Chemistry of Benzene: Electrophilic Aromatic Substitution

At what position, and on what ring, would you expect bromination of  Benzanilide to occur? Explain by drawing resonance structures of the intermediates.

Benzanilide

Would you expect the Friedel–Crafts reaction of benzene with (R)-2- chlorobutane to yield optically active or racemic product? Explain.

How would you synthesize the following substances starting from benzene?

(a)         

(b)    

(c)             

The compound MON-0585 is a nontoxic, biodegradable larvicide that is highly selective against mosquito larvae. Synthesize MON-0585 using either benzene or phenol as a source of the aromatic rings.

Phenylboronic acid, ${\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}\mathbf{B}{\mathbf{\left(}\mathbf{OH}\mathbf{\right)}}_{\mathbf{2}}$ , is nitrated to give 15% ortho substitution product and 85% meta. Explain the meta-directing effect of the $\mathbf{B}{\mathbf{\left(}\mathbf{OH}\mathbf{\right)}}_{\mathbf{2}}$ group.

Draw resonance structures of the intermediate carbocations in the bromination of naphthalene, and account for the fact that naphthalene undergoes electrophilic substitution at C1 rather than C2.

Propose a mechanism for the reaction of 1-chloroanthraquinone with methoxide ion to give the substitution product 1-methoxyanthraquinone. Use curved arrows to show the electron flow in each step.

p-Bromotoluene reacts with potassium amide to give a mixture of mand p-methylaniline. Explain.

Propose a mechanism to account for the reaction of benzene with 2,2,5,5-tetramethyltetrahydrofuran.

How would you synthesize the following compounds from benzene? Assume that ortho and para isomers can be separated.

Question: How would you synthesize the following compounds from benzene? Assume that ortho and para isomers can be separated.

a)

b) 

You know the mechanism of HBr addition to alkenes, and you know the effects of various substituent groups on aromatic substitution. Use this knowledge to predict which of the following two alkenes reacts faster with HBr. Explain your answer by drawing resonance structures of the carbocation intermediates.

Question: You know the mechanism of HBr addition to alkenes, and you know the effects of various substituent groups on aromatic substitution. Use this knowledge to predict which of the following two alkenes reacts faster with HBr. Explain your answer by drawing resonance structures of the carbocation intermediates.

Use your knowledge of directing effects, along with the following data, to deduce the directions of the dipole moments in aniline and bromobenzene.

Question: Use your knowledge of directing effects, along with the following data, to deduce the directions of the dipole moments in aniline and bromobenzene.

Question: Identify the reagents represented by the letters a–e in the following scheme:

Phenols (ArOH) are relatively acidic, and the presence of a substituent group on the aromatic ring has a large effect. The of unsubstituted phenol, for example, is 9.89, while that of p-nitrophenol is 7.15. Draw resonance structures of the corresponding phenoxide anions and explain the data.

Question: Phenols (ArOH) are relatively acidic, and the presence of a substituent group on the aromatic ring has a large effect. The ${\mathbf{pk}}_{\mathbf{a}}$ of unsubstituted phenol, for example, is 9.89, while that of p-nitrophenol is 7.15. Draw resonance structures of the corresponding phenoxide anions and explain the data.

Would you expect p-methylphenol to be more acidic or less acidic than unsubstituted phenol? Explain. (See Problem 16-75.)

Would you expect p-methyl phenol to be more acidic or less acidic than unsubstituted phenol? Explain. (See Problem 16-75.)

Question: Would you expect p-methyl phenol to be more acidic or less acidic than unsubstituted phenol? Explain. (See Problem 16-75.)

Melamine, used as a fire retardant and a component of the writing surface of white boards, can be prepared from s-trichlorotriazine through a series of SNAr reactions with ammonia. The first substitution takes place rapidly at room temperature. The second substitution takes place near 100 °C, and the third substitution requires even higher temperature and pressure. Provide an explanation for this reactivity.

Question: Melamine, used as a fire retardant and a component of the writing surface of white boards, can be prepared from s-trichlorotriazine through a series of SNAr reactions with ammonia. The first substitution takes place rapidly at room temperature. The second substitution takes place near      100 °C, and the third substitution requires even higher temperature and pressure. Provide an explanation for this reactivity.