Deck 22: Reactions of Benzene and Its Derivatives

Question 1

What is the electrophile in the reaction of benzene with acetyl chloride, CH₃COCl, and AlCl₃?

A) CH₃C≡O⁺
B) CH₃⁺
C) CH₃CO₂−
D) benzene

Answer 1

CH₃C≡O⁺

Question 2

What is the electrophile in the reaction of benzene with a mixture of nitric acid and sulfuric acid?

A) HONO
B) NO⁺
C) NO₂⁺
D) benzene

Answer 2

NO⁺

Question 3

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Answer 3

2

Question 4

Which of the following sets of substituents are all ortho/para directing in electrophilic aromatic substitution reactions?

A) Cl, CH₃, CN
B) Br, OH, COCH₃
C) Cl, OH, CH₃
D) CN, NO₂, COCH₃

Question 5

Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions?

A) Br, NH₂, CH₃
B) CH₃, NH₂, OCH₃
C) OH, COCH_3, CH₃,
D) Br, CN, NO₂

Question 6

What is the role of FeBr₃ in electrophilic aromatic bromination of benzene using Br₂?

A) nucleophile
B) electrophile
C) Lewis acid
D) base

Question 7

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 8

Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions?

A) CH₃, OCH₃, COCH₃
B) Cl, CN, NO₂
C) Cl, NH₂, CH₃
D) CH₃, NH₂, OCH₃

Question 9

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 10

Which of the following undergoes the most rapid acylation upon treatment with acetyl chloride and AlCl₃?

A) benzene
B) toluene
C) chlorobenzene
D) 1,4-dichlorobenzene

Question 11

Which of the following sets of substituents are all ortho/para directing in electrophilic aromatic substitution reactions?

A) Br, CH₃, NO₂
B) CH₃, NH₂, Br
C) Cl, OCH₃, COCH₃
D) NO₂, COCH₃, COOH

Question 12

Which of the following undergoes the most rapid sulfonation upon treatment with fuming sulfuric acid?

A) benzene
B) benzoic acid
C) benzonitrile
D) nitrobenzene

Question 13

Which of the following undergoes the most rapid bromination upon treatment with Br₂/FeBr₃?

A) benzene
B) nitrobenzene
C) bromobenzene
D) anisole

Question 14

Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions?

A) CH₃, OH, Br
B) Cl, NH₂, CN
C) COCH₃, NO_2, COOH
D) NH₂, COCH₃, OH

Question 15

Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions?

A) CN, NO_2, COCH₃
B) CH₃, OCH₃, COCH₃
C) Cl, NH₂, CH₃
D) CH₃, NH₃, OCH₃

Question 16

What is the electrophile in the reaction of benzene with tert-butyl chloride and AlCl₃?

A) CH₃⁺
B) Cl⁺
C) (CH₃)C⁺
D) benzene

Question 17

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 18

What is the role of AlCl₃ in Friedel Crafts acylations using acid chlorides?

A) Lewis acid
B) electrophile
C) base
D) nucleophile

Question 19

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 20

Which of the following undergoes the most rapid nitration upon treatment with HNO₃/H₂SO₄?

A) toluene
B) benzene
C) bromobenzene
D) nitrobenzene

Question 21

Which of the following is the structure of the complex of Br₂ with FeBr₃ involved in the electrophilic bromination of benzene?

A) 1
B) 2
C) 3
D) 4

Question 22

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 23

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 24

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 25

Which of the following substituents is ortho/para directing and deactivating in electrophilic aromatic substitution reactions?

A) OH
B) Cl
C) CH₃
D) NO₂

Question 26

Which of the following reactions or reaction sequences will not give isopropylbenzene as the major product?

A) treatment of benzene with isopropyl alcohol and HF
B) treatment of benzene with 1-chloropropane and AlCl₃
C) treatment of benzene with propanoyl chloride and AlCl₃; followed by reaction with Zn(Hg) and HCl
D) treatment of benzene with 1-propene and HF

Question 27

Why does nitrobenzene fail to undergo Friedel-Crafts alkylation with tert-butyl chloride and AlCl₃?

A) nitrobenzene reacts with AlCl₃
B) nitrobenzene is a poor nucleophile
C) the nitro group is a strong electron donating group
D) the tert-butyl cation is a poor electrophile

Question 28

Which of the following sets of substituents are all deactivating groups in electrophilic aromatic substitution reactions?

