JEE MainChemistryAmines
Which of the following sequences of reagents will successfully convert aniline into biphenyl?
Options
- A(i) NaNO ₂ , HCl, 273-278 K (ii) CuCl, HCl (iii) Mg, dry ether
- B(i) HNO ₃ , H ₂ SO ₄ , 288 K (ii) Sn, HCl (iii) Na, dry ether
- C(i) NaNO ₂ , HCl, 273-278 K (ii) H ₂ O, warm (iii) Na, dry ether
- D(i) NaNO ₂ , HCl, 273-278 K (ii) KI (iii) Na, dry ether
Correct answer
D. (i) NaNO ₂ , HCl, 273-278 K (ii) KI (iii) Na, dry ether
Step-by-step solution
The conversion of aniline to biphenyl requires a coupling reaction. Aniline cannot be directly coupled and must first be converted into an aryl halide. Step 1: Aniline is treated with nitrous acid (generated in situ from NaNO ₂ and HCl at 273-278 K) to undergo diazotization, forming benzene diazonium chloride. Step 2: The diazonium salt is treated with KI. The diazonium group is substituted by iodine to form iodobenzene. Step 3: Iodobenzene is treated with sodium in dry ether. This is the Fittig reaction, where two