Alcohol and Phenol
An alcohol is any organic compound in which the hydroxyl functional group (–OH) is bound to a saturated carbon atom. Alcohols are usually classified as primary, secondary and tertiary alcohols.
Phenol, also known as carbolic acid, is an aromatic organic compound with the molecular formula C6H5OH. It is a white crystalline solid that is volatile. The molecule consists of a phenyl group (−C6H5) bonded to a hydroxyl group (−OH). It is mildly acidic.
Preparation of Alcohols
From Reduction of Aldehydes and ketones
From Reduction of Carboxylic acid and esters
From Grignard Reagent
From hydration of alkenes
From Oxymercuration and Demercuration of Alkenes
From Aliphatic Primary Amines
Preparation of Phenols
From haloarenes: Chlorobenzene is an example of haloarenes which is formed by mono substitution of benzene ring. When chlorobenzene is fused with sodium hydroxide at 623K and 320 atm sodium phenoxide is produced. Finally, sodium phenoxide on acidification gives phenols.
From benzene sulphonic acid: Benzenesulphonic acid can be obtained from benzene by reacting it with oleum. Benzenesulphonic acid thus formed is treated with molten sodium hydroxide at high temperature which leads to the formation of sodium phenoxide. Finally, sodium phenoxide on acidification gives phenols.
From diazonium salts: When an aromatic primary amine is treated with nitrous (NaNO2 + HCl) acid at 273 – 278 K, diazonium salts are obtained. These diazonium salts are highly reactive in nature. Upon warming with water, these diazonium salts finally hydrolyse to phenols. Phenols can also be obtained from diazonium salts by treating it with dilute acids.