Step 1: Aniline reacts with to give phenyl isocyanide (carbylamine reaction), which has foul smell. Step 2: Aniline reacts with benzene sulphonyl chloride to form sulphonamide (Hinsberg reaction):
Step 3: This sulphonamide has acidic NāH proton and dissolves in forming soluble salt. Step 4: Structure of . Step 5: Different hydrogen environments:
\begin{itemize}
\item One NāH hydrogen
\item Three types (ortho, meta, para) on first phenyl ring
\item Three types (ortho, meta, para) on second phenyl ring
\end{itemize} Step 6: Total different hydrogens . Hence, correct answer is 7.
