What is the major product "P" of the following reaction?

Solution

Chemistry ma’am · 4 steps

Primary aliphatic amine plus nitrous acid: N₂ bubbles off and OH takes the place of NH₂.

1. Spot the amine. The NH₂ sits on a CH₂ attached to the ring carbon that also carries the methyl. So this is a primary aliphatic amine, not an aromatic one.
2. Diazotisation. NaNO₂ and HCl make HNO₂ in the flask. It turns R-NH₂ into the diazonium salt R-N₂⁺Cl⁻.
3. Salt falls apart. An aliphatic diazonium ion has no benzene ring to stabilise it by resonance. Even at 278 K it loses N₂ at once, and water attacks the carbon to give an alcohol.

   R-NH₂ + HNO₂ → R-OH + N₂ ↑ + H₂O

4. So. The CH₂NH₂ group becomes CH₂OH. The ring and the methyl are untouched, so P is (1-methylcycloheptyl)methanol, option (d). A primary carbocation like this one can also rearrange in a real flask, but no option shows a rearranged skeleton, so (d) is the answer.

The idea to keep. Cold HNO₂ keeps only aryl diazonium salts alive. A primary aliphatic amine gives a diazonium salt that loses N₂ at once and ends up as the alcohol.

Answer from the NTA final answer key. Solution by PrepWiser.