Carboxylic Acids and Derivatives
2.0 General Methods of Preparation
2.0 General Methods of Preparation
1. By oxidation of primary alcohol with acidic $KMn{O_4}$ or acidic ${K_2}C{r_2}{O_{7.}}$.
2. By oxidation of aldehydes: Aldehydes on oxidation with usual oxidizing agent gives carboxylic acid with same number of carbon atoms as in the aldehyde.
3. By oxidation of alkenes
(a)
(b)
4. By Carboxycation of Grignard Reagent
5. By hydrolysis of acyl derivatives of carboxylic acid and cyanide hydrolysis with dilute acids.
The mechanism of hydrolysis of $R—CN$ is as follows.
6. By oxidation of alkyl benzene
Alkyl group having no $-H$ atom will not be oxidized to $—COOH$. Any alkyl group containing at least one $-H$ atom will be oxidized to $—COOH$. Whatever the length of alkyl group attached to benzene ring. The product of oxidation will be benzoic acid.
The order of benzoic acid formation by oxidation of alkyl benzene.
$Methyl{\text{ }}benzene{\text{ }} > {\text{ }}1^\circ {\text{ }}alkyl{\text{ }}benzene{\text{ }} > {\text{ }}2^\circ {\text{ }}alkyl{\text{ }}benzene{\text{ }}?$
