Question

Explain all the methods for the preparation of Carboxylic acids.​

Answer 1

Answer:

Preparation from Primary Alcohols

Primary alcohol undergoes oxidation to produce carboxylic acid on the addition of the oxidizing agents. ... The strong oxidizing agents including potassium dichromate, potassium permanganate, and chromium trioxide can readily oxidize the aldehyde to form carboxylic acids.

Answer 2

Explanation:

The compound in which the carbonyl group is attached to hydroxyl then it is called Carboxylic acid. There are various methods that can be used for the preparation of Carboxylic acids.

By using primary Alcohols and Aldehyde

We will notice that the primary alcohol gets oxidized to carboxylic acid when oxidizing agents are added such as potassium permanganate (KMnO4) in an acidic, alkaline or neutral medium. On using a mild oxidizing agent we can get carboxylic acids from aldehydes.

From Alkylbenzenes

We can get aromatic carboxylic acids after vigorous oxidation of alkylbenzenes with chromic acid. Irrespective of the length of the chain the whole side chain is oxidized to a carbonyl group. The oxidation of primary and secondary alkyl groups can be done in this manner while the tertiary group is unaffected.

From Nitriles and Amides

Amides are prepared by the hydrolysis of nitriles and then is converted to acids in the presence of catalysts (H+ or OH-1). In order to stop the reaction at the amide stage, mild reaction conditions are used.

By using Grignard Reagents

When Grignard reagent reacts with carbon dioxide its forms salts of carboxylic acids which after some time gives corresponding carboxylic acid after the acidification with any mineral acid. We can prepare Grignard reagents as well as nitriles from alkyl halides. These methods are very useful for the conversion of alkyl halides into corresponding carboxylic acids which has one carbon atom more than what is present in alkyl halides.

By Acyl Halides and Anhydrides

When acid chloride is hydrolysed with water than carboxylic acid is produced and it is more readily hydrolysed with aqueous base and gives corresponding carboxylic ions which on further acidification gives the carboxylic acid.

By using Esters

A carboxylic acid is produced after the acidic hydrolysis of esters and carboxylates are produced after the basic hydrolysis of an ester.