Answer to Question #116261 in Organic Chemistry for Tiffany Steytler

Question

Explain why a methoxy group (CH3O) increases the rate of electrophilic
aromatic substitution, but decreases the rate of nucleophilic aromatic
substitution.
On which ring and at what position(s) of the compounds shown below will
electrophilic aromatic substitution take place? Explain your answer in detail.

C N
H
H3C
O


C N
H
O
O2N
CH3
The following scheme is proposed for the synthesis of 4-bromobenzoic acid:
NH2 NH2
Br2
I) NaNO2
/HCl
ii) CuCN
Br
CN
Br
CN
Br
H3O
+
Briefly discuss the limitations of the above scheme and then propose a route
that would accomplish the desired product.
Synthesize the following molecule from benzene and any other organic/
inorganic reagents
NO2
O

Propose a mechanism for a reaction propanal with1,2-ethanediol, H+ and heat

Propose a mechanism for an acid catalyzed reaction of benzaldehyde with
NH2OH

Propose a mechanism for a reaction butanone with PhMgBr then acidic workup

Answer 1

Methoy is an electron donating grp with increase electrophilic substitution but decreases nucleiphilic substition