O Chem Notecards Ch 17 Flashcards

Under what reaction conditions does the electrophilic chlorination of aromatic compounds usually occur?
A) Cl2, AlCl3
B) Cl2, H2O
C) Cl2, CCl4
D) NaCl, H2O
E) NaCl, CH3OH

In electrophilic aromatic substitution reactions a bromine substituent:
A) is a deactivator and a m-director.
B) is a deactivator and an o,p-director.
C) is an activator and a m-director.
D) is an activator and an o,p-director.
E) none of the above

Which of the following is the best choice of reagents to effect the electrophilic iodination of an aromatic ring?
A) KI, acetone
B) I2, CH3CN
C) KI, HNO3
D) I2, HNO3
E) none of the above

Which of the following is an incorrect statement about the bromination of benzene by Br2 and FeBr3?
A) FeBr3 functions to increase the electrophilicity of Br2.
B) Formation of the sigma complex is the rate-determining step of the mechanism.
C) The carbanionic intermediate is resonance stabilized.
D) There are two carbon-containing intermediates in the mechanism.
E) The final step of the mechanism is loss of H+.

Which of the following species is attacked by benzene in the electrophilic nitration reaction?
A) HNO3
B) NO2+
C) NO2
D) NO+
E) N3-

Which of the following is the strongest activating group in electrophilic aromatic substitution reactions?
A) -CH2CH3
B) -OCH3
C) -CO2CH3
D) -NO2
E) -N(CH3)2

Which of the following compounds will undergo bromination most rapidly using Br2, FeBr3?
A) p-methylacetanilide
B) bromobenzene
C) acetanilide
D) benzenesulfonic acid
E) dibromobenzene

In electrophilic aromatic substitution reactions, a -NHCOCH3 substituent on the aromatic ring is:
A) a deactivator and a m-director.
B) a deactivator and an o,p-director.
C) an activator and a m-director.
D) an activator and an o,p-director.
E) none of the above.

Which of the following compounds will undergo Friedel-Crafts alkylation with (CH3)3CCl, AlCl3 most rapidly?
A) toluene
B) iodobenzene
C) acetophenone
D) benzenesulfonic acid
E) cyanobenzene

Which of the following compounds will react most rapidly when treated with CH3CH2Cl and AlCl3?
A) benzene
B) chlorobenzene
C) nitrobenzene
D) anisole
E) toluene

Which sequence correctly ranks the following aromatic rings in order of increasing rate of reactivity with chlorine and aluminum chloride?

A) 1 < 2 < 3
B) 2 < 3 < 1
C) 3 < 2 < 1
D) 2 < 1 < 3
E) 1 < 3 < 2

In electrophilic aromatic substitution reactions the hydroxyl group is an o,p-director because:
A) it donates electron density to the ring by induction and destabilizes the meta sigma complex.
B) it donates electron density to the ring by resonance and stabilizes the ortho and para sigma complexes.
C) it donates electron density to the ring by induction and stabilizes the ortho and para sigma complexes.
D) it donates electron density to the ring by resonance and destabilizes the meta sigma complex.
E) it withdraws electron density from the ring by induction and destabilizes the meta sigma complex.

The nitration of anisole:
A) proceeds more rapidly than the nitration of benzene and yields predominantly the meta product.
B) proceeds more rapidly than the nitration of benzene and yields predominantly the ortho, para products.
C) proceeds more slowly than the nitration of benzene and yields predominantly the meta product.
D) proceeds more slowly than the nitration of benzene and yields predominantly the ortho, para products.
E) proceeds at the same rate as the nitration of benzene and yields predominantly the meta product.

In electrophilic aromatic substitution reactions, a phenyl substituent on the aromatic ring is:
A) a deactivator and a m-director.
B) a deactivator and an o,p-director.
C) an activator and a m-director.
D) an activator and an o,p-director.
E) none of the above

Which sequence correctly ranks the following aromatic rings in order of increasing
rate of reactivity in an electrophilic aromatic substitution reaction?

A) 1 < 2 < 3
B) 2 < 3 < 1
C) 3 < 1 < 2
D) 2 < 1 < 3

Derivatives of the compound shown below are currently being examined for their effectiveness in treating drug addiction and metabolic syndrome (J. Med. Chem. 2006, 872). Which sequence ranks the following aromatic rings of this compound in order of increasing reactivity in an electrophilic aromatic substitution reaction (slowest to fastest reacting)?
A) 1 < 2 < 3
B) 2 < 3 < 1
C) 3 < 2 < 1
D) 3 < 1 < 2
E) 2 < 1 < 3

) In electrophilic aromatic substitution reactions the nitro group is:
A) a m-director since it destabilizes the meta sigma complex more than the ortho, para.
B) a m-director since it destabilizes the meta sigma complex less than the ortho, para.
C) an o,p-director since it stabilizes the ortho, para sigma complex more than the meta.
D) an o,p-director since it stabilizes the ortho, para sigma complex less than the meta.
E) none of the above.

