Question

Which of the following compound cannot be produced if 1- propanamine is treated with $NaN{O_2}$ and $HCl$
A.Propan-1-ol
B.Propan-2-ol
C.2- chloropropane
D.2- propanamine

Answer 1

Hint: A mixture of and $HCl$ is used for the diazotization reaction. When this mixture of reagents is used, nitrous acid is prepared $NaN{O_2}$d in- situ which carries out the diazotization reaction. To answer this question, you must recall the products obtained on the diazotization of primary aliphatic amines.

Complete answer:
When nitrous acid reacts with a primary amine, initially we obtain an N- nitrosamine. It undergoes proton shift and converts into a dioic acid. This conversion is analogous to that occurring between a ketone and enol in tautomerism. The dioic acids under the presence of strong acids, decompose readily forming diazonium ions.
Diazonium ions can be seen as the combination of a primary carbocation and dinitrogen$\left( {R - N \equiv N} \right)$. Since nitrogen is extremely stable as dinitrogen gas, the diazonium ion decomposes leaving behind a primary carbocation with the release of nitrogen gas. Thus loss of nitrogen from the diazonium ion gives a very poorly stabilized primary carbocation which undergoes a variety of standard reactions shown by carbocations. Using the proper reagents, we can prepare alcohols, alkenes, or alkyl halides from the carbocation.
But there is no such mechanism by which the amino group of the primary amine can be shifted from the first carbon atom to second.

Thus, the correct answer is D.

Note:
Nitrous acid is an unstable acid and is always prepared in the reaction mixture by mixing a solution of $NaN{O_2}$ with a strong acid, generally $HCl$. This reagent under acidic conditions is a source of $N{O^ + }$ which readily attacks the nucleophilic nitrogen of the amines.