19. Reactions of Aromatics: EAS and Beyond

Show how you would synthesize the following compounds, starting with benzene or toluene and any necessary acyclic reagents. Assume para is the major product (and separable from ortho) in ortho, para mixtures.

a. 1-phenyl-1-bromobutane

Show how the following compounds can be synthesized from benzene:

a.

Show how the following compounds can be synthesized from benzene:

d. m-methylnitrobenzene

Describe how 3-methyl-1-phenyl-3-pentanol can be prepared from benzene. You can use any inorganic reagents and solvents, and any organic reagents provided they contain no more than two carbons.

Starting with benzene and any other reagents you need, show how you would synthesize the compound shown here. (Hint: Consider a Pd-catalyzed coupling for the final step.)

Show how you would synthesize the following aromatic derivatives from benzene.

b. p-toluenesulfonic acid

Show how you would synthesize the following aromatic derivatives from benzene.

a. p-tert-butylnitrobenzene

Phenolphthalein, a common nonprescription laxative, is also an acid–base indicator that is colorless in acid and red in base. Phenolphthalein is synthesized by the acid-catalyzed reaction of phthalic anhydride with 2 equivalents of phenol.

b. Propose a mechanism for the conversion of phenolphthalein to its red dianion in base.

c. Use resonance structures to show that the two phenolic oxygen atoms are equivalent (each with half a negative charge) in the red phenolphthalein dianion.

Show how the following compounds can be synthesized from benzene:

b.

What products would you expect from the following coupling reactions?

(c)

Predict the product(s) of each of the following multistep reactions.

(b)

Show how you would accomplish the following synthetic conversions efficiently and in good yield. You may use any necessary additional reagents and solvents.

(b)

Beginning with benzene, synthesize the benzyl bromide shown.

Show how you would use the Friedel–Crafts acylation, Clemmensen reduction, and/or Gatterman–Koch synthesis to prepare the following compounds:

g. n-butylbenzene