Chapter 16, Problem 16.43AP

Interpretation Introduction

(a)

Interpretation:

The laboratory synthesis of $p\text{-}$ nitrotoluene from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $p\text{-}$ nitrotoluene from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $p\text{-}$ nitrotoluene is shown below.

Figure 1

The methyl is an ortho and para directing group and nitro is a meta directing group. the compound is para compound. Therefore, the benzene will first undergo methylation reaction with chloromethane and ${\text{AlCl}}_{\text{3}}$ as a catalyst. The corresponding chemical reaction is shown below.

Figure 2

The toluene will undergo nitration reaction with nitric acid in sulfuric acid to from ortho and para-substituted compounds. The para-substituted gets separated from ortho compound with the help of fractional distillation process. The corresponding chemical reaction is shown below.

Figure 3

Conclusion

The laboratory synthesis of $p\text{-}$ nitrotoluene from benzene and any other reagents is shown in Figure 2 and Figure 3.

Interpretation Introduction

(b)

Interpretation:

The laboratory synthesis of $p\text{-}$ dibromobenzene from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $p\text{-}$ dibromobenzene from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $p\text{-}$ dibromobenzene is shown below.

Figure 4

Benzene reacts with an excess of bromine gas in the presence of a ${\text{FeBr}}_{\text{3}}$ catalyst. The catalyst helps in producing electrophile ${\text{Br}}^{+}$ which attacks the benzene ring. Another ${\text{Br}}^{+}$ will attack the para position of bromobenzene. The corresponding chemical reaction is shown below.

Figure 5

Conclusion

The laboratory synthesis of $p\text{-}$ dibromobenzene from benzene and any other reagents is shown in Figure 5.

Interpretation Introduction

(c)

Interpretation:

The laboratory synthesis of $p\text{-}$ chloroacetophenone from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $p\text{-}$ chloroacetophenone from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $p\text{-}$ dibromobenzene is shown below.

Figure 6

Benzene reacts with chlorine gas in the presence of a catalyst ${\text{FeCl}}_{\text{3}}$. The catalyst helps in producing electrophile ${\text{Cl}}^{+}$ which attacks the benzene ring. The corresponding chemical reaction is shown below.

Figure 7

The chlorobenzene undergoes Friedel Craft acylation reaction with acetyl chloride in the presence of ${\text{AlCl}}_{\text{3}}$ catalyst. The corresponding chemical reaction is shown below.

Figure 8

Conclusion

The laboratory synthesis of $p\text{-}$ chloroacetophenone from benzene and any other reagents is shown in Figure 7 and Figure 8

Interpretation Introduction

(d)

Interpretation:

The laboratory synthesis of $m\text{-}$ nitrobenzenesulfonic acid from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $m\text{-}$ nitrobenzenesulfonic acid from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $m\text{-}$ nitrobenzenesulfonic acid is shown below.

Figure 9

The benzene molecule will undergo sulfonation reaction with sulfuric acid. The electrophile $-{\text{SO}}_{\text{3}}\text{H}$ attacks the benzene ring to form benzenesulfonic acid. The corresponding chemical reaction is shown below.

Figure 10

The benzenesulfonic acid will undergo nitration reaction with fuming nitric acid in sulfuric acid to form $m\text{-}$ nitrobenzenesulfonic acid. The corresponding chemical reaction is shown below.

Figure 11

Conclusion

The laboratory synthesis of $m\text{-}$ nitrobenzenesulfonic acid from benzene and any other reagents is shown in Figure 10 and Figure 11.

Interpretation Introduction

(e)

Interpretation:

The laboratory synthesis of $p\text{-}$ chloronitrobenzene from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $p\text{-}$ chloronitrobenzene from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $p\text{-}$ chloronitrobenzene is shown below.

Figure 12

Benzene reacts with chlorine gas in the presence of a catalyst ${\text{FeCl}}_{\text{3}}$. The catalyst helps in producing electrophile ${\text{Cl}}^{+}$ which attacks the benzene ring. The corresponding chemical reaction is shown below.

Figure 13

The chlorobenzene will undergo nitration reaction with nitric acid in sulfuric acid to form $p\text{-}$ chloronitrobenzene. The corresponding chemical reaction is shown below.

Figure 14

Conclusion

The laboratory synthesis of $p\text{-}$ chloronitrobenzene from benzene and any other reagents is shown in Figure 13 and Figure 14.

Interpretation Introduction

(f)

Interpretation:

The laboratory synthesis of $\text{1, 3, 5-trinitrobenzene}$ from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $\text{1, 3, 5-trinitrobenzene}$ from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $\text{1, 3, 5-trinitrobenzene}$ is shown below.

Figure 15

The benzene will undergo nitration reaction with nitric acid in sulfuric acid to form nitrobenzene. The nitro group is a ring deactivating group and meta directing group. Therefore, some strong condition is required to substitute another electrophile on it. The nitrobenzene reacts with fuming nitric acid and sulfuric acid to form $\text{1, 3-dinitrobenzene}$ and further reacts to form $\text{1, 3, 5-trinitrobenzene}$. The corresponding chemical reaction is shown below.

Figure 16

Conclusion

The laboratory synthesis of $\text{1, 3, 5-trinitrobenzene}$ from benzene and any other reagents is shown in Figure 16.

