19. Reactions of Aromatics: EAS and Beyond

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

g. n-butylbenzene

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

h.

Describe two synthetic routes for the preparation of p-methoxyaniline from benzene.

Show how you would synthesize the following compounds, using the indicated starting materials.

(a) 3-phenylbutan-1-ol from styrene

The antioxidants BHA and BHT are commonly used as food preservatives. Show how BHA and BHT can be made from phenol and hydroquinone

Predict the major product at the end of each sequence.

(a)

Predict the major product at the end of each sequence.

(b)

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

(b)

The following steps were used in the synthesis of the antimalarial thiaplakortone A. Identify the missing reagents, (a) and (b), 

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

(a)

a. Describe three ways the following reaction can be carried out:

b. Describe two ways the following reaction can be carried out:

Show how you would accomplish the following syntheses.

(a) benzene → n-butylbenzene