Concept explainers
Interpretation:
The compound, which reacts faster with sodium methoxide in methanol in each of the given pair of compounds is to be determined and the chemical equation for the faster reaction is to be written.
Concept introduction:
Nucleophilic
In nucleophilic aromatic substitution reactions, the nucleophile substitutes a leaving group from the aryl ring.
Aryl halides bearing an electron withdrawing substituent undergo nucleophilic substitution rapidly.
The substituents attached ortho and para with respect to the halogen atom in the aryl halide react at similar rates. The substituents attached at meta position in the aryl halide react at slower rates than ortho and para substituents.
Electron withdrawing substituents stabilize the intermediate carbanion formed and thus are strongly activating substituents in the nucleophilic aromatic substitution reactions.
Electron donating substituents destabilize the intermediate carbanion formed and thus are strongly deactivating substituents in the nucleophilic aromatic substitution reactions.
Answer to Problem 43P
Solution:
a)
The reaction is as follows:
b) In between
The reaction is as follows:
c) In between
The reaction is as follows:
d) In between
The reaction is as follows:
e) In between
The reaction is as follows:
Explanation of Solution
a)
In this nucleophilic aromatic substitution reaction, sodium methoxide is a source of the nucleophile
In chlorobenzene, a chlorine atom is attached to the benzene ring while in
The reaction of
b)
In this nucleophilic aromatic substitution reaction, sodium methoxide is a source of the nucleophile
In both the given aryl halides, a strong electron withdrawing substituent is attached on the ring. In
The reaction of
c)
In this nucleophilic aromatic substitution reaction, sodium methoxide is a source of the nucleophile
In
In
Thus, in between
The reaction of
d)
In this nucleophilic aromatic substitution reaction, sodium methoxide is a source of the nucleophile
Nitro substituents are strong electron withdrawing substituents.
In
Electron withdrawing substituents at ortho and para positions activate the ring more than the electron withdrawing substituents at meta positions.
Thus, in between
The reaction of
e)
In this nucleophilic aromatic substitution reaction, sodium methoxide is a source of the nucleophile
In
The reaction of
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Chapter 13 Solutions
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