Interpretation Introduction

(g)

Interpretation:

The laboratory synthesis of $\text{2, 6-dibromo-4-nitrotoluene}$ from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $\text{2, 6-dibromo-4-nitrotoluene}$ from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $\text{2, 6-dibromo-4-nitrotoluene}$ is shown below.

Figure 17

The benzene will first undergo methylation reaction with chloromethane and ${\text{AlCl}}_{\text{3}}$ as a catalyst. The corresponding chemical reaction is shown below.

Figure 18

The toluene will undergo nitration reaction with nitric acid in sulfuric acid to form ortho and para-substituted compounds. The para-substituted gets separated from ortho compound with the help of fractional distillation process. The corresponding chemical reaction is shown below.

Figure 19

The compound $p\text{-}$ nitrotoluene reacts with an excess of bromine gas in the presence of a catalyst ${\text{FeBr}}_{\text{3}}$. The catalyst helps in producing electrophile ${\text{Br}}^{+}$ which attacks $p\text{-}$ nitrotoluene. Another ${\text{Br}}^{+}$ will also attack the aromatic ring to from the final product. The bromo groups are at ortho position to a methyl group and at meta-position to nitro group. The corresponding chemical reaction is shown below.

Figure 20

Conclusion

The laboratory synthesis of $\text{2, 6-dibromo-4-nitrotoluene}$ from benzene and any other reagents is shown in Figure 18, Figure 19 and Figure 20.

Interpretation Introduction

(h)

Interpretation:

The laboratory synthesis of $\text{2, 4-dibromo-6-nitrotoluene}$ from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $\text{2, 4-dibromo-6-nitrotoluene}$ from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $\text{2, 4-dibromo-6-nitrotoluene}$ is shown below.

Figure 21

The benzene will first undergo methylation reaction with chloromethane and ${\text{AlCl}}_{\text{3}}$ as a catalyst. The corresponding chemical reaction is shown below.

Figure 22

The toluene will undergo nitration reaction with nitric acid in sulfuric acid to form ortho and para-substituted compounds. The para-substituted gets separated from ortho compound with the help of fractional distillation process. The corresponding chemical reaction is shown below.

Figure 23

The compound $o\text{-}$ nitrotoluene reacts with an excess of bromine gas in the presence of a catalyst ${\text{FeBr}}_{\text{3}}$. The catalyst helps in producing electrophile ${\text{Br}}^{+}$ which attacks $p\text{-}$ nitrotoluene. Another ${\text{Br}}^{+}$ will also attack the aromatic ring to form the final product. The bromo groups are at ortho position to a methyl group and at meta-position to nitro group. The corresponding chemical reaction is shown below.

Figure 24

Conclusion

The laboratory synthesis of $\text{2, 4-dibromo-6-nitrotoluene}$ from benzene and any other reagents is shown in Figure 22, Figure 23 and Figure 24.

Interpretation Introduction

(i)

Interpretation:

The laboratory synthesis of $\text{4-ethyl-3-nitroacetophenone}$ from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of $\text{4-ethyl-3-nitroacetophenone}$ from benzene and any other reagents is shown below.

Explanation of Solution

The structure of $\text{4-ethyl-3-nitroacetophenone}$ is shown below.

Figure 25

The benzene will first undergo ethylation reaction with chloromethane and ${\text{AlCl}}_{\text{3}}$ as a catalyst. The corresponding chemical reaction is shown below.

Figure 26

The ethylbenzene undergoes Friedel Craft acylation reaction with acetyl chloride in the presence of ${\text{AlCl}}_{\text{3}}$ catalyst to form $\text{1-}\left(\text{4-ethylphenyl}\right)\text{ethanone}$. The corresponding chemical reaction is shown below.

Figure 27

The compound $\text{1-}\left(\text{4-ethylphenyl}\right)\text{ethanone}$ will undergo nitration reaction with fuming nitric acid in sulfuric acid to form $\text{4-ethyl-3-nitroacetophenone}$. The corresponding chemical reaction is shown below.

Figure 28

Conclusion

The laboratory synthesis of $\text{4-ethyl-3-nitroacetophenone}$ from benzene and any other reagents is shown in Figure 26, Figure 27 and Figure 28.

Interpretation Introduction

(j)

Interpretation:

The laboratory synthesis of cyclopentylbenzene from benzene and any other reagents is to be predicted.

Concept introduction:

The replacement of hydrogen atom attached to a carbon atom of electron-rich benzene ring by an incoming electrophile is known as electrophilic aromatic substitution reaction. The rate of electrophilic aromatic substitution reaction depends on the substituted group on the aromatic ring. The ring deactivating group retards the electrophilic aromatic substitution reaction and ring activating group enhances the electrophilic aromatic substitution reaction.

Answer to Problem 16.43AP

The laboratory synthesis of cyclopentylbenzene from benzene and any other reagents is shown below.

Explanation of Solution

The structure of cyclopentylbenzene is shown below.

Figure 29

Benzene reacts with cyclopentene in the presence of sulfuric acid to form cyclopentyl benzene. The sulfuric acid acts as a catalyst to generate carbocation from cyclopentene. This carbonation acts as an electrophile and attacks the benzene ring. The corresponding chemical reaction is shown below.

Figure 30

Conclusion

The laboratory synthesis of cyclopentylbenzene from benzene and any other reagents is shown in Figure 30.