Question

Which of the following method gives better yield of p-nitrophenol?

• A. Phenol $\xrightarrow[20^{\circ}C]{dil.HNO_3} p$ -Nitrophenol
• B. Phenol $\xrightarrow[(ii)HNO_3]{(i) NaNO_2 + H_2SO_4, 7 - 8^{\circ}C} p$ -Nitrophenol
• C. Phenol $\xrightarrow[(ii) Conc. HNO_3]{(i) NaOH}$
• D. None of the three.

Answer 1

Answer: (B)

Phenol $\xrightarrow[(ii)HNO_3]{(i) NaNO_2 + H_2SO_4, 7 - 8^{\circ}C} p$ -Nitrophenol

Answer 2

Thus here, oxidation of phenol is minimised by forming $p$-nitrosophenol.