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PAC 223 2021 ASSIGNMENT 1
Question One
(a) Show how each of the following conversions may be accomplished. More than
one step may be required for each conversion.
CH3
(i)
Cl
(ii)
CH2CH2Br
CH2CH3
(iii)
CO2H
(10)
(b) Supply structures for the expected products of the following reactions:
2
NO2
(i)
Cl2 / FeCl 3
CH3
Cl
(ii)
SO3/H 2SO4
CH3
(iii)
OCH3
Br2 / FeBr3
SO 3H
NH2
(iv)
HNO3 / H2SO4
CH3
NO2
(v)
CH3Cl / AlCl3
(10)
[20]
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Question Two
(a) Suggest a reasonable mechanism for each of the following reactions:
Chlorination of benzene
Sulphonation of benzne
Conversion of benzne to aniline
(12)
(b) Halogens are aromatic ring deactivators, yet are ortho, para - directors explain
this using suitable resonance structures.
(8)
[20]
Question Three
(a) As written the following reactions have flaws. What is wrong with each ?
COOH
CH3
(i)
1) Cl2 /AlCl3
2) KMnO4
Cl
(ii)
Cl
Cl
CH3
1) HNO 3 / H2SO4
2) CH3Cl / AlCl3
3) SnCl2, HCl
4) NaOH /H2O
NH2
(5)
(b) Discuss the limitations of the Friedel-Crafts alkylation reaction in organic
synthesis.
(7)
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(c ) Arrange the following compounds in order of increasing basicity and give reasons
NH2
CH3
NH2
for your answer.
NO2
NH2
A
B
C
(8)
[20]