Chapter 23, Problem 23.70P

(a)

Interpretation Introduction

Interpretation:

The synthesis is to be shown for the 4-chloro-3-nitrobenzoic acid from toluene.

Concept introduction:

Nitration: The formation of nitro group in a chemical reaction and it undergoes substitution reaction in organic synthesis. Nitronium ion $\left({\text{NO}}_{\text{2}}{}^{\text{+}}\right)$ is forming by the reaction of mixture of nitric acid and sulphuric acid, Nitronium ion $\left({\text{NO}}_{\text{2}}{}^{\text{+}}\right)$ is also called as nitryl cation, which is stronger electrophile.

Chromic Acid:

Chromic Acid (${\text{H}}_{\text{2}}{\text{CrO}}_{\text{4}}$) is used as an oxidizing agent, primary alcohol oxidized in to aldehyde or acid depends on the condition, secondary alcohol oxidized in to ketone.

(b)

Interpretation Introduction

Interpretation:

The reagent and condition is to be proposed for step 1.

(c)

Interpretation Introduction

Interpretation:

The mechanism is to be proposed for step 2.

Concept introduction:

Ipso substitution reaction: It is the one of the aromatic substitution reaction in which both the substituent (nucleophile and the parent substituent) present in the same ring position in an intermediate compound. Finally the parent substituent leave from the intermediate leads to the formation of product. The mechanism of desulfonation curved arrow pattern is given below.

(d)

Interpretation Introduction

Interpretation:

The reagent and condition is to be proposed for step 3.

Concept introduction:

Hydrogenolysis: Amine or alcohol reaction with H₂ in the presence of a transition

Metal catalyst gives the corresponding amine or alcohol.

Reductive amination reaction: Amination is the process by which an amine group is introduced into an organic molecule.

The conversion of Carbonyl group in to amine via imine intermediate is called reductive amination.

(e)

Interpretation Introduction

Interpretation:

The possible stereoisomer’s has to be shown if the product is chiral.

Concept introduction:

Isomer: A molecule having the same molecular formula but with different chemical structure is called isomer.

Enantiomers: A compound which is non-superimposable mirror image is called enantiomers.

Diastereomers: A compound which is non-superimposable and non-mirror image is called diastereomers.

Racemic mixture: A racemic mixture is simply a mixture containing an equal amount of each enantiomer.

Achiral:

A molecule is superimposable on its mirror image is called achiral molecule.