Deck 19: Aromatic Substitution Reactions

Question 1

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) none of these

Answer 1

III

Question 2

Which chemical test would you use to distinguish between ethylbenzene and styrene?

Answer 2

Styrene will react with Br₂/CCl₄, whereas ethylbenzene will not react.

Question 3

Which one of the following reactions is most likely to give a polysubstituted product?

A) Friedel-Crafts alkylation
B) Friedel-Crafts acylation
C) Nitration
D) Sulfonation
E) Halogenation

Answer 3

Friedel-Crafts alkylation

Question 4

Provide a stepwise curved arrow mechanism for chlorination of benzene in the presence of FeCl₃.

Question 5

Which of the following reagents are used to carry out chlorination of benzene?

A) Cl₂/CCl₄
B) Cl₂/FeCl₃
C) Cl₂/AlCl₃
D) NaCl/Fe
E) both B & C

Question 6

Which of the following reagents are used to carry out iodination of benzene?

A) I₂/CCl₄
B) I₂/FeCl₃
C) I₂/AlCl₃
D) I₂/CuCl₂
E) NaI/Acetone

Question 7

Which of these is the rate-determining step in the electrophilic aromatic substitution of benzene?

A) Formation of an electrophile
B) Formation of sigma complex.
C) Loss of proton from sigma complex.
D) Addition of electrophile & loss of proton
E) None of these

Question 8

Predict the product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 9

Formation of an electrophile

Question 10

Predict the product for the following reaction.

Question 11

Reaction of an electrophile with an aromatic ring to form the sigma complex

Question 12

Provide the curved arrow mechanism for the following reaction.

Question 13

The electrophile in the sulfonation reaction of benzene is:

A) SO₂⁺
B) H₂SO₄
C) SO₃⁺
D) H₂SO₃
E) SO₃

Question 14

Deprotonation of sigma complex to restore aromaticity

Question 15

Provide all the resonance structures of the sigma complex, when benzene reacts with an electrophile (E⁺).

Question 16

Cyclohexene undergoes addition reaction with bromine, but benzene does not. Instead benzene undergoes a substitution reaction with bromine. Explain why.

Question 17

Predict the product for the following reaction.

Question 18

Which of the following reagents would you use as the basis for a simple chemical test that would distinguish between ethylbenzene and styrene?

A) NaI/acetone
B) Br₂/CCl₄
C) NaOH/H₂O
D) NaBH₄/CH₃OH
E) HCl/H₂O

Question 19

The electrophilic bromination or chlorination of benzene requires ______ along with the halogen.

A) UV light
B) a bronsted base
C) a Lewis base
D) a Lewis acid
E) none of these

Question 20

Which one of the following compounds does not undergo Friedel-Crafts reaction?

A) benzene
B) chlorobenzene
C) nitrobenzene
D) toluene
E) t-butylbenzene

Question 21

Predict the major product for the reaction between benzene and 2-chlorobutane in the presence of AlCl₃.

A) chlorobenzene
B) sec-butylbenzene
C) ethylbenzene
D) isopropylbenzene
E) t-butylbenzene

Question 22

The electrophile in the nitration reaction of benzene is:

A) NO₂⁺
B) HNO₃
C) NO₃⁺
D) H₂SO₄
E) NO₂

Question 23

Predict the product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 24

Provide the structure of the major products formed in the following reaction sequence.

Question 25

Which of the following halides cannot be used for Friedel-Crafts alkylation reaction?

A) bromobenzene
B) vinylchloride
C) 2-chloropropane
D) chloroethane
E) both A & B

Question 26

Predict the major product for the following reaction.

Question 27

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 28

Provide a stepwise curved arrow mechanism for the following reaction.

Question 29

Predict the structure of the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 30

Predict the major product for the following reaction.

Question 31

Aryl and vinyl halides cannot be used in the Friedel-Crafts alkylation reaction, because they do not __________.

Question 32

Provide the structure(s) of the intermediate product(s) in the following reaction sequence

Question 33

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 34

Predict the structure of the major product for the following reaction.

Question 35

Predict the major product for the following reaction.

Question 36

Which of the following reactions would produce isopropylbenzene as the major product?

A) I
B) II
C) III
D) IV
E) all of these

Question 37

Predict the structure of the major product for the following reaction.

