Nucleophilic aromatic substitution provides one of the common methods for making phenols. (Another method is discussed in Section 19-17.) Show how you would synthesize the following phenols, using benzene or toluene as your aromatic starting material, and explain why mixtures of products would be obtained in some cases.
(a) p-nitrophenol
(b) 2,4,6-tribromophenol
(c) p-chlorophenol
(d) m-cresol
(e) p-n-butylphenol
Solution:
Here we will have to show the synthesis of following phenols
Step 1
(a) Synthesis of p-nitrophenol
The synthesis of p-nitrophenol involves an addition elimination mechanism. In this reaction benzene on reaction with chlorine in presence of AlCl3 gives chlorobenzene , which on nitration (in presence of HNO3 + H2SO4) forms 4-nitrochlorobenzene ,it is on heating in presence of NaOH gives p-nitrophenol.