A) Cl, CN, NO₂
B) Cl, NH₂, CH₃
C) CH₃, OCH₃, COCH₃
D) CH₃, NH₂, OCH₃

Question 29

Which of the following reactions or sequences will provide 1-propylbenzene as the major product?

A) treatment of benzene with isopropyl alcohol and HF
B) treatment of benzene with propanoyl chloride and AlCl₃; followed by reaction with Zn(Hg) and HCl
C) treatment of benzene with 1-chloropropane and AlCl₃
D) treatment of benzene with 1-propene and HF

Question 30

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 31

Which of the following are valid resonance structures of the electophile involved in Friedel-Crafts acylation of benzene upon treatment with CH₃COCl and AlCl₃?

A) 1
B) 2
C) 3
D) 4

Question 32

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 33

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 34

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 35

Which of the following sets of reagents does not result in alkylation of benzene?

A) tert-butyl chloride + AlCl₃
B) tert-butyl alcohol + H₃PO₄
C) methylpropene + HF
D) methylpropane + H₂SO₄

Question 36

Which of the following substituents is ortho/para directing and deactivating in electrophilic aromatic substitution reactions?

A) COCH₃
B) NH₃
C) Br
D) CH₂CH₃

Question 37

Why does anisole undergo bromination with Br₂ in the absence of FeBr₃ whereas bromination of benzene requires the presence of FeBr₃?

A) anisole is a better nucleophile than benzene
B) the methoxy group of anisole is an inductive electron withdrawing substituent
C) Br₂ is a good nucleophile
D) the reaction is accelerated by light

Question 38

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 39

Which of the following sets of substituents are all deactivating groups in electrophilic aromatic substitution reactions?

A) Cl, OH, CH₂CH₃
B) CH₃, Br, COCH₃
C) CH₃, NH₂, OH
D) COCH₃, NO₂, Br

Question 40

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 41

Which of the following is the reactive intermediate formed in the electrophilic nitration of nitrobenzene with HNO₃ and H₂SO₄?

A) 1
B) 2
C) 3
D) 4

Question 42

Which of the following is the reactive intermediate in the nucleophilic substitution of 4-bromo-1-nitrobenzene with sodium hydroxide?

A) 1
B) 2
C) 3
D) 4

Question 43

Which of the following is the reactive intermediate formed in the electrophilic bromination of toluene with Br₂, FeBr₃?

A) 1
B) 2
C) 3
D) 4

Question 44

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 45

Which of the following is the reactive intermediate formed in the electrophilic Friedel-Crafts acylation of toluene with CH₃COCl and AlCl₃?

A) 1
B) 2
C) 3
D) 4

Question 46

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 47

What is the major organic product obtained from the following reaction?

A) 1
B) 2
C) 3
D) 4

Question 48

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 49

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 50

Which mechanism accounts for the reaction of chlorobenzene with acetyl chloride and AlCl₃ to form 4-chloroacetophenone?

A) Bimolecular nucleophilic substitution (S_N2)
B) Nucleophilic aromatic substitution by elimination-addition
C) Nucleophilic aromatic substitution by addition-elimination
D) Electrophilic aromatic substitution

Question 51

Which of the following cannot be prepared from benzene in two synthetic steps?

A) 1
B) 2
C) 3
D) 4

Question 52

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 53

Which of the following compounds undergoes the most rapid nucleophilic substitution with hydroxide ion?

A) 1
B) 2
C) 3
D) 4

Question 54

Which of the following cannot be prepared from benzene in two synthetic steps?

A) 1
B) 2
C) 3
D) 4

Question 55

Which of the following chlorobenzenes produces a single isomer upon treatment with NaNH₂?

A) 1
B) 2
C) 3
D) 4

Question 56

Which mechanism accounts for the reaction of 4-bromo-1-nitrobenzene with sodium hydroxide to form 4-nitrophenol?

A) Bimolecular nucleophilic substitution (S_N2)
B) Nucleophilic aromatic substitution by elimination-addition
C) Nucleophilic aromatic substitution by addition-elimination
D) Electrophilic aromatic substitution

Question 57

Which of the following compounds undergoes the most rapid nucleophilic substitution with hydroxide ion?

