Which one of the following compounds forms a quaternary salt on reacting with excess methyl iodide?

• A

  $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OCH}_3$
• B

  $\left(\mathrm{CH}_3\right)_2 \mathrm{CHOC}_2 \mathrm{H}_5$
• Correct answer
  C

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2$
• D

  $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2$

Solution

Amines react with alkyl halide (excess) to give quaternary ammonium salt.

Hence, the correct answer is option: 'C'.