Aromatic Reaction Problems
Extra Problems
19. Show the product of each of the following compounds after adding a nitro group by reacting with nitric and sulfuric acid.
a) bromobenzene
b) o-nitrochlorobenzene
c) ethylbenzene
d) benzaldehyde
e) benzoic acid
f) benzonitrile (PhCN)
g) m-nitroanisole
h) p-bromobenzaldehyde
i) m-ethoxybenzoic acid
j) 3-ethylphenol
20. Fill in the reagents/products for the following reactions.
21. Describe the orbitals that overlap and are involved in making the “triple” bond in benzyne. A sketch might be helpful.
22. Provide the structure of the major organic product(s) in the following reactions.
23. Provide the structure of the major organic product(s) in the following reactions.
a) 2,4-dinitrochlorobenzene + NaOEt
b) 3-methylchlorobenzene + NaOH at 100°C
c) 1,3-dimethylbenzene (m-xylene) + Na/NH3
d) m-xylene + concentrated potassium permanganate
e) chlorobenzene + fuming sulfuric acid
f) 1-chloro-2-nitrobenzene + NaNH2
g) anisole + sodium in liquid ammonia
h) benzaldehyde + sodium in liquid ammonia
24. Devise an efficient method to prepare the following compounds from benzene.
a) 4-bromobenzonitrile
b) m-nitrobutylbenzene
c) p-nitropropylbenzene
d) p-nitrobenzoic acid
e) p-methylphenol (also called p-cresol)
f) p-methylbenzaldehyde
g) 3-bromoethylbenzene
h) m-chloroaniline
i) p-bromotoluene
j) phenol
k) 1-phenyl-1-bromohexane
l) 4-phenylheptan-4-ol
m) o-nitrobenzoic acid
n) p-t-butylnitrobenzene
o) n-butylbenzene
25. Show how you would use nitration, Friedel-Crafts alkylation, Friedel-Crafts acylation, Gatterman-Koch formylation, and/or Clemmensen reduction to make the following compounds from benzene.
a) ethylbenzene
b) p-ethylbenzaldehyde
c) benzophenone (PhCOPh)
d) PhCH2Ph
e) (CH3)2CHCOPh
f) n-pentylbenzene
g) CH3CH2COPh
h) m-nitrobenzaldehyde
26. Provide detailed, stepwise mechanisms for the following reactions.
27. Draw the three major resonance structures of the sigma complex intermediate in the reaction of benzaldehyde with HNO3/H2SO4 to yield o-nitrobenzaldehyde. Circle the resonance form that is less stable than the other two.
28. Predict the products of the following nucleophilic substitution reactions.
a) 4-chloronitrobezene + sodium ethoxide (NaOCH2CH3)
b) 2,4-dinitrobromobenzene + sodium hydroxide (NaOH), 100°C
c) 2,4,6-trinitrobromobenzene + methylamine
d) 4-bromotoluene + sodium hydroxide (NaOH), 350°C
e) 2-chloroethylbenzene + sodium amide (NaNH2)
29. Predict the products of the following reactions.
a) toluene (methyl benzene) + propyl chloride/AlCl3
b) anisole (methoxy benzene) + isopropyl chloride/AlCl3
c) benzaldehyde + ethyl chloride/AlCl3
d) n-pentylbenzene + CH3CH2COCl/AlCl3
e) chlorobenzene + CO, HCl, AlCl3, CuCl
30. Predict the products of ethyl benzene with the following:
a) Cl2/AlCl3
b) CH3CH2CH2COCl/AlCl3
c) HNO3/H2SO4
d) Hot, concentrated KMnO4
e) n-butyl chloride/AlCl3
f) Br2 and UV light
g) Na/NH3
h) NBS
i) fuming sulfuric acid
j) 1) Cl2/AlCl3 2) NaOH (350°C)
k) 3 Cl2, heat, pressure
l) H2, heat, pressure, metal catalyst
m) Br2/FeBr3
31. Devise an efficient method to prepare the following compounds from nitrobenzene.
a) iodobenzene
b) fluorobenzene
c) chlorobenzene
d) bromobezene
e) benzonitrile
f) phenol
g) 1,3,5-tribromobenzene
32. Predict the products of the following with hot, concentrated potassium permanganate, KMnO4.
a) toluene
b) o-xylene
c) hexylbenzene
d) t-butylbenzene
33. Show how to make the following compounds starting with benzene. Your reaction sequences should involve bromination or chlorination, making Grignard or Gilman reagents, and any other necessary reactions with a halide, carbonyl compound, or epoxide.
34. Show how to make the phenyl propyl ether starting with benzene. Your reaction sequence should involve bromination or chlorination, nucleophilic substitution with sodium hydroxide to form phenol, and any other necessary reactions.
35. Show how you would convert aniline to the following compounds:
a) chlorobenzene
b) bromobenzene
c) fluorobenzene
d) benzonitrile (PhCN)
e) benzene
f) phenol
g) iodobenzene
h) p-methylaniline
i) 1,3,5-tribromobenzene
36. Benzyne is a great dienophile in a Diels-Alder reaction. Show the Diels-Alder product when chlorobenzene reacts with sodium hydroxide at 350°C in the presence of furan.
37. Use benzene or toluene to make the following. You must first nitrate then do whatever else is necessary.
a) aniline
b) m-chloroaniline
c) p-bromobenzoic acid
d) para-fluorotoluene
e) 4-ethylbenzonitrile
38. Show the reagents that could be used to convert o-toluidine (o-methylaniline) to the following compounds.
39. Provide a series of synthetic steps by which the following compound can be prepared from phenol.
