Homework for Chapter 18
Chem 2320
Name _____________________________________
1. Draw the complete mechanism for a reaction between benzene and the complex formed between
chlorine and AlCl3.
Cl2
AlCl3
2. Circle the starting material which will react faster under electrophilic aromatic substitution conditions.
CH3
CF3
a)
O
Br
CN
b)
O
H
N
NH2
c)
O
d)
NO2
O
e)
ClH
N
f)
3. Draw the resonance structures of the following intermediates, and explain why the intermediate (as a
whole) is stabilized, destabilized, or neither relative to a benzene ring.
a) chlorination of isopropylbenzene at the para position
HW Ch 18 p 2
4. Fill in all of the missing elements in the following table. Draw arrows to indicate how the electrophile is
attacked.
name of reaction
reagents
product
electrophile
nitration
O
O
S
O
Cl2
AlCl3
I
Br
Br
Br
Fe Br
Br
Friedel-Crafts
alkylation
O
R
HW Ch 18 p 3
b) sulfonation of nitrobenzene at the para position
c) bromination of acetophenone at the ortho position
d) nitration of benzonitrile (benzene ring with a nitrile attached) in the meta position
e) iodination of phenol in the para position
f) bromination of ethoxybenzene in the meta position
g) nitration of bromobenzene at the ortho position
HW Ch 18 p 4
5. Give the products of the following reactions (don't show those with only a minimal amount of product).
Br
FeBr3
a)
Br2
CN
SO3
b)
H2SO4
H2SO4
c)
HNO3
O
I2
d)
HNO3
O
Br2
e)
NO2
FeBr3
Cl2
O
f)
AlCl3
H2SO4
g)
HNO3
O
H2SO4
h)
O
HNO3
HW Ch 18 p 5
6. Give the products of the following reactions and indicate whether the substituents are reinforcing or
conflicting.
O
Br2
a)
FeBr3
NC
O
O
SO3
b)
H2SO4
F3C
Cl2
c)
OH
AlCl3
O
Cl
I2
d)
HNO3
NO2
O
O
H2SO4
e)
HNO3
SO3H
Br2
f)
FeBr3
N
SO3
g)
H2SO4
OH
O
h)
H
H2SO4
HNO3
HW Ch 18 p 6
7. Why is it impossible to synthesize the following compound from benzene? Explain thoroughly!
NO2
HO3S
8. Synthesize the following from toluene. Assume that constitutional isomers can be separated,
including multiple substitutions from Friedel-Crafts alkylations.
a)
Cl
NO2
b)
O2N
SO3H
9. Give the product(s) of the following reactions. Where multiple substitution may occur, show at least
one disubstituted product.
AlCl3
a)
Cl
Zn/Hg
AlCl3
b)
HCl
Cl
O
AlCl3
c)
Cl
O
d)
AlCl3
CH3Cl
HW Ch 18 p 7
O
AlCl3
f)
CH3CH2Cl
Br
AlCl3
g)
Cl
N
AlCl3
h)
O
Cl
OH
i)
AlCl3
Zn/Hg
O
HCl
Cl
Cl
j)
O
+
O
AlCl3
O
Cl
10. Write out a reaction sequence including reagents and intermediate products by which the following
compound can be synthesized from those shown. Reactions from previous chapters will be needed in
some cases!
a)
Cl
b)
NO2
HW Ch 18 p 8
O
c)
Br
d)
O
O
OH
e)
SO3H
OH
f)
Br
OH
g)
HW Ch 18 p 9
11. Give the reagents needed for the following reaction sequences. Use your o-chem notebook to help
with the ones from previous chapters!
Br
N
a)
O2N
O2N
O2N
O
O
O
b)
O
Br
Cl
O
Cl
O
NO2
NO2
c)
O
d)
Br
O
OH
O
O
I
e)
OH
I
I
HO
Br
f)
MgBr