Chapter 23, Problem 23.80P

Interpretation Introduction

(a)

Interpretation:

Synthesis of given compound from benzene is to be shown.

Concept introduction:

In an electrophilic aromatic substitution reaction, a substituent influences the site of reaction. The electron-donating groups are ortho/para directing groups, while electron-withdrawing groups are meta directing groups in the electrophilic aromatic substitution reaction.

Answer to Problem 23.80P

The given compound is synthesized from benzene as:

Explanation of Solution

The given compound is:

It is noticed that an electron-withdrawing carbonyl group is at meta-position to the bromine atom. Since the bromine atom (halogen) is an ortho/para directing group, acylation (addition of acyl group) of the benzene is carried out in the first step. The next step is the addition of chlorine, as the acyl group is meta directing incoming Cl added at meta to acyl group.

So the complete reaction of synthesis for the given compound is as:

Conclusion

Synthesis of the given compound from benzene is shown on the basis of the directing nature of substituent groups in an electrophilic aromatic substitution reaction.

Interpretation Introduction

(b)

Interpretation:

Synthesis of given compound from benzene is to be shown.

Concept introduction:

In an electrophilic aromatic substitution reaction, a substituent influences the site of reaction. The electron-donating groups are ortho/para directing groups, while electron-withdrawing groups are meta directing groups in the electrophilic aromatic substitution reaction.

Answer to Problem 23.80P

The given compound is synthesized from benzene as:

Explanation of Solution

The given compound is:

Here acyl group and Br are at para to each other, the Br group is an ortho/para director thus it added first to the benzene ring through bromination. The second step is acylation, the addition of acyl group at the para position.

So the complete reaction of synthesis for the given compound is as:

Conclusion

Synthesis of the given compound from benzene is shown on the basis of the directing nature of substituent groups in an electrophilic aromatic substitution reaction.

Interpretation Introduction

(c)

Interpretation:

Synthesis of given compound from benzene is to be shown.

Concept introduction:

In an electrophilic aromatic substitution reaction, a substituent influences the site of reaction. The electron-donating groups are ortho/para directing groups, while electron-withdrawing groups are meta directing groups in the electrophilic aromatic substitution reaction.

Answer to Problem 23.80P

The given compound is synthesized from benzene as:

Explanation of Solution

The given compound is:

In the above compound both substituents are at para to each other, the Br group is an ortho/para director thus it added first to the benzene ring through bromination. The second step is acylation, addition of acyl group at the para position.

In the next step, the ketone is transformed into the ester by first converting the ketone to the carboxylic acid via oxidation then transforming the carboxylic acid into the ester by Fischer esterification.

So the complete reaction of synthesis for the given compound is as:

Conclusion

Synthesis of the given compound from benzene is shown on the basis of the directing nature of substituent groups in an electrophilic aromatic substitution reaction.

Interpretation Introduction

(d)

Interpretation:

Synthesis of given compound from benzene is to be shown.

Concept introduction:

In an electrophilic aromatic substitution reaction, a substituent influences the site of reaction. The electron-donating groups are ortho/para directing groups, while electron-withdrawing groups are meta directing groups in the electrophilic aromatic substitution reaction.

Answer to Problem 23.80P

The given compound is synthesized from benzene as:

Explanation of Solution

The given compound is:

Here both substituents are amino ${\text{(NH}}_{\text{2}}\text{)}$ groups. The ${\text{NH}}_{\text{2}}$ group is not added on the benzene ring by electrophilic aromatic substitution. The ring is nitrated in harsh conditions to get the nitro groups meta. The nitro groups are then reduced to the amino groups.

So the complete reaction of synthesis for the given compound is as:

Conclusion

Synthesis of the given compound from benzene is shown on the basis of the directing nature of substituent groups in an electrophilic aromatic substitution reaction.

Interpretation Introduction

(e)

Interpretation:

Synthesis of given compound from benzene is to be shown.

Concept introduction:

In an electrophilic aromatic substitution reaction, a substituent influences the site of reaction. The electron-donating groups are ortho/para directing groups, while electron-withdrawing groups are meta directing groups in the electrophilic aromatic substitution reaction.

Answer to Problem 23.80P

The given compound is synthesized from benzene as:

Explanation of Solution

The given compound is:

In the above compound, the amino and acyl groups are para to each other. The amino group is an ortho/para director and thus to be added first. The ${\text{NH}}_{\text{2}}$ group is not added to the benzene ring by electrophilic aromatic substitution. The ring is nitrated first and then reduced to an amino group. The amine is a Lewis base and would react with the strong base Lewis acid (used in acylation), ${\text{AlCl}}_{\text{3}}$, resulting in the highly deactivated ring. This would be prevented the necessary Fridal-Crafts acylation. Therefore, the amino group must be protected before the Fridal-Crafts acylation. The last step is deprotection to get amino group.

So the complete reaction of synthesis for the given compound is as:

Conclusion

Synthesis of the given compound from benzene is shown on the basis of the directing nature of substituent groups in an electrophilic aromatic substitution reaction.