A) 1
B) 2
C) 3
D) 4

Question 58

Which of the following is the reactive intermediate in the nucleophilic substitution of 4-bromo-1-toluene with sodium amide?

A) 1
B) 2
C) 3
D) 4

Question 59

What is the major organic product obtained from the following sequence of reactions?

A) 1
B) 2
C) 3
D) 4

Question 60

Which of the following chlorobenzenes does not undergo nucleophilic aromatic substitution upon treatment with NaNH₂?

A) 1
B) 2
C) 3
D) 4

Question 61

Which mechanism accounts for the reaction of benzyl chloride with sodium cyanide to form cyanomethylbenzene (phenylacetonitrile, PhCH₂CN)?

A) Bimolecular nucleophilic substitution (S_N2)
B) Nucleophilic aromatic substitution by elimination-addition
C) Nucleophilic aromatic substitution by addition-elimination
D) Electrophilic aromatic substitution

Question 62

What type of intermediate is formed in the reaction between bromobenzene and sodium amide to give aniline?

A) Meisenheimer complex
B) benzyne
C) cyclohexadienyl cation
D) benzyl radical

Question 63

What type of intermediate is formed in upon irradiation of a mixture of toluene and chlorine to give benzyl chloride?

A) Meisenheimer complex
B) benzyne
C) cyclohexadienyl cation
D) benzyl radical

Question 64

Among the following groups, 2, 3, and 5 are meta-directing.
1. -Cl
2. -NO₂
3. -SO₃H
4. -CH₃
5. -COCH₃

Question 65

The predominant intermediate in the electrophilic nitration of toluene is shown below.

Question 66

Which of the following is not true about benzynes?

A) They are planar
B) They are formed upon dehydrohalogenation of aryl halides
C) They are aromatic
D) They are intermediates in nucleophilic aromatic substitution reaction which take place by an addition-elimination mechanism

Question 67

The best sequence in which to carry out the following reaction is 1) Br₂, AlBr₃, 2) H₂SO₄, SO₃.

Question 68

The electrophile that could be used to make acetophenone (methyl phenyl ketone) from benzene is shown below. $\mathrm{CH}_{3} \stackrel{+}{\mathrm{C}} \mathrm{O}$

Question 69

The product of the following reaction would be 2-nitrotoluene.

Question 70

The compound shown below is (nitromethyl)benzene. One would expect this compound to more reactive than toluene toward electrophilic substitution.

Question 71

Tetracyclone (shown below) is often used to trap benzynes as Diels-Alder adducts. The structure of the Diels-Alder adduct that results when benzyne is trapped by tetracyclone would be

Question 72

What type of intermediate is formed in the reaction between chlorobenzene and tert-butyl chloride and AlCl₃ to give 4-chloro-1-tert-butylbenzene?

A) Meisenheimer complex
B) benzyne
C) cyclohexadienyl cation
D) benzyl radical

Question 73

The predominant intermediate in the electrophilic nitration of benzenesulfonic acid is shown below.

Question 74

All of the following can act as an electrophile in an electrophilic aromatic substitution reaction.
SO₃ (CH₃)₃C⁺ NO₂⁺

Question 75

What type of intermediate is formed upon treatment of 1-chloro-2,4-dinitrobenzene with sodium hydroxide to give 2,4-dinitrophenol?

A) Meisenheimer complex
B) benzyne
C) cyclohexadienyl cation
D) benzyl radical

Question 76

Which of the following is not true about Meissenheimer complexes?

A) They are resonance-stabilized anions
B) They are formed upon addition of a nucleophile to aryl halides
C) They are aromatic
D) They are intermediates in nucleophilic aromatic substitution reaction which take place by an addition-elimination mechanism

Question 77

Which mechanism accounts for the reaction of 4-bromotoluene with sodium amide to form a mixture of 3- and 4-aminotoluene?

A) Bimolecular nucleophilic substitution (S_N2)
B) Nucleophilic aromatic substitution by elimination-addition
C) Nucleophilic aromatic substitution by addition-elimination
D) Electrophilic aromatic substitution

Question 78

The number of mononitro products that can be produced when the following reactant is treated with nitric and sulfuric acids is _______.

Question 79

In electrophilic aromatic substitution reactions, the following molecule are considered to be ______ reactive than benzene

Question 80

The predominant product from sequential nitration and bromination of benzenesulfonic acid is shown below.