroxy benzene (C ₆ H ₅ OH).

Preparation of Phenols

Preparation of Phenol s: Nowadays, phenol is synthesized and sold commercially. In the laboratory, one of the following techniques is used to create phenols from benzene derivatives.

Preparation of phenols form Haloarenes

Preparation of phenols form Haloarenes: - The mono substitution of the benzene ring results in the formation of haloarenes, such as chlorobenzene. At 623 K and 300 atm, sodium hydroxide and chlorobenzene fuse to form sodium phenoxide. Finally, acidification produces phenol form sodium, phenoxide.

Elevated temperatures can be used to treat this benzene sulphonic acid in order to promote the formation of sodium phenoxide by melting sodium hydroxide. Finally, acidification produces phenol from sodium phenoxide.

Preparation of phenols form Benzene Sulphonic Acid

: - A reaction between benzene and oleum yields benzene sulphonic acid. Elevated temperatures can be used to treat this benzene sulphonic acid in order to promote the formation of sodium phenoxide by melting sodium hydroxide. Finally, acidification produces phenol from sodium phenoxide.

Preparation of phenols form Diazonium salts

Preparation of phenols form Diazonium salts: - Diazonium salts are produced by treating an aromatic primary amine at 273 –278 K with nitrous (NaNO ₂ + HCl) acid. These salts of diazonium have a very reactive nature. Finally, these diazonium salts hydrolyze phenols when heated with water. By treating diazonium salts with diluted acids, phenols can also be extracted from them.

Preparation of phenols form Cumene

Preparation of phenols form Cumene: - Friedel-Crafts alkylation of benzene with propylene yields cumene, an organic compound. When cumene (isopropyl benzene) is exposed to air, it oxidizes and produces cumene hydroperoxide. Phenols are produced when diluted acid is used to further treat cumene hydroperoxide. As a significant byproduct of this reaction, acetone is also produced in significant amounts. Therefore, purifications are necessary for phenols prepared using these methods.