Question 38

Predict the structure of the product for the following reaction.

Question 39

Predict the major product for the following reaction and provide a stepwise curved arrow mechanism for the formation of the product.

Question 40

Which of the following reactions would produce t-butylbenzene as the major product?

A) I
B) II
C) III
D) IV
E) all of these

Question 41

Predict the structure of the product for the following reaction.

Question 42

Predict the structure of the major product for the following reaction.

Question 43

Provide the reagents necessary to carry out the following conversion.

Question 44

Which of the following compounds will yield ortho substituted compound as the major product for nitation reaction?

A) toluene
B) ethylbenzene
C) cumene
D) t-butylbenzene
E) none of these

Question 45

Which of the following substituents will not direct the incoming group in the ortho/para position during electrophilic aromatic substitution?

A) -CH₂CH₃
B) -CF₃
C) -OCH₃
D) -NHCH₃
E) -Br

Question 46

Which one of the following compounds would be least reactive toward electrophilic aromatic substitution?

A) I
B) II
C) III
D) IV
E) V

Question 47

Which one of the following compounds will be most reactive towards electrophilic aromatic bromination reaction?

A) nitrobenzene
B) anisole
C) acetanilide
D) benzene
E) benzaldehyde

Question 48

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) I & IV

Question 49

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 50

Provide the reagent(s) that are necessary to carry out the following conversion. t-butylbenzene $\rightarrow$ t-butyl-4-chlorobenzene

A) Cl₂, heat
B) Cl₂, FeCl₃
C) SOCl₂, pyridine
D) HCl
E) PCl₃

Question 51

Which of the following substituents will direct the incoming group to the ortho/para position during electrophilic aromatic substitution?

A) -NO₂
B) -CF₃
C) -Br
D) -COOCH₃
E) none of these

Question 52

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 53

Which one of the following compounds will be least reactive towards Friedel-Crafts reaction?

A) nitrobenzene
B) anisole
C) phenol
D) benzene
E) chlorobenzene

Question 54

Predict the structure of the product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 55

Arrange the following compounds in order of decreasing reactivity towards electrophilic aromatic substitution:

A) V>II>I>III>IV
B) II>V>III>I>IV
C) IV>I>III>V>II
D) III>II>I>IV>V
E) IV>V>II>I>III

Question 56

Which one of the following compounds would be most reactive toward electrophilic aromatic substitution?

A) I
B) II
C) III
D) IV
E) V

Question 57

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) I & II

Question 58

Provide the structures of major resonance contributors when nitrobenzene reacts with an electrophile in electrophilic aromatic substitution at the meta position.

Question 59

Provide all resonance structures of the sigma complex when aniline reacts with an electrophile (E⁺) to yield the para-substituted product.

Question 60

Which one of the following substituents will not direct the incoming group to the meta position during electrophilic aromatic substitution?

A) -NO₂
B) -C $\equiv$ N
C) -OCH₃
D) -COOH
E) all of these

Question 61

Which one of the following substituents will direct the incoming group to the meta position during electrophilic aromatic substitution?

A) -NO₂
B) -C $\equiv$ N
C) -CCl₃
D) -COOH
E) all of these

Question 62

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 63

Which of the following substituents will direct the incoming group in the ortho/para position during electrophilic aromatic substitution?

A) -CH₂CH₃
B) -CF₃
C) -OCH₃
D) -COOCH₃
E) both A & C

Question 64

Predict the major product for the following reaction.

Question 65

Predict the major product for the following reaction.

Question 66

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) no reaction

Question 67

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 68

Provide the reagents necessary to carry out the following conversion.

Question 69

Provide the reagents necessary to carry out the following conversion.

Question 70

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) none of these

Question 71

Provide the reagents necessary to carry out the following conversion.

Question 72

Predict the major product for the following reaction.

Question 73

Predict the major product for the following reaction.

Question 74

Provide the reagents necessary to carry out the following conversion.

Question 75

Provide the structure(s) of the major intermediate product(s) in the following reaction sequence.

Question 76

Predict the major product for the following reaction.

A) I
B) II
C) III
D) IV
E) V

Question 77

Provide the reagents necessary to carry out the following conversion.

Question 78

Predict the major product for the following reaction.

Question 79

Predict the major product for the following reaction.

Question 80

Predict the major product for the following reaction.