In the addition of an electrophile to acetophenone, which of the following best describes the expected mode of reaction?
A) The o,p-positions are most activated to attack by the electrophile.
B) The m-positions are most activated to attack by the electrophile.
C) The o,p-positions are most deactivated to attack by the electrophile.
D) The m-positions are most deactivated to attack by the electrophile.
E) All positions (o, m, and p) are equally activated to attack by the electrophile.

In electrophilic aromatic substitution reactions, a -CO2H substituent on the aromatic ring is:
A) a deactivator and a m-director.
B) a deactivator and an o,p-director.
C) an activator and a m-director.
D) an activator and an o,p-director.
E) none of the above.

In electrophilic aromatic substitution reactions, a cyano substituent on the aromatic ring is:
A) a deactivator and a m-director.
B) a deactivator and an o,p-director.
C) an activator and a m-director.
D) an activator and an o,p-director.
E) none of the above.

Which of the following compounds will not undergo Friedel-Crafts acylation when treated with CH3CH2COCL, ALCL3 ?
A) toluene
B) p-xylene
C) anisole
D) ethoxybenzene
E) benzophenone

) Which of the following compounds will undergo bromination least rapidly when treated with Br2 and FeBr3?
A) p-methylacetanilide
B) bromobenzene
C) acetanilide
D) benzenesulfonic acid
E) benzene

Which of the following compounds will react least rapidly when treated with CH3CH2Cl and AlCl3?
A) o-xylene
B) acetanilide
C) toluene
D) benzene
E) bromobenzene

) Rank the following compounds in order of increasing reactivity towards chlorination with Cl2/AlCl3 (slowest reacting to fastest).
A) 3 < 4 < 2 < 1 < 5
B) 2 < 4 < 1 < 3 < 5
C) 4 < 2 < 1 < 3 < 5
D) 2 < 4 < 5 < 1 < 3
E) 2 < 4 < 1 < 5 < 3

Based upon the following energy profile diagram for the first step of an electrophilic aromatic substitution reaction, which of the following substituents is X mostly likely to be?
A) Cl
B) OCH3
C) CO2H
D) CH3

Which of the following compounds undergoes reaction with HNO3/H2SO4 at the fastest rate?
A) ethylbenzene
B) benzenesulfonic acid
C) nitrobenzene
D) chlorobenzene
E) acetophenone

Rank the following groups in order of increasing activating power in electrophilic aromatic substitution reactions: -OCH3, -OCOCH2CH3, -CH2CH3, -Br.

Rank the following sigma complexes in order of increasing stability.

Which of the following compounds would most likely be used in the preparation of isobutylbenzene from benzene?
A) (CH3)2CHCOCl
B) (CH3)2CHCH2Cl
C) (CH3)2CHCH2Br
D) CH3CH2CH2CH2Cl
E) CH3CH2CH2COCl

What intermediate is thought to occur in the elimination-addition nucleophilic aromatic substitution mechanism?
A) radical anion
B) radical cation
C) quinone
D) benzyne
E) positively charged sigma complex

Which of the following compounds is least reactive in the nucleophilic aromatic substitution reaction with NaOH?
A) 2,4-dinitrochlorobenzene
B) m-nitrochlorobenzene
C) o-nitrochlorobenzene
D) p-nitrochlorobenzene
E) 3,5-dinitrochlorobenzene

When 2,4-dinitrochlorobenzene is treated with sodium hydroxide at 100°C followed by protonation:
A) 2,4-dinitrophenol is formed via an addition-elimination nucleophilic aromatic substitution mechanism.
B) 2,4-dinitrophenol is formed via an elimination-addition nucleophilic aromatic substitution mechanism.
C) 3,5-dinitrophenol is formed via an elimination-addition nucleophilic aromatic substitution mechanism.
D) 3,5-dinitrophenol is formed via an electrophilic aromatic substitution mechanism.
E) 2,4-dinitrophenol is formed via an electrophilic aromatic substitution mechanism.

When o-fluorotoluene is treated with sodium amide, the product is:
A) only o-toluidine.
B) only m-toluidine.
C) only p-toluidine.
D) a mixture of o- and p-toluidine.
E) a mixture of o- and m-toluidine

Which toluidine isomers are possible products when m-bromotoluene is treated with NaNH2?
A) ortho, meta, and para
B) meta only
C) para only
D) ortho only
E) meta and para only

p-Methoxybenzaldehyde can be prepared from anisole using the Gatterman-Koch formylation. What mixture of reagents is necessary for this process?
A) CO, HCl, AlCl3, CuCl
B) CO, SO3, H2SO4
C) CO2, HCl, AlCl3
D) CO2, SO3, H2SO4
E) CO2, HNO3, H2SO4