Chapter 18.12, Problem 26PTS

(a)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(b)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(c)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(d)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(e)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(f)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(g)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(h)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(i)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds. 

(j)

Interpretation Introduction

Interpretation:

The given compounds have to be synthesized starting from benzene.

Concept Introduction:

• Benzene is a stable aromatic compound and it is the simplest form of the aromatic compounds. It is a very versatile compound that it furnishes various products with various reagents.
• The most common type of reactions that benzene undergoes is electrophilic substitution reactions.
• The various types of electrophilic substitution reactions in benzene are – Chlorination, Bromination, Nitration, Sulfonation, Friedel Crafts Alkylation/Acylation etc.
• Thus it is clear benzene can be converted to various range of compounds with appropriate reagents and reaction conditions. One of the useful method one can adapt to introduce any kind of group or atom onto the benzene ring is electrophilic substitution reaction.
• The position that the electrophile occupies in the aromatic ring system depends on various factors like – presence of substituents, activation and deactivation of the ring etc.
• The pi electrons of the aromatic system must be readily available so that the reaction proceeds easily. Presence of many bulk substituents and/or the presence of strong electron withdrawing groups diminish the ability of the delocalizing pi electrons to bond with the electrophile.
• If the presence of substituents enhances the electron density of the ring then the reaction between the benzene ring and the electrophile is triggered readily. Then the ring is said to be activated towards electrophilic substitution reactions.
• If the presence of substituents causes electron drain in the ring then the $\text{π}$ electrons are not available to bond with electrophile. The aromatic ring becomes devoid of electrons and deactivated towards electrophilic substitution reactions.
• Thus the substituents can be widely of two types – activators and deactivators. Activators are the substituents that enhance the electron density of the ring. Deactivators are the substituents that suppress the electron density of the benzene ring.
• The classification of activators and deactivators can be summarized as follows –

Activators			Deactivators
Strong	Moderate	Weak	Strong	Moderate	Weak
$\text{-OH}$	$\text{-NHCOR}$	$\text{-R}$	${\text{-NO}}_{\text{2}}$	$\text{-COR}$	$\text{-X}$(HALOGENS)
${\text{-NH}}_2$	$\text{-NROR}$		${\text{-NR}}_{\text{3}}$	$\text{-COH}$
${\text{-O}}^{\text{-}}$	$\text{-OR}$		${\text{-CX}}_{\text{3}}$	$\text{-COOR}$
$\text{-NHR}$	$\text{-O-C=OR}$			$\text{-COOH}$
${\text{-NR}}_{\text{2}}$				${\text{-CONH}}_{\text{2}}$
				${\text{-SO}}_{\text{3}}\text{H}$
				$\text{-CN}$

• The electronic effects caused by the substituents influence the position that the electrophile occupies. Activators enhance the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy ortho and para positions.
• Deactivators decrease the electron density of the ring at the ortho- and para- position to them and direct the electrophile to occupy meta position. Halogens are exception that they are weak deactivators yet they are ortho para directors.
• A blocking group is a functional group which can be inserted on to the aromatic ring to direct the electrophile to a certain position.
• For example there are reactions in which we get mixture of ortho and para products. But we can obtain either ortho product alone or para product alone if we use blocking groups. If all the ortho positions are blocked we will get para product. If the para position is blocked and the required reaction is carried out we will end up with ortho product. After obtaining the product with the substituent at the desired position, the blocking group can be removed easily using the reagents applicable. Such groups which can be installed easily and removed easily function as blocking groups and have versatile usage in the synthesis of various ranges of organic compounds.